bluuebunny/crossref_metadata_2025 huggingface dataset:
Reviews and syntheses: Revisiting the boron systematics of aragonite and their application to coral calcification
Authors: DeCarlo Thomas M. , Holcomb Michael , McCulloch Malcolm T.
Published: February 2018

Abstract. The isotopic and elemental systematics of boron in aragonitic coral skeletons have recently been developed as a proxy for the carbonate chemistry of the coral extracellular calcifying fluid. With knowledge of the boron isotopic fractionation in seawater and the B / Ca partition coefficient (KD) between aragonite and seawater, measurements of coral skeleton δ11B and B / Ca can potentially constrain the full carbonate system. Two sets of abiogenic aragonite precipitation experiments designed to quantify KD have recently made possible the application of this proxy system. However, while different KD formulations have been proposed, there has not yet been a comprehensive analysis that considers both experimental datasets and explores the implications for interpreting coral skeletons. Here, we evaluate four potential KD formulations: three previously presented in the literature and one newly developed. We assess how well each formulation reconstructs the known fluid carbonate chemistry from the abiogenic experiments, and we evaluate the implications for deriving the carbonate chemistry of coral calcifying fluid. Three of the KD formulations performed similarly when applied to abiogenic aragonites precipitated from seawater and to coral skeletons. Critically, we find that some uncertainty remains in understanding the mechanism of boron elemental partitioning between aragonite and seawater, and addressing this question should be a target of additional abiogenic precipitation experiments. Despite this, boron systematics can already be applied to quantify the coral calcifying fluid carbonate system, although uncertainties associated with the proxy system should be carefully considered for each application. Finally, we present a user-friendly computer code that calculates coral calcifying fluid carbonate chemistry, including propagation of uncertainties, given inputs of boron systematics measured in coral skeleton.
An improved and homogeneous altimeter sea level record from the ESA Climate Change Initiative
Authors: Legeais Jean-François , Ablain Michaël , Zawadzki Lionel , Zuo Hao , Johannessen Johnny A. , Scharffenberg Martin G. , Fenoglio-Marc Luciana , Fernandes M. Joana , Andersen Ole Baltazar , Rudenko Sergei , Cipollini Paolo , Quartly Graham D. , Passaro Marcello , Cazenave Anny , Benveniste Jérôme
Published: February 2018

Abstract. Sea level is a very sensitive index of climate change since it integrates the impacts of ocean warming and ice mass loss from glaciers and the ice sheets. Sea level has been listed as an essential climate variable (ECV) by the Global Climate Observing System (GCOS). During the past 25 years, the sea level ECV has been measured from space by different altimetry missions that have provided global and regional observations of sea level variations. As part of the Climate Change Initiative (CCI) program of the European Space Agency (ESA) (established in 2010), the Sea Level project (SL_cci) aimed to provide an accurate and homogeneous long-term satellite-based sea level record. At the end of the first phase of the project (2010–2013), an initial version (v1.1) of the sea level ECV was made available to users (Ablain et al., 2015). During the second phase of the project (2014–2017), improved altimeter standards were selected to produce new sea level products (called SL_cci v2.0) based on nine altimeter missions for the period 1993–2015 (https://doi.org/10.5270/esa-sea_level_cci-1993_2015-v_2.0-201612; Legeais and the ESA SL_cci team, 2016c). Corresponding orbit solutions, geophysical corrections and altimeter standards used in this v2.0 dataset are described in detail in Quartly et al. (2017). The present paper focuses on the description of the SL_cci v2.0 ECV and associated uncertainty and discusses how it has been validated. Various approaches have been used for the quality assessment such as internal validation, comparisons with sea level records from other groups and with in situ measurements, sea level budget closure analyses and comparisons with model outputs. Compared with the previous version of the sea level ECV, we show that use of improved geophysical corrections, careful bias reduction between missions and inclusion of new altimeter missions lead to improved sea level products with reduced uncertainties on different spatial and temporal scales. However, there is still room for improvement since the uncertainties remain larger than the GCOS requirements (GCOS, 2011). Perspectives on subsequent evolution are also discussed.
Representation of dissolved organic carbon in the JULES land surface model (vn4.4_JULES-DOCM)
Authors: Nakhavali Mahdi , Friedlingstein Pierre , Lauerwald Ronny , Tang Jing , Chadburn Sarah , Camino-Serrano Marta , Guenet Bertrand , Harper Anna , Walmsley David , Peichl Matthias , Gielen Bert
Published: February 2018

