bluuebunny/crossref_metadata_2025 huggingface dataset:
The emerging role of physical modeling in the future of structure determination
Authors: Gaalswyk Kari , Muniyat Mir Ishruna , MacCallum Justin L.
Published: December 2017

Biomolecular structure determination has long relied on heuristics based on physical insight; however, recent efforts to model conformational ensembles and to make sense of sparse, ambiguous, and noisy data have revealed the value of detailed, quantitative physical models in structure determination. We review these two key challenges, describe different approaches to physical modeling in structure determination, and illustrate several successes and emerging technologies enabled by physical modeling.

Highlights

Quantitative physical modeling is emerging as a key tool in structure determination

There are different approaches to incorporate physical modeling into structure determination

Modeling conformational ensembles and making sense of sparse, noisy, and ambiguous data are two challenges where physical modeling can play a prominent role
Plant–soil feedbacks between arbuscular- and ecto-mycorrhizal communities
Authors: Kadowaki Kohmei , Yamamoto Satoshi , Sato Hirotoshi , Tanabe Akifumi S. , Hidaka Amane , Toju Hirokazu
Published: December 2017

Soil microbiomes of adult trees exert species-specific effects on the survival and growth of seedlings1-6, yet empirical evidence that such plant–soil microbiome interaction drives seedling community assembly remains scarce. Here we show that mycorrhizal fungal communities determine seedling community assembly by controlling how resident plant communities alter the growth of newly established seedlings. We reciprocally introduced seedling communities of arbuscular-and ecto-mycorrhizal plant species to replicated mesocosms to follow the effects of mycorrhizal type match/mismatch with resident plant communities on seedling growth rates. The growth rates of recruited seedlings were generally higher under resident trees of the same mycorrhizal types than under those of different mycorrhizal types, generating positive plant–soil feedbacks through mycorrhizal-type matching. Such positive effects of matching were linked with seedlings’ greater acquisition rates of mycorrhizal symbionts from matched resident plants than from mismatched plants, and such linkage was pronounced for ecto-mycorrhizal plant species. In contrast, under the condition of mycorrhizal-type matching between resident plants and seedlings (i.e., within-mycorrhizal-type comparison), plant–soil feedback effects varied considerably in their sign and strength among resident–seedling species combinations. Consequently, the assembly of a temperate tree seedling community is driven by a combination of species-specific plant–soil feedbacks and the match/mismatch of mycorrhizal type between resident plants and seedlings.
Natural Variation of OsLG3 Controls Drought Stress Tolerance in Rice by Inducing ROS Scavenging
Authors: Xiong Haiyan , Yu Jianping , Li Jinjie , Wang Xin , Liu Pengli , Zhang Hongliang , Zhao Yan , Yin Zhigang , Li Yang , Guo Yan , Fu Binying , Wang Wensheng , Li Zhikang , Ali Jauhar , Li Zichao
Published: December 2017

Background

Improving performance of rice under drought stress has potential to significant impact on rice productivity. Previously we reported that OsLG3 positively control rice grain length and yield.

Results

In this study, we found that OsLG3 was more strongly expressed in upland rice compared to lowland rice under drought stress condition. Candidate gene association analysis showed that the natural variation in OsLG3 was associated with tolerance to water deficit stress in germinating rice seeds. Transgenic rice with enhanced OsLG3 expression exhibited improved tolerance to drought and that is most likely due to enhanced ROS scavenging efficiency. Phylogenetic analysis and pedigree records indicated that the tolerant allele of OsLG3 has potential to improve drought tolerance of japonica rice.

Conclusions

Collectively, our work revealed that the natural variation of OsLG3 contributes to rice drought tolerance and the elite allele of OsLG3 is a promising genetic resource for the development of drought-tolerant and high-yield rice varieties.
polyCluster: Defining Communities of Reconciled Cancer Subtypes with Biological and Prognostic Significance
Authors: Eason Katherine , Nyamundanda Gift , Sadanandam Anguraj
Published: December 2017

To stratify cancer patients for most beneficial therapies, it is a priority to define robust molecular subtypes using clustering methods and “big data”. If each of these methods produces different numbers of clusters for the same data, it is difficult to achieve an optimal solution. Here, we introduce “polyCluster”, a tool that reconciles clusters identified by different methods into context-specific subtype “communities” using a hypergeometric test or a measure of relative proportion of common samples. The polycluster was tested using a breast cancer dataset, and latter using uveal melanoma datasets to identify novel subtype communities with significant metastasis-free prognostic differences. Available at: https://github.com/syspremed/polyClustR
Accurate Determination of Bacterial Abundances in Human Metagenomes Using Full-length 16S Sequencing Reads
Authors: Perraudeau Fanny , Dudoit Sandrine , Bullard James H.
Published: December 2017

