bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dengue fever andAedes aegyptirisk in the Galápagos Islands, Ecuador
Authors: Nightingale Ryan , Lippi Catherine , Ryan Sadie J. , Borbor-Cordova Mercy J. , Cruz B Marilyn , Ortega Fernando , León Renato , Waggoner Egan , Stewart Ibarra Anna M. 
Published: March 2017

AbstractIntroductionDengue fever is an emerging infectious disease in the Galápagos Islands of Ecuador, with the first cases reported in 2002 and periodic outbreaks since then. Here we report the results of a pilot study conducted in two cities in 2014: Puerto Ayora (PA) on Santa Cruz Island, and Puerto Baquerizo Moreno (PB) on Santa Cristobal Island. The aims of this study were to assess the social-ecological risk factors associated with dengue and mosquito presence at the household-level.MethodsIn 2014 we conducted 100 household surveys (50 on each island) in neighborhoods with prior reported dengue. Adult mosquitoes were collected inside and outside the home, larval indices were determined through container surveys, and heads of households were interviewed to determine demographics, prior dengue infections, housing conditions, and knowledge, attitudes and practices regarding dengue. Multimodel selection methods were used to derive best-fit generalized linear regression (GLM) models of prior dengue infection, and the presence ofAe. aegyptiin the home.ResultsWe found that 24% of PB and 14% of PA respondents self-reported a prior dengue infection, and more PB homes than PA homes hadAe. aegypti.The top-ranked model for prior dengue infection included human movement – travel between neighborhoods, between islands, and to the mainland; demographics including salary level and education of the head of household, and increase with more people per room in a house, house condition, access to water quality issues, and dengue awareness. The top-ranked model for the presence ofAe. aegyptiincluded housing conditions, including the presence of window screens and air conditioners, mosquito control actions, and dengue risk perception.Discussion/conclusionTo our knowledge, this is the first study of dengue risk andAedes aegyptiin the Galápagos Islands. The findings that human movement within and between islands, and to and from the mainland, were important to reported dengue cases confirms concerns of this route of introduction and repeated transmission.
H3K27me3-mediated silencing of Wilms Tumor 1 supports the proliferation of brain tumor cells harboring the H3.3K27M mutation
Authors: Fang Dong , Gan Haiyun , Cheng Liang , Lee Jeong-Heon , Zhou Hui , Sarkaria Jann N. , Daniels David J. , Zhang Zhiguo 
Published: March 2017

AbstractThe lysine 27 to methionine mutation of histone H3.3 (H3.3K27M) is detected in over 75% of diffuse intrinsic pontine glioma (DIPG). The H3.3K27M mutant proteins inhibit H3K27 methyltransferase complex PRC2, resulting in a global reduction of tri-methylation of H3K27 (H3K27me3). Paradoxically, high levels of H3K27me3 were also detected at hundreds of genomic loci. However, it is not known how and why H3K27me3 is redistributed in DIPG cells. Here we show that lower levels of H3.3K27M mutant proteins at some genomic loci contribute to the retention of H3K27me3 peaks. But more importantly, Jarid2, a PRC2-associated protein, strongly correlates the presence of H3K27me3 and relieves the H3.3K27M-mediated inhibitionin vivo and in vitro.Furthermore, we show that H3K27me3-mediated silencing of tumor suppressor gene Wilms Tumor 1 (WT1) supports the proliferation of DIPG cells and reaction of WT1 inhibits DIPG proliferation. Together, these studies reveal mechanisms whereby H3K27me3 is retained in the environment of global loss of this mark, and how persistence of this mark contributes to DIPG tumorigenesis.
Demonstration ofde novochemotaxis inE. coliusing a real-time, quantitative, and digital-like approach
Authors: Davidov Tzila , Granik Naor , Zahran Sharbel , Adir Inbal , Elul Ofek , Fried Tal , Gil Asif , Mayo Bar , Ohayon Shilo , Sarig Shiran , Shasha Nofar , Tsedef Shirane , Weiner Shani , Brunwasser-Meirom Michal , Ereskovsky Alexandra , Katz Noa , Kaufmann Beate , Haimov Yuri , Leonard Heidi , Segal Ester , Amit Roee 
Published: March 2017

