bluuebunny/crossref_metadata_2025_split huggingface dataset:
From space to time: Spatial inhomogeneities lead to the emergence of spatio-temporal activity sequences in spiking neuronal networks
Authors: Spreizer Sebastian , Aertsen Ad , Kumar Arvind 
Published: September 2018

AbstractSpatio-temporal sequences of neuronal activity are observed in many brain regions in a variety of tasks and are thought to form the basis of any meaningful behavior. Mechanisms by which a neuronal network can generate spatio-temporal activity sequences have remained obscure. Existing models are biologically untenable because they require manual embedding of a feedforward network within a random network or supervised learning to train the connectivity of a network to generate sequences. Here, we propose a biologically plausible, generative rule to create spatio-temporal activity sequences in a network model of spiking neurons with distance dependent connectivity. We show that the emergence of spatio-temporal activity sequences requires: (1) individual neurons preferentially project a small fraction of their axons in a specific direction, and (2) the preferential projection direction of neighboring neurons is similar. Thus, an anisotropic but correlated connectivity of neuron groups suffices to generate spatio-temporal activity sequences in an otherwise random neuronal network model.
A florigen paralog is required for short-day vernalization in a pooid grass
Authors: Woods Daniel P. , Dong Yinxin , Bouché Frédéric , Bednarek Ryland , Rowe Mark , Ream Thomas S. , Amasino Richard M. 
Published: September 2018

AbstractPerception of seasonal cues is critical for reproductive success in many plants. Exposure to winter cold is a cue that can confer competence to flower in the spring via a process known as vernalization. In certain grasses, exposure to short days is another winter cue that can lead to a vernalized state. In Brachypodium distachyon, we find that natural variation for the ability of short days to confer competence to flower is due to allelic variation of the florigen paralog FT-like9 (FTL9). An active FTL9 allele is required for the acquisition of floral competence, demonstrating a novel role for a member of the florigen family of genes. Loss of the short-day vernalization response appears to have arisen once in B. distachyon and spread through diverse lineages indicating that this loss has adaptive value, perhaps by delaying spring flowering until the danger of cold damage to flowers has subsided.
Subcellular Time Series Modeling of Heterogeneous Cell Protrusion
Authors: Kim Yeesock , Choi Hee June , Lee Kwonmoo 
Published: September 2018

AbstractIn this paper, a new biological modeling approach is proposed for predicting complex heterogeneous subcellular behaviors. Cell protrusion which initiates cell migration has a significant amount of subcellular heterogeneity in micrometer length and minute time scales. It is driven by actin polymerization, e.g., pushing the plasma membrane forward, and then regulated by a multitude of actin regulators. While mathematical modeling is central to system-level understandings of cell protrusion, most of the modeling is based on the ensemble average of actin regulator dynamics at the cellular or population levels, preventing from capturing the heterogeneous cellular activities. With these in mind, a systematic modeling framework is proposed in this paper for predicting velocities of heterogeneous protrusion of migrating cells driven by multiple molecular mechanisms. The modeling framework is developed through the integration of the multiple AutoRegressive eXogenous (ARX) models employing probability density input variables. Unlike conventional ARX models, it provides an effective framework for modeling heterogeneous subcellular behaviors with complex nonlinearities and uncertainties of dynamic systems. To train and validate the proposed model, numerous subcellular time series are extracted from time-lapse movies of migrating PtK1 cells using spinning disk confocal microscope: The current edge velocities and fluorescent intensities of mDia1, actin at the leading edge are used as the input while the future cell edge velocities are selected as an output. It is demonstrated that the proposed approach is highly effective in predicting the future trends of heterogeneous cell protrusion. In particular, by capturing the various multiple activities from the dataset, it is expected that it would improve the understanding of the molecular mechanism underlying cellular and subcellular heterogeneity.
Reduced serotonin receptors and transporters in normal aging adults: a meta-analysis of PET and SPECT imaging studies
Authors: Karrer Teresa M. , McLaughlin Casey L. , Guaglianone Carmela P. , Samanez-Larkin Gregory R. 
Published: September 2018

