bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reconstructing long‐term human impacts on plant communities: an ecological approach based on lake sediment DNA
Authors: Pansu Johan , Giguet‐Covex Charline , Ficetola Gentile Francesco , Gielly Ludovic , Boyer Frédéric , Zinger Lucie , Arnaud Fabien , Poulenard Jérôme , Taberlet Pierre , Choler Philippe 
Published: March 2015

AbstractPaleoenvironmental studies are essential to understand biodiversity changes over long timescales and to assess the relative importance of anthropogenic and environmental factors. Sedimentary ancient DNA (sedaDNA) is an emerging tool in the field of paleoecology and has proven to be a complementary approach to the use of pollen and macroremains for investigating past community changes. SedaDNA‐based reconstructions of ancient environments often rely on indicator taxa or expert knowledge, but quantitative ecological analyses might provide more objective information. Here, we analysed sedaDNA to investigate plant community trajectories in the catchment of a high‐elevation lake in the Alps over the last 6400 years. We combined data on past and present plant species assemblages along with sedimentological and geochemical records to assess the relative impact of human activities through pastoralism, and abiotic factors (temperature and soil evolution). Over the last 6400 years, we identified significant variation in plant communities, mostly related to soil evolution and pastoral activities. An abrupt vegetational change corresponding to the establishment of an agropastoral landscape was detected during the Late Holocene, approximately 4500 years ago, with the replacement of mountain forests and tall‐herb communities by heathlands and grazed lands. Our results highlight the importance of anthropogenic activities in mountain areas for the long‐term evolution of local plant assemblages. SedaDNA data, associated with other paleoenvironmental proxies and present plant assemblages, appear to be a relevant tool for reconstruction of plant cover history. Their integration, in conjunction with classical tools, offers interesting perspectives for a better understanding of long‐term ecosystem dynamics under the influence of human‐induced and environmental drivers.
Differentially expressed genes match bill morphology and plumage despite largely undifferentiated genomes in a Holarctic songbird
Authors: Mason Nicholas A. , Taylor Scott A. 
Published: March 2015

AbstractUnderstanding the patterns and processes that contribute to phenotypic diversity and speciation is a central goal of evolutionary biology. Recently, high‐throughput sequencing has provided unprecedented phylogenetic resolution in many lineages that have experienced rapid diversification. The Holarctic redpoll finches (Genus: Acanthis) provide an intriguing example of a recent, phenotypically diverse lineage; traditional sequencing and genotyping methods have failed to detect any genetic differences between currently recognized species, despite marked variation in plumage and morphology within the genus. We examined variation among 20 712 anonymous single nucleotide polymorphisms (SNPs) distributed throughout the redpoll genome in combination with 215 825 SNPs within the redpoll transcriptome, gene expression data and ecological niche modelling to evaluate genetic and ecological differentiation among currently recognized species. Expanding upon previous findings, we present evidence of (i) largely undifferentiated genomes among currently recognized species; (ii) substantial niche overlap across the North American Acanthis range; and (iii) a strong relationship between polygenic patterns of gene expression and continuous phenotypic variation within a sample of redpolls from North America. The patterns we report may be caused by high levels of ongoing gene flow between polymorphic populations, incomplete lineage sorting accompanying very recent or ongoing divergence, variation in cis‐regulatory elements, or phenotypic plasticity, but do not support a scenario of prolonged isolation and subsequent secondary contact. Together, these findings highlight ongoing theoretical and computational challenges presented by recent, rapid bouts of phenotypic diversification and provide new insight into the evolutionary dynamics of an intriguing, understudied non‐model system.
Navigating the labyrinth: a guide to sequence‐based, community ecology of arbuscular mycorrhizal fungi
Authors: Hart Miranda M. , Aleklett Kristin , Chagnon Pierre‐Luc , Egan Cameron , Ghignone Stefano , Helgason Thorunn , Lekberg Ylva , Öpik Maarja , Pickles Brian J. , Waller Lauren 
Published: March 2015

Summary

Data generated from next generation sequencing (NGS) will soon comprise the majority of information about arbuscular mycorrhizal fungal (AMF) communities. Although these approaches give deeper insight, analysing NGS data involves decisions that can significantly affect results and conclusions. This is particularly true for AMF community studies, because much remains to be known about their basic biology and genetics.