AbstractChemotaxis is the movement of an organism in response to an external chemical stimulus. This system enables bacteria to sense their immediate environment and adapt to changes in its chemical composition. Bacterial chemotaxis is mediated by chemoreceptors, membrane proteins that bind an effector and transduce the signal to the downstream proteins. From a synthetic biology perspective, the natural chemotactic repertoire is of little use since bacterial chemoreceptors have evolved to sense specific ligands that either benefit or harm the cell. Here we demonstrate that using a combined computational design approach together with a quantitative, real-time, and digital detection approach, we can rapidly design, manufacture, and characterize a synthetic chemoreceptor inE. colifor histamine (a ligand for which there are no known chemoreceptors). First, we employed a computational protocol that uses the Rosetta bioinformatics software together with high threshold filters to design mutational variants to the native Tar ligand binding domain that target histamine. Second, we tested different ligand-chemoreceptors pairs with a novel chemotaxis assay, based on optical reflectance interferometry of porous silicon (PSi) optical transducers, enabling label-free quantification of chemotaxis by monitoring real-time changes in the optical readout (expressed as the effective optical thickness, EOT). We found that different ligands can be characterized by an individual set of fingerprints in our assay. Namely, a binary, digital-like response in EOT change (i.e. positive or negative) that differentiates between attractants and repellants, the amplitude of change of EOT response, and the rate by which steady state in EOT change is reached. Using this assay, we were able to positively identify and characterize a single mutational chemoreceptor variant for histamine that mediated chemotaxis comparably to the natural Tar-aspartate system. Our results demonstrate the possibility of not only expanding the natural chemotaxis repertoire, but also provide a new quantitative assay by which to characterize the efficacy of the chemotactic response.
Evolution of density-dependent movement during replicated experimental range expansions
Authors: Fronhofer Emanuel A. , Gut Sereina , Altermatt Florian 
Published: March 2017

AbstractRange expansions and biological invasions are prime examples of non-equilibrium systems that are likely impacted by rapid evolutionary changes. As a spatial process, range expansions are driven by dispersal and movement behaviour. While it is widely accepted that dispersal and movement may be context-dependent, for instance density-dependent, and best represented by reaction norms, the evolution of density-dependent movement during range expansions has received little experimental attention. We therefore tested current theory predicting the evolution of increased movement at low densities at range margins using highly replicated and controlled range expansion experiments across multiple genotypes of the protist model systemTetrahymena thermophila. Although rare, we found evolutionary changes during range expansions even in the absence of initial standing genetic variation. Range expansions led to the evolution of negatively density-dependent movement at range margins. In addition, we report the evolution of increased competitive ability and concurrently decreased population growth rates in range cores. Our findings highlight the importance of understanding movement and dispersal as evolving reaction norms and plastic life-history traits of central relevance for range expansions, biological invasions and the dynamics of spatially structured systems in general.Data accessibilityThe data will be made available at Dryad (http://dx.doi.org/xxxxx). Video analysis scripts can be found on GitHub (https://github.com/efronhofer/analysis_script_bemovi).
Modeling of a negative feedback mechanism explains age-dependent genetic architecture in reproduction in domesticatedC. elegansstrains
Authors: Large Edward E. , Padmanabhan Raghavendra , Watkins Kathie L. , Campbell Richard F. , Xu Wen , McGrath Patrick T. 
Published: March 2017