AbstractAlterations in serotonin (5-HT) function have been hypothesized to underlie a range of physiological, emotional, and cognitive changes in older age. Here, we conducted a quantitative synthesis and comparison of the effects of age on 5-HT receptors and transporters from cross-sectional PET and SPECT imaging studies. Random-effects meta-analyses of 31 studies including 1087 healthy adults yielded large negative effects of age in 5-HT-2A receptors (largest in global cortex), moderate negative effects of age in 5-HT transporters (largest in thalamus), and small negative effects of age in 5-HT-1A receptors (largest in parietal cortex). Presynaptic 5-HT-1A autoreceptors in raphe/midbrain, however, were preserved across adulthood. Adult age differences were significantly larger in 5-HT-2A receptors compared to 5-HT-1A receptors. A meta-regression showed that 5-HT target, radionuclide, and publication year significantly moderated the age effects. The findings overall identify reduced serotonergic signal transmission in healthy aging. The evidence for the relative preservation of 5-HT-1A compared to 5-HT-2A receptors may partially explain psychological age differences, such as why older adults use more emotion-focused rather than problem-focused coping strategies.
A unified framework for unconstrained and constrained ordination of microbiome read count data
Authors: Hawinkel Stijn , Kerckhof Frederiek-Maarten , Bijnens Luc , Thas Olivier 
Published: September 2018

AbstractExplorative visualization techniques provide a first summary of microbiome read count datasets through dimension reduction. A plethora of dimension reduction methods exists, but many of them focus primarily on sample ordination, failing to elucidate the role of the bacterial species. Moreover, implicit but often unrealistic assumptions underlying these methods fail to account for overdispersion and differences in sequencing depth, which are two typical characteristics of sequencing data. We combine log-linear models with a dispersion estimation algorithm and flexible response function modelling into a framework for unconstrained and constrained ordination. The method allows easy filtering of technical confounders. As opposed to most existing ordination methods, the assumptions underlying the method are stated explicitly and can be verified using simple diagnostics. The combination of unconstrained and constrained ordination in the same framework is unique in the field and greatly facilitates microbiome data exploration. We illustrate the advantages of our method on simulated and real datasets, while pointing out flaws in existing methods. The algorithms for fitting and plotting are available in the R-packageRCM.
Natural enemies of armored scales (Hemiptera: Diaspididae) and soft scales (Hemiptera: Coccoidae) in Chile: molecular and morphological identification
Authors: Amouroux P. , Crochard D. , Correa M.C.G. , Groussier G. , Kreiter P. , Roman C. , Guerrieri E. , Garonna A.P. , Malausa T. , Zaviezo T. 
Published: September 2018

AbstractScale insects (Hemiptera: Coccoidea) are key pests of agricultural crops and ornamental plants worldwide. Their populations are difficult to control, even with insecticides, due to their cryptic habits. Moreover, there is growing concern over the use of synthetic pesticides for their control, due to deleterious environmental effects and the emergence of resistant populations of target pests. In this context, biological control may be an effective and sustainable approach. Hymenoptera Chalcidoidea includes natural enemies of scale insects that have been successfully used in many biological control programs. However, the correct identification of pest scale species and their natural enemies is particularly challenging because these insects are very small and highly specialized. Integrative taxonomy, coupling DNA barcoding and morphological analysis, has been successfully used to characterize pests and natural enemy species. In this study, we performed a survey of parasitoids and predators of armored and soft scales in Chile, based on 28S and COI barcodes. Fifty-three populations of Diaspididae and 79 populations of Coccidae were sampled over the entire length of the country, from Arica (18°S) to Frutillar (41°S), between January 2015 and February 2016. The phylogenetic relationships obtained by Bayesian inference from multilocus haplotypes revealed 40 putative species of Chalcidoidea, five Coccinellidae and three Neuroptera. In Chalcidoidea, 22 species were identified morphologically, resulting in new COI barcodes for 12 species and new 28S barcodes for 14 species. Two predator species (Rhyzobius lophantae and Coccidophilus transandinus) were identified morphologically, and two parasitoid species, Chartocerus niger and Signiphora bifasciata, were recorded for the first time in Chile.
A high-throughput whole cell screen to identify inhibitors of Mycobacterium tuberculosis
Authors: Ollinger Juliane , Kumar Anuradha , Roberts David M. , Bailey Mai A. , Casey Allen , Parish Tanya 
Published: September 2018

