bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrasting biogeographic patterns of bacterial and archaeal diversity in the top- and subsoils of temperate grasslands
Authors: Liu Nana , Hu Huifeng , Ma Wenhong , Deng Ye , Liu Yuqing , Hao Baihui , Zhang Xinying , Dimitrov Dimitar , Feng Xiaojuan , Wang Zhiheng 
Published: April 2019

ABSTRACTBiogeographic patterns and drivers of soil microbial diversity have been extensively studied in the past few decades. However, most research has focused on the topsoil while the subsoil is assumed to have similar microbial diversity patterns as the topsoil. Here we compare patterns and drivers of microbial diversity in the top- (0-10 cm) versus subsoils (30-50 cm) of temperate grasslands in Inner Mongolia of China along an aridity gradient covering a ~1500-km transect from arid to mesic ecosystems. Counter to the conventional assumption, we find contrasting biogeographic patterns of diversity and influencing factors for different bacterial and archaeal groups and between depths. While bacterial diversity increases with increasing aridity, archaeal diversity decreases. Microbial diversity in the topsoil is most strongly influenced by aboveground vegetation, but is most strongly influenced by historical temperature anomaly since the Last Glacial Maximum (LGM) in the subsoil. Moreover, the biogeographic patterns of top-subsoil diversity difference varies for different microbial groups and is overall most strongly influenced by soil fertility difference between depths and historical temperature anomaly. These findings suggest that diversity patterns observed in the topsoil may not be readily applied to the subsoil horizons. For the subsoil in particular, historical climate plays a vital role in the distribution of various microbial groups. Overall, our study provides novel information for understanding and predicting soil microbial diversity patterns at depth.IMPORTANCEExploring the biogeographic patterns of soil microbial diversity is critical for understanding mechanisms underlying the response of soil processes to climate change. Using top- and subsoils from a ~1500-km temperature grassland transect, we find divergent patterns of microbial diversity and its determinants in the top-versus subsoils. Furthermore, we find important legacy effect of historical climate change on the microbial diversity of subsoil but not topsoil. Our findings challenge the conventional assumption of similar geographic patterns of soil microbial diversity along soil profiles and help to improve our understanding of how soil microbial communities may respond to future climate change in different regions with varied climate history.
Dynamics of adaptation in an anisotropic phenotype-fitness landscape
Authors: Hamel F. , Lavigne F. , Martin G. , Roques L. 
Published: April 2019

AbstractWe study the dynamics of adaptation of a large asexual population in a n-dimensional phenotypic space, under anisotropic mutation and selection effects. When n = 1 or under isotropy assumptions, the ‘replicator-mutator’ equation is a standard model to describe these dynamics. However, the n-dimensional anisotropic case remained largely unexplored.We prove here that the equation admits a unique solution, which is interpreted as the phenotype distribution, and we propose a new and general framework to the study of the quantitative behavior of this solution. Our method builds upon a degenerate nonlocal parabolic equation satisfied by the distribution of the ‘fitness components’, and a nonlocal transport equation satisfied by the cumulant generating function of the joint distribution of these components. This last equation can be solved analytically and we then get a general formula for the trajectory of the mean fitness and all higher cumulants of the fitness distribution, over time. Such mean fitness trajectory is the typical outcome of empirical studies of adaptation by experimental evolution, and can thus be compared to empirical data.In sharp contrast with the known results based on isotropic models, our results show that the trajectory of mean fitness may exhibit (n − 1) plateaus before it converges. It may thus appear ‘non-saturating’ for a transient but possibly long time, even though a phenotypic optimum exists. To illustrate the empirical relevance of these results, we show that the anisotropic model leads to a very good fit of Escherichia coli long-term evolution experiment, one of the most famous experimental dataset in experimental evolution. The two ‘evolutionary epochs’ that have been observed in this experiment have long puzzled the community: we propose that the pattern may simply stem form a climbing hill process, but in an anisotropic fitness landscape.
Extrinsic noise and heavy-tailed laws in gene expression
Authors: Ham Lucy , Brackston Rowan D. , Stumpf Michael P.H. 
Published: April 2019