During a workshop in 2013, representatives from seven research groups using NGS for AMF community ecology gathered to discuss common challenges and directions for future research. Our goal was to improve the quality and accessibility of NGS data for the AMF research community. Discussions spanned sampling design, sample preservation, sequencing, bioinformatics and data archiving.

With concrete examples we demonstrated how different approaches can significantly alter analysis outcomes. Failure to consider the consequences of these decisions may compound bias introduced at each step along the workflow.

The products of these discussions have been summarized in this paper in order to serve as a guide for any researcher undertaking NGS sequencing of AMF communities.
Dog and cat exposure and respective pet allergy in early childhood
Authors: Pyrhönen Kaisa , Näyhä Simo , Läärä Esa 
Published: March 2015

AbstractBackgroundThe association of dog and cat exposure in early childhood with the incidence of respective allergies has remained controversial. The aim of the study was to obtain population‐based evidence on the association of early exposure to dog or cat, or both, with dog and cat allergies.MethodsThe study population was identified from the nationwide population register comprising all children aged 1–4 yr (N = 4779) born between 2001 and 2005 and living in the province of South Karelia, Finland. Cross‐sectional questionnaire data on pet exposure in infancy and physician‐diagnosed pet allergies were obtained from 3024 participants and merged with longitudinally accumulated data on sIgE and skin prick tests indicating allergic sensitization abstracted from all patient records in the area.ResultsThe adjusted relative incidence of positive test results (with 95% confidence intervals) was 2.69 (1.45‐5.02) for dog and 5.03 (2.47‐10.2) for cat allergens among children exposed to a respective pet alone compared with children without such exposure. The corresponding adjusted prevalence odds ratios for diagnosed dog and cat allergies were 1.75 (0.77‐3.79) and 5.13 (2.30‐11.4), respectively. The association between pet exposure and the incidence of positive test results was independent of parents' allergies.ConclusionsEarly exposure to dog and cat at home is associated with a higher incidence of respective pet allergy during the first four years of life. Further evidence from population‐based studies with longer follow‐up is required to justify any recommendation concerning early pet contacts with a view to preventing pet allergies later in life.
Key molecular processes of the diapause to post‐diapause quiescence transition in the alfalfa leafcutting bee Megachile rotundata identified by comparative transcriptome analysis
Authors: Yocum George D. , Rinehart Joseph P. , Horvath David P. , Kemp William P. , Bosch Jordi , Alroobi Rami , Salem Saeed 
Published: March 2015

AbstractInsect diapause (dormancy) synchronizes an insect's life cycle to seasonal changes in the abiotic and biotic resources required for development and reproduction. Transcription analysis of diapause to post‐diapause quiescent transition in the alfalfa leafcutting bee Megachile rotundata Fabricius identifies 643 post‐diapause up‐regulated gene transcripts and 242 post‐diapause down‐regulated transcripts. The log2 fold change in gene expression levels ranges from −5 to 7. Transcripts from several pivotal diapause‐related processes, including chromatin remodelling, cellular signalling pathways, microRNA processing, anaerobic glycolysis, cell cycle arrest and neuroendocrine control, are identified as being differentially expressed during the diapause to post‐diapause transition. In conjunction with studies from other insect species, the data indicate that there are several common mechanisms of diapause control and maintenance.
Comparing the driving behaviours of individuals with frontotemporal lobar degeneration and those with Alzheimer's disease
Authors: Fujito Ryoko , Kamimura Naoto , Ikeda Manabu , Koyama Asuka , Shimodera Shinji , Morinobu Shigeru , Inoue Shimpei 
Published: March 2015