AbstractTuberculosis is a disease of global importance for which novel drugs are urgently required. We developed a whole-cell phenotypic screen which can be used to identify inhibitors of Mycobacterium tuberculosis growth. We used recombinant strains of virulent M. tuberculosis which express far-red fluorescent reporters and used fluorescence to monitor growth in vitro. We optimized our high throughput assays using both 96-well and 384-well plates; both formats gave assays which met stringent reproducibility and robustness tests. We screened a compound set of 1105 chemically diverse compounds previously shown to be active against M. tuberculosis and identified primary hits which showed ≥ 90% growth inhibition. We ranked hits and identified three chemical classes of interest – the phenoxyalkylbenzamidazoles, the benzothiophene 1–1 dioxides, and the piperidinamines. These new compound classes may serve as starting points for the development of new series of inhibitors that prevent the growth of M. tuberculosis. This assay can be used for further screening, or could easily be adapted to other strains of M. tuberculosis.
Bet-hedging strategies in expanding populations
Authors: Paula Villa Martín , Muñoz Miguel A. , Pigolotti Simone 
Published: September 2018

AbstractIn ecology, species can mitigate their extinction risks in uncertain environments by diversifying individual phenotypes. This observation is quantified by the theory of bet-hedging, which provides a reason for the degree of phenotypic diversity observed even in clonal populations. The theory of bet-hedging in well-mixed populations is rather well developed. However, many species underwent range expansions during their evolutionary history, and the importance of phenotypic diversity in such scenarios still needs to be understood. In this paper, we develop a theory of bet-hedging for populations colonizing new, unknown environments that fluctuate either in space or time. In this case, we find that bet-hedging is a more favorable strategy than in well-mixed populations. For slow rates of variation, temporal and spatial fluctuations lead to different outcomes. In spatially fluctuating environments, bet-hedging is favored compared to temporally fluctuating environments. In the limit of frequent environmental variation, no opportunity for bet-hedging exists, regardless of the nature of the environmental fluctuations. For the same model, bet-hedging is never an advantageous strategy in the well-mixed case, supporting the view that range expansions strongly promote diversification. These conclusions are robust against stochasticity induced by finite population sizes. Our findings shed light on the importance of phenotypic heterogeneity in range expansions, paving the way to novel approaches to understand how biodiversity emerges and is maintained.Author summaryEcological populations are often exposed to unpredictable and variable environmental conditions. A number of strategies have evolved to cope with such uncertainty. One of them is stochastic phenotypic switching, by which some individuals in the community are enabled to tackle adverse conditions, even at the price of reducing overall growth in the short term. In this paper, we study the effectiveness of these “bet-hedging” strategies for a population in the process of colonizing new territory. We show that bet-hedging is more advantageous when the environment varies spatially rather than temporally, and infrequently rather than frequently.
Unmanned aircraft automatic flight control algorithm in loop manoeuvre
Authors: Rogalski Tomasz 
Published: September 2018

Purpose
This paper aims to present the idea of an automatic control system dedicated to small manned and unmanned aircraft performing manoeuvres other than those necessary to perform a so-called standard flight. The character of these manoeuvres and the range of aircraft flight parameter changes restrict application of standard control algorithms. In many cases, they also limit the possibility to acquire complete information about aircraft flight parameters. This paper analyses an alternative solution that can be applied in such cases. The loop manoeuvre, an element of aerobatic flight, was selected as a working example.