DNA sequencing of PCR-amplified marker genes, especially but not limited to the 16S rRNA gene, is perhaps the most common approach for profiling microbial communities. Due to technological constraints of commonly available DNA sequencing, these approaches usually take the form of short reads sequenced from a narrow, targeted variable region, with a corresponding loss of taxonomic resolution relative to the full length marker gene. We use Pacific Biosciences single-molecule, real-time circular consensus sequencing to sequence amplicons spanning the entire length of the 16S rRNA gene. However, this sequencing technology suffers from high sequencing error rate that needs to be addressed in order to take full advantage of the longer sequence. Here, we present a method to model the sequencing error process using a generalized pair hidden Markov chain model and estimate bacterial abundances in microbial samples. We demonstrate, with simulated and real data, that our model and its associated estimation procedure are able to give accurate estimates at the species (or subspecies) level, and is more flexible than existing methods like SImple Non-Bayesian TAXonomy (SINTAX).
Structurally informed evolutionary models improve phylogenetic reconstruction for emerging, seasonal, and pandemic influenza viruses
Authors: Qiu Xueting , Bahl Justin
Published: December 2017

Precise estimation of genetic substitution patterns is critical for accurate reconstruction of pathogen phylogenies. Few studies of viral evolution account for variations of mutation rate across a single gene. This is especially true when considering evolution of segmented viruses where individual segments are short, encoding for few proteins. However, the structural and functional partitions of these proteins could provide valuable information for more accurate inference of viral evolution, due to the disparate immune selection pressure on different functional domains. Accurately reconstructed evolutionary features on specific functional domains can in turn provide biological information on viral protein and immune targets for vaccine design. In this study we developed and evaluated a structurally informed partitioning scheme that accounts for rate variation among immunogenic head and stalk domains of the surface protein hemagglutinin (HA) of influenza viruses. We evaluated the model fit and performance of four different models - HKY, SRD06 codon, HKY with a structurally informed partitioning scheme, SRD06 with a structurally informed partitioning scheme on pandemic A/H1N1pdm09, seasonal A/H1N1postpdm, A/H3N2, B-Yamagata-like and Victoria-like lineages, and two highly pathogenic avian influenza A viruses H5Nx and H7N9. Results showed that structurally informed partitioning with SRD06 performed better for all datasets with decisively statistical support. Significantly faster nucleotide substitution rates for head domain, compared to stalk domain was observed and may provide insight for stalk derived broadly-reactive vaccine design. Taken together, integrating a functionally informed partitioning scheme based on protein structures of immune targets allows for significant improvement of phylogenetic analysis and providing important biological insights.
Defining the relevant combinatorial space of the PKC/CARD-CC signal transduction nodes
Authors: Staal Jens , Driege Yasmine , Haegman Mira , Kreike Marja , Iliaki Styliani , Vanneste Domien , Affonina Inna , Braun Harald , Beyaert Rudi
Published: December 2017

Biological signal transduction typically display a so-called bow-tie or hour glass topology: Multiple receptors lead to multiple cellular responses but the signals all pass through a narrow waist of central signaling nodes. One such critical signaling node for several inflammatory and oncogenic signaling pathways in humans are the CARD-CC / Bcl10 / MALT1 (CBM) complexes, which get activated by upstream protein kinase C (PKC). In humans, there are four phylogenetically distinct CARD-CC family (CARD9, −10, −11 and −14) proteins and 9 true PKC isozymes (α to ι). At this moment, less than a handful of PKC/CARD-CC relationships are known from experimental evidence. In order to explore the biologically relevant combinatorial space out of all 36 potential permutations in this two-component signaling event, we made use of CRISPR/Cas9 genome-edited HEK293T cells to mutate CARD10 for subsequent pairwise cotransfections of all CARD-CC family members and activated mutants of all true PKCs. By quantitative reporter gene expression readout, we could define specific strong and weak PKC/CARD-CC relationships. Surprisingly as many as 21 PKC/CARD-CC combinations were found to have synergistic effects. We also discovered heterodimerization between different CARD-CC proteins, and that this can influence their PKC response profile. This information will be valuable for future studies of novel signaling pathways dependent on the CBM complex signaling nodes.
Pneumococcal vaccine impacts on the population genomics of non-typeable Haemophilus influenzae
Authors: Cleary David W. , Devine Vanessa T. , Morris Denise E. , Osman Karen L. , Gladstone Rebecca A. , Bentley Stephen D. , Faust Saul N. , Clarke Stuart C.
Published: December 2017

