bluuebunny/crossref_metadata_2025 huggingface dataset:
Silver(I) coordination polymers assembled from flexible cyclotriphosphazene ligand: structures, topologies and investigation of the counteranion effects
Authors: Davarcı Derya , Gür Rüştü , Beşli Serap , Şenkuytu Elif , Zorlu Yunus
Published: May 2016

The reactions of a flexible ligand hexakis(3-pyridyloxy)cyclotriphosphazene (HPCP) with a variety of silver(I) salts (AgX;X= NO3−, PF6−, ClO4−, CH3PhSO3−, BF4−and CF3SO3−) afforded six silver(I) coordination polymers, namely {[Ag2(HPCP)]·(NO3)2·H2O}n(1), {[Ag2(HPCP)(CH3CN)]·(PF6)2}n(2), {[Ag2(HPCP)(CH3CN)]·(ClO4)2}n(3), [Ag3(HPCP)(CH3PhSO3)3]n(4), [Ag2(HPCP)(CH3CN)(BF4)2]n(5) and {[Ag(HPCP)]·(CF3SO3)}n(6). All of the isolated crystalline compounds were structurally determined by X-ray crystallography. Changing the counteranions in the reactions, which were conducted under similar conditions ofM/Lratio (1:1), temperature and solvent, resulted in structures with different types of topologies. In complexes (1)–(6), the ligand HPCP shows different coordination modes with AgIions giving two-dimensional layered structures and three-dimensional frameworks with different topologies. Complex (1) displays a new three-dimensional framework adopting a (3,3,6)-connected 3-nodal net with point symbol {4.62}2{42.610.83}. Complexes (2) and (3) are isomorphous and have a two-dimensional layered structure showing the same 3,6L60 topology with point symbol {4.26}2{48.66.8}. Complex (4) is a two-dimensional structure incorporating short Ag...Ag argentophilic interactions and has a uninodal 4-connectedsql/Shubnikov tetragonal plane net with {44.62} topology. Complex (5) exhibits a novel three-dimensional framework and more suprisingly contains twofold interpenetrated honeycomb-like networks, in which the single net has a trinodal (2,3,5)-connected 3-nodal net with point symbol {63.86.12}{63}{8}. Complex (6) crystallizes in a trigonal crystal system with the space group R\bar 3 and possesses a three-dimensional polymeric structure showing a binodal (4,6)-connectedfshnet with the point symbol (43.63)2.(46.66.83). The effect of the counteranions on the formation of coordination polymers is discussed in this study.
Conformational polymorphs of isobutyl-6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate: spectroscopic, structural and DFT approach
Authors: Prasad A. Aditya , Kumar C. Udhaya , Prakasam B. Arul , Meenakshisundaram S. P.
Published: May 2016

The crystal structure of a new crystalline phase, polymorph (II) of isobutyl-6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate, was accurately determined by single-crystal X-ray diffraction analysis providing a clean identification of polymorphic forms. Comparison with a known phase, referred to as polymorph (I), reveals the type of supramolecular assembly. Inter- and intramolecular hydrogen-bonding interactions exhibit various supramolecular architectures in crystal packing and these variations confirm well the polymorphism in isobutyl-6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate (IAPC) crystal structure. Crystal cohesion is achieved by N—H...N, N—H...O and C—H...H—C interactions, responsible for the formation and strengthening of the supramolecular assembly. The objective of this investigation is to study crystalline forms which can offer enhanced physicochemical properties, and also to recognize the molecular orientations between such forms. The conformational polymorphs of IAPC were compared spectroscopically by FT–IR and FT–Raman. The bulk phases were studied by X-ray powder diffraction patterns. External morphology was investigated using scanning electron microscopic images. The molecular interactions were quantified using Hirshfeld surface and fingerprint analysis. Density functional theory (DFT) computations were used to optimize the structure. The optimized structure is further subjected to an analysis of Mulliken population, natural population and electrostatic potential.
One-pot green synthesis of biologically relevant novel spiro[indolin-2-one-3,4′-pyrano[2,3-c]pyrazoles] and studies on their spectral and X-ray crystallographic behaviors
Authors: Sharma Sakshi , Brahmachari Goutam , Kant Rajni , Gupta Vivek K.
Published: May 2016

