Discrimination capacity in species distribution models depends on the representativeness of the environmental domain

Aim When faced with dichotomous events, such as the presence or absence of a species, discrimination capacity (the ability to separate the instances of presence from the instances of absence) is usually the only characteristic that is assessed in the evaluation of the performance of predictive models. Although neglected, calibration or reliability (how well the estimated probability of presence represents the observed proportion of presences) is another aspect of the performance of predictive models that provides important information. In this study, we explore how changes in the distribution of the probability of presence make discrimination capacity a context-dependent characteristic of models. For the first time,we explain the implications that ignoring the context dependence of discrimination can have in the interpretation of species distribution models

Deducción de calificaciones individuales en actividades cooperativas: una oportunidad para la coevaluación y la autoevaluación en la enseñanza de las ciencias

El aprendizaje cooperativo es una técnica pedagógica que permite a los estudiantes aprender más eficazmente, pero no implica necesariamente la evaluación individual de los estudiantes en los grupos cooperativos. En este artículo se discute el uso de la coevaluación como método para cuantificar la responsabilidad individual en actividades cooperativas en la enseñanza de las ciencias y se propone un método para deducir calificaciones individuales a partir de la calificación obtenida por el proyecto del grupo. En dicho método los estudiantes valoran confidencialmente el cumplimiento de las responsabilidades grupales (o ciudadanía de equipo) de ellos mismos y del resto de los miembros de su grupo. Estas valoraciones se convierten en factores de corrección individuales que, aplicados a la calificación común del proyecto, permiten obtener puntuaciones específicas para cada estudiante. Para ilustrar el método, se describe una aplicación del mismo en una actividad cooperativa medioambiental.Palabras claves: Aprendizaje cooperativo; Coevaluación; Autoevaluación; Evaluación Cooperativa; Responsabilidad Individual; Educación Ambiental.Deduction of individual qualifications in cooperative activities: an opportunity for co-evaluation and self-assessment in science teachingCooperative learning is a means to help students to learn more effectively but it does not lead to assessment of individual students in groups by default. The use of peer assessment as a way of accounting for individual performance on cooperative projects in Science education is discussed and a method of deriving individual performance marks from the group effort is proposed. This method consists on team members confidentially rating how well they and each of their teammates fulfilled their responsabilities (citizenship team). The ratings are then converted to individual weighting factors, and individual project grades are computed as the product of the team project grade and the weighting factor. An application of this method in a cooperative environmental activity is included.Keywords: Cooperative Learning, Peer Assessment, Self-Assessment, Cooperative Assessment, Individual Accountability, Environmental Education

Cooperación en entornos telemáticos y la enseñanza de la química

En la presente comunicación se detalla una innovadora experiencia llevada a cabo durante los cursos 2001-02 y 2002-03 consistente en el uso del BSCW, un entorno telemático para el trabajo cooperativo, en el Ciclo Formativo de Grado Superior de Química Ambiental. En el artículo se detallan las principales características del entorno, cómo fue aplicado y los resultados que se obtuvieron, presentados en páginas web creadas por los propios estudiantes sobre diferentes aspectos de metales en aguas. El alumnado, a través de una encuesta, respaldó esta experiencia y mostró una actitud muy positiva en la creación de materiales hipermedia.Palabras claves: TICs e Internet; Didáctica de la Química; Aprendizaje Cooperativo Asistido por Ordenador; Entornos telemáticos; Creación de Materiales Hipermedia.Cooperation in telematic environments and the teaching of ChemistryIn this article we present an innovative 2-year experience using BSCW with students from a Higher-Level Vocational Training course of Environmental Chemistry. BSCW is a groupware tool which enables cooperation over the Web. The characteristics and main functionalities of this tool are described in the article, as well as how it was used with these students, who created web-based projects about metals in waters. Student feedback showed a high acceptance of this cooperative hypermedia-authoring experience.Keywords: ICTs and the Internet; Teaching of Chemistry, Computer-Supported Cooperative Learning; Telematic Environments; Hypermedia authoring