Between 2008/09 and 2012/13 the molecular epidemiology of non-typeable Haemophilus influenzae (NTHi) carriage in children <5 years of age was determined; a period that included pneumococcal conjugate vaccine (PCV) 13 introduction. Significantly increased carriage in post-PCV13 years was observed and lineage-specific associations with S. pneumoniae were observed before and after PCV13 introduction. NTHi were characterised into eleven discrete, temporally stable lineages, congruent with current knowledge regarding the clonality of NTHi. This increase could not be linked to the expansion of a particular clone and demonstrates different dynamics to before PCV13 implementation during which time NTHi co-carried with vaccine serotype pneumococci.
Gaze Bias Differences Capture Individual Choice Behavior
Authors: Thomas Armin W. , Molter Felix , Krajbich Ian , Heekeren Hauke R. , Mohr Peter N. C.
Published: December 2017

How do we make simple consumer choices (e.g., deciding between an apple, an orange, and a banana)? Recent empirical evidence suggests a close link between choice behavior and eye movements at the group level, with generally higher choice probabilities for items that were looked at longer during the decision process. However, it is unclear how variable this effect is across individuals. Here, we investigate this question in a multialternative forced-choice experiment using a novel computational model that can be easily applied to the individual participant level. We show that a link between gaze and choice is present for most individuals, but differs considerably in strength, namely, the choices of some individuals are almost independent of gaze allocation, while the choices of others are strongly associated with gaze behavior. Accounting for this variability in our model allows us to explain and accurately predict individual differences in observed choice behavior.
Electron microscopy reveals unique spore-like nano forms of Bacillus cereus
Authors: Ghosh Sumanta , Chakraborty Biprashekhar , Ghosh Shreya , Dey Sandip , Biswas Chiranjit , Chowdhury Rukhsana , Chattopadhyay Krishnananda , Sengupta Jayati
Published: December 2017

Endospore formation under environmental stress conditions is a well-established phenomenon for members of bacterial phylum Firmicutes, among which the most well studied ones belong to genus Bacillus and Clostridium. So far, known sizes of the spores are all larger than 500 nm. Nano-forms of bacteria have been reported but the notion still remains controversial.

In this study, we provide visual evidences of living nano-entities (named here as ‘nano-spores’) formed by a bacterial species Bacillus cereus under prolonged stress, which are capable of escaping though standard sterile filtration procedure. The existence of nano-forms of bacteria was initially identified in a yeast ribosome preparation. We further demonstrate the transformation of the ‘nano-spores’ into mature cells upon nutrient supply. Our study not only demonstrates the ability of bacteria to get transformed into yet-unknown form in order to survive under harsh environment, but also brings to light the existence of the smallest possible form of life.
The transcriptional dynamics of two filmy ferns from Hymenophyllaceae with different niche preferences unravel key aspects of their desiccation tolerance and vertical distribution along host trees
Authors: Larama Giovanni , Ostria-Gallardo Enrique , Berrios Graciela , Gutierrez Ana , Ensminger Ingo , Bravo Leon A.
Published: December 2017

Ferns from the Hymenophyllaceae family are one of the main components of the epiphytic species diversity in the Chilean temperate rain forest. Having membranous fronds of a single layer of cells, they show a poikilohydric strategy most typical from bryophytes. Although Hymenophyllaceae species shows the ability to tolerate desiccation, there are interspecific differences in their water loss kinetic. Counter-intuitively, those species that have rapid desiccation kinetic are able to reach higher host height and tolerate higher light exposure and vapor pressure deficit. Therefore, what are the mechanisms (constitutive and/or induced) responsible of the desiccation tolerance in this fern family? As this primitive fern family is closely related with mosses, it can be hypothesized that desiccation tolerance in this particular group would be associated with constitutive features rather than induced responses during dehydration. However, the inter-specific differences in water loss and vertical distribution would be associated to different degrees of induction either within the dehydration or rehydration phases. We applied an ecophysiological transcriptomic approach to study the dynamic of gene expression in two species of filmy ferns with contrasting desiccation kinetics and vertical distribution on the host tree. Our analysis identified commonalities and differences in gene regulation, and key genes correlated with the fronds hydration state, providing the patterns of gene expression responding to microenvironmental signals and behind the physiology of their resurrection strategy
Identifying important interaction modifications in ecological systems
Authors: Terry J. Christopher D. , Bonsall Michael B. , Morris Rebecca J.
Published: December 2017