AbstractBackgroundAssessing driving aptitude in dementia patients is critically important for both patient and public safety. However, there have been only a few reports on the driving behaviours and accident risk of patients with dementia, especially frontotemporal lobar degeneration (FTLD). Therefore, we compared the characteristics of driving behaviours in patients with FTLD and those with Alzheimer's disease (AD).MethodsThe subjects were 28 FTLD and 67 AD patients who visited the Department of Psychiatry, Kochi Medical School Hospital. We conducted semi‐structured interviews with their families and caregivers about traffic accident history and changes in patient driving behaviours after dementia onset and then compared the findings between the two groups.ResultsOverall changes in driving behaviours were reported in 89% (25/28) and 76% (51/67) of the FTLD and AD patients, respectively (P = 0.17). In the FTLD group, difficulty in judging inter‐vehicle distances, ignoring road signs and traffic signals, and distraction were reported in 50% (14/28), 61% (17/28), and 50% (14/28) of patients, respectively, and 75% (21/28) patients had caused a traffic accident after dementia onset. The risk of causing an accident was higher in the FTLD group than in the AD group (odds ratio = 10.4, 95% confidence interval = 3.7–29.1). In addition, the mean duration between dementia onset and a traffic accident was 1.35 years in the FTLD group compared with 3.0 years in the AD group (P < 0.01).ConclusionsPatients with FTLD were more likely to show dangerous driving behaviours than those with AD, and the risk of causing a traffic accident may be higher in patients with FTLD from an early disease stage.
Forecasting Distributions of Inflation Rates: the Functional Auto-Regressive Approach
Authors: Chaudhuri Kausik , Kim Minjoo , Shin Yongcheol 
Published: March 2015

SummaryIn line with recent developments in the statistical analysis of functional data, we develop the semiparametric functional auto-regressive modelling approach to the density forecasting analysis of national rates of inflation by using sectoral inflation rates in the UK over the period January 1997–September 2013. The pseudo-out-of-sample forecasting evaluation and test results provide an overall support to superior performance of our proposed models over the aggregate auto-regressive models and their statistical validity. The fan chart analysis and the probability event forecasting exercise provide further support for our approach in a qualitative sense, revealing that the modified functional auto-regressive models can provide a complementary tool for generating the density forecast of inflation, and for analysing the performance of a central bank in achieving announced inflation targets. As inflation targeting monetary policies are usually set with recourse to the medium-term forecasts, our proposed work may provide policy makers with an invaluably enriched information set.
A warning threshold for monitoring tuberculosis surveillance data: an alternative to hidden Markov model
Authors: Rafei Ali , Pasha Einollah , Jamshidi Orak Roohangiz 
Published: March 2015

AbstractObjectivesAlthough hidden Markov model (HMM) is known as a powerful tool for the detection of epidemics based on the historical data, the frequent use of such a model poses some limitation especially when decision‐making is required for new observations. This study was aimed to address a warning threshold for monitoring the weekly incidences of tuberculosis as an alternative toHMM.MethodsWe extracted the weekly counts of newly diagnosed patients with sputum smear‐positive pulmonaryTBfrom 2005 to 2011 nationwide. To detect unexpected incidences of the disease, two approaches: Serfling andHMM, were applied in presence/absence of linear, seasonal and autoregressive components. Models were subsequently evaluated in terms of goodness of fit, and their results were compared in detection of the disease phases. Then, multiple hypothetical thresholds were constructed based on the estimate of models and the optimal one was revealed throughROCcurve analysis.ResultsFindings from both adjusted R‐square () and Bayesian information criterion (BIC) presented a higher goodness of fit for periodic autoregressiveHMM(BIC = −1323.6;) than other models. According toROCanalysis, better values for both Youden's index and area under curve (0. 96 and 0. 98 respectively) were obtained by the threshold based on the estimate of periodic autoregressive model.ConclusionsAs the optimal threshold presented in this study is simple in concept and has no limitation in practice, especially for monitoring new observations, we would recommend such a threshold to be used for monitoring ofTBincidence data in the surveillance system.
Hot Streaks and Phantom Cooling in a Turbine Rotor Passage: Part 2 — Combined Effects and Analytical Modelling
Authors: Rdback Richard J. , Dring Robert P. 
Published: March 2015

