bluuebunny/crossref_metadata_2025_split huggingface dataset:
Agonistic character displacement of genetically based male color patterns across darters
Authors: Moran Rachel L. , Fuller Rebecca C. 
Published: June 2018

AbstractA growing number of studies are demonstrating that interspecific male-male competitive interactions can promote trait evolution and contribute to speciation. Agonistic character displacement (ACD) occurs when selection to avoid maladaptive interspecific aggression leads to the evolution of agonistic signals and/or associated behavioral biases in sympatry. Here we test for a pattern consistent with ACD in male color pattern in darters (Percidae:Etheostoma). Despite the presence of traditional sex roles and sexual dimorphism, male color pattern has been shown to function in male-male competition in several darter species, rather than female mating preferences. A pattern consistent with divergent ACD in male behavioral biases has also been documented in darters. Males bias their aggression towards conspecific over heterospecific males in sympatry but not in allopatry. Here we use a common garden approach to show that differences in male color pattern among four closely related darter species are genetically based. We also demonstrate that male color pattern exhibits enhanced differences in sympatric compared to allopatric populations of two darter species. This study provides evidence that interspecific male-male aggressive interactions alone can promote elaborate male signal evolution both between and within species. We discuss the implications this has for male-driven ACD and cascade ACD.
Seasonal Changes in Bird Assemblages of a Forest-Steppe Ecotone in North Patagonia
Authors: Cueto Víctor R. , Gorosito Cristian A. 
Published: June 2018

AbstractWe evaluate seasonal variations at the community level, analyzing changes in species richness, species composition and total abundance, and at the species level, evaluating differences in breeding and molting seasonality among bird species in a forest-steppe ecotone of north Patagonia. The bird assemblage showed a low seasonal variation in richness and total abundance, but a great change in species composition between spring-summer and fall-winter. The change in species composition promoted few seasonal variations in richness and total abundance, because they were compensated by the presence of abundant species that visit the area in different seasons. At the species level, resident birds and short distance migrants tended to begin breeding earlier than long distance migrants, and birds began to molt body and flight feathers after breeding. Therefore, we found a low overlap of these two demanding activities. Our results highlight the importance of bird movements in response to seasonal variations in the availability of resources, which promote migration or local displacements of birds.Resumen. Cambios estacionales en los ensambles de aves en un ecotono bosque-estepa del norte de PatagoniaEvaluamos las variaciones estacionales a nivel comunitario, analizando la riqueza de especies, la composición de especies y la abundancia total, y a nivel de las especies, evaluando las diferencias en la estacionalidad reproductiva y de muda entre las especies de aves en un ecotono bosque-estepa del norte de Patagonia. El ensamble de aves mostró pocas variaciones estacionales en la riqueza y abundancia total, pero un notable cambio en la composición de especies entre la primavera-verano y el otoño-invierno. El cambio en la composición de especies promovió pocas variaciones estaciones en la riqueza y la abundancia total, porque fueron compensadas por la abundancia de las especies que visitan el área en las diferentes estaciones. A nivel de las especies, las aves residentes y migrantes de corta distancia tendieron a comenzar la reproducción antes que las migrantes de larga distancia, y las aves comenzaron la muda de plumas del cuerpo y del ala al finalizar la reproducción. Por lo cual encontramos una baja superposición de estas dos demandantes actividades. Nuestros resultados remarcan la importancia del movimiento de las aves en respuesta a las variaciones en la disponibilidad de recursos, que promueven la migración o el desplazamiento local de las aves.
A machine learning method for subgroup analysis of randomized controlled trials
Authors: Buturović Ljubomir 
Published: June 2018

AbstractWe developed a machine learning method for subgroup analyses of randomized controlled trials (RCT), and applied it to the results of the SPRINT RCT for treatment of hypertension. To date, the subgroup analyses mostly focused on detecting associations between certain factors and outcome, in the hope that the results will point out biologically (for example, carriers of a certain mutation) or clinically (for example, smokers) distinct subgroups with different outcomes. This seldom worked in the sense of re-launching the intervention for the detected subgroup only and successfully treating it. In contrast, we propose an empirical and general method to develop a predictive multivariate classifier using the RCT outcomes and baseline data. The classifier identifies patients likely to benefit from the intervention, is not limited to a single factor of interest, and is ready for validation in a subsequent pivotal trial. We believe this approach has a better chance of succeeding in identifying the relevant subgroups because of increased accuracy made possible by the use of multiple predictor variables, and opportunity to use advanced machine learning. The method effectiveness is demonstrated by the analysis of the SPRINT trial.
No evidence that mate choice in humans is dependent on the MHC
Authors: Cretu-Stancu Mircea , Kloosterman Wigard P. , Pulit Sara L. 
Published: June 2018