Synthesesviagreen route and single-crystal X-ray structural investigations have been carried out for three spiro[indolin-2-one-3,4′-pyrano[2,3-c]pyrazole] derivatives, 6′-amino-2-oxo-3′-propyl-2′H-spiro[indoline-3,4′-pyrano[2,3-c]pyrazole]-5′-carbonitrile dimethyl sulfoxide monosolvate (5a), 6′-amino-5-fluoro-2-oxo-3′-propyl-2′H-spiro[indoline-3,4′-pyrano[2,3-c]pyrazole]-5′-carbonitrile dimethyl sulfoxide monosolvate (5b) and methyl 6′-amino-5-cyano-1-methyl-2-oxo-3′-propyl-2′H-spiro[indoline-3,4′-pyrano[2,3-c]pyrazole]-3′-carboxylate 0.25 hydrate (5c), respectively. Compounds (5a) and (5b) crystallize in the triclinic space group P\bar 1, whereas compound (5c) crystallizes in the monoclinic space groupC2/c. In molecules (5a) and (5b) all the rings are practically flat, while in (5c), the heterocyclic pyran ring adopts a flattened-boat conformation. In (5a) and (5b) the cyanide group is oriented in a (−ap)conformation, while the amino group is oriented in a (+ap)conformation with a pyran ring, but in (5c) both the cyanide and amino groups are oriented in a (−ap) conformation with the pyran ring. In the crystal structure of (5a) and (5b), the molecules are linked by an elaborate system of N—H...O and N—H...N hydrogen bonds to generate a zigzag-like construct. In (5c) molecules are linked by N—H...O hydrogen bonds, thereby generating extended chains. The present communication focuses on the detailed and comparative information about spectral behaviors, single-crystal X-ray crystallographic properties and solid-state supramolecular architectures of these synthesized compounds of potential biological interests.
Faces of root polytopes in all dimensions
Authors: Szajewska Marzena
Published: May 2016

In this paper the root polytopes of all finite reflection groupsWwith a connected Coxeter–Dynkin diagram in {\bb R}^n are identified, their faces of dimensions 0 ≤d≤n− 1 are counted, and the construction of representatives of the appropriateW-conjugacy class is described. The method consists of recursive decoration of the appropriate Coxeter–Dynkin diagram [Champagneet al.(1995).Can. J. Phys.73, 566–584]. Each recursion step provides the essentials of faces of a specific dimension and specific symmetry. The results can be applied to crystals of any dimension and any symmetry.
Properties of X-ray resonant scattering in the Bragg case revealed on the Riemann surface
Authors: Saka Takashi
Published: May 2016

Continuing the work described in the previous paper [Saka (2016).Acta Cryst.A72, 338–348], the dynamical theory for perfect crystals in the Bragg case is reformulated using the Riemann surface. In particular, diffraction under resonant scattering conditions is investigated. The characteristic features of the dispersion surface and the rocking curve are analytically revealed using four parameters, which are the real and imaginary parts of two quantities specifying the degree of departure from the exact Bragg conditions and the reflection strength. Characteristic properties that have been deduced through numerical analysis are derived analytically using these four parameters. Visualization of the geometric relationships between the four parameters on the Riemann surface is useful for understanding many properties such as symmetry and sharpness of the rocking curve under special conditions. Therefore, employing the Riemann surface is instructive for numerical analysis and useful for understanding dynamical diffraction in the Bragg case.
Volatility transmission in African foreign exchange markets
Authors: Carsamer Emmanuel
Published: May 2016

Purpose

– The concept of volatility transmission and co-movement has witnessed a resurgence in the international finance literature in recent years after the black swan events which gave evidence of financial market linkages. The purpose of this paper is to examine the dynamic sources of volatility transmission in the foreign exchange market in recent financial market integration in Africa.

Design/methodology/approach

– A conceptual framework was adapted from the extant literature and was used as the basis of modeling exchange rate volatility transmission. This paper adopts a quantitative research approach and opts for augmented DCC model to empirically unearth the sources of exchange rate volatility transmission.

Findings

– The key findings of the study are that, the African market is more prone to shock from outside than in the region. Macroeconomic news surprises influence volatility transmission and co-movements. Robust support is found for trade balance, interest rate and gross domestic product. These findings clearly demonstrate the low level of financial development and challenges that sometimes exist in exchange rate-policy implementation by policy makers.

Research limitations/implications

– Interested academics and practitioners working in the area might incorporate bilateral investment into the model of exchange rate correlation in future research.

Originality/value

– Unilaterally considering exchange rate volatility transmission and subsequent augmentation of the DCC model, this study makes a modest contribution to the examination of exchange rate correlations in Africa. This study makes an important contribution in not only addressing this imbalance, but more importantly improving the relative literature on exchange rate volatility transmission.
New empirics of monetary policy dynamics: evidence from the CFA franc zones
Authors: Asongu Simplice
Published: May 2016

Purpose

– A major lesson of the European Monetary Union crisis is that serious disequilibria in a monetary union result from arrangements not designed to be robust to a variety of shocks. With the specter of this crisis looming substantially and scarring existing monetary zones, the purpose of this paper is to complement existing literature by analyzing the effects of monetary policy on economic activity (output and prices) in the CEMAC and UEMOA CFA franc zones.

Design/methodology/approach

– VARs within the frameworks of Vector Error-Correction Models and Granger causality models are used to estimate the long- and short-run effects, respectively. Impulse response functions are further used to assess the tendencies of significant Granger causality findings. A battery of robustness checks are also employed to ensure consistency in the specifications and results.