This paper presents experimental documentation and analytical correlations demonstrating the effects of hot streak accumulation and phantom cooling on turbine rotor airfoil surface temperature. In particular, results are shown which quantify the impact of (1) a non-uniform temperature profile at the entrance of a turbine due to combustor-generated hot and cold streaks, and (2) cooling air discharged from the trailing edge of the upstream stator.
In Part 1 of this paper, experimental results are shown for a range of controlling variables to identify where streak accumulation and phantom cooling were most likely to be strongest. These variables include streak-to-free stream density ratio, streak injection location and coolant-to-free stream density and velocity ratios.
In Part 2 of this paper, experimental results are shown for the combined effects of hot streak and stator coolant on the adiabatic recovery temperature on the rotor. An analytical model is also developed to correlate the experimental results documented in Parts 1 and 2 of the paper.
Development of Gas Turbine Steam-Injection Water Recovery (SIWR) System
Authors: Nguyen H. B. , Otter A. den 
Published: March 2015

This paper describes and discusses a “closed loop” steam injection water recovery (SIWR) cycle that was developed for steam injected gas turbine applications. This process is needed to support gas turbine steam injection especially in areas where water can not be wasted and complex water treatment is discouraged.
The development of the SIWR was initiated by NOVA in an effort to reduce environmental impact of operating gas turbines and to find suitable solutions for its expanding gas transmission system to meet future air emission restrictions. While turbine steam injection provides many benefits, it has not been considered for remote, less supported environments such as gas transmission applications due to its high water consumption. The SIWR process can alleviate this problem regardless of the amount of injection required.
The paper also covers conceptual designs of a prototype SIWR system on a small gas turbine unit. However, because of relatively high costs, it is generally believed that the system is more attractive to larger size turbines and especially when it is used in conjunction with co-generation or combined cycle applications.
Combined Closed Cycle (C3) Systems for Underwater Power Generation
Authors: Massardd Aristide , Arnulfi Gian Marid 
Published: March 2015

In this paper three Closed Combined Cycle (C3) systems for underwater power generation are analyzed. In the first, the waste heat rejected by a Closed Brayton Cycle (CBC) is utilized to heat the working fluid of a bottoming Rankine Cycle; in the second, the heat of a primary energy loop fluid is used to heat both CBC and Rankine cycle working fluids; the third solution involves a Metal Rankine Cycle (MRC) combined with an Organic Rankine Cycle (ORC).
The significant benefits of the Closed Combined Cycle concepts, compared to the simple CBC system, such as efficiency increase and specific mass reduction, are presented and discussed. A comparison between the three C3 power plants is presented taking into account the technological maturity of all the plant components.
Comparison of Spectrometric Techniques for the Analysis of Liquid Gas Turbine Fuels
Authors: Lukas Malte 
Published: March 2015

High temperature corrosion and fuel system fouling are major concerns that confront gas turbine users. Fuel treatment is a critical requirement for gas turbine operators burning alternative fuels and even so called “clean fuels”. Spectrometric fuel analysis is used to determine the amount of treatment required as well as the efficiency of the treatment. In most cases, analytical techniques developed by chemists for use in laboratory environments have been adopted for field use.
This paper describes the various spectrometric techniques available to the gas turbine user to analyze fuels for contaminants such as sodium, potassium, vanadium, lead, calcium, silicon etc. and additives such as magnesium compounds. Atomic absorption spectroscopy (AAS) and various atomic emission spectroscopy (AES) techniques will be discussed and compared.
Flutter of Grouped Turbine Blades
Authors: Whitehead D. S. , Evans D. H. 
Published: March 2015

