bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model
Authors: Stap Lennert B. , van de Wal Roderik S. W. , de Boer Bas , Bintanja Richard , Lourens Lucas J. 
Published: September 2017

Abstract. Since the inception of the Antarctic ice sheet at the Eocene–Oligocene transition (∼ 34 Myr ago), land ice has played a crucial role in Earth's climate. Through feedbacks in the climate system, land ice variability modifies atmospheric temperature changes induced by orbital, topographical, and greenhouse gas variations. Quantification of these feedbacks on long timescales has hitherto scarcely been undertaken. In this study, we use a zonally averaged energy balance climate model bidirectionally coupled to a one-dimensional ice sheet model, capturing the ice–albedo and surface–height–temperature feedbacks. Potentially important transient changes in topographic boundary conditions by tectonics and erosion are not taken into account but are briefly discussed. The relative simplicity of the coupled model allows us to perform integrations over the past 38 Myr in a fully transient fashion using a benthic oxygen isotope record as forcing to inversely simulate CO2. Firstly, we find that the results of the simulations over the past 5 Myr are dependent on whether the model run is started at 5 or 38 Myr ago. This is because the relation between CO2 and temperature is subject to hysteresis. When the climate cools from very high CO2 levels, as in the longer transient 38 Myr run, temperatures in the lower CO2 range of the past 5 Myr are higher than when the climate is initialised at low temperatures. Consequently, the modelled CO2 concentrations depend on the initial state. Taking the realistic warm initialisation into account, we come to a best estimate of CO2, temperature, ice-volume-equivalent sea level, and benthic δ18O over the past 38 Myr. Secondly, we study the influence of ice sheets on the evolution of global temperature and polar amplification by comparing runs with ice sheet–climate interaction switched on and off. By passing only albedo or surface height changes to the climate model, we can distinguish the separate effects of the ice–albedo and surface–height–temperature feedbacks. We find that ice volume variability has a strong enhancing effect on atmospheric temperature changes, particularly in the regions where the ice sheets are located. As a result, polar amplification in the Northern Hemisphere decreases towards warmer climates as there is little land ice left to melt. Conversely, decay of the Antarctic ice sheet increases polar amplification in the Southern Hemisphere in the high-CO2 regime. Our results also show that in cooler climates than the pre-industrial, the ice–albedo feedback predominates the surface–height–temperature feedback, while in warmer climates they are more equal in strength.
The Plio-Pleistocene climatic evolution as a consequence of orbital forcing on the carbon cycle
Authors: Paillard Didier 
Published: September 2017

Abstract. Since the discovery of ice ages in the 19th century, a central question of climate science has been to understand the respective role of the astronomical forcing and of greenhouse gases, in particular changes in the atmospheric concentration of carbon dioxide. Glacial–interglacial cycles have been shown to be paced by the astronomy with a dominant periodicity of 100 ka over the last million years, and a periodicity of 41 ka between roughly 1 and 3 million years before present (Myr BP). But the role and dynamics of the carbon cycle over the last 4 million years remain poorly understood. In particular, the transition into the Pleistocene about 2.8 Myr BP or the transition towards larger glaciations about 0.8 Myr BP (sometimes referred to as the mid-Pleistocene transition, or MPT) are not easily explained as direct consequences of the astronomical forcing. Some recent atmospheric CO2 reconstructions suggest slightly higher pCO2 levels before 1 Myr BP and a slow decrease over the last few million years (Bartoli et al., 2011; Seki et al., 2010). But the dynamics and the climatic role of the carbon cycle during the Plio-Pleistocene period remain unclear. Interestingly, the δ13C marine records provide some critical information on the evolution of sources and sinks of carbon. In particular, a clear 400 kyr oscillation has been found at many different time periods and appears to be a robust feature of the carbon cycle throughout at least the last 100 Myr (e.g. Paillard and Donnadieu, 2014). This oscillation is also visible over the last 4 Myr but its relationship with the eccentricity appears less obvious, with the occurrence of longer cycles at the end of the record, and a periodicity which therefore appears shifted towards 500 kyr (see Wang et al., 2004). In the following we present a simple dynamical model that provides an explanation for these carbon cycle variations, and how they relate to the climatic evolution over the last 4 Myr. It also gives an explanation for the lowest pCO2 values observed in the Antarctic ice core around 600–700 kyr BP. More generally, the model predicts a two-step decrease in pCO2 levels associated with the 2.4 Myr modulation of the eccentricity forcing. These two steps occur respectively at the Plio-Pleistocene transition and at the MPT, which strongly suggests that these transitions are astronomically forced through the dynamics of the carbon cycle.
Several years of experience with automatic DI-flux systems: theory, validation and results
Authors: Poncelet Antoine , Gonsette Alexandre , Rasson Jean 
Published: September 2017