AbstractNoise in gene expression is one of the hallmarks of life at the molecular scale. Here we derive analytical solutions to a set of models describing the molecular mechanisms underlying transcription of DNA into RNA. Our Ansatz allows us to incorporate the effects of extrinsic noise – encompassing factors external to the transcription of the individual gene – and discuss the ramifications for heterogeneity in gene product abundance that has been widely observed in single cell data. Crucially, we are able to show that heavy-tailed distributions of RNA copy numbers cannot result from the intrinsic stochasticity in gene expression alone, but must instead reflect extrinsic sources of variability.
Parameter inference in dynamical systems with co-dimension 1 bifurcations
Authors: Roesch Elisabeth , Stumpf Michael P.H. 
Published: April 2019

AbstractDynamical systems with intricate behaviour are all-pervasive in biology. Many of the most interesting biological processes indicate the presence of bifurcations, i.e. phenomena where a small change in a system parameter causes qualitatively different behaviour. Bifurcation theory has become a rich field of research in its own right and evaluating the bifurcation behaviour of a given dynamical system can be challenging. An even greater challenge, however, is to learn the bifurcation structure of dynamical systems from data, where the precise model structure is not known. Here we study one aspects of this problem: the practical implications that the presence of bifurcations has on our ability to infer model parameters and initial conditions from empirical data; we focus on the canonical co-dimension 1 bifurcations and provide a comprehensive analysis of how dynamics, and our ability to infer kinetic parameters are linked. The picture thus emerging is surprisingly nuanced and suggests that identification of the qualitative dynamics — the bifurcation diagram — should precede any attempt at inferring kinetic parameters.
Within-population genome size variation is mediated by multiple genomic elements that segregate independently during meiosis
Authors: Stelzer Claus-Peter , Pichler Maria , Stadler Peter , Hatheuer Anita , Riss Simone 
Published: April 2019

AbstractWithin-species variation in genome size has been documented in many animals and plants. Despite its importance for understanding eukaryotic genome diversity, there is only sparse knowledge about how individual-level processes mediate genome size variation in populations. Here we study a natural population of the rotifer Brachionus asplanchnoidis whose members differ up to 1.9-fold in genome size, but were still able to interbreed and produce viable offspring. We show that genome size is highly heritable and can be artificially selected up or down, but not beyond a minimum diploid genome size. Analyses of segregation patterns in haploid males reveal that large genomic elements (several megabases in size) provide the substrate of genome size variation. These elements, and their segregation patterns, explain the generation of new genome size variants, the short-term evolutionary potential of genome size change in populations, and some seemingly paradoxical patterns, like an increase in genome size variation among highly inbred lines. Our study suggests that a conceptual model involving only two variables, (1) a minimum genome size of the population, and (2) a vector containing information on additional elements that may increase genome size in this population (size, number, and meiotic segregation behaviour), can effectively address most scenarios of short-term evolutionary change of genome size in a population.
Human rDNA Copy Number Is Unstable in Metastatic Breast Cancers
Authors: Valori Virginia , Tus Katalin , Laukaitis Christina , Harris David T. , LeBeau Lauren , Maggert Keith A. 
Published: April 2019