Design/methodology/approach
This paper used theoretical discussion and breakdowns to create basics for designing structures of control algorithms. A simplified analytical approach was then applied to tune regulators. Research results were verified in a series of computer-based software-in-the-loop rig test computer simulations.

Findings
The structure of the control system enabling aerobatic flight was found and the method for tuning regulators was also created.

Practical implications
The findings could be a foundation for autopilots working in non-conventional flight scenarios and automatic aircraft recovery systems.

Originality/value
This paper presents the author’s original approach to aircraft automated control where high precision control is not the priority and flight parameters cannot be precisely measured or determined.
Design optimization of helicopter rotor using kriging
Authors: Kizhakke Kodakkattu Saijal , Nair Prabhakaran , M.L. Joy 
Published: September 2018

Purpose
The purpose of this study is to obtain optimum locations, peak deflection and chord of the twin trailing-edge flaps and optimum torsional stiffness of the helicopter rotor blade to minimize the vibration in the rotor hub with minimum requirement of flap control power.

Design/methodology/approach
Kriging metamodel with three-level five variable orthogonal array-based data points is used to decouple the optimization problem and actual aeroelastic analysis.

Findings
Some very good design solutions are obtained using this model. The best design point in minimizing vibration gives about 81 per cent reduction in the hub vibration with a penalization of increased flap power requirement, at normal cruise speed of rotor-craft flight.

Practical implications
One of the major challenges in the helicopters is the high vibration level in comparison with fixed wing aircraft. The reduction in vibration level in the helicopter improves passenger and crew comfort and reduces maintenance cost.

Originality/value
This paper presents design optimization of the helicopter rotor blade combining five design variables, such as the locations of twin trailing-edge flaps, peak deflection and flap chord and torsional stiffness of the rotor. Also, this study uses kriging metamodel to decouple the complex aeroelastic analysis and optimization problem.
Awareness and accessibility of the Dutch mental health care system for people with borderline intellectual functioning or mild intellectual disabilities
Authors: Wieland Jannelien , ten Doesschate Mascha 
Published: September 2018

Purpose
In The Netherlands, curative mental health care and supportive care for people with an intellectual disability (ID) are organised in separate domains. Prevalence of mental health problems is known to be high among people with borderline intellectual functioning (BIF) or mild intellectual disabilities (MID). By contrast, according to recent findings, prevalence of BIF and MID is high among patients in mental health care (17.5–58 per cent). In The Netherlands, a new quality standard of care (QSOC) on mental health care for people with BIF or MID is developed. It is designed to supplement existing guidelines on mental health care so that they can be used appropriately in people with BIF or MID and meant for use in both mental health care organisations (MHCO) as in organisations for ID care. To a large extent, the QSOC should describe the existing practice. This paper aims to discuss these issues.

Design/methodology/approach
To assess the existing practice in current mental health care for people with BIF or MID in The Netherlands, the authors examined the views and accessibility of MHCO on the mental health care for patients with and IQ<85. In addition, the authors reviewed published criteria for in- and exclusion of all 39 top clinical mental health care departments for criteria on BIF or (mild) ID.

Findings
The authors found there is a clear awareness of the high prevalence of BIF and MID among large Dutch MHCO. Dutch MHCO estimate the prevalence of BIF and MID among their patients to be around 30 per cent. Nonetheless, most MCHO surveyed (76 per cent) indicated they do not routinely estimate or measure IQ among their patients and 53 per cent of MHCO indicated not having knowledge and expertise on the dual diagnoses of mental health problems and BIF or MID. Fitting in with the new QSOC most of the MHCO (59 per cent) agreed on the statement in the survey that professionals should be able to treat patients with BIF or ID and all but one of the MHCO stated to have some form of collaboration with an institute for ID care.