An analysis is presented to predict flutter in a wheel of turbine blades which are connected together into a number of identical groups. The natural frequencies and mode shapes of a group are assumed to be known. The unsteady aerodynamic coefficients for free-standing blades are assumed to be known from an unsteady aerodynamic program, and FINSUP is used here. The work fed into the vibration by the aerodynamic forces is then calculated.
This is illustrated by two examples of low pressure steam turbine blade rows GR-1 and GR-2. On GR-1 the three modes considered are all found to be stable, but on GR-2 the lowest frequency mode shows some instability. Tying the blades together in groups is found to be stabilizing.
Blade response, measured by a Blade Vibration Monitor at two different installations, is shown for a range of operating conditions. The measured responses indicate the GR-1 blade is stable whereas the GR-2 blade shows, at the lowest frequency, high response that is dependent on turbine operating conditions.
Navier-Stokes Computation on a Pivoting Doors Thrust Reverser and Comparison With Tests
Authors: Schreiber L. , Legras M. 
Published: March 2015

An engine thrust reverser must meet different aerodynamic requirements to take into account the engine and airplane integration.
These requirements are:
- Control of the exit area in order to assess a convenient engine compatibility during the reverser operation.
- Generation of reverse thrust meeting the level specified by the airframe in order to slowdown the airplane.
- Mimization of the reversed flow field interaction with the airplane structure such as wing and shutters.
- Avoid the flow reingestion by the engine fan.
In order to reduce the tests number, to decrease the development delay and to improve aerodynamic performance, SNECMA group (SNECMA and HISPANO-SUIZA) has decided to develop a CFD method adapted to pivoting doors thrust reverser aerodynamic calculation.
This method uses a Navier-Stokes 3D solver (PHOENICS code) well adapted to complex geometry and complex flow field. The mesh is generated with an analytical method and only one domain is used. The computation has been completed assuming laminar viscosity.
The numerical data got with this method have been compared to static test realized on a model similar to actual CFM56-5C four doors reverser. The comparison parameters are the static pressure on the doors, the flow rate and the axial reverse thrust.
Development of an Indirect Coal-Fired High Performance Power Generation System
Authors: Bannister R. L. , Amos D. J. , Scalzo A. J. , Datsko S. C. 
Published: March 2015

The U.S. Department of Energy/Pittsburgh Energy Technology Center (DOE/PETC) initiated the Engineering Development of Coal-Fired High Performance Power Generation Systems Program to develop an advanced technology for coal-fired electric plants that can boost efficiency and reduce emissions. This three phase program includes concept definition and preliminary R&D, engineering development and testing which will culminate in the operation of a prototype plant by the year 2005.
This paper presents an overview of the work proposed by a Westinghouse-led R&D team which includes Babcock and Wilcox, Black and Veatch, FluiDyne Engineering, and Allegheny Power Systems to design and evaluate the technical and economic feasibility and relevant R&D required for one or more advanced power generation concepts developed during Phase I. Allison Division of General Motors, ERC and SeiTec are also supporting the Westinghouse team in the initial phase of this program.
Key objectives include evaluation of plant cycle designs capable of at least 47-percent efficiency, substantial reductions in airborne emissions below current new source performance standards (NSPS) for coal-fired boilers, and solid waste generation of only benign material.
The proposed design approach includes an indirect coal-fired combustion turbine combined cycle system which incorporates a high-temperature advanced furnace with ceramic heat exchanger components. The indirect-fired system circumvents some of the technical challenges of a direct coal-fired system (Bannister et al., 1990). Proposed alternative designs have plant efficiencies that range up to 53 percent.