AbstractA long-standing hypothesis in biology proposes that various species select mates with a major histocompatibility complex (MHC) composition divergent from their own, so as to improve immune response in offspring. However, human and animal studies investigating this mate selection hypothesis have returned inconsistent results. Here, we analyze 239 mate-pairs of Dutch ancestry, all with whole-genome sequence data collected by the Genome of the Netherlands project, to investigate whether mate selection in humans is MHC dependent. We find no evidence for MHC-mediated mate selection in this sample (with an average MHC genetic similarity in mate pairs (Qc) = 0.829; permutation-based p = 0.703). Limiting the analysis to only common variation or considering the extended MHC region does not change our findings (Qc = 0.671, p = 0.513; and Qc = 0.844, p = 0.696, respectively). We demonstrate that the MHC in mate-pairs is no more genetically dissimilar (on average) than a pair of two randomly selected individuals, and conclude that there is no evidence to suggest that mate choice is influenced by genetic variation in the MHC.Author summaryStudies within various animal species have shown that the genetic content of the major histocompatibility complex (MHC) can influence mate choice. Such mate selection would be advantageous, as mating between individuals with different alleles across MHC genes would produce offspring with a more diverse MHC and therefore possess improved immune response to various pathogens. Studies of the influence on the MHC in human mate selection have been far less conclusive. Two studies of MHC-dependent mate selection performed on SNP data collected as part of the HapMap Consortium returned conflicting results: the first study reported significantly different MHC variation between mate pairs, and the second report refuted this claim. Here, we analyze a dataset comprised of 239 whole-genome sequenced Dutch mate pairs, a sample set an order of magnitude larger than the HapMap data and containing denser characterization of genetic variation. We find no evidence that the MHC influences mate selection in our population, and we show that this finding is robust to potential confounding factors and the types and frequencies of genetic variants analysed.
A variably imprinted epiallele impacts seed development
Authors: Pignatta Daniela , Novitzky Katherine , Satyaki P.R. V. , Gehring Mary 
Published: June 2018

AbstractThe contribution of epigenetic variation to phenotypic variation is unclear. Imprinted genes, because of their strong association with epigenetic modifications, represent an opportunity for the discovery of such phenomena. In mammals and flowering plants, a subset of genes are expressed from only one parental allele in a process called gene imprinting. Imprinting is associated with differential DNA methylation and chromatin modifications between parental alleles. In flowering plants imprinting occurs in a seed tissue – endosperm. Proper endosperm development is essential for the production of viable seeds. We previously showed that inArabidopsis thalianaintraspecific imprinting variation is correlated with naturally occurring DNA methylation polymorphisms. Here, we investigated the mechanisms and function of allele-specific imprinting of the class IV homeodomain-Leucine zipper (HD-ZIP) transcription factorHDG3. In imprinted strains,HDG3is expressed primarily from the methylated paternally inherited allele. We manipulated the methylation state of endogenousHDG3in a non-imprinted strain and demonstrated that methylation of a proximal transposable element is sufficient to promoteHDG3expression and imprinting. Gain ofHDG3imprinting was associated with earlier endosperm cellularization and changes in seed weight. These results indicate that epigenetic variation alone is sufficient to explain imprinting variation and demonstrate that epialleles can underlie variation in seed development phenotypes.Author SummaryThe contribution of genetic variation to phenotypic variation is well-established. By contrast, it is unknown how frequently epigenetic variation causes differences in organismal phenotypes. Epigenetic information is closely associated with but not encoded in the DNA sequence. In practice, it is challenging to disentangle genetic variation from epigenetic variation, as what appears to be epigenetic variation might have an underlying genetic basis. DNA methylation is one form of epigenetic information.HDG3encodes an endosperm specific transcription factor that exists in two states inA. thaliananatural populations: methylated and expressed and hypomethylated and repressed. We show that pure epigenetic variation is sufficient to explain expression variation ofHDG3– a naturally lowly expressed allele can be switched to a higher expressed state by adding DNA methylation. We also show that expression ofHDG3in strains where it is normally hypomethylated and relatively repressed causes a seed development phenotype. These data indicate that naturally circulating epialleles have consequences for seed phenotypic variation.
Motives of mergers and acquisitions in the European public utilities
Authors: Brahma Sanjukta , Boateng Agyenim , Ahmad Sardar 
Published: June 2018