AbstractEpigenetic silencing, including the formation of heterochromatin, silent chromosome territories, and repressed gene promoters, acts to stabilize patterns of gene regulation and the physical structure of the genome. Reduction of epigenetic silencing can result in genome rearrangements, particularly at intrinsically unstable regions of the genome such as transposons, satellite repeats, and repetitive gene clusters including the rRNA gene clusters (rDNA). It is thus expected that mutational or environmental conditions that compromise heterochromatin function might cause genome instability, and diseases associated with decreased epigenetic stability might exhibit genome changes as part of their etiology. We find support of this hypothesis in invasive ductal breast carcinoma, in which reduced epigenetic silencing has been previously described, by using a facile method to quantify rDNA copy number in biopsied breast tumors and pair-matched healthy tissue. We found that rDNA and satellite DNA sequences had significant copy number variation – both losses and gains of copies – compared to healthy tissue, arguing that these genome rearrangements are common in developing breast cancer. Thus, any proposed etiology onset or progression of breast cancer should consider alterations to the epigenome, but must also accommodate concomitant changes to genome sequence at heterochromatic loci.Authors’ StatementOne of the common hallmarks of cancer is genome instability, including hypermutation and changes to chromosome structure. Using tumor tissues obtained from women with invasive ductal carcinoma, we find that a sensitive area of the genome – the ribosomal DNA gene repeat cluster – shows hypervariability in copy number. The patterns we observe as not consistent with an adaptive loss leading to increased tumor growth, but rather we conclude that copy number variation at repeat DNA is a general consequence of reduced heterochromatin function in cancer progression.
Isolated occurrences of membrane perturbation by mechanosensing from weakly aggregating silver nanoparticles
Authors: Perez Marcos Arribas , Moriones Oscar H. , Bastús Neus G. , Puntes Victor , Nelson Andrew , Beales Paul A. 
Published: April 2019

ABSTRACTSilver nanoparticles (AgNPs) have wide-ranging applications, including as additives in consumer products and in medical diagnostics and therapy. Therefore understanding how AgNPs interact with biological systems is important for ascertaining any potential health risks due to the likelihood of high levels of human exposure. Besides any severe, acute effects, it is desirable to understand more subtle interactions that could lead to milder, chronic health impacts. Nanoparticles are small enough to be able to enter biological cells and interfere with their internal biochemistry. The initial contact between nanoparticle and cell is at the plasma membrane. To gain fundamental mechanistic insight into AgNP-membrane interactions, we investigate these phenomena in minimal model systems using a wide-range of biophysical approaches applied to lipid vesicles. We find a strong dependence on the medium composition, where colloidally stable AgNPs in a glucose buffer have negligible effect on the membrane. However, at a physiological salt concentrations, the AgNPs start to weakly aggregate and sporadic but significant membrane perturbation events are observed. Under these latter conditions, transient poration and structural remodelling of some vesicle membranes is observed. We observe that the fluidity of giant vesicle membranes universally decreases by an average of 16% across all vesicles. However, we observe a small population of vesicles display a significant change in mechanical properties with lower bending rigidity and higher membrane tension. Therefore we argue that the isolated occurrences of membrane perturbation by AgNPs are due to low probability mechanosensing events of AgNP aggregation at the membrane.GRAPHICAL ABSTRACT
Conformational Flexibility of p150Glued(1-191) Subunit of Dynactin Assembled with Microtubules
Authors: Guo C. , Williams J. C. , Polenova T. 
Published: April 2019