Culturing requirements and commercial quality of four different species of Ulva (Ulvales, chlorophyta)

The commercial production of Ulva spp. by aquaculture is gaining in importance due both to the qualitative and quantitative increase in the use of the harvested biomass and its new applications in inland IMTA techniques. However, very little is known about the specific culturing requirements and commercial quality of the different species of Ulva. The aim of this work is to try from this point of view four Ulva species that could be grown in southern Europe: U. australis, U. fasciata, U. ohnoi and U. rigidaPostprint (author's final draft

ENVIRONMENTAL CORRELATION STRUCTURE AND ECOLOGICAL NICHE MODEL PROJECTIONS

Non

Discrimination capacity in species distribution models depends on the representativeness of the environmental domain

[Aim]: When faced with dichotomous events, such as the presence or absence of a species, discrimination capacity (the ability to separate the instances of presence from the instances of absence) is usually the only characteristic that is assessed in the evaluation of the performance of predictive models. Although neglected, calibration or reliability (how well the estimated probability of presence represents the observed proportion of presences) is another aspect of the performance of predictive models that provides important information. In this study, we explore how changes in the distribution of the probability of presence make discrimination capacity a context-dependent characteristic of models. For the first time, we explain the implications that ignoring the context dependence of discrimination can have in the interpretation of species distribution models. [Innovation]: In this paper we corroborate that, under a uniform distribution of the estimated probability of presence, a well-calibrated model will not attain high discrimination power and the value of the area under the curve will be 0.83. Under non-uniform distributions of the probability of presence, simulations show that a well-calibrated model can attain a broad range of discrimination values. These results illustrate that discrimination is a context-dependent property, i.e. it gives information about the performance of a certain algorithm in a certain data population. [Main conclusions]: In species distribution modelling, the discrimination capacity of a model is only meaningful for a certain species in a given geographic area and temporal snapshot. This is because the representativeness of the environmental domain changes with the geographical and temporal context, which unavoidably entails changes in the distribution of the probability of presence. Comparative studies that intend to generalize their results only based on the discrimination capacity of models may not be broadly extrapolated. Assessment of calibration is especially recommended when the models are intended to be transferred in time or space.The study was partially supported by projects CGL2009-11316/BOS-FEDER and CGL2011-25544. A.J.-V. was supported by the MEC Juan de la Cierva Program. P.A. was supported by the Vicerrectorado de Investigación of the University of Málaga. A.M.B. was supported by a post-doctoral fellowship from Fundação para a Ciência e aTecnologia (Portugal), co-financed by the European Social Fund. The ‘Rui Nabeiro’ Biodiversity Chair receives funding from Delta Cafés.Peer Reviewe

Assessing the areas under risk of invasion within islands through potential distribution modelling: the case of Pittosporum undulatum in São Miguel, Azores

Copyright © 2009 Elsevier GmbH. All rights reserved.Non-indigenous plant species have been frequently reported as successful invaders in island environments, changing plant community composition and structure. This is the case of the sweet pittosporum (Pittosporum undulatum), native from Australia, which is one of the most successful plant invaders in the Azores archipelago. Data extracted from recent forestry inventories were used to model and map the potential distribution of P. undulatum in São Miguel, the larger island of the Azores. Current distribution of P. undulatum is related to climate, altitude and some human activity effects. Further analysis of the areas under risk of invasion showed that protected areas are under potential threat, although only a few native forest remnants seem to be threatened due to future expansion of P. undulatum, since the current distribution of these native communities has been reduced due to clearing and competition with invasive plants. We discuss the threats that any further expansion of the species will represent for low-altitude native forests, as well as the utility of species distribution models in the assessment of the areas under risk of invasion

Influence of ball milling on CaO crystal growth during limestone and dolomite calcination: Effect on CO2 capture at Calcium Looping conditions