Findings

–H1. monetary policy variables affect prices in the long-run but not in the short-run in the CFA zones (broadly untrue). This invalidity is more pronounced in CEMAC (relative to all monetary policy variables) than in UEMOA (with regard to financial dynamics of activity and size).H2. monetary policy variables influence output in the short-term but not in the long-run in the CFA zones. First, the absence of cointegration among real output and the monetary policy variables in both zones confirm the neutrality of money in the long term. With the exception of overall money supply, the significant effect of money on output in the short-run is more relevant in the UEMOA zone, than in the CEMAC zone in which only financial system efficiency and financial activity are significant.

Practical implications

– First, compared to the CEMAC region, the UEMOA zone’s monetary authority has more policy instruments for offsetting output shocks but fewer instruments for the management of short-run inflation. Second, the CEMAC region is more inclined to non-traditional policy regimes while the UEMOA zone dances more to the tune of traditional discretionary monetary policy arrangements. A wide range of policy implications are discussed. Inter alia: implications for the long-run neutrality of money and business cycles; implications for credit expansions and inflationary tendencies; implications of the findings to the ongoing debate; country-specific implications and measures of fighting surplus liquidity.

Originality/value

– The paper’s originality is reflected by the use of monetary policy variables, notably money supply, bank and financial credits, which have not been previously used, to investigate their impact on the outputs of economic activities, namely, real GDP output and inflation, in developing country monetary unions.
Political risk and sovereign spreads in Latin America
Authors: Hansen Erwin , Zegarra Jennifer
Published: May 2016

Purpose

The purpose of this paper is to explore the relationship between six different dimensions of political risk in a country and its spread for a sample of 12 Latin American countries.

Design/methodology/approach

The methodology applied consists of panel estimators with fixed effects. In addition, a panel data model with instrumental variables is considered to tackle with potential problems of endogeneity in the model.

Findings

The results show there is a strong positive relationship between political risk and sovereign spread in Latin America, i.e., greater political risk is associated with greater sovereign spread. This effect is particularly significant when the political risk is associated with a weak rule of law or low-quality regulation in the country.

Research limitations/implications

The main limitation of this study concerns the potential risks of endogeneity which might exist between sovereign risk and political risk measures, which may not have been completely eliminated with the econometric methodology used.

Originality/value

This paper contributes to the literature of sovereign risk by studying the dimension of political risk in detail. Specifically, six dimensions of political risk are studied. Additionally, it provides empirical evidence, including the 2008 financial crisis period, regarding the determinants of spreads on Latin American economies.
Copreneurial women in start-ups
Authors: Kuschel Katherina , Lepeley María-Teresa
Published: May 2016

Purpose

Latin American investors are commonly suspicious of investing in copreneurial ventures (a male and female couple, integrated as a working team) and show even higher levels of uncertainty when the start-ups are led by a female founder. The purpose of this paper is to address issues related to women as leaders in copreneurial tech ventures and analyses whether these ventures are growth-oriented or conform to limited partnerships aimed primarily to meet their living standards.

Design/methodology/approach

A qualitative, inductive and constructive approach was required for addressing the research question. Three copreneurial women and two divorced copreneurs were interviewed. A grounded theory approach was used to analyze data and emerging themes.

Findings

Copreneurial teams that work in the technology industry have similar and complementary levels of education and skills development. After three years working together, each partner becomes well aware of mutual skills and strengths. This allows them to define their respective roles. Both divide work and family, and have developed a level of mutual trust and commitment that is essential to move forward. Commonly they show workaholic tendencies with a high rational underpinning. All of these factors strengthen collaboration and in many instances this business liaison can remain intact despite a breakdown in the partners’ sentimental relationship. Additional findings show that their growth orientation takes multiple structures.

Practical implications

This study provides information that can help investors make decisions to support copreneurial teams that optimize from the use of diverse talents of female and male partners.

Originality/value

Although representing an increasingly common type of start-up team, copreneurship in technology has not yet capture much attention of scholars as case study in family business research.
Exploring the issue of naming rights of public sports facilities in Greece
Authors: Anestos Kostas , Gargalianos Dimitris , Thamnopoulos Yannis
Published: May 2016

Purpose

The aim of this study was to conduct a primary examination of people’s perceptions toward the concept of selling of naming rights for publicly owned sports facilities in Greece to explore the possibilities for this sponsorship practice to be introduced in the future.

Design/methodology/approach

In all, 410 research participants filled out a questionnaire that focused on the level of acceptance, in relation to variations of agreements, and considering decision outcomes scenarios, as also on other naming rights parameters, such as sponsors’ fit features. A modification of methods used in previous research in the context of consumers’ price perceptions in sport was adopted to investigate the potential effects from the provision of decision outcomes messages.

Findings

The research findings indicated that, in terms of acceptance from the public, there might be grounds to implement this type of sponsorship. It is suggested that an optimal way of introducing the concept should be with marketing campaigns outlining the main purpose and the prospective benefits.