PurposeThe purpose of this paper is to investigate the motivation and post-merger operating performance (OP) of European utility sectors following mergers and acquisitions (M&A).Design/methodology/approachMotives behind M&A are examined by looking into the relationships between total gains, target gains and acquirer gains. Post-merger OP is measured by comparing the sample of European utilities with a matched portfolio based on size and market to book ratio with respect to five accounting indicators: growth in turnover, growth in earnings before interest and tax, return on assets, net profit margin and growth in fixed assets.FindingsSynergy is the primary motive for M&A in the European utility firms. This study also found that post-merger OP is negative and significant across all the five accounting indicators matched by size, and market to book ratio suggesting that utility mergers underperform in the long term. The findings suggest that gains accruing to utilities involved in acquisitions are short term in nature.Practical implicationsNegative post-merger OP bears important policy implications as in future antitrust/competition authorities should be more vigilant before approving utility mergers.Originality/valuePublic utilities possess several characteristics that are different from industrial firms and therefore need to be examined separately. Empirical literature on M&A is very limited on utilities. This study has addressed this gap by examining the motivation and post-merger OP of the European utility firms.
Financial disclosure practices among Malaysian local authorities: a case study
Authors: Teruki Neilson Anak , Nyamori Robert Ochoki , Ahmed Kamran 
Published: June 2018

PurposeThe purpose of this paper is to understand and explain the financial disclosure processes among Malaysian local authorities (MLAs).Design/methodology/approachEmploying semi-structured interviews, data were collected from 26 members in five case study organisations, and interpreted using Gibbinset al.(1990, 1992) framework of financial disclosure.FindingsThe study finds that financial disclosure is influenced by a hierarchical structure consisting of accountants, the Financial Accounts Committee, the mayor and other managers. The decision to disclose or not disclose was influenced by how sensitive the issue was. External auditors and mediators influenced both the identification of issues, disclosure position and disclosure output. Though there are many laws governing financial accounting, MLAs opportunistically chose to apply the Federal Treasury Circular largely because the external auditors used it.Research limitations/implicationsThis study contributes to the literature by illuminating who makes disclosure decisions, what influences these decisions and how. The study reveals hitherto un-researched contextual factors that affect disclosure, namely, religion and external auditors and the opportunistic choice of which laws and regulations to apply in financial disclosure. Future studies might want to apply this approach in other contexts to see what we can learn from them.Originality/valueUsing case studies in the study of financial disclosure provided valuable insights into the complex and multi-dimensional phenomenon of financial information disclosure. The application of Gibbinset al.(1990, 1992) framework in the public sector and in Malaysia is novel.
Mayors’ leadership roles in direct participation processes – the case of community-owned wind farms
Authors: Wallmeier Franziska , Thaler Julia 
Published: June 2018

PurposeThe design of participation processes influences their effectiveness. In light of processes which include both mandated and non-mandated direct participation and take place in collaboration with other actors, adequate leadership roles are an indispensable but challenging process element. The purpose of this paper is to analyze how mayors exercise leadership roles in such processes and how this relates to effective participation processes.Design/methodology/approachApplying a qualitative comparative case study design (n=7), this study investigates mayors’ leadership roles relative to other actors’ roles in the process of establishing a community-owned wind farm. Data collection relied on 21 semi-structured interviews, triangulated with documentary analyses and nine field-level expert interviews.FindingsFindings reveal mayors’ exclusive roles of guarantor, formal convener, facilitator, and sponsor based on authority. Mayors’ various shared roles relate primarily to non-mandated participation. Mayors face tensions in their role exercise due to citizens’ expectations and their personal involvement. They experience a positive impact of shared leadership on the effectiveness of the participation process.Practical implicationsMayors need to exercise specific leadership roles relative to other actors to effectively manage participation processes. Adequate role exercise relates to sensitization and mobilization for the issue, weakened opposition, and project adjustment to citizen demands. A strategic approach to process design can support mayors in their leadership efforts.Originality/valueThis paper adds to the knowledge on mayors’ leadership roles in participation processes and concretizes tensions and effectiveness of collaborative leadership. The paper reflects on the inference of findings for administrators as compared to mayors.
The role of uncertainty in performance information disclosure
Authors: Allegrini Veronica , Monteduro Fabio 
Published: June 2018

