679 research outputs found
Niche divergence and limits to expansion in the high polyploid Dianthus broteri complex
Niche evolution in plant polyploids remains controversial and evidence for alternative patterns has been reported. Using the autopolyploid Dianthus broteri complex (2×, 4×, 6× and 12×) as a model, we aimed to integrate three scenarios – competitive exclusion, recurrent origins of cytotypes and niche filling – into a single framework of polyploid niche evolution. We hypothesized that high polyploids would tend to evolve towards extreme niches when low ploidy cytotypes have nearly filled the niche space. We used several ecoinformatics and phylogenetic comparative analyses to quantify differences in the ecological niche of each cytotype and to evaluate alternative models of niche evolution. Each cytotype in this complex occupied a distinct ecological niche. The distributions were mainly constrained by soil characteristics, temperature and drought stress imposed by the Mediterranean climate. Tetraploids had the highest niche breadth and overlap due to their multiple origins, whereas the higher ploidy cytotypes were found in different, restricted, nonoverlapping niches. Niche evolution analyses suggested a scenario with one niche optimum for each ploidy, including the two independent tetraploid lineages.Our results suggest that the fate of nascent polyploids could not be predicted without accounting for phylogenetic relatedness, recurrent origins or the niche occupied by ancestors.Aridos La Melera S.L. (FIUS project 2234/0724
Problem-based learning in a course of Environmental Science and Technology
Uno de los objetivos específicos de la asignatura de Ciencia y Tecnología del
Medioambiente (CTMA) del Grado y de Ingeniería Técnica Agrícola es la
identificación y la valoración de impactos que ocasionan las diferentes
actividades agropecuarias sobre el medioambiente. Tradicionalmente, la forma
en la que se ha abordado el estudio de esta parte de la asignatura ha sido a través
de clases magistrales. Entre las líneas fundamentales de la adaptación al Espacio
Europeo de Educación Superior (EEES) está el cambio de modelos basados en la
enseñanza expositiva (enseñanza) a modelos basados en el aprendizaje (alumno).
Uno de los métodos de aprendizaje son las técnicas de aprendizaje basadas en el
desarrollo de proyectos colectivos “proyect-learning cooperation”. El objetivo de
este trabajo fue incorporar la metodología de ‘aprendizaje por proyectos
colaborativos’ en la asignatura de Ciencia y Tecnología del Medioambiente. El
proyecto consistió en el seguimiento por parte de grupos de alumnos de un
ensayo de invernadero de dosis-respuesta, en el que se analizó el efecto
producido por el incremento de la dosis de compost (subproducto de actividades
agrícolas) sobre dos especies de herbáceas con carácter forrajero. Los diferentes
grupos de alumnos tuvieron que realizar una evaluación e identificación de los
efectos producidos sobre ambas especies. La valoración de los proyectos
realizados por los alumnos se realizó mediante la revisión de los documentos
técnicos que se entregarán al profesor, y con una exposición oral de síntesis.One of the specific objectives of the course ‘Environmental Sciences and
Technology’ of the Agronomy Degree, is the identification and the assessment of
the impacts that agricultural activities cause on the environment. Traditionally,
the way it has approached the study of this part of the course is through lectures.
An important aspect of the adaptation of higher education to European Higher
Education Area (EHEA) is the change of models based on teaching to a model
learning-based. One of the methods of learning are the techniques based in the
development of collective projects “project-learning cooperation”. The aim of
this work was incorporate the project-learning cooperation methodology in the
subject ‘Environmental Sciences and Technology’. The project consisted in
monitoring a greenhouse experiment (dose-response) by students groups. Each
group analyzed the effect of different doses of compost (product of agricultural
activities) on two grass species with forage use (including the identification and
the assessment of impacts). For review of the success rate achieved in the
implementation of this methodology, the student´s projects were revised
Impact of short-term extreme temperature events on physiological performance of Salicornia ramosissima J. Woods under optimal and sub-optimal saline conditions
Increasing extreme temperature climatic events could exert an important effect on plant photosynthetic performance, which could be modulated by the co-occurrence with other environmental factors, such as salinity, in estuarine ecosystems. Therefore, a mesocosm experiment was designed to assess the impact of temperature events for three days (13/5 °C, 25/13 °C and 40/28 °C) in combination with two NaCl concentrations (171 and 1050 mM NaCl) on the physiological performance of Salicornia ramosissima. Extreme temperature events had a negative impact on S. ramosissima photosynthetic efficiency, this effect being more marked with cold wave at both salinities, compared with heat wave, even in presence of NaCl excess. This differential thermotolerance in the photosynthetic apparatus was ascribed to the greater integrity and functioning of its photosynthetic pathway at high temperature, as indicated by constant gs, Vc,max values at optimal salinity and the higher values of those parameters and gm recorded in combination with NaCl excess. Moreover, S. ramosissima was able to upregulate the energy sink capacity of its photochemical apparatus at elevated temperature and salinity by a greater energy excess dissipation capacity. This could have contributed to reducing the risk of oxidative stress, along with the recorded higher capacity for antioxidant enzyme activity modulation under these conditions.España, MINECO Project CGL2016– 75550-
