(+)-Echinobetaine B: isolation, structure elucidation, synthesis and preliminary SAR studies on a new nematocidal betaine from a southern Australian marine sponge, Echinodictyum sp.

The principle nematocidal agent present in a southern Australian marine sponge of the genus Echinodictyum has been isolated and identfied as the novel betaine (+)-echinobetaine B (6), and the structure assigned by spectroscopic analysis has been confirmed by total synthesis. Preliminary SAR conclusions are drawn from analysis of synthetic intermediates and the known marine metabolites zooanemonin (12) and norzooanemonin (13), and the new sponge metabolite norzooanemonin methyl ester (14). The latter compound is reported for the first time from a selection of Australian sponges, including an Axinyssa sp., a Niphates sp., an Axinella sp. and a Ptilocaulis sp.

Temperature dependence of the crystal structure and g-values of [(HC(Ph2PO)(3))(2)Cu] (ClO4)(2)center dot 2H(2)O: Influence of dynamic Jahn-Teller coupling and lattice strain interactions

The temperature dependence of the X-ray crystal structure and powder EPR spectrum of [(HC(Ph2PO)(3))(2)CU]-(ClO4)(2)center dot 2H(2)O is reported, and the structure at room temperature confirms that reported previously. Below similar to 100 K, the data imply a geometry with near elongated tetragonal symmetry for the [(HC(Ph2PO)(3))(2)Cu](2+) complex, but on warming the two higher Cu-O bond lengths and g-values progressively converge, and by 340 K the bond lengths correspond to a compressed tetragonal geometry. The data may be interpreted satisfactorily assuming an equilibrium among the energy levels of a Cu-O-6 polyhedron subjected to Jahn-Teller vibronic coupling and a lattice strain. However, agreement with the experiment is obtained only if the orthorhombic component of the lattice strain decreases to a negligible value as the temperature approaches 340 K.

Effects of fire on the structure and composition of open eucalypt forests

Fires are integral to the healthy functioning of most ecosystems and are often poorly understood in policy and management, however, the relationship between floristic composition and habitat structure is intrinsically linked, particularly after fire. The aim of this study was to test whether the variability of habitat structure or floristic composition and abundance in forests at a regional scale can be explained in terms of fire frequency using historical data and experimental prescribed burns. We tested this hypothesis in open eucalypt forests of Fraser Island off the east coast of Australia. Fraser Island dunes show progressive stages in plant succession as access to nutrients decreases across the Island. We found that fire frequency was not a good predictor of floristic composition or abundance across dune systems; rather, its affects were dune specific. In contrast, habitat structure was strongly influenced by fire frequency, independent of dune system. A dense understorey occurred in frequently burnt areas, whereas infrequently burnt areas had a more even distribution of plant heights. Plant communities returned to pre-burn levels of composition and abundances within 6 months of a fire and frequently burnt areas were dominated by early successional species of plant. These ecosystems were characterized by low diversity and frequently burnt areas on the east coast were dominated by Pteridium. Greater midstorey canopy cover in low frequency areas reduces light penetration and allows other species to compete more effectively with Pteridium. Our results strongly indicate that frequent fires on the Island have resulted in a decrease in relative diversity through dominance of several species. Prescribed fire represents a powerful management tool to shape habitat structure and complexity of Fraser Island forests.

Design of high quality doped CeO2 solid electrolytes with nanohetero structure

Doped ceria (CeO2) compounds are fluorite related oxides which show oxide ionic conductivity higher than yttria-stabilized zirconia in oxidizing atmosphere. As a consequence of this, a considerable interest has been shown in application of these materials for low (400-650 degrees C) temperature operation of solid oxide fuel cells (SOFCs). In this paper, our experimental data about the influence of microstructure at the atomic level on electrochemical properties were reviewed in order to develop high quality doped CeO2 electrolytes in fuel cell applications. Using this data in the present paper, our original idea for a design of nanodomain structure in doped CeO2 electrolytes was suggested. The nanosized powders and dense sintered bodies of M doped CeO2 (M:Sm,Gd,La,Y,Yb, and Dy) compounds were fabricated. Also nanostiructural features in these specimens were introduced for conclusion of relationship between electrolytic properties and domain structure in doped CeO2. It is essential that the electrolytic properties in doped CeO2 solid electrolytes reflect in changes of microstructure even down to the atomic scale. Accordingly, a combined approach of nanostructure fabrication, electrical measurement and structure characterization was required to develop superior quality doped CeO2 electrolytes in the fuel cells.