The multicycle CO2 capture performance of CaO derived from the calcination of ball-milled limestone and dolomite have been tested under high temperature and high CO2 concentration environment for the first time. Here it is shown that the CO2 capture capacity of CaO is inversely related to the milling power applied to the starting mineral and the size of nascent CaO nanocrystals. In situ X-ray diffraction analysis used to follow the average crystallite size of CaCO3 and CaO during the calcination process as a function of temperature demonstrates that crystal growth is notably enhanced in a CO2-rich atmosphere for milled sorbents. Contrary to early reports suggesting improved reactivity towards carbonation of CaO from milled sorbents, promoted agglomeration, and crystal growth under these more “realistic” conditions lead to a severe deterioration of both capture capacity and recyclability, as observed from the multicyclic carbonation/calcination experiments. Yet the negative effect of milling is less pronounced in dolomite due to the constrained sintering effect of the inert MgO grains that results in smaller CaO crystallite sizes, reduced crystal growth rate, and improved performance. These results provide insight on the role of CaO crystallinity on the carbonation reaction, useful for devising strategies to improve sorbents performance.Peer reviewe

Mono and Di-Fucosylated Glycans of the Parasitic Worm S. Mansoniare Recognized Differently by the Innate Immune Receptor DC-SIGN

The parasitic worm,Schistosoma mansoni, expresses unusual fucosylated glycans in a stage-dependent manner that can be recognized by the human innate immune receptor DC-SIGN, thereby shaping host immune responses. We have developed a synthetic approach for mono- and bis-fucosylated LacdiNAc (LDN-F and LDN-DF, respectively), which are epitopes expressed on glycolipids and glycoproteins ofS. mansoni. It is based on the use of monosaccharide building blocks having carefully selected amino-protecting groups, facilitating high yielding and stereoselective glycosylations. The molecular interaction between the synthetic glycans and DC-SIGN was studied by NMR and molecular modeling, which demonstrated that the alpha 1,3-fucoside of LDN-F can coordinate with the Ca2+-ion of the canonical binding site of DC-SIGN allowing for additional interactions with the underlying LDN backbone. The 1,2-fucoside of LDN-DF can be complexed in a similar manner, however, in this binding mode GlcNAc and GalNAc of the LDN backbone are placed away from the protein surface resulting in a substantially lower binding affinity. Glycan microarray binding studies showed that the avidity and selectivity of binding is greatly enhanced when the glycans are presented multivalently, and in this format Le(x)and LDN-F gave strong responsiveness, whereas no binding was detected for LDN-DF. The data indicates thatS. mansonihas developed a strategy to avoid detection by DC-SIGN in a stage-dependent manner by the addition of a fucoside to a number of its ligands.This research was supported by the Netherlands Organization for Scientific Research (NWO; TOP-PUNT grant 718.015.003 to G.-J.B.), the Human Frontier Science Program Organization (HFSP; grant LT000747/2018-C to L.U.), the European Research Council (ERC-2017-AdG, project number 788143-RECGLYC-ANMR to J.J.-B.), the Agencia Estatal Investigacion of Spain (AEI; grant RTI2018-094751-B-C21 to J.J.-B.) and the Severo Ochoa Excellence Accreditation (SEV-2016-0644 to J.J.-B.)

Using Ecological Modelling Tools to Inform Policy Makers of Potential Changes in Crop Distribution: An Example with Cacao Crops in Latin America

International audienceSpecies distribution models (SDM) is a powerful simulation tool that has become widely used in the ecological and agronomical sciences. The use of easily available presence data, global downscaled climate layers and software that can run on desktop computer has contributed to their popularity. The most used application is based on maximum entropy models that fit presence data to a series of environmental descriptors. SDM can be used to predict crop distribution under future conditions but the level of uncertainty of those models can be very high. The best use of these models is to be used as generators of hypothesis to be combined with other type of analysis