Aplication of active-learning cooperation strategy in the course of Principles, Instrumentation and Methods in Ecology and Soil Science
La sociedad actual requiere la formación de profesionales capaces de
integrarse en grupos de trabajo que se autogestionen. Así, dentro del proceso de
convergencia universitaria europea destaca como uno de sus objetivos el
desarrollo de titulados capaces de integrarse en equipos de trabajo con la
capacidad para la construcción individual y colectiva del conocimiento. Un
aspecto importante de la adaptación de la enseñanza superior al Espacio Europeo
de Educación Superior (EEES) es el cambio de modelos basados en la enseñanza
a modelos basados en el aprendizaje. Este trabajo presenta una experiencia en la
asignatura de ‘Principios Instrumentación y Métodos en Ecología y Edafología’
del primer curso del Grado en Biología (Facultad de Biología de la Universidad
de Sevilla, 2010-2011), sustentada en la metodología del aprendizaje cooperativo
entre los alumnos, con un enfoque de aprendizaje basado en problemas. Para
obtener una valoración sobre el porcentaje de éxito conseguido en la aplicación
de esta metodología se consideraron dos indicadores: 1) grado de
asistencia/abandono y de aprobados de los alumnos de la parte práctica de la
asignatura y 2) encuesta de satisfacción del alumnado sobre la metodología
docente empleada. Con respecto al primer indicador se observó un alto nivel de
implicación y compromiso por los alumnos en el proceso de aprendizaje, de
forma que los niveles de abandono de la parte práctica de la asignatura fueron
mínimos. Por otro lado, más de un 90% de los alumnos que habían optado por la
asistencia continúa a las clases y por la participación en las dinámicas de grupo
superaron esta parte de la asignatura. Finalmente, existió una valoración muy
positiva por parte de los alumnos en la aplicación de este tipo de métodos
docentes y los estudiantes fueron capaces de encontrarles numerosos aspectos
positivos para su formación.Today's society requires the training of professionals able to integrate into
working groups. So within the European university convergence process stands
out as one of its objectives the development of graduates capable of integrating
into teams with the capacity for individual and collective construction of
knowledge. An important aspect of the adaptation of higher education to
European Higher Education Area (EHEA) is the change of models based on
teaching to a model learning-based. This paper presents an experience in the
subject of 'Principles, Instrumentation and Methods in Ecology and Soil Science'
of the first year of Biology (Faculty of Biology, University of Seville, 2010-
2011), based on the methodology of cooperative learning among students, with a
focus on problem-based learning. For review of the success rate achieved in the
implementation of this methodology was considered two indicators: 1) degree of
attendance/dropout and students who approved the practice of the subject and 2)
Student satisfaction on the teaching methodology used (surveys). Regarding the
first indicator was observed a high level of involvement and commitment by
students in the learning process. So, the levels of abandonment of the practices
subject were minimal. Furthermore, over 90% of students who opted for the
assistance continues to classes and participated in group dynamics, exceeded this
part of the course. Finally, students were capable of finding many positive
aspects for his training and they had a very positive evaluation in applying these
types of teaching methods
El futuro de las relaciones población-territorio: nuevas pautas de ocupación y nuevos objetivos de gobernanza
Polyploidy promotes divergent evolution across the leaf economics spectrum and plant edaphic niche in the Dianthus broteri complex
The evolution of the leaf economics spectrum (LES) is known to be constrained by genetic relatedness but also promoted at small geographical and phylogenetic scales. In those cases, we hypothesized that polyploidy would play a prominent role as an outstanding source of functional divergence and adaptive potential.
We registered leaf-level nutrient, water- and light-economy-related traits from the LES as well as edaphic properties in the four cytotypes of the autopolyploid Dianthus broteri complex (2×, 4×, 6× and 12×). We analysed the effect of ploidy level on the integration of the LES network, checked if concerted evolution occurred between LES and soil niche and tested the influence of phylogeny on the variables. Alternative evolutionary models for both sets of traits were compared.
We found higher divergence of polyploids (especially 6× and 12×) compared to diploids in the LES and soil niche, but these traits are not coevolving. 6× and 12× showed opposite ecological strategies regarding resource use and higher uncoupling of the LES network. Early divergence of traits prevailed in both LES and edaphic niche (supported by better fitted evolutionary models with one optimum per cytotype), but post-polyploidization processes played an important role for the photochemical behaviour.