Abstract. The previous release of our automatic DI-flux instrument, called AutoDIF mk2.2, has now been running continuously since June 2012 in the absolute house of Dourbes magnetic observatory performing measurement every 30 min. A second one has been working in the tunnel of Conrad observatory (Austria) since December 2013. After this proof of concept, we improved the AutoDIF to version mk2.3, which was presented at the 16th IAGA workshop in Hyderabad. As of publication, we have successfully deployed six AutoDIFs in various environments: two in Dourbes (DOU), one in Manhay (MAB), one in Conrad (CON), one in Daejeon (South Korea) and one is used for tests. The latter was installed for 10 months in Chambon-la-Forêt (CLF) and, since 2016, has been in Kakioka (KAK). In this paper, we will compare the automatic to the human-made measurements and discuss the advantages and disadvantages of automatic measurements.
Reverse engineering model structures for soil and ecosystem respiration: the potential of gene expression programming
Authors: Ilie Iulia , Dittrich Peter , Carvalhais Nuno , Jung Martin , Heinemeyer Andreas , Migliavacca Mirco , Morison James I. L. , Sippel Sebastian , Subke Jens-Arne , Wilkinson Matthew , Mahecha Miguel D. 
Published: September 2017

Abstract. Accurate model representation of land–atmosphere carbon fluxes is essential for climate projections. However, the exact responses of carbon cycle processes to climatic drivers often remain uncertain. Presently, knowledge derived from experiments, complemented by a steadily evolving body of mechanistic theory, provides the main basis for developing such models. The strongly increasing availability of measurements may facilitate new ways of identifying suitable model structures using machine learning. Here, we explore the potential of gene expression programming (GEP) to derive relevant model formulations based solely on the signals present in data by automatically applying various mathematical transformations to potential predictors and repeatedly evolving the resulting model structures. In contrast to most other machine learning regression techniques, the GEP approach generates readable models that allow for prediction and possibly for interpretation. Our study is based on two cases: artificially generated data and real observations. Simulations based on artificial data show that GEP is successful in identifying prescribed functions, with the prediction capacity of the models comparable to four state-of-the-art machine learning methods (random forests, support vector machines, artificial neural networks, and kernel ridge regressions). Based on real observations we explore the responses of the different components of terrestrial respiration at an oak forest in south-eastern England. We find that the GEP-retrieved models are often better in prediction than some established respiration models. Based on their structures, we find previously unconsidered exponential dependencies of respiration on seasonal ecosystem carbon assimilation and water dynamics. We noticed that the GEP models are only partly portable across respiration components, the identification of a general terrestrial respiration model possibly prevented by equifinality issues. Overall, GEP is a promising tool for uncovering new model structures for terrestrial ecology in the data-rich era, complementing more traditional modelling approaches.
Effects of sample size on estimation of rainfall extremes at high temperatures
Authors: Boessenkool Berry , Bürger Gerd , Heistermann Maik 
Published: September 2017