ABSTRACTMicrotubule-associated proteins (MAPs) perform diverse functions in cells. These functions are dependent on their interactions with microtubules. Dynactin, a cofactor of dynein motor, assists the binding of dynein to various organelles and is crucial to the long-distance processivity of dynein-based complexes. The largest subunit of dynactin, the p150glued, contains a N-terminus segment that is responsible for the microtubule-binding interactions and long-range processivity of dynactin. We employed solution and magic angle spinning NMR spectroscopy to characterize the structure and dynamics of the p150glued N-terminal region, both free and in complex with polymerized microtubules. This 191-residue region encompasses the CAP-Gly domain, the basic domain and serine-proline-rich (SP-rich) domain. We demonstrate that the basic and SP-rich domains are intrinsically disordered in solution and significantly enhance the binding affinity to microtubules as these regions contain the second microtubule-binding site on the p150Glued subunit. The majority of the basic and SP-rich domains are predicted to be random-coil, while the segments S111–I116, A124–R132 and K144–T146 in the basic domain contain short α-helical or β-sheet structures. These three segments possibly encompass the microtubule binding site. Surprisingly, the protein retains high degree of flexibility upon binding to microtubules except for the regions that are directly involved in the binding interactions with microtubules. This conformational flexibility may be essential for the biological functions of the p150Glued subunit.STATEMENT OF SIGNIFICANCEMicrotubule-associated proteins (MAPs) perform diverse functions in cells. Many of them comprises intrinsically disordered regions, whose structural flexibility are central to microtubule-based cellular functions of MAPs. We employed solution and magic angle spinning NMR spectroscopy to characterize the structure and dynamics of the p150glued N-terminal region encompassing the CAP-Gly domain, the basic domain and serine-proline-rich (SP-rich) domain, both free and in complex with polymerized microtubules. The results reveal that the basic and SP-rich domains are largely unstructured and retains high degree of flexibility upon binding to microtubules except for the regions that are possibly involved in the binding interactions with microtubules. This approach is informative for dynamics studies of intrinsically disordered MAPs and other disordered proteins in large biological assemblies.
Diverse accounting standards on disclosures of Islamic financial transactions
Authors: Ahmed Habib , Tajul Ariffin Faruq Arif , Karbhari Yusuf , Shafii Zurina 
Published: April 2019

Purpose
Since International Financial Reporting Standards (IFRS) are not primarily meant for the accounting needs of Islamic banks, the Accounting and Auditing Organisation for Islamic Financial Institutions (AAOIFI) was established to develop specific accounting standards for Shari’ah compliance. The purpose of this paper is to assess the de jure harmonisation between the disclosure requirements of the IFRS-based Malaysian Accounting Standards (MAS) and those of the AAOIFI.

Design/methodology/approach
Using Malaysia as a case study, the paper examines the extent of the de jure congruence between the IFRS-based MAS and AAOIFI’s Financial Accounting Standard No 1 (FAS1), which is considered to be one of the key disclosure standards for Islamic banks. We employ leximetrics and content analysis to analyse these accounting standards and the additional guidelines introduced by the Malaysian Accounting Standards Board (MASB) and the Central Bank of Malaysia (Bank Negara Malaysia, BNM) to identify the gaps between different tiers of MAS and FAS1.

Findings
The study finds that de jure congruence between the IFRS-based MAS and AAOIFI standards has improved through the introduction of additional accounting guidelines by both the MASB and the banking regulator, BNM. However, some gaps remain between the two standards. These gaps may be difficult to completely eliminate due to differences in the fundamental principles underlying the development of both standards.

Originality/value
While some studies have explored the de facto congruence between AAOIFI accounting standards and others, this paper is the first, to the best of the authors’ knowledge, to examine the de jure congruence between those standards with the IFRS-based MAS.
Boundary element method for 3D conductive thin layer in eddy current problems
Authors: Issa Mohammad , Poirier Jean-René , Perrussel Ronan , Chadebec Olivier , Péron Victor 
Published: April 2019

Purpose
Thin conducting sheets are used in many electric and electronic devices. Solving numerically the eddy current problems in presence of these thin conductive sheets requires a very fine mesh which leads to a large system of equations, and it becomes more problematic in case of higher frequencies. The purpose of this paper is to show the numerical pertinence of equivalent models for 3D eddy current problems with a conductive thin layer of small thickness e based on the replacement of the thin layer by its mid-surface with equivalent transmission conditions that satisfy the shielding purpose, and by using an efficient discretization using the boundary element method (BEM) to reduce the computational work.

Design/methodology/approach
These models are solved numerically using the BEM and some numerical experiments are performed to assess the accuracy of the proposed models. The results are validated by comparison with an analytical solution and a numerical solution by the commercial software Comsol.

Findings
The error between the equivalent models and analytical and numerical solutions confirms the theoretical approach. In addition to this accuracy, the computational work is reduced by considering a discretization method that requires only a surface mesh.