Research limitations/implications

Possibly, the participants perceived the prospect and scenarios provided as not very likely to happen and this might influence their responses. Future research should investigate the effects of other factors, such as attitudes toward commercialization, stadium identification and perceived financial status.

Originality/value

The study provides a basis for the consideration of naming rights as a sponsorship option for public sports facilities in Greece, and also offers a new perspective in the use of treatment messages as a tool for altering potential negative perceptions.
Shared student residential space: a post occupancy evaluation
Authors: Khajehzadeh Iman , Vale Brenda
Published: May 2016

Purpose

In Iran, as elsewhere, a great number of student dormitory-style buildings have been built with shared rooms either side of a central corridor as a simple and affordable building form. Highly populated shared rooms with common facilities in such buildings can produce problems in terms of personal space but, at the same time, have many advantages for social interactions and better use of resources, which is a feature of sustainability. Most of these buildings are old and need fundamental refurbishment. This study aims to provide some guidelines to improve advantages and control disadvantages of this building type for future refurbishment and new developments.

Design/methodology/approach

The advantages and disadvantages of shared spaces have been analysed using a Post Occupancy Evaluation approach in a case study which is representative of more than 30 university dormitories in Iran. Interview, observation and questionnaire survey tools are used in this study.

Findings

Results show students have some problems regarding privacy, interaction, security, noise, circulation, access hierarchy, storage spaces, use of rooms and territory definition.

Practical implications

Based on the results of the study, some design suggestions are made for more efficient shared spaces for future designs and also for improving the case study dormitory, in terms of both access hierarchy and internal room arrangements.

Originality/value

Post Occupancy Evaluation has not previously been used to provide guidelines for architects to improve the quality of design according to existing functional/behavioural problems in similar buildings.
Sustainability and competitive advantage from a developing economy
Authors: Kwarteng Amoako , Dadzie Samuel Ato , Famiyeh Samuel
Published: May 2016

Purpose

The purpose of this study is to empirically examine the impact of sustainability as measured by the triple bottom line constructs on the competitive advantage of manufacturing firms in Ghana.

Design/methodology/approach

To understand the impact of sustainability on competitive advantage, a survey was conducted where managers were asked about their engagement in the sustainability issues and how it affects their competitive advantage. The study uses the structural equation modelling (SEM) and, in particular, the partial least square (PLS) approaches to SEM.

Findings

The results of this study indicate that economic and social have a positive impact on the corporate image but not the environment. In addition, corporate image and social have positive impact on corporate performance, whilst economic and environment seem not to have any impact on corporate performance.

Research limitations/implications

The study is limited to only manufacturing firms operating in the Ghanaian environment. It is important, therefore, for firms in Ghana to invest in social sustainability initiatives, as it will ultimately affect their bottom line performance. This study provides policy implications to Ghana and other developing countries to implement the necessary policies and provide incentives to improve environmental awareness.

Originality/value

There have been just a few studies that tried to find out the impact of sustainability constructs and performance and how corporate image mediates this relationship.
Goal integration through transformational leadership
Authors: Dartey-Baah Kwasi
Published: May 2016

Purpose

The purpose of this study was to present a conceptual analysis of how the issue of corruption in Ghana’s public sector can be curbed through an integration of individual (public sector worker) and organisational goals (the public sector itself). It further sought to explain this possibility by focusing on a goal integration process through transformational leadership.

Design/methodology/approach

To meet this end, the study conducted a review of literature on goal, goal-setting, corruption, employee motivation and transformational leadership to develop a conceptual framework to explain this link between goal integration through transformational leadership and corruption reduction.

Findings

Findings from this study showed that dissatisfaction with work (especially pay) amongst Ghana’s public sector workers is a major factor necessitating the emergence of corruption in the country. It is also shown in the study that through the transformational leadership approach, individual worker concerns such as concerns with pay (a facet of job satisfaction) when treated as an institutional concern and appropriately dealt with could curb corruption in the public sector.

Research limitations/implications

Based on these findings, the study recommends that leaders in Ghana’s public sector (both political and administrative) must exhibit qualities of transformational leaders to foster individual and organisational growth as a means to curb corruption in the sector. The study also recommends that training programmes be organised for leaders to equip them with the needed knowledge and practice of transformational leadership. Furthermore, the study recommends that further studies could be done by other researchers on the training programmes that could be useful in equipping these leaders, as well as how and when to organise these programmes.

Originality/value

The study is novel in that it demonstrates the relevance of integrating individual and organisational goals through the application of the transformational leadership concept as a tool for reducing corruption in Ghana’s public sector.
Ethical communication on society issues: a story from Indonesia
Authors: Hanifa Abi , Cahaya Fitra Roman
Published: May 2016

Purpose

This paper aims to examine Indonesia Stock Exchange (IDX)-listed companies’ society disclosures.

Design/methodology/approach

Year-ending 2012 annual report disclosures of 75 IDX-listed companies are analyzed. The widely acknowledged Global Reporting Initiative guidelines are used as the disclosure index checklist.