Trophic interaction modifications, where a consumer-resource link is affected by additional species, are widespread and significant causes of indirect effects in ecological networks. The sheer number of potential interaction modifications in ecological systems poses a considerable challenge, making prioritisation for empirical study essential. Here, we introduce measures to quantify the topological relationship of individual interaction modifications relative to the underlying network. We use these, together with measures for the strength of trophic interaction modifications to identify modifications that are most likely to exert significant effects on the dynamics of whole systems. Using a set of simulated food webs and randomly distributed interaction modifications, we test whether a subset of interaction modifications important for the local stability and direction of species responses to perturbation of complex networks can be identified. We show that trophic interaction modifications affecting interactions with a high biomass flux, those that connect species otherwise distantly linked, and those where high trophic-level species modify to interactions lower in the web have particular importance for dynamics. In contrast, the centrality of modifications in the network provided little information. This work demonstrates that analyses of interaction modifications can be tractable at the network scale and highlights the importance of understanding the relationship between the distributions of trophic and non-trophic effects.
Antiretroviral treatment, prevention of transmission, and modeling the HIV epidemic: why the ART efficacy and effectiveness parameter matters
Authors: Granich Reuben , Gupta Somya , Wollmers Matt , Williams Brian
Published: December 2017

Introduction

HIV remains a major public health threat with over 75 million deaths, 2 million annual infections and over 1 million HIV-associated TB cases a year. Population-based studies suggest a marked decline in incidence, prevalence and deaths, mostly likely due to treatment expansion, in countries in East and Southern Africa. This calls into question the ART efficacy, effectiveness and coverage parameters used by many modelers to project HIV incidence and prevalence.

Methods

For 2015 and 2016 we reviewed global and national mathematical modeling studies regarding ART impact (with or without other HIV prevention interventions) and/or 90-90-90 on either new HIV infections or investment or both. We reviewed these HIV epidemiologic and costing models for their structure and parameterization around ART; we directly compared two models to illustrate differences in outcome.

Results

The nine models published in 2015 or 2016 included parameters for ART effectiveness ranging from 20% to 86% for ART effectiveness. Model 1 limits eligibility for ART initiation to 80% coverage of people living with HIV and with a CD4+ cell count below 350 cells/μL, 70% retention, and ART reduces transmission by 80%, with a derived ART effectiveness of 20%. Model 2 assumes 90-90-90 by 2020 (i.e., 73% viral suppression of estimated PLHIV), ART reduces transmission by 96% in those on ART and virally suppressed, and by 88% in those on ART but not virally suppressed with a derived effectiveness of 86% and consequent decline towards ending AIDS and HIV elimination. ART parameter selection and assumptions dominate and low ART effectiveness translates into lower impact.

Discussion

Using more realistic parameters for ART effectiveness suggests that through expanding access and supporting sustainable viral suppression it will be possible to significantly reduce transmission and eliminate HIV in many settings.
Localization of adaptive variants in human genomes using averaged one-dependence estimation
Authors: Sugden Lauren Alpert , Atkinson Elizabeth G. , Fischer Annie P. , Rong Stephen , Henn Brenna M. , Ramachandran Sohini
Published: December 2017

Statistical methods for identifying adaptive mutations from population-genetic data face several obstacles: assessing the significance of genomic outliers, integrating correlated measures of selection into one analytic framework, and distinguishing adaptive variants from hitchhiking neutral variants. Here, we introduce SWIF(r), a probabilistic method that detects selective sweeps by learning the distributions of multiple selection statistics under different evolutionary scenarios and calculating the posterior probability of a sweep at each genomic site. SWIF(r) is trained using simulations from a user-specified demographic model and explicitly models the joint distributions of selection statistics, thereby increasing its power to both identify regions undergoing sweeps and localize adaptive mutations. Using array and exome data from 45 ‡Khomani San hunter-gatherers of southern Africa, we identify an enrichment of adaptive signals in genes associated with metabolism and obesity. SWIF(r) provides a transparent probabilistic framework for localizing beneficial mutations that is extensible to a variety of evolutionary scenarios.
Neural Coding of Noisy and Reverberant Speech in Human Auditory Cortex
Authors: Puvvada Krishna C , Villafañe-Delgado Marisel , Brodbeck Christian , Simon Jonathan Z
Published: December 2017

Speech communication in daily listening environments is complicated by the phenomenon of reverberation, wherein any sound reaching the ear is a mixture of the direct component from the source and multiple reflections off surrounding objects and the environment. The brain plays a central role in comprehending speech accompanied by such distortion, which, frequently, is further complicated by the presence of additional noise sources in the vicinity. Here, using magnetoencephalography (MEG) recordings from human subjects, we investigate the neural representation of speech in noisy, reverberant listening conditions as measured by phase-locked MEG responses to the slow temporal modulations of speech. Using systems-theoretic linear methods of stimulus encoding, we observe that the cortex maintains both distorted and distortion-free (cleaned) representations of speech. Also, we show that, while neural encoding of speech remains robust to additive noise in absence of reverberation, it is detrimentally affected by noise when present along with reverberation. Further, using linear methods of stimulus reconstruction, we show that theta-band neural responses are a likely candidate for the distortion free representation of speech, whereas delta band responses are more likely to carry non-speech specific information regarding the listening environment.
Understanding the relationship between health and internal migration in the United Kingdom
Authors: Moh’d Rabi’u Isah , Ajefu Joseph Boniface
Published: December 2017

Purpose

Studies on the relationship between migration and health status of individuals most often concentrate on international migrants. In contrast, the purpose of this paper is to examine the relationship between health and internal migration using the first 18 waves of the British Household Survey.