Abstract. Current global models of the carbon (C) cycle consider only vertical gas exchanges between terrestrial or oceanic reservoirs and the atmosphere, thus not considering the lateral transport of carbon from the continents to the oceans. Therefore, those models implicitly consider all of the C which is not respired to the atmosphere to be stored on land and hence overestimate the land C sink capability. A model that represents the whole continuum from atmosphere to land and into the ocean would provide a better understanding of the Earth's C cycle and hence more reliable historical or future projections. A first and critical step in that direction is to include processes representing the production and export of dissolved organic carbon in soils. Here we present an original representation of dissolved organic C (DOC) processes in the Joint UK Land Environment Simulator (JULES-DOCM) that integrates a representation of DOC production in terrestrial ecosystems based on the incomplete decomposition of organic matter, DOC decomposition within the soil column, and DOC export to the river network via leaching. The model performance is evaluated in five specific sites for which observations of soil DOC concentration are available. Results show that the model is able to reproduce the DOC concentration and controlling processes, including leaching to the riverine system, which is fundamental for integrating terrestrial and aquatic ecosystems. Future work should include the fate of exported DOC in the river system as well as DIC and POC export from soil.
Potential evaporation at eddy-covariance sites across the globe
Authors: Maes Wouter H. , Gentine Pierre , Verhoest Niko E. C. , Miralles Diego G.
Published: February 2018

Abstract. Potential evaporation (Ep) is a crucial variable for hydrological forecast and in drought monitoring systems. However, multiple interpretations of Ep exist, and these reflect a diverse range of methods to calculate Ep. As such, a comparison of the performance of these methods against field observations in different global ecosystems is badly needed. In this study, we used eddy-covariance measurements from 107 sites of the FLUXNET2015 database, covering 11 different biomes, to parameterize and compare the main Ep methods and uncover their relative performance. For each site, we extracted the days for which ecosystems are unstressed based on both an energy balance approach and on a soil water content approach. The evaporation measurements during these days were used as reference to validate the different methods to estimate Ep. Our results indicate that a simple radiation-driven method calibrated per biome consistently performed best, with a mean correlation of 0.93, an unbiased RMSE of 0.56 mm day−1, and a bias of −0.02 mm day−1 against in situ measurements of unstressed evaporation. A Priestley and Taylor method, calibrated per biome, performed just slightly worse, yet substantially and consistently better than more complex Penman, Penman-Monteith-based or temperature-based approaches. We show that the poor performance of Penman-Monteith based approaches relates largely to the fact that the unstressed stomatal conductance was assumed constant. Further analysis showed that the biome-specific parameters required for the simple radiation-driven methods are relatively constant per biome. This makes this simple radiation-driven method calibrated per biome a robust method that can be incorporated into models for improving our understanding of the impact of global warming on future global water use and demand, drought severity and ecosystem productivity.
Stratified Kelvin-Helmholtz turbulence of compressible shear flows
Authors: Maulik Romit , San Omer
Published: February 2018

Abstract. We study the scaling laws and structure functions of stratified shear flows by performing high-resolution numerical simulations of inviscid compressible turbulence induced by Kelvin-Helmholtz instability. An implicit large eddy simulation approach is adapted to solve our conservation laws for both two-dimensional (with a spatial resolution of 16,3842) and three-dimensional (with a spatial resolution of 5123) configurations utilizing different compressibility characteristics such as shocks. For three-dimensional turbulence, we find that both kinetic energy and density-weighted energy spectra follow the classical Kolmogorov k−5/3 inertial scaling. This phenomenon is observed due to the fact that the power density spectrum of three-dimensional turbulence yields the same k−5/3 scaling. However, we demonstrate that there is a significant difference between these two spectra in two-dimensional turbulence since the power density spectrum flattens to k−1/4. This flattening may be assumed to be a reason for the k−7/3 scaling observed in the two-dimensional density-weight kinetic every spectra for high compressibility as compared to the k−3 scaling traditionally assumed with incompressible flows. Further inquiries are made to validate the statistical behavior of the various configurations studied through the use of second and third order velocity structure functions where it is noticed that scaling behavior differs between the two- and three-dimensional cases wherein only the latter is seen to follow trends from K41 theory.
Parametric covariance dynamics for the nonlinear diffusive Burgers' equation
Authors: Pannekoucke Olivier , Bocquet Marc , Ménard Richard
Published: February 2018

Abstract. The parametric Kalman filter (PKF) is a computationally efficient alternative method to the ensemble Kalman filter (EnKF). The PKF relies on an approximation of the error covariance matrix by a covariance model with space-time evolving set of parameters. This study extends the PKF to nonlinear dynamics using the diffusive Burgers' equation as an application, focusing on the forecast step of the assimilation cycle. The covariance model considered is based on the diffusion equation, with the diffusion tensor and the error variance as evolving parameter. An analytical derivation of the parameter dynamics highlights a closure issue. Therefore, a closure model is proposed based on the so-called kurtosis of the local correlation functions. Numerical experiments compare the PKF forecast with the statistics obtained from an large ensemble of nonlinear forecasts. These experiments strengthen the closure model and demonstrate the ability of the PKF to reproduce the tangent-linear covariance dynamics, at a low numerical cost.
Numerical study of hydrodynamic and salinity transport process in Pink Beach wetlands of Liao River Estuary, China
Authors: Qiao Huiting , Zhang Mingliang , Jiang Hengzhi , Xu Tianping , Zhang Hongxing
Published: February 2018