Findings

The results show a relatively low level of voluntary society disclosure (40.27 per cent). The highest level of communication is for issues related to society programs. Very few companies disclosed information about public policy, donations to political parties and actions taken in response to corruption incidents. Statistical analysis reveals that company size is a positively significant predictor of “society” communication. Ethical stakeholder theory partially explains the variability of these disclosures.

Research limitations/implications

The main implication of the findings is that Indonesian companies are not involved in the public policy-making process. Companies also probably attempt to hide certain information regarding corruption issues to protect their image and reputation.

Originality/value

This paper provides insights into the disclosure practices of society issues, a specific social disclosure theme which is rarely examined in prior literature, within the framework of ethical stakeholder theory. The research also includes corruption issues to be investigated in the disclosure analysis.
Making the climate change issue “real” for managers
Authors: Pineda Rodley
Published: May 2016

Purpose

Although businesses face various types of risks because of climate change, the level of concern among managers seem to lag behind the institutional pressure to deal with the climate change issue. This paper aims to bridge this gap in perceptions by presenting a framework to assist business leaders in translating the climate change issue into a format that managers can appreciate.

Design/methodology/approach

Drawing from the supply chain literature, this paper presents a model that shows how climate change-related policy and resource risks affect a firm’s supply, operations and demand domains and the risk management approaches appropriate for each type of risk. Excerpts from 10-K annual reports filed by US automotive and food retailers are used to show how the model works.

Findings

Although majority of companies examined do not report climate change-related risks, the evidence from those that do affirm the framework’s ability to translate these risks into manager-friendly supply chain terminology.

Originality/value

Managers can participate in sustainability actions by focusing on the risks and effects of climate change. Business leaders, researchers and policymakers can adopt supply chain risk management terminology to connect with otherwise indifferent managers.
Experimental insight into the process of parasite community assembly
Authors: Budischak Sarah A. , Hoberg Eric P. , Abrams Art , Jolles Anna E. , Ezenwa Vanessa O.
Published: May 2016

Community assembly is a fundamental process that has long been a central focus in ecology. Extending community assembly theory to communities of co‐infecting parasites, we used a gastrointestinal nematode removal experiment in free‐ranging African buffalo to examine the community assembly patterns and processes.

We first asked whether reassembled communities differ from undisturbed communities by comparing anthelmintic‐treated and control hosts. Next, we examined the temporal dynamics of assembly using a cross‐section of communities that reassembled for different periods of time since last experimental removal. Next, we tested for evidence of assembly processes that might drive such reassembly patterns: environmental filtering based on host traits (i.e. habitat patches), interspecific interactions, priority effects and chance dispersal from the environmental pool of infective stages (i.e. the regional species pool).

On average, reassembled parasite communities had lower abundance, but were more diverse and even, and these patterns varied tightly with reassembly time. Over time, the communities within treated hosts progressively resembled controls as diversity and evenness decreased, while total abundance increased. Notably, experimental removal allowed us to attribute observed differences in abundance, diversity and evenness to the process of community assembly.

During early reassembly, parasite accumulation was biased towards a subordinate species and, by excluding stochastic assembly processes (i.e. chance dispersal and priority effects), we were able to determine that early assembly is deterministic. Later in the reassembly process, we established that host traits, as well as stochastic dispersal from the environmental pool of infective stages, can affect the community composition.

Overall, our results suggest that there is a high degree of resiliency and environmental dependence to the worm communities of buffalo. More generally, our data show that both deterministic and stochastic processes may play a role in the assembly of parasite communities of wild hosts, but their relative importance may vary temporally. Consequently, the best strategy for managing reassembling parasite communities may also need to shift over time.
Parasite specialization in a unique habitat: hummingbirds as reservoirs of generalist blood parasites of Andean birds
Authors: Moens Michaël A. J. , Valkiūnas Gediminas , Paca Anahi , Bonaccorso Elisa , Aguirre Nikolay , Pérez‐Tris Javier
Published: May 2016

Understanding how parasites fill their ecological niches requires information on the processes involved in the colonization and exploitation of unique host species. Switching to hosts with atypical attributes may favour generalists broadening their niches or may promote specialization and parasite diversification as the consequence.

We analysed which blood parasites have successfully colonized hummingbirds, and how they have evolved to exploit such a unique habitat. We specifically asked (i) whether the assemblage of Haemoproteus parasites of hummingbirds is the result of single or multiple colonization events, (ii) to what extent these parasites are specialized in hummingbirds or shared with other birds and (iii) how hummingbirds contribute to sustain the populations of these parasites, in terms of both prevalence and infection intensity.

We sampled 169 hummingbirds of 19 species along an elevation gradient in Southern Ecuador to analyse the host specificity, diversity and infection intensity of Haemoproteus by molecular and microscopy techniques. In addition, 736 birds of 112 species were analysed to explore whether hummingbird parasites are shared with other birds.