Design/methodology/approach

The authors use the 12-version of General Health Questionnaire (GHQ), an indicator of mental health, and physical health indicators as the health variables. This study uses different econometrics estimation methods in modelling the relationship in order to address omitted variable bias as well as unobserved heterogeneity. The econometric estimation methods include Pooled OLS, random effects (RE), fixed effects (FE) and then probit RE. The authors explore the relationship by comparing the health status of movers and non-movers and different types of internal migration such as between local authority districts and between regions.

Findings

The results of this research suggest that there is healthy migrant effect on migration within UK on some indicators of physical health like arm/leg, heart and migraine/headache problems, but not on mental health indicator. And the effects are similar for both males and females. It is advised therefore that the department of health should improve the health of those affected by these ailments so that they can have a chance to move perhaps to better their lots.

Originality/value

This study uses different econometrics estimation methods in modelling the relationship in order to address omitted variable bias as well as unobserved heterogeneity. The econometric estimation methods include Pooled OLS, RE, FE and then probit RE.
Efectos de la realización de un megaevento deportivo sobre una economía local. El caso de los Juegos Mundiales 2013 Cali
Authors: Aguado Luis F. , Osorio Ana M. , Arbona Alexei , Peña-Vinces Jesús C.
Published: December 2017

Purpose

A summary of the economic impact resulting from the celebration of a sporting mega-event in the city of Cali, Colombia, is carried out in this article.

Design/methodology/approach

The impacts are estimated by means of the systematic effects produced by the activities of investment/expenditure of the identified agents and the consequent multiplying effects captured from an input-output model.

Findings

The World Games represented a new income flow to the city of Cali of $101.036 million pesos (≡US$53.4 mill.) and 9.598 jobs were created (≡7,711 full-time jobs). Additionally, 2,174 foreign tourists and 11,250 national tourists were attracted to the city.

Originality/value

The article contributes with innovative aspects methodologically speaking, useful for future studies of economic impact in cities with low tourism located in developing countries.
The use of the recognition heuristic as an investment strategy in European stock markets
Authors: Lobão Júlio , Pacheco Luís , Pereira Carlos
Published: December 2017

Purpose

People often face constraints such as a lack of time or information in taking decisions, which leads them to use heuristics. In these situations, fast and frugal rules may be useful for making adaptive decisions with fewer resources, even if it leads to suboptimal choices. When applied to financial markets, the recognition heuristic predicts that investors acquire the stocks that they are aware of, thereby inflating the price of the most recognized stocks. This paper aims to study the profitability against the market of the most recognized stocks in Europe.

Design/methodology/approach

In this paper, the authors perform a survey and use Google Trends to study the profitability against the market of the most recognized stocks in Europe.

Findings

The authors conclude that a recognition heuristic portfolio yields poorer returns than a market portfolio. In contrast, from the data collected on Google Trends, weak evidence was found that strong increases in companies monthly search volumes may lead to abnormal returns in the following month.

Research limitations/implications

The applied investment strategy does not account for transaction costs, which may jeopardize its profitability given the fact that it is necessary to revise the portfolio on a monthly basis. Despite the results obtained, they are useful to understanding the performance of recognition heuristic strategies over a comprehensive time horizon, and it would be interesting to depict its viability during different market conditions. This analysis could provide additional information about a preferable scenario for employing our strategies and, ultimately, enhance the profitability of recognition heuristic strategies.

Practical implications

Through the exhaustive analysis performed here on the recognition heuristic in the European stock market, it is possible to conclude that no evidence was found for the viability of exploring this type of strategy. In fact, the investors would always gain better returns when adopting a passive investment strategy. Therefore, it would be wise to assume that the European market presents at least a degree of efficiency where no investment would yield abnormal returns following the recognition heuristic.

Originality/value

The main objective of this paper is to study the performance of the recognition heuristic in the financial markets and to contribute to the knowledge in this field. Although many authors have already studied this heuristic when applied to financial markets, there is a lack of consensus in the literature.
The valuation performance of mathematically-optimised, equity-based composite multiples
Authors: Nel Soon , le Roux Niël
Published: December 2017

Purpose

This paper aims to examine the valuation precision of composite models in each of six key industries in South Africa. The objective is to ascertain whether equity-based composite multiples models produce more accurate equity valuations than optimal equity-based, single-factor multiples models.

Design/methodology/approach

This study applied principal component regression and various mathematical optimisation methods to test the valuation precision of equity-based composite multiples modelsvis-à-visequity-based, single-factor multiples models.