ABSTRACTMost biological traits and common diseases have a strong but complex genetic basis, controlled by large numbers of genetic variants with small contributions to a trait or disease risk. The effect-size of most genetic variants is not absolute, but can depend on a number of factors including the age and genetic background of an organism. In order to understand the mechanisms that cause these changes, we are studying heritable trait differences between two domesticated strains of C. elegans. We previously identified a major effect locus, caused by a mutation in a component of the NURF chromatin remodeling complex, that regulated reproductive output in an age-dependent manner. The effect-size of this locus changes from positive to negative over the course of an animal’s reproductive lifespan. Using a previously published macroscale model of egg-laying rate in C. elegans, we show how time-dependent effect-size can be explained by an unequal use of sperm combined with negative feedback between sperm and ovulation rate. We validate a number of key predictions of this model using controlled mating experiments and quantification of oogenesis and sperm use. By incorporating this model into QTL mapping, we identify and partition new QTLs into specific aspects of the egg-laying process. Finally, we show how epistasis between two genetic variants is predicted by this modeling as a consequence of unequal use of sperm. This work demonstrates how modeling of multicellular communication systems can improve our ability to predict and understand the role of genetic variation on a complex phenotype. Negative autoregulatory feedback loops, common in transcriptional regulation, could play an important role in modifying genetic architecture in other traits.AUTHOR SUMMARYComplex traits are influenced not only by the individual effects of genetic variants, but also how these variants interact with the environment, age, and each other. While complex genetic architectures seem to be ubiquitous in natural traits, little is known about the mechanisms that cause them. Here we identify an example of age-dependent genetic architecture controlling the rate and timing of reproduction in the hermaphroditic nematodeC. elegans.Using computational modeling, we demonstrate how this age-dependent genetic architecture can arise as a consequence of two factors: hormonal feedback on oocytes mediated by major sperm protein (MSP) released by sperm stored in the spermatheca and life history differences in sperm use caused by genetic variants. Our work also suggests how age-dependent epistasis can emerge from multicellular feedback systems.
Characterizing and interpreting the influence of internal variables on sensory activity
Authors: Lange Richard D. , Haefner Ralf M. 
Published: March 2017

AbstractThe concept of a tuning curve has been central for our understanding of how the responses of cortical neurons depend on external stimuli. Here, we describe how the influence of unobserved internal variables on sensory responses, in particular correlated neural variability, can be understood in a similar framework. We suggest that this will lead to deeper insights into the relationship between stimulus, sensory responses, and behavior. We review related recent work and discuss its implication for distinguishing feedforward from feedback influences on sensory responses, and for the information contained in those responses.HighlightsRe-interpretation of neural correlations in terms of internal variables……can clarify whether they limit or enhance informationInfluence of internal variables can be captured by interpretable ‘tuning functions’Estimation of both internal variables and tuning possible from population recordings
Differences in the spatial and temporal patterns of head motion during MRI of adults and infants
Authors: Cusack Rhodri , Linke Annika C. , Zubiaurre-Elorza Leire , Duffy Hester , Herzmann Charlotte , Stojanoski Bobby , Han Victor K. , Lee David S.C. , Wild Conor 
Published: March 2017

AbstractAimHead motion has a profound effect on MRI, and will contaminate comparisons of function or structure between groups that move differently. This work compares adults and infants. Infants might move differently for physical, physiological and cognitive reasons, but so far these differences have not been quantified.MethodsThe spatial modes and total magnitude of motion in the MRI scanner were measured (N=211). The effects of group (infant vs. adult) and stimulation paradigm (auditory vs. visual) were evaluated.ResultsSpatial modes of motion were found to be distinct between infant and adult groups. Infants had less anterior-posterior translational motion, but greater motion in other dimensions, often with complex multi-axis patterns. In magnitude distribution, sleeping infants often remained more still than adults, but when movement did occur it was more extreme and abrupt. Two groups of adults presented with different stimulation showed similar shapes of motion.ConclusionThe spatial modes and magnitude distribution of motion differed substantially between groups, and must be considered carefully as a confound in comparisons of structure or function. The abruptness and magnitude of movement suggests that for infants relative to adults post-processing strategies such as de-noising are likely to be more effective than prospective motion correction.Key notesQuantified the spatial and temporal distribution of motion during MRI in 211 adults and neonatesThe different spatial modes in adults and infants were visualized and statistically contrastedThe magnitude of motion had “heavier tails” in infants, with more still periods, and more large movements, than adults.
Simulation-based steady-state aero-thermal model for small-scale turboprop engine
Authors: Yazar Isil , Yasa Tolga , Kiyak Emre 
Published: March 2017

Purpose
An aircraft engine control system consists of a large scale of control parameters and variables because of the complex structure of aero-engine. Monitoring and adjusting control variables and parameters such as detecting, isolating and reconfiguring the system faults/failures depend on the controller design. Developing a robust controller is based on an accurate mathematical model.