Abstract. The interaction study of vegetation with the flow environment is essential for the determination of the bank protection, morphological characteristics and ecological conditions for the wetlands. This paper uses MIKE 21 hydrodynamic and salinity model to simulate the hydrodynamic characteristics and salinity transport process in Pink Beach wetlands of Liao River estuary. The effect of wetland plant on tidal flow in areas of wetland waters is represented by a varying Manning's coefficient in the bottom friction term. Acquisition of vegetation distribution is based on Landsat TM satellites through remote sensing techniques. The detailed comparisons between field observation and simulated result of water depth, salinity and tidal currents at neap tide and spring tide are presented in vegetated domain of Pink Beach. Satisfactory results are obtained in simulating both flow characteristic and salinity concentration with or without vegetation. Several stations from upstream to downstream in the Pink Beach are selected to estimate the longitudinal variation of salinity under different river runoffs and the results show that the salinity concentration decreases with an increase of river runoff. This study can help to increase understanding of the favorable salinity conditions for the special vegetation growth in the Pink Beach wetlands of Liao River estuary. The results provide crucial guidance for related interaction studies among vegetation, flow and salinity in other wetland waters.
Physical Modulation to the Biological Productivity in the
Summer Vietnam Upwelling System
Authors: Lu Wenfang , Liao Enhui , Yan Xiao-Hai , Oey Lie-Yauw , Zhuang Wei , Jiang Yuwu
Published: February 2018

Abstract. Biological productivity in the summer Vietnam boundary upwelling system in the western South China Sea, as in many coastal upwelling systems, is strongly modulated by wind. However, the role of ocean circulation and mesoscale eddies has not been elucidated. Here we show a close spatio-temporal covariability between primary production and kinetic energy. High productivity is associated with high kinetic energy, which accounts for ~ 15 % of the production variability. Results from a physical-biological coupled model reveal that the elevated kinetic energy and intensified circulation can be explained by the separation of the upwelling current system. The separated current forms an eastward jet into the interior South China Sea, and the associated southern gyre traps nutrient and favors productivity. When separation is absent, the model shows weakened circulation and eddy activity, with ~ 21 % less nitrate inventory and ~ 16 % weaker primary productivity.
The characteristics of gravelly soil physical properties and
their effects on permafrost dynamics: A case study on the
central Qinghai-Tibetan Plateau
Authors: Yi Shuhua , He Yujie , Guo Xinlei , Chen Jianjun , Wu Qingbai , Qin Yu , Ding Yongjian
Published: February 2018

Abstract. Soils on the Qinghai-Tibetan Plateau (QTP) have distinct physical properties from agricultural soils due to weak weathering and strong erosion. These properties might affect permafrost dynamics. However, few studies have investigated both quantitatively. In this study, we selected a permafrost site on the central region of the QTP and excavated soil samples from 20 cm to 200 cm. We measured soil porosity, thermal conductivity, saturated hydraulic conductivity and matric potential in the laboratory. Finally, we ran a simulation model replacing default sand or silty clay parameters with different combinations of these measured parameters. Results showed that gravel content (diameter > 2 mm) was ~ 55 % on average in soil profile; soil porosity was less than 0.3; saturated hydraulic conductivity ranged from 0.004–0.03 mm s−1; saturated matric potential ranged from −14 to −604 mm. When default sand or silty clay parameters were substituted with these measured values, the model errors of soil temperature, soil liquid water content, active layer depth and permafrost lower boundary were reduced. The root mean squared errors of active layer depths simulated using measured parameters, and the default sand and silty clay parameters were about 0.28, 1.06, 1.83 m, respectively. Among these measured parameters, porosities, which were much smaller than soil textures used in land surface models, played a dominant role in reducing model errors. We also demonstrated that soil water dynamic processes should be considered, rather than using static properties under frozen and unfrozen soil states as in most permafrost models. We concluded that it is necessary to consider the distinct physical properties of soil and water dynamics on the QTP when simulating dynamics of permafrost in this region. It is important to develop methods for systematic measuring physical properties of gravelly soil and to develop a spatial dataset for porosity because of its importance in simulating permafrost dynamics in this region.
Experiencia de cuidadores familiares de mujeres con cáncer de mama: una revisión integradora
Authors: Moreno-González María Mercedes , Salazar-Maya Ángela María , Tejada-Tayabas Luz María
Published: February 2018

Objetivo: identificar la evidencia científica de enfermería relacionada con la experiencia de los cuidadores familiares de mujeres con cáncer de mama. Metodología: revisión integradora siguiendo los lineamientos de Ganong; búsqueda en bases de datos: EMBASE, OVID, PUBMED, SAGE journals, SCIELO, Google Academic, ISI Web of Science y SCOPUS, artículos publicados entre los años 2000 y 2016. Resultados: se incluyeron 18 artículos producto de investigaciones primarias de tipo cualitativo, cuyos referentes teórico-metodológicos fueron fenomenología y teoría fundamentada, las técnicas de recolección de datos fueron la entrevista semiestructurada y en profundidad. Se presentan y discuten como hallazgos las siguientes categorías: impacto del diagnóstico; lo que implica ser cuidador; efectos en el cuidador; estrategias de afrontamiento; cambios en los roles y las relaciones; apoyo social. Conclusiones: las características de los cuidadores son variables, es necesario conocer sobre la cultura y recursos propios de cada contexto. Los cuidadores requieren información clara y oportuna en relación su función y las habilidades a desarrollar, especialmente para otorgar apoyo emocional. Es necesaria la indagación de dichas experiencias en el contexto mexicano. Las relaciones padres e hijos en las familias de mujeres con cáncer de mama es un asunto poco estudiado, se requieren futuros estudios en este tema.
Toxicodynamic Effects of ‘Red Bull’ Energy Drink in A Randomised Controlled Study on Local Strains of Adult Rabbits
Authors: Oluwakemi Iyaniwura Taiwo, , Ayoade Abdulfatai Adesokan,
Published: February 2018