Findings

The findings confirmed that equity-based composite multiples models consistently produced valuations that were substantially more accurate than those of single-factor multiples models for the period between 2001 and 2010. The research results indicated that composite models produced up to 67 per cent more accurate valuations than single-factor multiples models for the period between 2001 and 2010, which represents a substantial gain in valuation precision.

Research implications

The evidence, therefore, suggests that equity-based composite modelling may offer substantial gains in valuation precision over single-factor multiples modelling.

Practical implications

In light of the fact that analysts’ reports typically contain various different multiples, it seems prudent to consider the inclusion of composite models as a more accurate alternative.

Originality/value

This study adds to the existing body of knowledge on the multiples-based approach to equity valuations by presenting composite modelling as a more accurate alternative to the conventional single-factor, multiples-based modelling approach.
The role of liquidity in asset pricing: the special case of the Portuguese Stock Market
Authors: Miralles-Quirós María del Mar , Miralles-Quirós José Luis , Oliveira Celia
Published: December 2017

Purpose

The aim of this paper is to examine the role of liquidity in asset pricing in a tiny market, such as the Portuguese. The unique setting of the Lisbon Stock Exchange with regards to changes in classification from an emerging to a developed stock market, allows an original answer to whether changes in the development of the market affect the role of liquidity in asset pricing.

Design/methodology/approach

The authors propose and compare two alternative implications of liquidity in asset pricing: as a desirable characteristic of stocks and as a source of systematic risk. In contrast to prior research for major stock markets, they use the proportion of zero returns which is an appropriated measure of liquidity in tiny markets and propose the separated effects of illiquidity in a capital asset pricing model framework over the whole sample period as well as in two sub-samples, depending on the change in classification of the Portuguese market, from an emerging to a developed one.

Findings

The overall results of the study show that individual illiquidity affects Portuguese stock returns. However, in contrast to previous evidence from other markets, they show that the most traded stocks (hence the most liquid stocks) exhibit larger returns. In addition, they show that the illiquidity effects on stock returns were higher and more significant in the period from January 1988 to November 1997, during which the Portuguese stock market was still an emerging market.

Research limitations/implications

These findings are relevant for investors when they make their investment decisions and for market regulators because they reflect the need of improving the competitiveness of the Portuguese stock market. Additionally, these findings are a challenge for academics because they exhibit the need for providing alternative theories for tiny markets such as the Portuguese one.

Practical implications

The results have important implications for individual and institutional investors who can take into account the peculiar effect of liquidity in stock returns to make proper investment decision.

Originality/value

The Portuguese market provides a natural experimental area to analyse the role of liquidity in asset pricing, because it is a tiny market and during the period studied it changed from an emerging to a developed stock market. Moreover, the authors have to highlight that previous evidence almost exclusively focuses on the US and major European stock markets, whereas studies for the Portuguese one are scarce. In this context, the study provides an alternative methodological approach with results that differ from those theoretically expected. Thus, these findings are a challenge for academics and open a theoretical and a practical debate.
Factors influencing E- procurement usage
Authors: Dooley Ken , Purchase Sharon
Published: December 2017

Research indicates that e-procurement is being implemented slowly in many organizations, especially government organizations. This article investigates positive factors influencing e-procurement intentions within semi-government organizations. A web-based survey was carried out on Australian government purchasing professional's perspectives of e-procurement. Findings from a multiple regression analysis indicate that suppliers' participation, internal managerial support and the perceived benefits gained through implementation all influence e-procurement intentions.
The utilization and effectiveness of citizen advisory committees in the budget process of local governments
Authors: Callahan Kathe
Published: December 2017

This paper examines the role of citizen budget advisory committees in local government to gain a better understanding of what exists, what works, and what does not. Specifically this paper seeks to answer the following questions: How are citizen advisory committees utilized? What influence do citizen advisory committees have on the planning and decision making process of local governments? What variables influence the effectiveness of citizen advisory committees? What obstacles prevent meaningful citizen participation from taking place? Through a better understanding of what makes some committees more effective than others, recommendations can be made that will improve the effectiveness of this type of citizen participation.
Reporting cash flows: an investigation of college and university compliance with SFAS no. 117
Authors: Fisher Mary , Gordon Teresa , Myers Kraut Marla , Malone David
Published: December 2017

Reporting cash flows is a relatively recent development in college and university financial reporting. An examination of the purported usefulness of cash flow information to the users of college and university financial statements including an examination of the relationship between accrual-based change in net assets and cash provided by operations found private universities have implemented the cash flow reporting requirements with a relatively high level of compliance employing the indirect format for reporting operating cash flows. The principal areas of deficiency were the reporting of split-interest, restricted gift activities and the required disclosures of cash outflows related to interest and taxes. The discussion of the compliance deficiencies and display findings leads to needed disclosure guidance and future research.
The economics and politics of revenue reform: a case study
Authors: Ramsey James R.
Published: December 2017