Design/methodology/approach
In this study, a small-scale turboprop engine is modeled. Simulation is carried out on MATLAB/Simulink for design and off-design operating conditions. Both steady-state and transient conditions (from idle to maximum thrust levels) are tested. The performance parameters of compressor and turbine components are predicted via trained Neuro-Fuzzy model (ANFIS) based on component maps. Temperature, rotational speed, mass flow, pressure and other parameters are generated by using thermodynamic formulas and conservation laws. Considering these calculated values, error calculations are made and compared with the cycle data of the engine at the related simulation conditions.

Findings
Simulation results show that the designed engine model’s simulation values have acceptable accuracy for both design and off-design conditions from idle to maximum power operating envelope considering cycle data. The designed engine model can be adapted to other types of gas turbine engines.

Originality/value
Different from other literature studies, in this work, a small-scale turboprop engine is modeled. Furthermore, for performance prediction of compressor and turbine components, ANFIS structure is applied.
Aerodynamic wing shape optimization based on the computational design framework CEASIOM
Authors: Zhang Mengmeng , Rizzi Arthur 
Published: March 2017

Purpose
A collaborative design environment is needed for multidisciplinary design optimization (MDO) process, based on all the modules those for different design/analysis disciplines, and a systematic coupling should be made to carry out aerodynamic shape optimization (ASO), which is an important part of MDO.

Design/methodology/approach
Computerized environment for aircraft synthesis and integrated optimization methods (CEASIOM)-ASO is developed based on loosely coupling all the existing modules of CEASIOM by MATLAB scripts. The optimization problem is broken down into small sub-problems, which is called “sequential design approach”, allowing the engineer in the loop.

Findings
CEASIOM-ASO shows excellent design abilities on the test case of designing a blended wing body flying in transonic speed, with around 45 per cent drag reduction and all the constraints fulfilled.

Practical implications
Authors built a complete and systematic technique for aerodynamic wing shape optimization based on the existing computational design framework CEASIOM, from geometry parametrization, meshing to optimization.

Originality/value
CEASIOM-ASO provides an optimization technique with loosely coupled modules in CEASIOM design framework, allowing engineer in the loop to follow the “sequential approach” of the design, which is less “myopic” than sticking to gradient-based optimization for the whole process. Meanwhile, it is easily to be parallelized.
A nonlinear control approach for a hypersonic vehicle
Authors: Tao Chao , Wan Jing , Ai Jianliang 
Published: March 2017

Purpose
The purpose of the paper is to design a robust control system for a generic hypersonic vehicle which includes dynamic nonlinear, open loop unstable and parametric uncertainties.

Design/methodology/approach
For a complex longitudinal model of a generic hypersonic vehicle which includes dynamic nonlinear, open loop unstable and parametric uncertainties, a nonlinear dynamic inverse (NDI) approach combined with proportional differential (PD) control is used to design a strong robust control system to deal with the sensitivity to changes of atmosphere condition. In this way, a simple genetic algorithm is used to search a group of parameters of the control system to satisfy the specific performance indices. Then parametric uncertainties are considered to verify the robustness of the control system.

Findings
The PD hypersonic vehicle control system using NDI approach can satisfy the specific flight performance. And it has strong robustness under the parametric uncertainties.

Originality/value
The paper fulfills a complete process of the nonlinear control system design for a generic hypersonic vehicle. And, the simulation results show the efficiency and robustness of the control system.
Geographical perspective of modeling primary healthcare accessibility
Authors: Surage Justice , Tawiah Richard , Twumasi-Mensah Timothy 
Published: March 2017

Purpose
The purpose of this paper is to measure the spatial accessibility of primary healthcare facility in Ghanaian rural areas, by determining the barriers to healthcare accessibilities in the Amansie Central District.