Hummingbirds hosted a phylogenetically diverse assemblage of generalist Haemoproteus lineages shared with other host orders. Among these parasites, Haemoproteus witti stood out as the most generalized. Interestingly, we found that infection intensities of this parasite were extremely low in passerines (with no detectable gametocytes), but very high in hummingbirds, with many gametocytes seen. Moreover, infection intensities of H. witti were positively correlated with the prevalence across host species.

Our results show that hummingbirds have been colonized by generalist Haemoproteus lineages on multiple occasions. However, one of these generalist parasites (H. witti) seems to be highly dependent on hummingbirds, which arise as the most relevant reservoirs in terms of both prevalence and gametocytaemia. From this perspective, this generalist parasite may be viewed as a hummingbird specialist. This challenges the current paradigm of how to measure host specialization in these parasites, which has important implications to understand disease ecology.
The effect of competition on responses to drought and interannual climate variability of a dominant conifer tree of western North America
Authors: Carnwath Gunnar C. , Nelson Cara R.
Published: May 2016

To accurately predict how ecosystems will respond to climate change – and how management actions can influence such responses – scientists and managers need a better understanding of how and when biotic interactions modify climate–growth relationships. However, current research has largely ignored the role of competition in modulating climate–growth relationships of mature trees. In this study, we assessed the effect of competition on tree responses to drought and interannual climate variability as well as linkages between climate sensitivity and morphological characteristics of the stem wood.

We sampled 10 sites in north‐eastern Washington,USA, and used dendroecology to quantify responses of Douglas‐fir (Pseudotsuga menziesii) to drought and climate variability. Tree‐ring series were converted to basal area increment series, and the effects of competition on climate–growth relationships were assessed at the tree and site levels using a combination of correlation analyses and linear mixed‐effects models.

Competition did not affect tree responses to extreme drought. When soil moisture was below average, tree growth was tightly coupled to climate variability for all trees, regardless of their competitive status. However, in wet years, competition had a pronounced, positive effect on climate sensitivity of growth.

Trees with more competition from neighbours exhibited a significantly higher proportion of sapwood area in latewood (a morphological trait associated with greater drought resistance).

Synthesis. Our results suggest that a tree's ability to cope with environmental variability is driven not just by the proximate effects of neighbours on resource availability, but also by phenotypic plasticity and long‐term adaptations to competitive stress (such as changes in carbon allocation). Findings have important implications for individual‐tree and stand‐level growth models and may help managers better understand how their activities will modify tree responses to climate change.
Women's prepregnancy underweight as a risk factor for preterm birth: a retrospective study
Authors: Girsen AI , Mayo JA , Carmichael SL , Phibbs CS , Shachar BZ , Stevenson DK , Lyell DJ , Shaw GM , Gould JB ,   the March of Dimes Prematurity Research Center at Stanford University School of Medicine
Published: May 2016

Objective

To investigate the distribution of known factors for preterm birth (PTB) by severity of maternal underweight; to investigate the risk‐adjusted relation between severity of underweight and PTB, and to assess whether the relation differed by gestational age.

Design

Retrospective cohort study.

Setting

State of California, USA.

Methods

Maternally linked hospital and birth certificate records of 950 356 California deliveries in 2007–2010 were analysed. Singleton live births of women whose prepregnancy body mass index (BMI) was underweight (<18.5 kg/m2) or normal (18.50–24.99 kg/m2) were analysed. Underweight BMI was further categorised as: severe (<16.00), moderate (16.00–16.99) or mild (17.00–18.49). PTB was grouped as 22–27, 28–31, 32–36 or <37 weeks (compared with 37–41 weeks). Adjusted multivariable Poisson regression modeling was used to estimate relative risk for PTB.

Main outcome measures

Risk of PTB.

Results

About 72 686 (7.6%) women were underweight. Increasing severity of underweight was associated with increasing percent PTB: 7.8% (n = 4421) in mild, 9.0% (n = 1001) in moderate and 10.2% (475) in severe underweight. The adjusted relative risk of PTB also significantly increased: adjusted relative risk (aRR) = 1.22 (95% CI 1.19–1.26) in mild, aRR = 1.41 (95% CI 1.32–1.50) in moderate and aRR = 1.61 (95% CI 1.47–1.76) in severe underweight. These findings were similar in spontaneous PTB, medically indicated PTB, and the gestational age groupings.

Conclusion

Increasing severity of maternal prepregnancy underweight BMI was associated with increasing risk‐adjusted PTB at <37 weeks. This increasing risk was of similar magnitude in spontaneous and medically indicated births and in preterm delivery at 28–31 and at 32–36 weeks of gestation.

Tweetable abstract

Increasing severity of maternal underweight BMI was associated with increasing risk of preterm birth.
Lowering the high rate of caesarean delivery in China: an experience from Shanghai
Authors: Liu X , Lynch CD , Cheng WW , Landon MB
Published: May 2016

Objective

To examine the trends of caesarean delivery (CD) after an intervention to lower the high rate of CD at a Chinese maternity hospital.

Design

Retrospective cohort study.