Increasing reports of anecdotal cases of acute adverse effects associated with the consumption of energy drink have been expressed by international bodies. This has necessitated the need to assess toxicological effects of Red Bull (RB) energy drink in this study. Eighteen adult rabbits were randomly divided into 3 groups of 6 rabbits (3 males and 3 females). Rabbits in groups 1, 2 and 3 (control) received daily oral doses of 23.1 ml RB, 11.5 ml RB and water respectively for 21 days. Venous samples were collected on days 1 (baseline), 14, 21 and 28, and animals were sacrificed on days 21 and 28. Biochemical assessment of liver and renal functions, and muscle activity were carried out by spectrophotometry, in addition to haematological and histological studies. Mortality of 11.1% was recorded, involving 2 female rabbits in group 1. For male rabbits in this group, significant increase (p<0.05) in total protein (TP) concentration and in activity of ALT and ALP occurred on days 14 and 21, with significant decrease in platelet counts. For female rabbits in group 2, significant increases in TP concentration and ALT activity were observed with significant decrease in albumin concentration and AST activity. Apart from slight increase in ALP activity of female rabbits, there were no significant differences in mean values of all rabbit parameters measured in the control group. Histology of rabbits in group 1 showed congestion and balloon degeneration of hepatocytes. This result showed that administration of RB to rabbits at doses lower than the manufacturer’s recommended equivalent daily human intake of 500 ml caused adverse effects. There is need for caution in consumption of this drink.
Environmental Health Risk Assessment Due to Exposure to Mercury in Artisanal and Small-Scale Gold Mining Area of Lebak District
Authors: Haq Arinil , Achmadi Umar Fahmi , Mallongi Anwar
Published: February 2018

In Indonesia it is estimated that there are around 250,000 artisanal and small-scale gold mining (ASGM) and generally use mercury for amalgamation process and then release it to the environment during gold refining process. This study aims to analyze mercury levels in the environment around ASGM in Lebaksitu Sub-District, Lebak District, Banten Province and identify hazardous exposure that may occur. The study design used was descriptive observational with Environmental Health Risk Assessment (EHRA) method. Environmental data taken include water and food samples. Social-demographic and dietary interviews were conducted. The study population was 72 residents of Lebaksitu Sub-District obtained through sample size formula and selected by simple random sampling. The study was conducted from April to May 2017. Exposure assessment is an important part of risk assessment. Exposure is a process that causes contact with environmental hazards such as risk agents, as a bridge connecting 'hazards' to 'risks'. Exposure analysis needs to consider all routes (inhalation, ingestion, absorption) and media (air, water, soil, food, drinking water) so that the total intake can be calculated. Exposure route analysis usually generate a critical pathway, the dominant exposure path. This pathway concerns which environmental media is the vehicle of risk agent and how it enters the body. Once a critical pathway is found, other possibility pathways contribution may be small and can be ignored. Mercury is a toxic pollutant that bioaccumulated and biomagnetic continuously through the food chain. The levels of mercury at the research sites on rice, fish, and vegetables have average of 0.027 mg/kg; 0.283 mg/kg; and 0.410 mg/kg. The calculation of risk assessment obtained value of risk quotient (RQ) of 3.79 (RQ>1). The results of this calculation of risk assessment showed that mercury content in samples of rice, fish, and vegetables originating from Lebaksitu Sub-District potentially cause a health risk for the community surrounding the gold mining area who consume it.
Use of the Movies in the Turkish Language and Literature Education in Turkey
Authors: Ince Yakar Halide
Published: February 2018

The aim of the present research is to investigate the teachers’ use of movies in their classes for the teaching of literature and their opinions on this technique. The research is designed as a case study. The target group of the research, selected on information-oriented sampling, consists of 44 Turkish Language and Literature teachers who graduated from 27 different Turkish universities and work in education centers, state and foundation schools and enrolled in Okan University pedagogical formation program. The responses given to the open-ended questionnaire items prepared by the researcher are interpreted qualitatively by means of content analysis. The data obtained from the research are interpreted under the categories of (1) the movies used in the classroom, (2) the purpose for which the movie is used in the classroom, (3) the selection of movies according to literary genres, (4) benefits of the educational movies for research group, (5) limitations of the educational movies for research group. Depending on the research results, some recommendations are made for the use of movies in the classroom.
Phytopythium leanoi sp. nov. and Phytopythium dogmae sp. nov., Phytopythium species associated with mangrove leaf litter from the Philippines
Authors: Bennett Reuel M. , Nam Bora , Dedeles Gina R. , Thines Marco
Published: February 2018