Design/methodology/approach
Both network and proximity analyses were performed on the digitized data such as road networks, settlements, population, district boundary, natural resources (rivers, streams and forest) and site location (health facilities). To quantify the population who have access to healthcare the authors used the Ghana Health Service access criteria that health facility should be accessible to an estimated population within 8 km radius from the facility.

Findings
The overall mean distance to the nearest health facility in the district was 8.9 km. Fiankoma sub-district recorded the highest mean distance whereas Tweapease sub-district recorded the least. In general, 31.2 percent of the district population has no access to healthcare facility. Transportation was identified to be one of the major hindrances to healthcare accessibility and this was as a result of poor road network in the district.

Research limitations/implications
The study was restricted to the Amansie Central District of Ghana. This limits the extent of generalization of results.

Originality/value
The study proposed additional sites for siting new health facilities base on criteria such as population, distance, centrality and existing infrastructural development. This will consequently improve healthcare accessibility and utilization by increasing total coverage closer to 100 percent.
Implicit bias in US medicine: complex findings and incomplete conclusions
Authors: Chisolm-Straker Makini , Straker Howard 
Published: March 2017

Purpose
Implicit bias is the application of an unconscious attitude or belief; in the clinical setting, a provider’s perception of a patient, based upon perceived race or ethnicity, is hypothesized to affect clinical decisions, provider-patient interactions and patient health. The purpose of this paper is to provide a brief synopsis of and critique the relevant works over the past 15 years while highlighting the strengths of this body of literature.

Design/methodology/approach
A MEDLINE search, from 2000 to 2015, using the terms “implicit bias,” “unconscious bias” and “aversive racism” was performed. US-based studies investigating the effect of racial or ethnic implicit bias on the clinical encounter or patient outcomes were assessed. In total, 15 articles were eligible for review.

Findings
Despite well-reasoned hypotheses that racial/ethnic bias negatively affects patient care, this review found mixed results. Largely, studies showed that US-providers hold an anti-black implicit bias negatively affecting patient-provider communication and patient satisfaction. But studies have not shown that this bias consistently negatively affects diagnosis and treatment regimens of black patients in comparison to white patients. There is a significant dearth of implicit bias literature addressing the care of other patient groups of color.

Originality/value
This review of the recent literature challenges the black-white dichotomy of most implicit bias research in the USA and highlights the lack of patient-oriented outcome research in this field. Furthermore, it demonstrates that regardless of the effect of implicit bias on patient outcomes, focus on eliminating implicit bias is insufficient to improve the health of people of color.
The impact of an unconditional parental benefit on employment of mothers
Authors: Kurowska Anna 
Published: March 2017

PurposeThe purpose of this paper is to solve the puzzle of the disproportionately lower employment rate of mothers of toddlers with relation to the employment rate of mothers of preschool and school-age children in Estonia.Design/methodology/approachThe research is based on the Most Similar System Design and compares Estonia with Lithuania. The applied methods include inferential statistics and microsimulation techniques, employing the OECD Benefits and Wages Calculator, the OECD Family Support Calculator and EUROMOD – the European tax-benefit microsimulation model.FindingsThe comparison revealed that the overwhelming majority of the crucial aspects of socio-cultural, economic and institutional conditions were more favourable for maternal employment in Estonia than in Lithuania. This explains the higher maternal employment rates both for mothers of pre-schoolers and school-age children in Estonia. However, one particular element of the institutional context targeted to the mothers of toddlers – the unconditional parental benefit – had an entirely opposite character. This particular feature of the parental leave scheme was the only factor that could explain why the employment rate of mothers of toddlers is disproportionately lower than the employment rate of mothers of older children in Estonia and much lower than the employment of mothers of toddlers in Lithuania.Originality/valueThis study complements previous research by providing evidence on the relative importance of universal parental benefit schemes in the context of other country-specific conditions for maternal employment, including the availability of institutional childcare. Furthermore, the results presented show that childcare regime typologies, at least those that characterise Eastern European countries, should be more sensitive to children’s age.