Regional distribution and temporal changes in density and biomass of Didymosphenia geminata in two Mediterranean river basins

This study aimed to strengthen the knowledge of Didymosphenia geminata distribution in Spain, and to determine which environmental variables were related to its regional distribution and temporal changes in growth and production in two Ebro River tributary basins (Iregua and Najerilla¸ La Rioja Region). Living cells of D. geminata were present in 40% of the studied sites of both basins but only four of the sites developed massive growths. The diatom is widely distributed only in mountain areas of both basins (above 690 masl), which have low average annual air temperature (8.27 ± 0.28 ºC) and low water Soluble Reactive Phosphorus (SRP) concentration (average value 0.024 ± 0.007 ppm). Massive growths occur in sites with high light intensity, hydrological regulation of river flow and the lowest measured SRP concentrations (below 0.018 ppm SRP). We carried out an intensive spatio-temporal survey in the Lumbreras River (Iregua basin), where the first massive growth was detected in La Rioja Region. The highest cell densities (1.6 × 105 cells cm−2) and biomass values (480 gDWm−2) were recorded in late summer. An increase in solar radiation and slight rise in water temperature were associated with an increase in biomass over time, but always in waters with low SRP concentration, the key factor that enhances massive growth development. The alteration of the natural streamflow in the Lumbreras River by the Pajares Reservoir and the fact that water is discharged from the hypolimnion (which decreases the summer river water temperature) are important factors in understanding why D. geminata shows such an increase in biomass in a Mediterranean river. This paper provides new insights into the importance of different factors controlling D. geminata massive proliferations in the Mediterranean climate zone, where it is assumed that the species should not develop such massive growths, compared to temperate zones where the majority of previous studies have been carried out. We suggest that changing the reservoir management strategy would be a very important contribution to the control of such significant developments

SOS: EMERGENCIA CLIMÁTICA EN LAS AULAS DE EDUCACIÓN SECUNDARIA

La creciente gravedad de la crisis climática exige desarrollar estrategias educativas adaptadas a las necesidades del alumnado de las diferentes etapas. El presente estudio trata de contribuir al diagnóstico sobre el conocimiento e implicación del alumnado de educación secundaria en materia climática y conocer su evolución respecto a la educación primaria, evaluada previamente. Los resultados muestran que el alumnado de educación secundaria desconoce en gran medida las bases científicas del cambio climático, sus causas y consecuencias. Muestra confusión con otros fenómenos climáticos y presta menor atención a cuestiones locales y especialmente a implicaciones sociales del cambio climático. Se observan escasos avances respecto al alumnado de educación primaria, manteniendo una actitud pasiva y poco comprometida ante este problema ambiental. Los resultados evidencian la necesidad de fomentar de manera más decidida en las aulas de secundaria la alfabetización climática del alumnado, que englobe una mayor formación científica para comprender las bases físicas del problema y una formación social, que permita la identificación de la gravedad de la crisis climática en todas sus aristas y desarrollar actitudes críticas y comprometidas entre el alumnado

Effects of Didymosphenia geminata massive growth on stream communities: Smaller organisms and simplified food web structure

This study aims to contribute to the understanding of the impact of Didymosphenia geminata massive growths upon river ecosystem communities' composition and functioning. This is the first study to jointly consider the taxonomic composition and functional structure of diatom and macroinvertebrate assemblages in order to determine changes in community structure, and the food web alterations associated with this invasive alga. This study was carried out in the Lumbreras River (Ebro Basin, La Rioja, Northern Spain), which has been affected by a considerable massive growth of D. geminata since 2011. The study shows a profound alteration in both the river community composition and in the food web structure at the sites affected by the massive growth, which is primarily due to the alteration of the environmental conditions, thus demonstrating that D. geminata has an important role as an ecosystem engineer in the river. Thick filamentous mats impede the movement of large invertebrates especially those that move and feed up on it and favor small, opportunistic, herbivorous organisms, mainly chironomids, that are capable of moving between filaments and are aided by the absence of large trophic competitors and predators -prey release effect-. Only small predators, such as hydra, are capable of surviving in the new environment, as they are favored by the increase in chironomids, a source of food, and by the reduction in both their own predators and other midge predators -mesopredator release-. This change in the top-down control affects the diatom community, since chironomids may feed on large diatoms, increasing the proportion of small diatoms in the substrate. The survival of small and fast-growing pioneer diatoms is also favored by the mesh of filaments, which offers them a new habitat for colonization. Simultaneously, D. geminata causes a significant reduction in the number of diatoms with similar ecological requirements (those attached to the substrate). Overall, D. geminata creates a community dominated by small organisms that is clearly different from the existing communities in the same stream where there is an absence of massive growths