PurposeThe purpose of this paper is to investigate the relationship between the environmental uncertainty faced by public administrations and their likelihood of disclosing performance information, particularly at municipal level.Design/methodology/approachThe existence of the relationship between environmental uncertainty and performance information disclosure is explored, drawing on organizational information processing theory. The paper describes an empirical quantitative investigation in a sample of 490 Italian municipalities.FindingsMunicipalities facing more uncertainty are more likely to disclose performance information. There is no unique set of factors that can explain the difference in the disclosure activity of Italian municipalities, but this activity appears to be contingent on the level of environmental uncertainty.Originality/valueThe paper explores the under-investigated field of factors influencing the disclosure of performance information by public administrations. It identifies uncertainty as one of the determinants of performance information disclosure. The findings suggest that the use of theories and variables not previously used in this type of study can improve understanding of the phenomenon. The study also suggests that public officials should consider adequate enforcement mechanisms to promote performance information disclosure, especially for organizations with lower incentives to improve information processing capabilities.
Females perpetrating honour-based abuse: controllers, collaborators or coerced?
Authors: Bates Lis 
Published: June 2018

PurposeThe purpose of this paper is to address an emerging international debate about the involvement of females in perpetrating honour-based abuse (HBA). Presenting new empirical data, this study profiles the different roles played by women, discussing them in relation to gender and their relationships to victims, and argues that acknowledgement of female perpetrators does not fundamentally challenge a gendered interpretation of HBA.Design/methodology/approachSome 1,474 case files flagged as HBA were gathered from one police force in Southern England and 50 domestic abuse agencies across England and Wales. Descriptive statistics explored which victim, perpetrator and abuse characteristics were associated with female perpetration. Case narratives were thematically analysed to profile the different roles females played. Findings were explored in eight key informant interviews with caseworkers from the services data came from.FindingsThis paper finds that: females are more involved in perpetrating HBA than other forms of domestic abuse, but primary perpetrators are still mostly male; victims are overwhelmingly female; the context for abuse is the maintenance of patriarchal values on gender roles; female perpetrator roles vary, meriting further exploration; and female perpetrators can be conceptualised within a gendered framework.Originality/valueThis paper presents important new empirical data to advance the debate on the role of women in perpetrating HBA. It will be of interest to academics, researchers, policy-makers, and practitioners alike.
pH in nature, humans and skin
Authors: Proksch Ehrhardt 
Published: June 2018

AbstractThe pH plays an important physiological role in nature and humans. pH varies from 1 to 8 in human organs with tight regulation in blood and epithelia of barrier organs. The physiological pH of the stratum corneum is 4.1–5.8 and several mechanisms contribute to its formation: filaggrin degradation, fatty acid content, sodium‐hydrogen exchanger (NHE1) activation and melanosome release. First, the acidic pH of the stratum corneum was considered to present an antimicrobial barrier preventing colonization (e.g. by Staphylococcus aureus and Malassezia). Later on, it was found that the pH influences skin barrier function, lipid synthesis and aggregation, epidermal differentiation and desquamation. Enzymes of ceramide metabolism (e.g. β‐glucocerebrosidase or acid sphingomyelinase) as well as proteases (e.g. chymotryptic enzyme or cathepsin D linked to epidermal differentiation and desquamation) are regulated by the pH. Experimental disruption of the physical barrier leads to an increase of pH, returning to normal levels only after many hours. Inflammatory skin diseases and diseases with an involvement of the epidermis exhibit a disturbed skin barrier and an increased pH. This is known for atopic dermatitis, irritant contact dermatitis, ichthyosis, rosacea and acne, but also for aged and dry skin. Normalizing the pH by acidification through topical treatment helps to establish a physiological microbiota, to repair skin barrier, to induce epidermal differentiation and to reduce inflammation.
Overcoming Challenges to Evidence‐Based Policy Development in a Large, Integrated Delivery System
Authors: Frakt Austin B. , Prentice Julia C. , Pizer Steven D. , Elwy A. Rani , Garrido Melissa M. , Kilbourne Amy M. , Atkins David 
Published: June 2018

ObjectiveTo describe a new Veterans Health Administration (VHA) program to foster the learning health system paradigm by rigorously evaluating health care initiatives and to report key lessons learned in designing those evaluations.Principal FindingsThe VHA's Quality Enhancement Research Initiative and its Health Services Research and Development Service are cooperating on several large, randomized program evaluations aimed at improving the care veterans receive and the efficiency with which it is delivered. The evaluations we describe involve collaborative design, outcomes assessment, and implementation science through partnerships between VHA operations and researchers. We review key factors to assess before committing to an evaluation. In addition to traditional design issues (such as ensuring adequate power and availability of data), these include others that are easily overlooked: the stability of intervention financing, means of controlling and commitment to adhering to randomized roll‐out, degree of buy‐in from key implementation staff, and feasibility of managing multiple veto points for interventions that span several programs, among others.ConclusionsSuccessful program implementation and rigorous evaluation require resources, specialized expertise, and careful planning. If the learning health system model is to be sustained, organizations will need dedicated programs to prioritize resources and continuously adapt evaluation designs.