Originality/value
Based on a hybrid formulation, the authors present briefly a formal derivation of impedance transmission conditions for 3D thin layers in eddy current problems where non-conductive materials are considered in the interior and the exterior domain of the sheet. BEM is adopted to discretize the problem as there is no need for volume discretization.
Effect of eliminating mandatory reconciliation requirements for foreign issuers in the U.S.
Authors: Kumar Gaurav , Saini Jagjit S. 
Published: April 2019

Purpose
The purpose of this paper is to examine the effect of choice of accounting standards on the value relevance and accrual quality of reported earnings and book values under International Financial Reporting Standards (IFRS) versus US Generally Accepted Accounting Principles (GAAP).

Design/methodology/approach
The authors examine the effect of choice of accounting standards on the value relevance and accrual quality of reported earnings and book values under IFRS versus US GAAP using 404 firms from 37 countries listed in the USA. They use the modified Jones (1991) model to measure accruals.

Findings
The authors find that value relevance of the book value of equity is increasing (significantly) when the sample firms use IFRS to prepare their financial statements. They also find some evidence in support of the mediating effect of the choice of accounting standards on the accrual quality of the sample firms. The results of this paper indicate that sample firms with lower accrual quality (larger discretionary accruals) experience higher returns during the fiscal year. However, the authors also find that the positive association between size of discretionary accruals and returns is decreasing in the use of IFRS by the sample firms.

Originality/value
This paper adds to prior literature on the harmonization of accounting standards and emphasizes the role of accounting standards in the quality of financial reporting. By using the financial data of all foreign registrants listed in the USA, the authors are able to provide deeper and more representative evidence.
‘Technologies of the self and other’: how self-tracking technologies also shape the other
Authors: Gabriels Katleen , Coeckelbergh Mark 
Published: April 2019

Purpose
This paper aims to fill this gap (infra, originality) by providing a conceptual framework for discussing “technologies of the self and other,” by showing that, in most cases, self-tracking also involves other-tracking.

Design/methodology/approach
In so doing, we draw upon Foucault’s “technologies of the self” and present-day literature on self-tracking technologies. We elaborate on two cases and practical domains to illustrate and discuss this mutual process: first, the quantified workplace; and second, quantification by wearables in a non-clinical and self-initiated context.

Findings
The main conclusion is that these shapings are never (morally) neutral and have ethical implications, such as regarding “quantified otherness,” a notion we propose to point at the risk that the other could become an object of examination and competition.

Originality/value
Although there is ample literature on the quantified self, considerably less attention is given to how the relation with the other is being shaped by self-tracking technologies that allow data sharing (e.g. wearables or apps such as Strava or RunKeeper).
What influences the course major decision of accounting and non-accounting students?
Authors: Owusu Godfred Matthew Yaw , Bekoe Rita Amoah , Okyere Sarah Anobil , Welbeck Edem Emerald 
Published: April 2019

Purpose
The purpose of this study is to investigate the factors that influence the course major decisions of accounting and non-accounting students.

Design/methodology/approach
A set of questionnaires was developed and administered to 550 undergraduate business students from the University of Ghana Business School. Statistical tests were conducted to examine the mean differences of students’ views on the factors that influence course major selection. Logistic regression analysis was employed to investigate the factors that influence the course major selection of students.

Findings
The results demonstrate that students’ confidence in their academic strength and abilities to manage academic work are good predictors of their course major decisions. Also, students who major in accounting are driven more by self-interest, while non-accounting students are largely motivated by extrinsic interest. Moreover, students’ academic performances were found to be influential on their course major decisions.

Research limitations/implications
This study relied on the views of students from only one university in Ghana, which, in some respect, limits the extent of generalization of the findings.

Practical implications
The paper provides some useful insights into the factors that inspire students to major in accounting. As a means of addressing the supply deficit of accountants globally, policymakers should find the results useful in developing the appropriate strategy that will attract students to the accounting field.

Originality/value
The study provides new insights into the course major selection discourse from a developing-country perspective.