The genus Phytopythium is a monophyletic taxon of the Peronosporaceae with characteristics intermediate between Phytophthora and Pythium. In the Philippines, reports of Phytopythium are scarce, with the mangrove-swamp-inhabiting species Phytopythium kandeliae being the only species recorded to date. It was the aim of the current study to investigate the diversity of Phytopythium in mangrove habitats in more detail. Based on culture characteristics, morphology, and molecular phylogenetic position, two new species of Phytopythium are described from Philippine mangroves, P. leanoi USTCMS 4102 and P. dogmae USTCMS 4101. Phytopythium leanoi is a species morphologically similar to P. kandeliae, but with the ability to develop gametangia in a homothallic fashion. The other new species, P. dogmae, is characterized by having a short discharge tube, semipapillate to papillate sporangia and frequently exhibiting a clustering of two sporangia per sporangiogenic hypha. With the addition of the two species described in this study, the genus Phytopythium has grown from around 10 to beyond 20 recognized species over the past decade, and it seems likely that several more species of this genus await discovery.
RESEÑA de: Cristina de Alba Galvan. Habilidades de comunicación y promoción de conductas adaptadas de la persona con discapacidad / Comunications skills and promoting adaptative behaviors in persons with disabilitis. 2015. Madrid: Paraninfo
Authors: Hernández Sánchez Ana Lucía
Published: February 2018

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Living in the intertidal; desiccation and shading reduce seagrass growth, but high salinity or population of origin have no additional effect
Authors: Suykerbuyk Wouter , Govers Laura L. , van Oven W. G. , Giesen Kris , Giesen Wim B.J.T. , de Jong Dick J. , Bouma Tjeerd J. , van Katwijk Marieke M.
Published: February 2018

The limiting effects of stressors like desiccation, light and salinity on seagrass growth and distribution are well-studied. However, little is known about their interactive effects, and such interactive effects might differ among populations that are adapted to different local conditions. In two laboratory experiments we tested a) if growth and development of intertidal, temperate Zostera noltii is affected by emergence time (experiment 1 and 2), and b) how this is affected by an additional, second stressor, namely shading (experiment 1) or high salinity (25, 30 and 35 PSU, experiment 2). In addition, we tested c) whether the effects of emergence time and salinity varied between three different European seagrass populations (Saint-Jacut / France, Oosterschelde / The Netherlands, and Sylt / Germany), which are likely adapted to different salinity levels (experiment 2). In both experiments, emergence of 8 hours per tidal cycle (of 12 hours) had a negative effect on seagrass relative growth rate (RGR), and aboveground biomass. Emergence furthermore reduced either rhizome length (experiment 1) or belowground biomass (experiment 2). Shading (experiment 1) resulted in lower RGR and a two-fold higher above ground / below ground (AG/BG) ratio. We found no interactive effects of emergence and shading stress. Salinity (experiment 2) did not affect seagrass growth or morphology of any of the three populations. The three tested populations differed greatly in morphology but showed no differential response to emergence or salinity level (experiment 2). Our results indicate that the two applied stressors: emergence time (desiccation stress) and shading, simply add-up (no synergistic or antagonistic effect), making the plants still vulnerable to such combination, whereas Z. noltii of different populations seem tolerant to variations in salinity within the tested range. Secondly, our results indicate that the three tested populations show morphotypic rather then ecotypic variation, at least regarding the salinity and emergence, as there were no interactive effects with origin. Intruigingly, North-west European Z. noltii beds generally do not extend downwards to the subtidal, while our study shows that the shorter emergence periods towards the subtidal are more favourable. In our study areas, where light is ample, the lower depth limit may be determined by increasing sediment dynamics.
Characterizing ecologically significant areas to evaluate marine conservation efforts in the South Brazilian Continental Shelf
Authors: Muelbert Jose H , Macedo-Soares Luis CP , Costa Micheli DP , Favareto Luciane R , Muelbert Monica MC
Published: February 2018

Ecologically Significant Areas (EBSAs) are regions of high productivity and species richness, and their identification and characterisation can be an important tool for marine conservation. We compiled information for the South Brazilian Shelf to evaluate if the existing areas of marine conservation are sufficient to protect biodiversity. Species distribution for ichthyoplankton, fish, birds and marine mammals was overlayed to identify biodiversity hotspots, producing maps of species richness ranging from 0 (absence of species) to 1 (maximum species richness). Suitable areas for ichthyoplankton distribution were accessed by species distribution modelling (MaxEnt) using in situ temperature, salinity and bathymetry (GEBCO). For the other groups, their distribution was obtained from the IUCN and BirdLife spatial datasets. We defined biodiversity hotspots as marine areas with pixels values of species richness greater than the upper 95th percentile. Then, we used this information to characterise the EBSAs in our study area. Our results revealed a biodiversity hotspot of approximately 35.909,9 Km². Of this, only approximately 115km² (0.32%) are currently protected according to the World Database on Protected Areas. This reveals that the concept of EBSAs can be useful to identify conservation regions and evaluate efforts to achieve conservation of marine ecosystems.
Mild myelin disruption elicits early alteration in behavior and proliferation in the subventricular zone
Authors: Gould Elizabeth A , Busquet Nicolas , Shepherd Douglas , Dietz Robert M , Herson Paco S , Simoes de Souza Fabio M , Li Anan , George Nicholas M , Restrepo Diego , Macklin Wendy B
Published: February 2018