Synthesis. Our results indicated shifts in ecological strategies across Dianthus broteri cytotypes and suggested a powerful role of polyploidy in overcoming constraints for the evolution of plant functional traits.PGC2018-098358-B-I00 from the Spanish MICINNÁridos La Melera S.L. (FIUS project 2234/0724
Zinc tolerance and accumulation in the halophytic species Juncus acutus
The research on species with capacity to tolerate and accumulate zinc is of paramount importance for phytoremediation purposes. An experiment was designed to investigate the effect of Zn from 0 to 100mmoll-1 on the growth, photosynthetic apparatus and nutrient uptake of the halophytic species Juncus acutus. Gas exchange, chlorophyll fluorescence and photosynthetic pigments concentration were measured. We also determined total zinc, magnesium, potassium, phosphorus and sodium concentrations, as well as C/N ratio. J. acutus showed high tolerance to Zn-induced stress, since all plants survived and none of them showed any toxicity symptoms, such as chlorosis, necrosis or growth reduction at concentrations up to 100mmoll-1 Zn. The integrity and functionality of the photosynthetic apparatus were unaffected even at zinc concentrations greater than 500mgkg-1 on tillers. Likewise, nutrient absorption was relatively unaffected. Zn tolerance was associated with the capacity to accumulate Zn in roots (with values up to 2500mgkg-1) and largely avoid its transport to tillers. These characteristics, along with its ability to establish in a wide variety of ecosystems, render this species a useful phytostabilizer for revegetation of Zn-contaminated lands
Implementation and Didactic Validation of STEM Experiences in Primary Education: Analysis of the Cognitive and Affective Dimension
Several studies highlight the need to improve STEM competencies from an early age, where the first attitudes and vocations toward these subjects begin to be forged. This research pursued two general objectives: First, to analyze the cognitive and affective dimension of primary education students in relation to STEM content, using a sample of 801 students. Second, to implement and validate STEM experiences as didactic strategies that improve the teaching/learning of these areas in students aged 10–12, using a sample of 455 students. The design of the research was quasi-experimental with pretest, posttest, control, and experimental groups, analyzing both cognitive and affective variables. The inferential statistical analysis of the obtained data reveals that STEM education promotes a positive evolution in the students both in the learning and emotional variables, existing statistically significant differences compared to a traditional methodology
El concepto de cohesión territorial: escalas de aplicación, sistemas de medición y políticas derivadas
El concepto de cohesión territorial ha ido cobrando fuerza durante la última década como una de las expresiones más citadas en el ámbito temático de las políticas territoriales. Sin embargo, hasta fechas muy recientes ha adolecido de un escaso nivel de concreción, tanto teórica como práctica. Este texto se propone avanzar en dicha concreción, abordando las
cuestiones clave del concepto de cohesión territorial en Europa, en cuanto a su definición; escala y ámbito de actuación; planteamiento de fórmulas para mejorar la cooperación y coordinación entre las políticas sectoriales y territoriales; o el debate, esencial para su aplicabilidad práctica, acerca del establecimiento de indicadores para la evaluación de las características
y tendencias de dicha cohesión territorial. Todo ello en el contexto teórico del debate suscitado por la publicación del Libro Verde sobre la cohesión territorial, elaborado y difundido por la Comisión de las Comunidades Europeas.The concept of territorial cohesion has gained strength during the last decade as one of the most quoted in the subject area of territorial policies. However, until very recently, has suffered from a low level of detail, both theoretical and practical. This paper seeks to be another step in specifying the main territorial cohesion-related issues by addressing the key issues of the concept in Europe, in terms of its definition, the scale and scope of territorial action; the question of how to improve co-operation and co-ordination between sectorial and territorial policies as well as the type of indicators that must be developed in order to evaluate both the characteristics and trends in territorial cohesion. These and other questions are addressed in the context of the theoretical debate raised after the publication in 2008 of the Green Paper on Territorial Cohesion by the Commission of the European Communities
Evaluación de la efectividad de programas destinados a la promoción y mejora de la convivencia en un centro de Educación Secundaria de la provincia de Ciudad Real
Nos propusimos aplicar y evaluar medidas de intervención para prevenir, reducir y atajar las conductas desajustadas y el comportamiento disruptivo; con ello pretendíamos mejorar el clima de trabajo en el aula. Aplicamos en el marco de la tutoría programas de modificación de conducta, entrenamiento en habilidades sociales y técnicas de mediación. También perseguíamos conocer, la dimensión de la conflictividad y la manera de resolver conflictos en el aula.
Desde la investigación-acción hemos empleado distintas metodologías: experimental y no experimental (encuestas y entrevista en profundidad). Los programas de entrenamiento en habilidades sociales se muestran eficaces para reducir el comportamiento perturbador y mejorar el comportamiento social de los alumnos de Primer Ciclo de la ESO.
El discurso del profesorado en relación con la convivencia es que se está deteriorando por el incremento de conductas disruptivas. Los profesores son partidarios de utilizar un estilo de enseñanza democrático y estrategias de solución de conflicto
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