Setting

A large tertiary obstetric centre in Shanghai, China, from 2007 to 2014.

Sample

81 459 nulliparous women who delivered a term singleton infant.

Methods

Logistic regression was used to calculate the odds of CD while adjusting for confounders.

Main outcome measure

Rate of CD before and after the intervention.

Results

The rate of CD decreased from 51.5% in 2008 to 36.1% in 2014, mostly due to a reduction in non‐indicated antepartum CD from 27.9% in 2010 to 11.9% in 2014. After adjustment, a period effect remained with delivery between 2011 and 2014 associated with a 31% reduction in the odds of CD compared with delivery between 2007 and 2010 [odds ratio (OR): 0.69, 95% CI: 0.66–0.71)] and a 33% reduction in the odds of antepartum CD (OR: 0.67, 95% CI: 0.64–0.69). The frequencies of perinatal mortality (0.5 versus 0.4/1000), hypoxic ischaemic encephalopathy (0.9 versus 1.2/1000), meconium aspiration syndrome (0.5/1000), birth trauma (0.6/1000), respiratory distress syndrome (0.5% versus 0.4%) and necrotising enterocolitis (0.9 versus 0.6/1000) were similar. The frequency of neonatal infection increased slightly (0.6% versus 0.8%), although this could be explained by other factors.

Conclusions

A marked reduction in CD has occurred at an urban tertiary care centre as a result of efforts to reduce the high rate of caesarean delivery. No notable differences in neonatal outcomes were observed.

Tweetable abstract

High rates of caesarean delivery can be lowered without increases in neonatal morbidity and mortality.
Private and Public Incentives for Prevention of Livestock Diseases on Danish Farms
Authors: Biira Juliet , Hougaard Jens Leth , Lund Mogens
Published: May 2016

Denmark is one of the EU countries with a highly recognised agricultural sector, a high level of animal health and one of the lowest medication usages. In this article we aim to provide an overview of both private and public animal health incentives nested in the cattle and pig production industry that influence the decisions and behaviours of farmers in prevention of livestock disease epidemics. Not only do individual Danish pig and cattle farmers aim at highly efficient animal production, they are also involved in collective marketing and contracting which can enhance social capital, peer pressure and instill a greater sense of ownership of disease control prevention. Public incentives including rules on how animals should be transported within Denmark, SPF certification requirements and rules on farm biosecurity further improve farmer incentives to prevent animal diseases. However, Danish pig and cattle farmers’ incentives could be further improved by specifying consequences for not following requirements such as failure to make a compulsory biosecurity plan. The relatively high compensation in case of a disease outbreak provides a safety net for farmers, encourages them to quickly report suspected notifiable diseases but it could also reduce incentives for disease prevention due to the relatively high amounts of compensation.
Undermined by Adverse Selection: Australia's Direct Action Abatement Subsidies
Authors: Burke Paul J.
Published: May 2016

This paper examines the economic challenges faced by Australia's Direct Action abatement subsidy scheme. Introduced in 2014, the scheme operates by reverse auction, funding projects voluntarily proposed by the private sector. Because the Government cannot know true project counterfactuals, the lowest auction bids are likely to often be non‐additional “anyway” projects. The scheme is hence likely to exhibit a systematic skew towards low‐quality abatement. The paper presents a model of the adverse selection problem and describes the early experience with Direct Action. A discussion of a way forward is also provided.
Evaluation of a novel saliva‐based epidermal growth factor receptor mutation detection for lung cancer: A pilot study
Authors: Pu Dan , Liang Hao , Wei Fang , Akin David , Feng Ziding , Yan QingXiang , Li Yin , Zhen Yan , Xu Lin , Dong Gaochao , Wan Huajing , Dong Jingsi , Qiu Xiaoming , Qin Changlong , Zhu Daxing , Wang Xi , Sun Tong , Zhang Wenbiao , Li Canjun , Tang Xiaojun , Qiao Youlin , Wong David T.W. , Zhou Qinghua
Published: May 2016

Background

This article describes a pilot study evaluating a novel liquid biopsy system for non‐small cell lung cancer (NSCLC) patients. The electric field‐induced release and measurement (EFIRM) method utilizes an electrochemical biosensor for detecting oncogenic mutations in biofluids.

Methods

Saliva and plasma of 17 patients were collected from three cancer centers prior to and after surgical resection. The EFIRM method was then applied to the collected samples to assay for exon 19 deletion and p.L858 mutations. EFIRM results were compared with cobas results of exon 19 deletion and p.L858 mutation detection in cancer tissues.

Results

The EFIRM method was found to detect exon 19 deletion with an area under the curve (AUC) of 1.0 in both saliva and plasma samples in lung cancer patients. For L858R mutation detection, the AUC of saliva was 1.0, while the AUC of plasma was 0.98. Strong correlations were also found between presurgery and post‐surgery samples for both saliva (0.86 for exon 19 and 0.98 for L858R) and plasma (0.73 for exon 19 and 0.94 for L858R).