Originality/value
The authors concluded there is a clear awareness of the high prevalence of BIF and MID among large Dutch MHCO. The new QSOC on mental health care for people with BIF or MID can help improve accessibility and quality of mental health care for these patients.
A service-oriented context-awareness reasoning framework and its implementation
Authors: Cheng Xiufeng , Yang Jinqing , Xia Lixin 
Published: September 2018

Purpose
This paper aims to propose an extensible, service-oriented framework for context-aware data acquisition, description, interpretation and reasoning, which facilitates the development of mobile applications that provide a context-awareness service.

Design/methodology/approach
First, the authors propose the context data reasoning framework (CDRFM) for generating service-oriented contextual information. Then they used this framework to composite mobile sensor data into low-level contextual information. Finally, the authors exploited some high-level contextual information that can be inferred from the formatted low-level contextual information using particular inference rules.

Findings
The authors take “user behavior patterns” as an exemplary context information generation schema in their experimental study. The results reveal that the optimization of service can be guided by the implicit, high-level context information inside user behavior logs. They also prove the validity of the authors’ framework.

Research limitations/implications
Further research will add more variety of sensor data. Furthermore, to validate the effectiveness of our framework, more reasoning rules need to be performed. Therefore, the authors may implement more algorithms in the framework to acquire more comprehensive context information.

Practical implications
CDRFM expands the context-awareness framework of previous research and unifies the procedures of acquiring, describing, modeling, reasoning and discovering implicit context information for mobile service providers.

Social implications
Support the service-oriented context-awareness function in application design and related development in commercial mobile software industry.

Originality/value
Extant researches on context awareness rarely considered the generation contextual information for service providers. The CDRFM can be used to generate valuable contextual information by implementing more reasoning rules.
Semantic Web and ontology-based applications for digital libraries
Authors: Khan Shakeel Ahmad , Bhatti Rubina 
Published: September 2018

Purpose
The purpose of this paper is to explore useful Semantic Web technologies and ontology-based applications for digital libraries. It also investigates the perceptions of university librarians and academicians in Pakistan about Semantic Web technologies and their use in digital libraries.

Design/methodology/approach
An exploratory research design based on Delphi research strategy was conducted to answer the research questions. Interviews were conducted with a purposive sample of 50 key informants including university librarians and academicians to explore their perceptions about Semantic Web technologies and their use in digital libraries. Thematic analysis of interview data was conducted to obtain results.

Findings
The results of this paper showed that DuraCloud, Semantic information mashup, OntoEdit and resource description framework (RDF) are the various Semantic Web applications which are useful for digital libraries to develop semantic relationships among digital contents and increase their accessibility in the web environment. Findings revealed that Semantic Web provides precise results and meets user information needs in an effective way. Results also showed that next-generation digital libraries use context-awareness technology, intelligent agent software and detecting sensors to analyze user information needs and provide dynamic information services. This paper recommended that librarians should embrace the use of emerging web technologies in libraries and offer library services through the medium of the web.

Practical implications
This paper envisaged the future of digital library services and Semantic Web applications that can be used to re-structure metadata of digital library. This paper has practical implications for librarians to consider the useful applications of Semantic Web for digital library and enhance the interoperability of metadata among heterogeneous information systems. Practically, results obtained from this paper are highly useful for library schools and LIS teachers to up-date their curriculum by incorporating new contents related to web languages and Semantic Web applications for digital libraries.

Originality/value
This paper identifies various Semantic Web applications which are useful for developing Semantic Digital Libraries.
Endogenous cases and the evolution of the common law
Authors: Parameswaran Giri 
Published: September 2018

AbstractI develop a dynamic model of judge‐made law in which the ideal legal rule is unknown but can be learned. In contrast to existing articles, the flow of cases heard by the court is affected by the court's prior decisions. The model highlights the significance of this feedback in explaining when and why the court will write broader or narrower opinions, and the long‐run properties of common law. In equilibrium, the law settles endogenously, because the incentives to make legally controversial choices disappear as the law evolves. Settled law exhibits residual uncertainty and ambiguity, and potentially implements inefficient outcomes.