Abstract. High precipitation quantiles tend to rise with temperature, following the so-called Clausius–Clapeyron (CC) scaling. It is often reported that the CC-scaling relation breaks down and even reverts for very high temperatures. In our study, we investigate this reversal using observational climate data from 142 stations across Germany. One of the suggested meteorological explanations for the breakdown is limited moisture supply. Here we argue that, instead, it could simply originate from undersampling. As rainfall frequency generally decreases with higher temperatures, rainfall intensities as dictated by CC scaling are less likely to be recorded than for moderate temperatures. Empirical quantiles are conventionally estimated from order statistics via various forms of plotting position formulas. They have in common that their largest representable return period is given by the sample size. In small samples, high quantiles are underestimated accordingly. The small-sample effect is weaker, or disappears completely, when using parametric quantile estimates from a generalized Pareto distribution (GPD) fitted with L moments. For those, we obtain quantiles of rainfall intensities that continue to rise with temperature.
MobRISK: a model for assessing the exposure of road users to flash flood events
Authors: Shabou Saif , Ruin Isabelle , Lutoff Céline , Debionne Samuel , Anquetin Sandrine , Creutin Jean-Dominique , Beaufils Xavier 
Published: September 2017

Abstract. Recent flash flood impact studies highlight that road networks are often disrupted due to adverse weather and flash flood events. Road users are thus particularly exposed to road flooding during their daily mobility. Previous exposure studies, however, do not take into consideration population mobility. Recent advances in transportation research provide an appropriate framework for simulating individual travel-activity patterns using an activity-based approach. These activity-based mobility models enable the prediction of the sequence of activities performed by individuals and locating them with a high spatial–temporal resolution. This paper describes the development of the MobRISK microsimulation system: a model for assessing the exposure of road users to extreme hydrometeorological events. MobRISK aims at providing an accurate spatiotemporal exposure assessment by integrating travel-activity behaviors and mobility adaptation with respect to weather disruptions. The model is applied in a flash-flood-prone area in southern France to assess motorists' exposure to the September 2002 flash flood event. The results show that risk of flooding mainly occurs in principal road links with considerable traffic load. However, a lag time between the timing of the road submersion and persons crossing these roads contributes to reducing the potential vehicle-related fatal accidents. It is also found that sociodemographic variables have a significant effect on individual exposure. Thus, the proposed model demonstrates the benefits of considering spatiotemporal dynamics of population exposure to flash floods and presents an important improvement in exposure assessment methods. Such improved characterization of road user exposures can present valuable information for flood risk management services.
Interannual evolution of (sub)mesoscale dynamics in the Bay of Biscay
Authors: Charria Guillaume , Theetten Sébastien , Vandermeirsch Frédéric , Yelekçi Özge , Audiffren Nicole 
Published: September 2017

Abstract. In the north-east Atlantic Ocean, the Bay of Biscay is an intersection between a coastal constrained dynamics (wide continental shelf and shelf break regions) and an eastern boundary circulation system. In this framework, the eddy kinetic energy is 1 order of magnitude lower than in western boundary systems. To explore this coastal complex system, a high-resolution (1 km, 100 vertical sigma layers) model experiment including tidal dynamics over a period of 10 years (2001–2010) has been implemented. The ability of the numerical environment to reproduce main patterns over interannual scales is demonstrated. Based on this experiment, the features of the (sub)mesoscale processes are described in the deep part of the region (i.e. abyssal plain and continental slope). A system with the development of mixed layer instabilities at the end of winter is highlighted. Beyond confirming an observed behaviour of seasonal (sub)mesoscale activity in other regions, the simulated period allows exploring the interannual variability of these structures. A relationship between the winter maximum of mixed layer depth and the intensity of (sub)mesoscale related activity (vertical velocity, relative vorticity) is revealed and can be explained by large-scale atmospheric forcings (e.g. the cold winter in 2005). The first submesoscale-permitting exploration of this 3-D coastal system shows the importance of (sub)mesoscale activity in this region with its evolution implying a potentially significant impact on vertical and horizontal mixing.
BLAST: A Promising Approach to Service, Ethics, and Leadership Development in Rural Canada
Authors: Saleh Zia , Nakonechny Vance , St. Denis Maurice , Nichols Darren 
Published: September 2017