Conclusion

Our study demonstrates the feasibility of utilizing EFIRM to rapidly, non‐invasively, and conveniently detect epidermal growth factor receptor mutations in the saliva of patients with NSCLC, with results corresponding perfectly with the results of cobas tissue genotyping.
Experimentally derived likelihoods for light‐based geolocation
Authors: Basson Marinelle , Bravington Mark V. , Hartog Jason R. , Patterson Toby A.
Published: May 2016

Electronic tags have revolutionised animal movement studies, but the reliability of subsequent ecological inference hinges on being able to quantify uncertainty in location estimates. Light‐based geolocation, which uses the time series of light intensity during twilight events, remains the only viable technology for many species (e.g. fish and small birds) despite its limited accuracy. Modern approaches to movement modelling, such as Kalman filters and gridded hidden Markov models, require a valid likelihood for each observed twilight.

It is difficult to directly construct such a likelihood (i.e. the probability density of the light data during a twilight period) given any location on the globe, because of complicated autocorrelation structures and non‐standard statistical distributions. We therefore use data from moored tags at known locations to construct a transformation that turns a simple one‐dimensional statistic into a quantity with the properties of a log‐likelihood.

The result is a set of calibration splines that can be used with light data from a similar tag deployed on a real animal: for each twilight, the one‐dimensional statistic is calculated for any location (e.g. on a grid of, or all possible, locations) and then transformed into a likelihood using the calibration splines. The likelihoods can then be input to any state‐space model to estimate a track. We show an example track from a grid‐based hidden Markov model applied to light data from a tag deployed on a southern bluefin tuna.

This approach to light‐based geolocation provides the flexibility to integrate movement and behaviour modelling in a novel way. The likelihood surfaces from our approach can be used in any state‐space model of animal movement and behaviour, irrespective of whether estimation is by maximum‐likelihood or Bayesian methods. Our approach is primarily aimed at users interested in developing and fitting their own state‐space models to explore biological hypotheses about animal behaviour.
Treating perinatal asphyxia with theophylline at birth helps to reduce the severity of renal dysfunction in term neonates
Authors: Raina Alok , Pandita Aakash , Harish Rekha , Yachha Monika , Jamwal Ashu
Published: May 2016

Aim

Perinatal asphyxia is a common neonatal problem and contributes significantly to neonatal morbidity and mortality. This study was designed to determine whether theophylline could prevent or ameliorate renal dysfunction in term neonates with perinatal asphyxia.

Methods

We randomised 159 severely asphyxiated term newborns to receive a single dose of 5 mg/kg intravenous theophylline (n = 78) or a placebo (n = 81) during the first hour of life. The infant's 24‐hour fluid intake, urine volume, serum creatinine, creatinine clearance and sodium excretion were recorded during days one, three and five of life, starting 12 hours after the theophylline or placebo infusion.

Results

Neonates in the theophylline group had lower serum creatinine levels (0.83 ± 0.35 versus 1.47 ± 0.61; p = 0.00) and higher endogenous creatinine clearance (32.16 ± 16.34 versus 17.73 ± 7.92; p = 0.00) than the placebo group. Severe renal dysfunction, namely acute kidney injury, was present in 36 (15%) of the neonates in the theophylline group versus 117 (48%) in the placebo group (p < 0.01).

Conclusion

A single dose of intravenous theophylline administered to term neonates with perinatal asphyxia within the first hour of life significantly decreased serum creatinine levels and significantly increased creatinine clearance.
Cow's milk protein intolerance in adolescents and young adults with chronic fatigue syndrome
Authors: Rowe Peter C. , Marden Colleen L. , Jasion Samantha E. , Cranston Erica M. , Flaherty Marissa A. K. , Kelly Kevin J.
Published: May 2016

Aim

To examine the prevalence, clinical features and influence on illness severity of cow's milk protein intolerance in young people with chronic fatigue syndrome.

Methods

In a two‐year prospective study of 55 adolescents and young adults with chronic fatigue syndrome, we defined intolerance to milk protein if subjects reported (i) no evidence of immediate or anaphylactic reactions to milk, (ii) at least 2 of the following 3 chronic symptoms: gastroesophageal reflux, early satiety and epigastric/abdominal pain, (iii) improvement in upper gastrointestinal symptoms on a milk protein elimination diet and (iv) at least 2 recurrences of upper gastrointestinal symptoms >two hours following open re‐exposure to milk protein. Subjects completed three quality of life surveys at baseline and at six months.

Results

The mean (SD) age of the 55 participants was 16.5 (2.1) years. Seventeen (31%; 95% CI, 19–43%) met study criteria for cow's milk protein intolerance. Compared to milk‐tolerant subjects, milk‐sensitive participants had significantly worse health‐related quality of life at baseline but not at six months (after institution of the milk‐free diet).

Conclusion

Cow's milk protein intolerance is a common problem in young people with chronic fatigue syndrome and is a treatable contributor to their symptoms.