The 1990s witnessed unprecedented economic growth and state revenue growth. Many states used this strong growth to improve their financial position by building their “rainy day” funds and/or to cut taxes. This paper presents a case study of a state which experienced strong economic and revenue growth and was able to build its Budget Reserve Trust Fund, while also cutting taxes. This Case Study focuses on a Governor who understood that strong economic and revenue growth was not sustainable and that his state needed to ensure an elastic General Fund revenue base as protection against an economic downturn, thus proposing a revenue reform package that would increase taxes and enhance the adequacy of the state’s General Fund. This paper presents a historical development of the revenue reform package from the time it was submitted as part of the state budget through the end of the legislative session. This paper provides a series of “lessons learned” that can be helpful to public policy makers in other jurisdictions.
The challenge to improve citizen participation in public budgeting: a discussion
Authors: Beckett Julia , King Cheryl Simrell
Published: December 2017

This article considers the recent emphasis on the importance and value of citizen participation, involvement, and engagement in local government and how active participation extends to public budgeting. The inclusion of citizen participation in local government budget processes challenges the traditional budget discourse between managers and representatives. Active citizen participation provides valuable comments and insight as well as complexity and challenges to administrative processes. This article discusses the themes, opportunities, techniques and strategies developed in this symposium to expand citizen participation in public budgeting. Continued discussion and innovation in active citizen participation in budgeting is encouraged.
Accrual accounting reforms in belgian local governments: a comparative examination
Authors: Christiaens Johan R.
Published: December 2017

This paper presents an overview of the current accounting reforms of two types of Belgian local governments from cameralistic accounting to business-like accrual accounting. Similarities and differences between important kinds of local government accounting are explored by focusing on important conceptual issues. The examination reveals that governmental accounting is relatively new and that a number of basic accounting problems remain even after some years of experience. Apparently, there is the need for a user oriented accounting framework applicable for different kinds of governments instead of transferring business accounting principles in practice without any further study.
Biennial budgeting debates in congress: 1977-2000
Authors: Boatright Robert G.
Published: December 2017

Biennial budgeting and appropriations cycles have been a popular idea among many members of Congress for the past twenty years. Despite widespread bipartisan support for biennial budgeting in the 1980s, the first House vote on the subject, in 2000, resulted in a narrow defeat for biennial budgeting. This article analyzes the merits of biennial budgeting and the reasons for its defeat, arguing that during the 1990s biennial budgeting lost its sense of urgency because of the erasure of the federal deficit and became a more partisan issue than it previously had been.
The contribution of organizational justice in budget decision-making to federal managers' organizational commitment
Authors: Staley Andrew Blair , Dastoor Barbara , Magner Nace R. , Stolp Chandler
Published: December 2017

This study examines the contribution of distributive, procedural, and interactional justice in Federal budget decision-making to Federal managers' commitment to the Federal government as an employing organization. A total of 1,358 useable surveys were received from a sample of 9,643 managers. Reliability coefficients were acceptable (> .70), and intercorrelations consistent with previous studies. Hierarchical regression analysis supported only maineffect relationships between procedural justice and interactional justice and managers' organizational commitment. No support was found for a main effect relationship between distributive justice and organizational commitment -- or for any interactive effects. Contrary to models of bureaucratic behavior based on economic theory, these findings may suggest that Federal managers may be motivated primarily by psychological outcomes of budget decisions.
Citizen surveys: a component of the budgetary process
Authors: Hassett Wendy L. , Watson Douglas J.
Published: December 2017

An annual citizen survey can be a valuable component of the municipal budgeting process for cities that elect to institutionalize the process as a way to translate citizen feedback into budgetary priorities. This article explores uses of citizen surveys in identifying latent needs of the community that may not be detected through public hearings or other citizen participation methods. The authors suggest that properly developed and conducted citizen surveys can provide decision-makers with research data that will lead to more responsive public spending and debt financing decisions. The article concludes with a case study of Auburn, Alabama, a city that has successfully used citizen surveys in its budgeting system for the past seventeen years.
The property tax and public education: are state-initiated tax cuts sustainable?
Authors: Snyder Nancy McCarthy
Published: December 2017

During the 1990s many states used budget surpluses to refinance public education and provide property tax relief. This paper uses a case study of Kansas to assess the sustainability of state-initiated property tax cuts. It finds that the cuts are not fully sustainable over time because of court and federal mandates that require additional spending on education, economic fluctuations that reduce the ability of state budgets to maintain a given share of education spending, and demands for local control to allow school districts to spend more or less than state-mandated levels. The paper also argues that the property tax is essential to economic efficiency and local control.
Changes in state tax structures: true comprehensive reform or artifacts of incrementalism?
Authors: Wolfson Gabriela S. , Hackbart Merl M.
Published: December 2017