As youth define their identity and the values by which they live their lives, formative programs have the potential to change their life trajectories in productive ways. This study aimed to investigate the impact of a rural youth development program that focused on service, ethics, and leadership. In this program, nine rural students (aged 13-18) initiated and led community service projects, engaged in educational sessions on ethics and character development, and formed a diverse social support network. Survey data and a thematic focus group analysis revealed that the program resulted in: (a) skill-building in the areas of teamwork, planning and life management, social interaction, and self-confidence; (b) increased interest and confidence in initiating service projects; (c) development of leadership skills; (d) maturation of personal ethical foundations; and (e) an appreciation of pluralism through working with others in the community. Potential improvements to the model were also uncovered through this process.
Urban Youth Perceptions of Agriculture
Authors: Jean-Philippe Sharon , Richards Jennifer , Gwinn Kimberly , Beyl Caula 
Published: September 2017

To change public perceptions, particularly from urban populations, of agriculture and natural resources (ANR) fields, the University of Tennessee developed a model of strategic educational recruitment to extend beyond traditional college fair experiences to educate underrepresented candidates. The High School Agricultural Education Initiative (HSAI) provided 10th-grade students with opportunities to: (a) gain knowledge of and appreciation for disciplines in agriculture and natural resources, (b) learn about college admissions standards, (c) network with college students and staff to learn about campus resources, and (d) understand how a college education improves professional opportunities. The HSAI (n = 122) was effective at increasing urban high school student knowledge of postsecondary opportunities in agriculture and natural resources, particularly with regards to ANR career paths. Additionally, students placed high value on the importance of scholarships and they believed that their parents would be supportive of majoring in an ANR discipline. The HSAI program targeted 10th-grade students for a one-time intervention, however, in further reflection and based on the results of this study, establishing long-term partnerships with Title I urban high schools may be more effective at increasing the number of youth who actually apply and enroll in ANR programs in college.
O Sujeito no Estruturalismo e as Implicações de uma Relação com a Teoria da Moldura de Hans Kelsen
Authors: Simões Sandro Nery , Santos Gustavo 
Published: September 2017

O movimento filosófico conhecido como estruturalismo teve um papel inovador como metodologia científica para as ciências sociais. Este artigo analisa o papel do sujeito nesse movimento e suas consequências para abordagem científica de Claude Lévi-Strauss acerca das relações de parentesco e da criação dos mitos. Abordando esse papel, finaliza por fazer um cotejo entre o estruturalismo e a teoria da moldura proposta por Hans Kelsen. ABSTRACT: The philosophical movement known as structuralism had na innovative role in the social sciences, especially in the área of scientific methodology. This article examines the role of the individual within the structuralism, focusing on Claude Levi-Strauss ideias of kindship and creation of myths. Finally, the article examines a possible relationship between structuralism and Hans Kelsen’s frame theory of legal interpretacion.
Anatomia foliar de Varronia curassavica Jaqc (Cordiaceae)
Authors: Leal-Costa Marcos Vinicus , Amélia Renata Pegoral 
Published: September 2017

Varronia curassavica Jacq. (=Cordia verbenacea DC), Cordiaceae, é uma espécie amplamente distribuída da Argentina ao México. A espécie é tradicionalmente utilizada para fins medicinais com atividade anti-inflamatória, sendo matéria-prima do primeiro fitoterápico brasileiro (Acheflan®, Aché). Neste trabalho, objetivou-se descrever a morfoanatomia de V. curassavica, buscando características úteis para sua identificação. A espécie tem venação craspedódroma e folha de margem ondulada a denteada. A epiderme é uniestratificada, com dois tipos de tricomas glandulares pedunculados, um possuindo uma cabeça globular e outro uma cabeça em reniforme, e dois tipos de tricomas não-glandulares, um deles possuindo cistólito. A lâmina foliar é hipoestomática. O mesofilo é dorsiventral. Tricomas glandulares são, possivelmente, as melhores características para identificar a espécie, uma vez que podemos usá-los para distinguir V. curassavica de duas outras espécies congêneres.
Estudo Etnobotânico em Comunidade Quilombola Salamina/Putumujú em Maragogipe, Bahia
Authors: Lisboa Marisa dos Santos 
Published: September 2017