Myelin, the insulating sheath around axons, supports axon function. An important question is the impact of mild myelin disruption. In the absence of the myelin protein proteolipid protein (PLP1), myelin is generated but with age, axonal function/maintenance is disrupted. Axon disruption occurs in Plp1-null mice as early as 2 months in cortical projection neurons. High-volume cellular quantification techniques revealed a region-specific increase in oligodendrocyte density in the olfactory bulb and rostral corpus callosum that increased during adulthood. A distinct proliferative response of progenitor cells was observed in the subventricular zone (SVZ), while the number and proliferation of parenchymal oligodendrocyte progenitor cells was unchanged. This SVZ proliferative response occurred prior to evidence of axonal disruption. Thus, a novel SVZ response contributes to the region-specific increase in oligodendrocytes in Plp1-null mice. Young adult Plp1-null mice exhibited subtle but substantial behavioral alterations, indicative of an early impact of mild myelin disruption.
Association of Polymorphism in Gene of Pregnancy-Associated Plasma Protein A (PAPPA) and Preeclampsia
Authors: Moghaddam Nasrin , Karimi Maryam , Ebrahimi Ahmad
Published: February 2018

Background: Preeclampsia is a common disorder of pregnancy. Current study was conducted to determine the association of polymorphism in gene of pregnancy-associated plasma protein A (PAPPA) and preeclampsia.Methods: In this prospective cohort study, 134 pregnant women were consecutively enrolled and the blood sampling was performed for genetic analysis in a single lab. Then the subjects were followed-up for preeclampsia and it was seen that 34 women developed preeclampsia and the polymorphism of PAPPA gene was compared between those with and without preeclampsia.Results: The results demonstrated that despite twice higher proportion of CC condition of PAPPA in those with preeclampsia in comparison with those with normal pregnancy, there was no significant difference between two groups (P > 0.05).Conclusions: Totally, according to the obtained results, it may be concluded that polymorphism of pregnancy-associated plasma protein A is not related to occurrence of preeclampsia in pregnant women.
Journal of Open Source Software (JOSS): design and first-year review
Authors: Smith Arfon M. , Niemeyer Kyle E. , Katz Daniel S. , Barba Lorena A. , Githinji George , Gymrek Melissa , Huff Kathryn D. , Madan Christopher R. , Cabunoc Mayes Abigail , Moerman Kevin M. , Prins Pjotr , Ram Karthik , Rokem Ariel , Teal Tracy K. , Valls Guimera Roman , Vanderplas Jacob T.
Published: February 2018

This article describes the motivation, design, and progress of the Journal of Open Source Software (JOSS). JOSS is a free and open-access journal that publishes articles describing research software. It has the dual goals of improving the quality of the software submitted and providing a mechanism for research software developers to receive credit. While designed to work within the current merit system of science, JOSS addresses the dearth of rewards for key contributions to science made in the form of software. JOSS publishes articles that encapsulate scholarship contained in the software itself, and its rigorous peer review targets the software components: functionality, documentation, tests, continuous integration, and the license. A JOSS article contains an abstract describing the purpose and functionality of the software, references, and a link to the software archive. The article is the entry point of a JOSS submission, which encompasses the full set of software artifacts. Submission and review proceed in the open, on GitHub. Editors, reviewers, and authors work collaboratively and openly. Unlike other journals, JOSS does not reject articles requiring major revision; while not yet accepted, articles remain visible and under review until the authors make adequate changes (or withdraw, if unable to meet requirements). Once an article is accepted, JOSS gives it a digital object identifier (DOI), deposits its metadata in Crossref, and the article can begin collecting citations on indexers like Google Scholar and other services. Authors retain copyright of their JOSS article, releasing it under a Creative Commons Attribution 4.0 International License. In its first year, starting in May 2016, JOSS published 111 articles, with more than 40 additional articles under review. JOSS is a sponsored project of the nonprofit organization NumFOCUS and is an affiliate of the Open Source Initiative (OSI).
Estimating common dolphin bycatch in the pole-and-line tuna fishery in the Azores
Authors: Cruz Maria João , Machete Miguel , Menezes Gui , Rogan Emer , Silva Mónica A.
Published: February 2018