Using data obtained from the National Conference of State Legislatures (NCSL), we investigate modifications in state tax codes to determine their characteristics, the apparent trends of state tax reform, and whether changes constituted comprehensive reform or mere incremental adjustments to existing tax structures. Based on the data, we find that few states achieved comprehensive tax reform in the 1990s despite the fiscal surplus that provided an environment conducive to widespread change. Moreover, we find that a significant number of changes that were enacted in the 1990s involved increases or decreases in state tax revenue that were ultimately tied to economic cycles. We suggest that adequacy in state tax collections may be the most common tax principle adhered to with regard to changes in tax structure. We also conclude that reform efforts in the 1990s were most successful when approached in an incremental fashion in the absence of a significant precipitating reform driver.
Supporting government performance by capturing the values and expertise of key stakeholders: a delphi/decision support system approach to local revenue planning
Authors: Wooldridge Blue , Weistroffer H. Roland
Published: December 2017

Past research suggests that decision-making can be improved by gauging diverse view points from key stakeholders, where a stakeholder is any group or individual that can affect or is affected by the decisions. Two key stakeholders in public policy making are economic experts that can predict the economic consequences of policy decisions, and elected policy-makers who are accountable to the citizens for the outcomes of these decisions. A two-step model combining a Decision Support System and a Delphi type approach is proposed. To test the methodology, the proposed approach was applied to revenue planning in a mid-sized city.
The fiscal impact of economic growth and development on local government revenue capacity
Authors: Wong John D.
Published: December 2017

The focus of this article is to examine the relationship between local economic growth and development and local government revenue capacity. A model is established to determine the relationship between the number of agricultural, manufacturing, service, and retail establishments per capita and employees per capita on real local government property tax capacity per capita. High property tax levies are highly negatively correlated with tax capacity. Population density, the general price level, and the presence of local retail sales taxes also play a role in determining tax capacity. New business creation in the service industry does appear to have a positive impact on local government tax capacity, while increases in agricultural, manufacturing, and retail activity do not. Although increasing concentration in the number of service establishments has a positive impact on tax capacity, increasing concentration in the number of service workers alone does not seem to lead to increases in tax capacity.
Regime transition and economic development: the question of “who’s on first?”
Authors: Wong John D. , Pritz Maurice G.
Published: December 2017

Local governments have long been concerned with economic growth and development. Some local governments take an aggressive, proactive stance on economic development, while others take a more incremental, reactionary approach. When economic development opportunities arise, the frequently asked question is “Who’s on first?” Is it the responsibility of local government to take the lead in promoting economic development opportunities, or should local government remain in the background leaving development activities to private developers? This article uses community power theory to examine the evolution of economic development in Wichita, Kansas and the roles played by the public and private sectors and their impact on the course of development activities. In order for a booster regime to be successful, the lead government must establish the legitimacy of the development effort with other potential members of the coalition. The lead government must establish a hospitable business climate and establish a commitment to support the infrastructure and service needs of developers. Coalition members must view the undertaking as a positive-sum gain.
Privatization of government services: an overview and review of the literature
Authors: Brooks Richard C.
Published: December 2017

Privatization continues to receive serious consideration at the federal, state, and local government levels. The most frequent reason cited for privatizing services is to reduce the size and cost of government. While many government entities have privatized services, it is often up to academic researchers to determine if the goals of privatization have been realized and to shed light on the organizational and service characteristics that make it more likely that the results of privatizing a particular service will be positive. This paper seeks to provide a background to those researchers interested in examining the privatization of government services. The paper reviews and synthesizes prior privatization research and discusses future research directions.
The lottery, educatiion, and the southern states: a measure of utility in per pupil expenditures among lottery states in the south
Authors: Stanley Rodney E. , French P. Edward
Published: December 2017

State operated lotteries have recently been asserted by public administrators and academicians as panaceas for eradicating revenue disparities existing across public school districts in the American states. The purpose of this research project is to empirically confirm the accusations against attributing credibility to this social intervention program because educational disparity portrays a grave injustice in the U.S. Pooled time series cross sectional analysis is the methodology mechanism employed to test the data in this research project. This study found that lotteries, since their inception, despite expressed high regards, display insufficient significance in generating revenue for educational programs in the southern states. One highly probable reason for the lottery’s insignificant effect in generating educational revenue is the idea of fungibility. One of the major limitations of this study is the small sample size of only using southern states to test the theory that lotteries contribute significantly to educational expenditures in the southern states of America. Using pooled time series cross sectional analysis of all fifty states is a highly recommended approach for future studies concerned with assessing the impact of lotteries on public education expenditures.