What Do Students Know about Rivers and Their Management? Analysis by Educational Stages and Territories

The overall purpose of this study was to assess the knowledge that students have about the ecosystem concept of rivers and their sustainable management. A survey of nine questions gathered responses from 3447 students at three different Spanish education levels (Primary, Secondary, and bachelor’s degree in Primary Education) and six different geographic territories in the Iberian Peninsula. Respondents showed a limited understanding of rivers, much simpler than the ecosystem concept, which was related to proposals of unsustainable management of these ecosystems. Although the results were analogous among territories, undergraduate students had a more complex concept of rivers as well as more sustainable ideas regarding their management compared with Primary and Secondary Education students. This study demonstrates the lack of knowledge transfer between science and students regarding river ecosystems. Current educational programs should be adapted to address, even at early stages of education, the sustainability challenges around river ecosystems

Impact of potash mining in streams: the Llobregat basin (northeast Spain) as a case study

Potash mining is significantly increasing the salt concentration of rivers and streams due to lixiviates coming from the mine tailings. In the present study, we have focused on the middle Llobregat basin (northeast Spain), where an important potash mining activity exists from the beginning of the XX century. Up to 50 million tonnes of saline waste have been disposed in the area, mainly composed of sodium chloride. We assessed the ecological status of streams adjacent to the mines by studying different physicochemical and hydromorphological variables, as well as aquatic macroinvertebrates. We found extraordinary high values of salinity in the studied streams, reaching conductivities up to 132.4 mS/cm. Salt-polluted streams were characterized by a deterioration of the riparian vegetation and the fluvial habitat. Both macroinvertebrate richness and abundance decreased with increasing salinity. In the most polluted stream only two families of macroinvertebrates were found: Ephydridae and Ceratopogonidae. According to the biotic indices IBMWP and IMMi-T, none of the sites met the requirements of the Water Framework Directive (WFD; i.e., good ecological status). Overall, we can conclude that potash-mining activities have the potential to cause severe ecological damage to their surrounding streams. This is mainly related to an inadequate management of the mine tailings, leading to highly saline runoff and percolates entering surface waters. Thus, we urge water managers and policy makers to take action to prevent, detect and remediate salt pollution of rivers and streams in potash mining areas

Teaching-learning around wine

Los derechos culturales, el patrimonio, la diversidad y la creatividad juegan un papel esencial en el éxito de la agenda 2030 porque son componentes centrales del desarrollo humano y sostenible. En este contexto, resulta esencial y prioritaria la formación del alumnado riojano en el mundo vitivinícola, ya que la Comunidad de La Rioja es una referencia internacional en este sector por su gran trascendencia cultural, tradicional, económica y turística. Para realizar esta innovación docente se ha utilizado una metodología de aprendizaje entre iguales con la participación de alumnado de Grado en Enología y de Grado en Educación Primaria, que se encargó de la adecuación didáctica y transferencia del conocimiento en la escuela, mediante talleres relacionados con el vino. Como medida del éxito alcanzado se utilizaron encuestas de satisfacción y un formulario sobre los conocimientos vitivinícolas antes y después de la intervención educativa. La educación entre iguales dentro del contexto universitario ha hecho visibles los conocimientos de cada grado, mejorando así la organización académica en la utilización de recursos humanos y materiales. En concreto, ha permitido mejorar los conocimientos vitivinícolas de los estudiantes, que han valorado satisfactoriamente esta innovación docente, considerándola como un buen método de aprendizaje.Cultural rights, heritage, diversity, and creativity play an essential role in the success of the 2030 agenda because they are central components of human and sustainable development. In this context, training La Rioja students in the wine world is essential, since the Community of La Rioja is an international reference in this sector due to its great cultural, traditional, economic and tourist significance. To carry out this teaching innovation, a peer-learning methodology has been used with the participation of students from the Degree in Oenology and the Degree in Primary Education, who were in charge of didactic adaptation and transfer of knowledge in school, through workshops related to wine. Satisfaction surveys and forms on wine knowledge, before and after the educational intervention, were used as a measure of the success achieved. Peer education within university context has made knowledge of each degree visible, improving the academic organization related to human and material resources. Specifically, it has made it possible to improve students' wine knowledge, who have satisfactorily assessed this teaching innovation, considering it a good learning method