Board composition, ownership structure and dividend policies in an emerging market: further evidence from CASE 50

Purpose – The purpose of this study is to examine dividend policies in an emerging capital market, in a country undergoing a transitional period. Design/methodology/approach – Using pooled cross-sectional observations from the top 50 listed Egyptian firms between 2003 and 2005, this study examines the effect of board of directors’ composition and ownership structure on dividend policies in Egypt. Findings – It is found that there is a significant positive association between institutional ownership and firm performance, and both dividend decision and payout ratio. The results confirm that firms with a higher return on equity and a higher institutional ownership distribute higher levels of dividend. No significant association was found between board composition and dividend decisions or ratios. Originality/value – This study provides additional evidence of the applicability of the signalling model in the emerging market of Egypt. It was found that despite the high institutional ownership and the closely held nature of the firms, which imply lower agency costs, the payment of higher dividend was considered necessary to attract capital during this transitional period.

Institutions and firm ownership structure:evidence from Central and Eastern Europe

FDI plays a key role in development, particularly in resource-constrained transition economies of Central and Eastern Europe with relatively low savings rates. Gains from technology transfer play a critical role in motivating FDI, yet potential for it may be hampered by a large technology gap between the source and host country. While the extent of this gap has traditionally been attributed to education, skills and capital intensity, recent literature has also emphasized the possible role of institutional environment in this respect. Despite tremendous interest among policy-makers and academics to understand the factors attracting FDI (Bevan and Estrin, 2000; Globerman and Shapiro, 2003) our knowledge about the effects of institutions on the location choice and ownership structure of foreign firms remains limited. This paper attempts to fill this gap in the literature by examining the link between institutions and foreign ownership structures. To the best of our knowledge, Javorcik (2004) is the only papers, which use firm-level data to analyse the role of institutional quality on an outward investor’s entry mode in transition countries. Our paper extends Javorcik (2004) in a number of ways: (a) rather than a cross-section, we use panel data for the period 1997-2006; (b) rather than a binary variable, we use the percentage foreign ownership as continuous variable; (c) we consider multi-dimensional institutional variables, such as corruption, intellectual property rights protection and government stability. We also use factor analysis to generate a composite index of institutional quality and see how stronger institutional environment could affect foreign ownership; (d) we explore how the distance between institutional environment in source and host countries affect foreign ownership in a host country. The firm-level data used includes both domestic and foreign firms for the period 1997-2006 and is drawn from ORBIS, a commercially available dataset provided by Bureau van Dijk. In order to examine the link between institutions and foreign ownership structures, we estimate four log-linear ownership equations/specifications augmented by institutional and other control variables. We find evidence that the decision of a foreign firm to either locate its subsidiary or acquire an existing domestic firm depends not only on factor cost differences but also on differences in institutional environment between the host and source countries.

A comparative and longitudinal analysis of the evolving relationship between the environment and the strategy, structure and performance of selected organisations in the British carpet industry 1959-1986:a firms in sector perspective of organisational adaptation

Orthodox contingency theory links effective organisational performance to compatible relationships between the environment and organisation strategy and structure and assumes that organisations have the capacity to adapt as the environment changes. Recent contributions to the literature on organisation theory claim that the key to effective performance is effective adaptation which in turn requires the simultaneous reconciliation of efficiency and innovation which is afforded by an unique environment-organisation configuration. The literature on organisation theory recognises the continuing confusion caused by the fragmented and often conflicting results from cross-sectional studies. Although the case is made for longitudinal studies which comprehensively describe the evolving relationship between the environment and the organisation there is little to suggest how such studies should be executed in practice. Typically the choice is between the approaches of the historicised case study and statistical analysis of large populations which examine the relationship between environment and organisation strategy and/or structure and ignore the product-process relationship. This study combines the historicised case study and the multi-variable and ordinal scale approach of statistical analysis to construct an analytical framework which tracks and exposes the environment-organisation-performance relationship over time. The framework examines changes in the environment, strategy and structure and uniquely includes an assessment of the organisation's product-process relationship and its contribution to organisational efficiency and innovation. The analytical framework is applied to examine the evolving environment-organisation relationship of two organisations in the same industry over the same twenty-five year period to provide a sector perspective of organisational adaptation. The findings demonstrate the significance of the environment-organisation configuration to the scope and frequency of adaptation and suggest that the level of sector homogeneity may be linked to the level of product-process standardisation.

