1,720,993 research outputs found
Macroalgas de las islas de Providencia y Santa Catalina
Full text linkfotografíasLas algas son organismos ecológicamente importantes al ser los productores primarios de la base de la cadena trófica. También, proveen alimento y refugio a una gran variedad de organismos, muchos de importancia económica; de igual modo, contribuyen en la estructura tridimensional del hábitat.
Además, responden de forma rápida a las variaciones ambientales, convirtiéndolas en excelentes bioindicadores del cambio climático, así como de la presencia de metales pesados y otros contaminantes. (texto tomado de la fuente
Science Education and Teachers Training Research in Partnership
No full textInternational researches put to evidence a worrying decrease in science disciplines’ roll in many countries, especially in European Community and a poor quality in scientific competences, as issues of TIMMS (trends in international mathematics and science study) and PISA (programme for international student assessment) have proved, together with a low interest concerning science knowledge of young people. According to our experience, the most important school-related factor in raising student achievement is the quality of the teacher. We investigated Italian pre-service teachers’ scientific competences and their mind conceptions about teaching models/styles, students’ learning, role of teacher and role of science in daily life. The aim of our research outlined in the present paper is to: (1) improve motivation, learning and pupils’ attitudes in science education; (2) develop a critical thinking, stimulate intuition and creativity; and (3) increase scientific literacy in the community. We designed flexible materials, paths and courses within cooperation involving different institutions. The findings of this work concerning both pre-service and in-service teachers’ training are: increased awareness about conceptual knots related to scientific concepts; more sensitiveness and attention to students’ involvement; reflection about the effectiveness of daily school work-increased awareness about meta-cognition and cooperative learning
Spring composition of the macroalgal vegetation of a small offshore island in the north-western Mediterranean (Gallinara Island, Ligurian Sea)
Full text linkGallinara Island, a small island located 1.5 km off the shore of Liguria (Italy, north-western Mediterranean Sea) was included in a list of proposed Marine Protected Areas (MPA) in the early 90s. Since then, its benthic assemblages have been studied in detail and the main macrophytic communities have been mapped. A detailed assessment of its benthic macroalgal flora, however, has never been made. Gallinara was visited in the course of 5 consecutive years and its macroalgal flora was studied based on collections made by snorkelling and SCUBA diving. Overall, 141 macroalgal taxa were collected and identified (23 Chlorophyta, 94 Rhodophyta, 24 Ochrophyta); 91 of them represent new records for the island. One of the most notable new records is the non-indigenous red alga Womersleyella setacea, previously unreported from the island and widely distributed, particularly on the south-eastern shore. Observations made in the course of the surveys confirm the rarefaction of some large-sized brown algae (particularly Sargassum vulgare) but indicate also that others previously reported as rare (Cystoseira compressa, Dictyopteris polypodioides) are still common on the island
Massive quantities of pelagic sargassum on the shores of san andres island, southwestern caribbean
No full textWe report an unusual biomass of floating Sargassum, composed of the species S. fluitans and S. natans, that reached the northeastern coast of San Andres island in September 2014. The time and size of the event is unprecedented to the island
Supplementary material 1 from: Rindi F, Gavio B, Pezzolesi L, Pica D, Ponti M, Torsani F, Cerrano C (2022) Spring composition of the macroalgal vegetation of a small offshore island in the north-western Mediterranean (Gallinara Island, Ligurian Sea). Italian Botanist 13: 45-65. https://doi.org/10.3897/italianbotanist.13.81812
No full textSummary table summarizing the macroalgal flora of Gallinara Island based on comparison of the floristic list of the present study with floristic information presented in the main literature report