Agricultural impacts on streams near Nitrate Vulnerable Zones: a case study in the Ebro basin, Northern Spain

Agricultural intensification during the last century has caused river degradation across Europe. From the wide range of stressors derived from agricultural activities that impact rivers, diffuse agricultural pollution has received most of the attention from managers and scientists. The aim of this study was to determine the main stressors exerted by intensive agriculture on streams around Nitrate Vulnerable Zones (NVZs), which are areas of land that drain into waters polluted by nitrates according to the European Nitrate Directive (91/676/EEC). The study area was located in the NW of La Rioja (Northern Spain), which has some of the highest nitrate concentrations within the Ebro basin. The relationships between 40 environmental variables and the taxonomic and functional characteristics of the macroinvertebrate assemblages (which are useful indicators of water quality) were analyzed in 11 stream reaches differentially affected by upstream agricultural activity. The streams affected by a greater percentage of agricultural land cover in the surrounding catchment had significantly higher nitrate concentrations than the remaining sites. However, hydromorphological alteration (i.e. channel simplification, riparian forest and habitat degradation), which is closely linked to agricultural practices, was the main factor affecting macroinvertebrate assemblages. We suggest that 'good agricultural practices' should be implemented in streams affected by NVZs to reverse stream degradation, in concordance with the European Water Framework Directive (WFD)

Tumor marker analyses from the phase III, placebo-controlled, FASTACT-2 study of intercalated erlotinib with gemcitabine/platinum in the first-line treatment of advanced non-small-cell lung cancer

AbstractObjectivesThe FASTACT-2 study of intercalated erlotinib with chemotherapy in Asian patients found that EGFR mutations were the main driver behind the significant progression-free survival (PFS) benefit noted in the overall population. Further exploratory biomarker analyses were conducted to provide additional insight.Materials and methodsThis multicenter, randomized, placebo-controlled, double-blind, phase III study investigated intercalated first-line erlotinib or placebo with gemcitabine/platinum, followed by maintenance erlotinib or placebo, for patients with stage IIIB/IV non-small cell lung cancer (NSCLC). Provision of samples for biomarker analysis was encouraged but not mandatory. The following biomarkers were analyzed (in order of priority): EGFR mutation by cobas® test, KRAS mutation by cobas® KRAS test, HER2 by immunohistochemistry (IHC), HER3 by IHC, ERCC1 by IHC, EGFR gene copy number by fluorescence in-situ hybridization (FISH) and EGFR by IHC. All subgroups were assessed for PFS (primary endpoint), overall survival (OS), non-progression rate and objective response rate.ResultsOverall, 256 patients provided samples for analysis. Considerable overlap was noted among biomarkers, except for EGFR and KRAS mutations, which are mutually exclusive. Other than EGFR mutations (p<0.0001), no other biomarkers were significantly predictive of outcomes in a treatment-by-biomarker interaction test, although ERCC1 IHC-positive status was predictive of improved OS for the erlotinib arm versus placebo in EGFR wild-type patients (median 18.4 vs 9.5 months; hazard ratio [HR] HR=0.32, 95% confidence intervals [CI]: 0.14–0.69, p=0.0024).ConclusionActivating EGFR mutations were predictive for improved treatment outcomes with a first-line intercalated regimen of chemotherapy and erlotinib in NSCLC. ERCC1 status may have some predictive value in EGFR wild-type disease, but requires further investigation