Small-scale artisanal fisheries can have a significant negative impact in cetacean populations. Cetacean bycatch has been documented in the pole-and-line tuna fishery in the Azores with common dolphins being the species more frequently taken. Based on data collected by observers on ∼50% of vessels operating from 1998 to 2012, we investigate the influence of various environmental and fisheries-related factors in common dolphin bycatch and calculate fleet-wide estimates of total bycatch using design-based and model-based methods. Over the 15-year study dolphin bycatch occurred in less than 0.4% of the observed fishing events. Generalized additive modelling results suggest a significant relationship between common dolphin bycatch and duration of fishing events, sea surface temperature and location. Total bycatch calculated from the traditional stratified ratio estimation approach was 196 (95% CI: 186–205), while the negative binomial GAM estimated 262 (95% CI: 249–274) dolphins. Bycatch estimates of common dolphin were similar using statistical approaches suggesting that either of these methods may be used in future bycatch assessments for this fishery. Our work shows that rates of common dolphin bycatch in the pole-and-line tuna fishery in the Azores are low, despite considerable variations between years. Dolphins caught were released alive although the fate of these individuals is unknown. Continued monitoring will provide a better understanding of dolphin bycatch and more accurate estimates essential in the development of potential mitigation measures.
Refined Estimates of Net Community Production in the Subarctic Northeast Pacific Derived From ΔO2/Ar Measurements With N2O‐Based Corrections for Vertical Mixing
Authors: Izett Robert W. , Manning Cara C. , Hamme Roberta C. , Tortell Philippe D.
Published: February 2018

We present the first field application of a N2O‐based approach to correct for vertical mixing in the estimation of net community production (NCP) from mixed layer O2 measurements. Using new ship‐based observations of N2O and biological oxygen saturation anomalies (ΔO2/Ar) from the Subarctic Northeast Pacific, we provide refined mixed layer NCP estimates across contrasting hydrographic regimes and a comprehensive assessment of the methodological considerations and limitations of the approach. Increased vertical mixing coefficients at the base of the mixed layer, derived using N2O measurements, corresponded with periods of heightened wind speed and coastal upwelling. Corrections were most significant in coastal regions where the vertical supply of low‐O2 water can otherwise falsely imply net heterotrophy from negative ΔO2/Ar measurements. After correcting for the mixing flux, all coastal stations showed autotrophic signatures, with maximum NCP exceeding 100 mmol O2 m−2 d−1 in the spring and summer. Vertical fluxes were lower in off‐shelf waters but often contributed more than 50% to corrected NCP. At some oceanic stations, however, the cooccurrence of N2O minima and O2 maxima resulted in biased (overestimated) N2O corrections. Evaluating vertical fluxes in these regions remains a challenge for ship‐based studies. Nonetheless, our refined NCP estimates show better coherence with surface chlorophyll, temperature, and mixed layer depth than uncorrected values. Potential mixed layer N2O production introduces some uncertainty in the approach, but errors are likely to be small. Ultimately, this work provides rationale for the adoption of the N2O correction to refine NCP estimates, particularly in coastal waters.
Fine‐Scale Layering of Mars Polar Deposits and Signatures of Ice Content in Nonpolar Material From Multiband SHARAD Data Processing
Authors: Campbell Bruce A. , Morgan Gareth A.
Published: February 2018

The variation of Shallow Radar (SHARAD) echo strength with frequency reveals material dielectric losses and polar layer properties. Loss tangents for Elysium and Amazonis Planitiae deposits are consistent with volcanic flows and sediments, while the Medusae Fossae Formation, lineated valley fill, and lobate debris aprons have low losses consistent with a major component of water ice. Mantling materials in Arcadia and Utopia Planitiae have higher losses, suggesting they are not dominated by ice over large fractions of their thickness. In Gemina Lingula, there are frequent deviations from a simple dependence of loss on depth. Within reflector packets, the brightest reflectors are often different among the frequency subbands, and there are cases of reflectors that occur in only the high‐ or low‐frequency echoes. Many polar radar reflections must arise from multiple thin interfaces, or single deposits of appropriate thickness, that display resonant scattering behaviors. Reflector properties may be linked to climate‐controlled polar dust deposition.
The Geological Susceptibility of Induced Earthquakes in the Duvernay Play
Authors: Pawley Steven , Schultz Ryan , Playter Tiffany , Corlett Hilary , Shipman Todd , Lyster Steven , Hauck Tyler
Published: February 2018

Presently, consensus on the incorporation of induced earthquakes into seismic hazard has yet to be established. For example, the nonstationary, spatiotemporal nature of induced earthquakes is not well understood. Specific to the Western Canada Sedimentary Basin, geological bias in seismogenic activation potential has been suggested to control the spatial distribution of induced earthquakes regionally. In this paper, we train a machine learning algorithm to systemically evaluate tectonic, geomechanical, and hydrological proxies suspected to control induced seismicity. Feature importance suggests that proximity to basement, in situ stress, proximity to fossil reef margins, lithium concentration, and rate of natural seismicity are among the strongest model predictors. Our derived seismogenic potential map faithfully reproduces the current distribution of induced seismicity and is suggestive of other regions which may be prone to induced earthquakes. The refinement of induced seismicity geological susceptibility may become an important technique to identify significant underlying geological features and address induced seismic hazard forecasting issues.
Irrigation as a Potential Driver for Anomalous Glacier Behavior in High Mountain Asia
Authors: de Kok Remco J. , Tuinenburg Obbe A. , Bonekamp Pleun N. J. , Immerzeel Walter W.
Published: February 2018