Caracterización florística de cianobacterias y macroalgas marinas de los bancos Roncador y Serrana del Archipiélago de San Andrés, Providencia y Santa Catalina, Mar Caribe colombiano
Full text linkLa riqueza de especies de macroalgas y cianobacterias es importante para el entendimiento de las dinámicas ecológicas de los arrecifes de coral. En este escenario, los estudios de caracterización florística se convierten en herramientas indispensables para la toma de información que contribuya en la comprensión del estado de los ecosistemas marinos. Con este propósito, se realizó una identificación taxonómica de las macroalgas y cianobacterias marinas de los atolones remotos de Serrana y Roncador, ubicados en el Archipiélago de San Andrés, Providencia y Santa Catalina, Reserva de la Biosfera, Mar Caribe colombiano. En este trabajo se identificaron 201 especies, de las cuales 44% pertenecen al Phylum Rhodophyta, 10% a las Ochrophyta (Phaeophyceae), el 30% a las Chlorophyta y el 16% a las Cyanobacteria. De estas, 53 especies son nuevos registros para Colombia y 27 son nuevos para el Archipiélago. Al comparar estos resultados con estudios previos, se evidencia un deterioro de los arrecifes de coral de estas zonas, asociado principalmente con un aumento en el número de algas filamentosas formadoras de céspedes algales. Conjuntamente, se vislumbra una elevada diversidad y una composición heterogénea de las especies en cada uno de los ambientes evaluados. Entre los factores que más influyen en la riqueza de especies, se encuentra la disponibilidad de sustrato por parte de macroalgas de mayor tamaño para aquellas algas epifitas, las cuales constituyen la mayor porción de diversidad. Entre los hallazgos, se encontraron unas especies exóticas, posiblemente introducidas por agua de lastre. Este trabajo denota la importancia de realizar monitoreos contantes en estas zonas protegidas.Abstract: It is important to know the species richness of macroalgae and cyanobacteria in a coral reef in order to understand its ecological dynamics. Floristic studies may become important tools to determine the status of coral reefs and marine ecosystems in general. With this in mind, the present research focused on taxonomic identification of macroalgae and cyanobacteria collected at oceanic atolls Serrana and Roncador, part of the Archipelago of San Andres, Old Providence and Sainte Cataline, Seaflower Biosphere Reserve, in the Caribbean Sea. In total I identified 201 species, 44% of which belong to the Phylum Rhodophyta, 10% to Ochrophyta (Phaeophyceae), 30% to Chlorophyta and 16% to Cyanobacteria. Of these taxa, 53 species are new records for Colombia and additional 27 for the Archipelago. When compared to previous studies, these results highlight a decline in the coral reef of this part of the Archipelago, and this is associated to an increase of filamentous algae, which form turfs. The research also highlights a high diverse and heterogeneous community of algae. Among the factors influencing macroalgal species richness, there is substrate availability in the form of large seaweeds which may be colonized by epiphytes. Among the findings, it is important to mention the presence of exogenous species, probably introduced by ballast water. Due to the ecological and economical importance of these atolls, it is important to monitor macroalgae on coral reef to understand the health condition of the ecosystem.Maestrí
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ensamble de algas bentónicas en territorios de Stegastes acapulcoensis (Pomacentridae) en la Isla Gorgona, Pacífico colombiano
Full text linkLos peces damisela del género Stegastes, abundantes en el Pacífico Oriental Tropical (POT), protegen "jardines de algas" de los cuales se alimentan y que presentan una mayor diversidad de flora que sus alrededores. Este estudio describe por primera vez la composición de la comunidad de algas bentónicas en territorios de Stegastes acapulcoensis, y la compara entre un arrecife rocoso (El Laberinto) y uno coralino (La Azufrada) en Isla Gorgona, Pacífico colombiano. En total se registraron 74 taxa, superando el número de taxa registrado en estudios anteriores, especialmente por la diversidad de cianobacterias y algas epífitas flamentosas. Dos especies fueron nuevos registros para la Isla Gorgona, 27 lo fueron para el Pacífico colombiano y 12 para el POT, aumentando la diversidad de algas conocida de la isla en un 38% y del Pacífico colombiano en un 3 0%.PregradoBIOLOGO(A
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