Structure and thermal properties of yttrium alumino-phosphate glasses

The structure and thermal properties of yttrium alumino-phosphate glasses, of nominal composition (Y2O3)(0.31-z)(Al2O3)(z)(P2O5)(0.69) with 0 less than or similar to z less than or similar to 0.31, were studied by using a combination of neutron diffraction, Al-27 and P-31 magic angle spinning nuclear magnetic resonance, differential scanning calorimetry and thermal gravimetric analysis methods. The Vickers hardness of the glasses was also measured. The data are compared to those obtained for pseudo-binary Al2O3-P2O5 glasses and the structure of all these materials is rationalized in terms of a generic model for vitreous phosphate materials in which Y3+ and Al3+ act as modifying cations that bind only to the terminal (non-bridging) oxygen atoms of PO4 tetrahedra. The results are used to help elucidate the phenomenon of rare-earth clustering in phosphate glasses which can be reduced by substituting Al3+ ions for rare-earth R3+ ions at fixed modifier content.

Board composition, ownership structure and dividend policies in an emerging market: further evidence from CASE 50

Purpose – The purpose of this study is to examine dividend policies in an emerging capital market, in a country undergoing a transitional period. Design/methodology/approach – Using pooled cross-sectional observations from the top 50 listed Egyptian firms between 2003 and 2005, this study examines the effect of board of directors’ composition and ownership structure on dividend policies in Egypt. Findings – It is found that there is a significant positive association between institutional ownership and firm performance, and both dividend decision and payout ratio. The results confirm that firms with a higher return on equity and a higher institutional ownership distribute higher levels of dividend. No significant association was found between board composition and dividend decisions or ratios. Originality/value – This study provides additional evidence of the applicability of the signalling model in the emerging market of Egypt. It was found that despite the high institutional ownership and the closely held nature of the firms, which imply lower agency costs, the payment of higher dividend was considered necessary to attract capital during this transitional period.

Category structure affects the developmental trajectory of children’s inductive inferences for both natural kinds and artefacts

Inductive reasoning is fundamental to human cognition, yet it remains unclear how we develop this ability and what might influence our inductive choices. We created novel categories in which crucial factors such as domain and category structure were manipulated orthogonally. We trained 403 4-9-year-old children to categorise well-matched natural kind and artefact stimuli with either featural or relational category structure, followed by induction tasks. This wide age range allowed for the first full exploration of the developmental trajectory of inductive reasoning in both domains. We found a gradual transition from perceptual to categorical induction with age. This pattern was stable across domains, but interestingly, children showed a category bias one year later for relational categories. We hypothesise that the ability to use category information in inductive reasoning develops gradually, but is delayed when children need to process and apply more complex category structures. © 2014 © 2014 Taylor & Francis.

Crystal structure and physical properties of the new linear chain compound [Cu(1,2-bis(tetrazol-1-yl)ethane)3](ClO4)2

The synthesis and crystal structure of a novel one-dimensional Cu(II) compound [Cu(1,2-bis(tetrazol-1-yl)ethane)3](ClO4)2 are described. The single-crystal X-ray structure determination was carried out at 298 K. The molecular structure consists of a linear chain in which the Cu(II) ions are linked by three N4,N4' coordinating bis(tetrazole) ligands in syn conformation. The Cu(II) ions are in a Jahn-Teller distorted octahedral environment (Cu(1)-N(11)=2.034(2) Å, Cu(1)-N(21)=2.041(2) Å and Cu(1)-N(31)=2.391(2) Å). The Cu⋯Cu separations are 7.420(3) Å.

Az élelmiszer-fogyasztás szerkezete és környezeti hatása Magyarországon (Analysing the structure and environmental impact of food consumption in hungary)

Egyre többen ismerik fel, hogy az élelmiszer-fogyasztás egészségügyi és környezeti hatása is jelentős. A különböző életstílusú társadalmi csoportok fogyasztási szerkezete eltérő lehet. Jelen tanulmány ezerfős, országos reprezentatív minta alapján vizsgálja az élelmiszer-fogyasztási szerkezet eltéréseit a nemek és különböző iskolázottságú fogyasztók körében. Jellemző fogyasztási klasztereket tár fel a fogyasztás szerkezete alapján. A fogyasztás szerkezeti és mennyiségi értékein túlmenően az ökológiai lábnyom indikátorával a fogyasztás környezetterhelését is számszerűsíti. _____ Concern about both health and environmental impacts of food consumption is increasing. Social groups with various lifestyles can have different food consumption structure. The present study analyses the differences in the food consumption structure among genders and educational groups based on a national, representative survey of 1000 adults. Food consumption clusters are identified based on food consumption structure. Beyond the analysis of food consumption and its structure, its environmental impact is quantified by the ecological footprint indicator.