Many glaciers in the northwest of High Mountain Asia (HMA) show an almost zero or positive mass balance, despite the global trend of melting glaciers. This phenomenon is often referred to as the “Karakoram anomaly,” although strongest positive mass balances can be found in the Kunlun Shan mountain range, northeast of the Karakoram. Using a regional climate model, in combination with a moisture‐tracking model, we show that the increase in irrigation intensity in the lowlands surrounding HMA, particularly in the Tarim basin, can locally counter the effects of global warming on glaciers in Kunlun Shan, and parts of Pamir and northern Tibet, through an increase in summer snowfall and decrease in net radiance. Irrigation can thus affect the regional climate in a way that favors glacier growth, and future projections of glacier melt, which may impact millions of inhabitants surrounding HMA, will need to take into account predicted changes in irrigation intensity.
Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation?
Authors: Sun Shantong , Eisenman Ian , Stewart Andrew L.
Published: February 2018

Paleoclimate proxy data suggest that the Atlantic Meridional Overturning Circulation (AMOC) was shallower at the Last Glacial Maximum (LGM) than its preindustrial (PI) depth. Previous studies have suggested that this shoaling necessarily accompanies Antarctic sea ice expansion at the LGM. Here the influence of Southern Ocean surface forcing on the AMOC depth is investigated using ocean‐only simulations from a state‐of‐the‐art climate model with surface forcing specified from the output of previous coupled PI and LGM simulations. In contrast to previous expectations, we find that applying LGM surface forcing in the Southern Ocean and PI surface forcing elsewhere causes the AMOC to shoal only about half as much as when LGM surface forcing is applied globally. We show that this occurs because diapycnal mixing renders the Southern Ocean overturning circulation more diabatic than previously assumed, which diminishes the influence of Southern Ocean surface buoyancy forcing on the depth of the AMOC.
Forecasting the Eruption of an Open‐Vent Volcano Using Resonant Infrasound Tones
Authors: Johnson Jeffrey B. , Watson Leighton M. , Palma Jose L. , Dunham Eric M. , Anderson Jacob F.
Published: February 2018

Open‐vent volcanic systems with active degassing are particularly effective at producing infrasound that exhibits resonant tones controlled by the geometry of the volcano's crater. Changes in the infrasound character can thus provide constraints on a crater's lava level, which may vary dynamically in the lead‐up to an eruption. Here we show that the increasing frequency content and damping characteristics of the resonant infrasound at Volcán Villarrica (Chile) relate to lava lake position in its crater/conduit preceding its 2015 eruption. We model the acoustic response of Villarrica's crater to determine that the lake began to rise on 27 February and reached the flared upper part of Villarrica's crater before oscillating during the two days prior to the 3 March paroxysm and 1.5 km‐high lava fountain. This study demonstrates the utility of remote infrasound monitoring for future eruptions of Villarrica and other analogous open‐vent volcanoes.
Relationship Between Earthquake b‐Values and Crustal Stresses in a Young Orogenic Belt
Authors: Wu Yih‐Min , Chen Sean Kuanhsiang , Huang Ting‐Chung , Huang Hsin‐Hua , Chao Wei‐An , Koulakov Ivan
Published: February 2018

It has been reported that earthquake b‐values decrease linearly with the differential stresses in the continental crust and subduction zones. Here we report a regression‐derived relation between earthquake b‐values and crustal stresses using the Anderson fault parameter (Aϕ) in a young orogenic belt of Taiwan. This regression relation is well established by using a large and complete earthquake catalog for Taiwan. The data set consists of b‐values and Aϕ values derived from relocated earthquakes and focal mechanisms, respectively. Our results show that b‐values decrease linearly with the Aϕ values at crustal depths with a high correlation coefficient of −0.9. Thus, b‐values could be used as stress indicators for orogenic belts. However, the state of stress is relatively well correlated with the surface geological setting with respect to earthquake b‐values in Taiwan. Temporal variations in the b‐value could constitute one of the main reasons for the spatial heterogeneity of b‐values. We therefore suggest that b‐values could be highly sensitive to temporal stress variations.
Spatial and Temporal Features of the Topside Ionospheric Electron Density by a New Model Based On GPS Radio Occultation Data
Authors: Prol Fabricio dos Santos , Hernández‐Pajares Manuel , Camargo Paulo de Oliveira , Muella Marcio Tadeu de Assis Honorato
Published: February 2018

A new method for probing the spatial and temporal features of the topside ionosphere is presented. The Vary‐Chap model given by linear functions was used to discover and report features of the topside scale height and its gradient. Based on the global coverage of the radio occultation data, spherical harmonic functions were applied to detect some spatial features of the estimated topside. In addition, a Fourier time‐dependent method was applied in 10 consecutive years to both estimate and predict the temporal evolution of the topside. As a result, the temporal variation of the peak height showed high correlation with the scale height. And on the other hand, the electron density peak showed a strong anticorrelation with the gradient of the scale height. This suggests that the equatorial topside was mainly controlled by the E × B equatorial vertical drift, which increases the scale height in the equatorial region, and the diffusion of the electrons along the geomagnetic field lines, which reduces the gradient of the scale height. Also, a 1 year prediction with a reasonable accuracy showed that the proposed model can be considered a practical and useful tool for predicting features of the topside ionosphere, which may have special interest for the development of climatological models.