Este estudo tem como objetivos resgatar e documentar os conhecimentos tradicionais relativos às plantas de uso medicinal utilizadas pela comunidade quilombola Salamina/Putumujú, Maragogipe, Bahia. O estudo teve como base a pesquisa-participante por meio de entrevistas e questionários semiestruturados. O universo amostral foi constituído de 50 famílias informantes, todas residentes no município há mais de cinco anos, de ambos os sexos, entre 20-90 anos de idade. Foram realizadas turnês guiadas, fotografias e vídeos. Neste estudo foram levantados 126 espécimes vegetais para fins medicinais e/ou ritualísticos, sendo que, destas, 70 espécimes foram coletados, distribuídos em 22 famílias, 38 gêneros e 36 espécies. As famílias mais citadas foram, Poaceae, Myrtaceae, Fabaceae, Verbenaceae e Anacardiaceae. Após identificação, as espécies nativas foram predominantes com 54%, seguidas das exóticas com 29% e das naturalizadas com 17%. Os dados obtidos no Quilombo Salamina/Putumujú demonstram que a comunidade é detentora de um conhecimento rico sobre a flora medicinal da localidade e destaca-se a diversidade botânica existente na região.
The contemporary faith in educational technology – a critical perspective
Authors: Player-Koro Catarina 
Published: September 2017

The purpose of this article is to contribute to the discussion about the contradictions between the optimistic faith in improving education through the implementation of technology and the actual realities of educational use of technology. This is done through a summary and overview of the results of three different studies in the field of educational technology that started in 2005 and that is still on going. The aim of these studies has been to contribute to development of a critical perspective on educational technology and thereby contribute to knowledge development about education of today.
Medición del impacto social y económico: políticas públicas de emprendimiento en Andalucía
Authors: Casado Ruiz José María , Bernal Jurado Enrique , Mozas Moral Adoración , Fernández Uclés Domingo , Medina Viruel Miguel Jesús 
Published: September 2017

En los últimos años hemos padecido una crisis económica que ha intensificado la preocupación de los gobiernos por corroborar la eficacia y eficiencia con la que se utilizan los fondos públicos. Esta situaciónse justifica (Wiesner, 2000), entre otras, por la mayor necesidad de responsabilidad y de transparencia, por el alto coste político que se sufre cuando la opinión pública estima la falta de eficiencia de los programas públicos y por la importancia de que los ajustes o correcciones fiscales sean racionales. Por otra parte, la necesidad de evaluación de los programas de desarrollo empresarial está justificada por la gran cantidad de fondos destinados a su implementación (Awasthi y Sebastián, 1996). El objetivo de este trabajo es evaluar las políticas públicas y constatar cómo, a través de la medición del impacto económico y social de los programas públicos, se puede conocer el retorno de la inversión pública a la sociedad. Tomando como caso de estudio la Junta de Andalucía, se analizará el retorno de la inversión pública en materia de emprendimiento de Andalucía Emprende, Fundación Pública Andaluza en el año 2015. Se ha utilizado la metodología coste-beneficio. Los resultados indican que el retorno a la sociedad supera la inversión realizada.
¿Cómo se puede mejorar la competitividad de las cooperativas agroalimentarias?
Authors: Lajara-Camilleri Natalia , Server-Izquierdo Ricardo José 
Published: September 2017

El entorno de alta competitividad que existe en los mercados agroalimentarios ha incrementado notablemente la presión sobre todos los agentes que operan en ellos. En el caso de las cooperativas, debido posiblemente a su reducida dimensión empresarial, esta cuestión reviste especial importancia puesto que aboca a estas entidades a adoptar cambios que mejoren su competitividad y aseguren la supervivencia. Existe un buen número de trabajos que analizan el papel de distintos aspectos de gestión sobre la competitividad de las empresas en general, sin embargo no se ha abordado el grado de importancia relativa de dichos elementos. El objetivo de este trabajo es establecer una jerarquía en una serie de aspectos de gestión empresarial que inciden en el éxito y competitividad de las cooperativas agroalimentarias. Para ello se ha realizado una consulta a expertos mediante el método Delphi a fin de obtener un orden de importancia percibida por parte del sector. Los resultados obtenidos señalan a la orientación al mercado y a la innovación como los elementos más destacados por los expertos de cara a mejorar la competitividad actual de las cooperativas agroalimentarias españolas.