Lessons learned from the effect of tight monetary conditions and crises on corporate capital structure

The study reviews the theoretical and empirical literature on the effect of tight monetary conditions, crisis on corporate capital structure, further creates a framework for analyzing their relation, as well as sheds light on the lessons learned and open research areas. The results highlight that the supply side of capital has an effect on corporate capital structure, though the analysis of this relation is scarce. However, the impact of tight monetary conditions on capital structure is analyzed by several studies, there is limited evidence on the financial policy and the development of financing mix during a crisis period. The impact of the 2007/08 crisis on the corporate capital structure and especially in case of firms with impaired access to external financing is scarce. The study also highlights our lack in understanding of the relation of crisis and capital structure in case of the CEE region.

The effects of fertilization and simulated grazing on the community structure of a seagrass bed in South Florida

The importance of resource supply and herbivory in driving competitive interactions among species has been an important but contentious issue within ecology. These variables exhibit different effects on species competition when manipulated in isolation but interact when manipulated together. I tested the direct and interactive effects of nutrient addition and simulated grazing (clipping) on the competitive performance of primary producers and community structure of a seagrass bed in South Florida. One square meter experimental plots were established in a mixed seagrass meadow from August 2007 to July 2009. The experiment was a 3 x 3 factorial experiment: 3 fertility treatments: control, medium (2.4 mg N d−1 and 80 µg P day −1) and high (4.8 mg N d−1 and 160 µg P day−1) x 3 clipping intensities (0, 25% and 50 % biomass removal (G)) x 5 replicates for each treatment = 45 plots). Nutrient additions and simulated grazing were done every two months. Fertilization and simulated grazing decreased sexual reproduction in S. filiforme. Fertilization increased competitive dominance within the primary producers while simulated grazing counteracted this effect by removal of the dominant species. Fertilization ameliorated the negative impacts of simulated grazing while simulated grazing prevented competitive exclusion in the fertilized plots. Nutrient addition and simulated grazing both exerted strong control on plant performance and community structure. Neither bottom up nor top down influences was eliminated in treatments where both factors where present. The effects of fertilization on plant performance were marked under all clipping intensities indicating that the system is regulated by nutrient availability both in the presence or absence of grazers. Clipping effects were strong under both fertilized and unfertilized conditions indicating that the seagrass bed can be simultaneously under top-down control by grazers.

Importance of storm events in controlling ecosystem structure and function in a Florida gulf coast estuary

From 8/95 to 2/01, we investigated the ecological effects of intra- and inter-annual variability in freshwater flow through Taylor Creek in southeastern Everglades National Park. Continuous monitoring and intensive sampling studies overlapped with an array of pulsed weather events that impacted physical, chemical, and biological attributes of this region. We quantified the effects of three events representing a range of characteristics (duration, amount of precipitation, storm intensity, wind direction) on the hydraulic connectivity, nutrient and sediment dynamics, and vegetation structure of the SE Everglades estuarine ecotone. These events included a strong winter storm in November 1996, Tropical Storm Harvey in September 1999, and Hurricane Irene in October 1999. Continuous hydrologic and daily water sample data were used to examine the effects of these events on the physical forcing and quality of water in Taylor Creek. A high resolution, flow-through sampling and mapping approach was used to characterize water quality in the adjacent bay. To understand the effects of these events on vegetation communities, we measured mangrove litter production and estimated seagrass cover in the bay at monthly intervals. We also quantified sediment deposition associated with Hurricane Irene's flood surge along the Buttonwood Ridge. These three events resulted in dramatic changes in surface water movement and chemistry in Taylor Creek and adjacent regions of Florida Bay as well as increased mangrove litterfall and flood surge scouring of seagrass beds. Up to 5 cm of bay-derived mud was deposited along the ridge adjacent to the creek in this single pulsed event. These short-term events can account for a substantial proportion of the annual flux of freshwater and materials between the mangrove zone and Florida Bay. Our findings shed light on the capacity of these storm events, especially when in succession, to have far reaching and long lasting effects on coastal ecosystems such as the estuarine ecotone of the SE Everglades.