Production and decomposition in floating soils of the Iberá wetlands (Argentina)

Floating soils grow due to the deposition of dead material onto their surface as well as the increment in belowground biomass. The imbalance between biomass production and decomposition is the source of organic matter accumulation. The Esteros del Iberá wetland (Argentina) features extensive areas of floating soils, locally known as "embalsados". The annual aboveground biomass production, decomposition rate, and changes in nitrogen content in Thalia multiflora, a common species of Iberá, were determined in order to assess the organic matter addition and the nitrogen dynamics in the floating soils dominated by this species. The aboveground net primary production was estimated by measuring the standing crop at the peak registered during the sampling period. The decomposition rates of leaves and stems were determined by the litterbag method. The litterbags were collected periodically during a year. The annual organic matter addition was estimated from the relation between aboveground production and the amount of mass lost in a year. The maximum aboveground biomass was 1368 g/m2 (± 271 SD), 71 % stems and 29 % leaves. The loss of weight in the sampling period (399 days) corresponds to 78 % of the initial mass: the total biomass exponential decay coefficient was significantly (ANCOVA; p<0.001) lower in stems (k = 0.0036) than in leaves (k = 0.0040). Both the decomposition rate value as well as the P/D ratio = 1.37, indicate that in T. multiflora stands the organic matter incorporated to the floating soil's surface is small when compared to other peatlands. Initial nitrogen concentration in leaves and stems was 1.07 % and 0.32 %, respectively, this value increased to 1.76 % and 1.25 % in both substrates. Immobilization was observed in intermediate stages; by day 399, when leaves and stems lost nearly 2/3 of their initial weight, N values were similar to the initials, in agreement with the low nutrient availability that is characteristic of peatlands.Los suelos flotantes crecen tanto debido al deposito de materia orgánica muerta en su superficie como al incremento en la biomasa subterránea. La acumulación de materia orgánica es el resultado de la diferencia entre la producción de biomasa aérea y su descomposición. Esteros del Iberá es un humedal que posee grandes extensiones de suelos flotantes, localmente llamados "embalsados". En este trabajo se determinaron la producción de biomasa aérea, la tasa de descomposición y los cambios en el contenido de nitrógeno de Thalia multiflora, una especie abundante en Iberá, con el propósito de estimar el agregado anual de materia orgánica y la dinámica del nitrógeno en los embalsados dominados por esta especie. La producción de biomasa aérea anual fue estimada como la biomasa máxima registrada durante el período. Las tasas de descomposición de hojas y tallos fueron determinadas mediante la recolección de bolsas con material muerto de la especie, periódicamente a lo largo de un año. El agregado anual de materia orgánica al embalsado se estimó como la relación entre la producción de biomasa aérea y el peso perdido en un año. La biomasa máxima fue de 1368 g/m2 (± 271 DE), 71 % de tallos y 29 % de hojas. En el período de muestreo se perdió el 78 % del peso inicial, la tasa de descomposición fue significativamente (p<0.001) más lenta para tallos (k = 0.0036) que para hojas (k = 0.0040). Tanto la tasa de descomposición como la razón P/D = 1.37 indican que T. multiflora incorpora en forma superficial a los embalsados una pequeña cantidad de materia orgánica si se compara con otros humedales. La concentración inicial de nitrógeno en hojas y tallos fue de 1.07 % y 0.32 % respectivamente, aumentando hasta 1.76 % y 1.25 %. Se observó inmovilización en etapas intermedias del período de estudio, pero al final de 399 días cuando las hojas y tallos habían perdido cerca de 2/3 de su peso inicial, los valores de nitrógeno eran próximos a lo iniciales, lo que concuerda con la baja disponibilidad de nutrientes señalada para humedales con características de turbera

Competència social i ciutadana. Aprendre a ser persona, a conviure amb els altres i a habitar el món

En el marc d'una societat global, les polítiques educatives impulsen la formació d'una ciutadania democràtica a través de l'educació. Tanmateix, el desenvolupament de les competències socials i ciutadanes, acompanyat de la implantació de l'assignatura d'Educació per a la Ciutadania (EpC) en les diferents etapes del sistema educatiu, remou el ja clàssic debat a l'entorn de les finalitats de l'educació: excel·lència versus equitat. Tant el dèficit democràtic com la inquietud social per les conductes incíviques entre els joves indiquen la urgència de promoure els valors de la convivència democràtica als centres. Però l'educació per una nova ciutadania requereix que tots els agents educatius passin d'espectadors a actors capaços d'incidir i transformar el propi context. Així, doncs, no n'hi ha prou amb el desenvolupament curricular de l'EpC que, tot i reconèixer la rellevància de les competències socials i ciutadanes, ha d'anar acompanyat d'oportunitats per a l'exercici de la democràcia dins de l'aula i fora. És per aquest motiu, que tant les metodologies d'ensenyament i aprenentatge, com les activitats d'avaluació han d'encaminar-se a la creació d'escenaris de participació en què sigui possible aprendre.Social and civic competencies: learning to be a person, to live with others and to inhabit the world. Within the context of a global society, education policies promote the training of democratic citizenship through education. Nevertheless, the development of social and civic competencies, together with the implementation of the subject Education for Citizenship (EfC) at different educational stages, stirs up the already classic debate about the aim of education: excellence versus equity. Both the democratic deficit and the social concern about antisocial behaviour among youths point to the urgent need to promote values of democratic coexistence in schools. But this education for a new citizenship requires all educational agents to go from being spectators to actors, with an ability to affect and transform their own context. Thus, developing the EfC curriculum is not enough. Although social and civic competencies are relevant, opportunities to implement democracy inside and outside the classroom also need to exist. For this reason, teaching-learning methods and assessment activities should lead to the creation of scenarios of participation, where learning by doing is possible

School Mediation under the Spotlight: What Spanish Secondary Students Think of Mediation

Educational professionals and policy-makers need to update their strategies to address and prevent school violence. Mediation has proved to be a useful tool for peace-building in different countries by developing individuals, their relationships, and the school climate. However, little research has assessed mediation practices. This study aims to evaluate mediation through the perceptions of secondary school students in Spain in order to highlight strengths and weaknesses of school mediation programs. It specifically aims to learn from the assessment by those who attended mediation and to detect whether there exist any significant differences regarding gender and school year. To do this, we conducted a survey study, and data from 1,198 students were collected by means of an ad hoc questionnaire. A descriptive-inferential study shows the high level of agreement between the students, who rate mediation positively, in particular, those who have used mediation for conflict resolution. Regarding necessary improvements, it is imperative to offer more information about the mediation services provided by the educational centres, to train the entire educational community and to broaden the role played by mediation, which has still to unleash its potential

Mediación, arbitraje y demás vías de gestión de conflictos en contextos educativos

The processes of positive tackling with conflicts at schools stand upon their potential power to transform an educational system immersed in complexity. Therefore, the approach adopted by a school to face a conflict becomes an indicator of its capacity to accept a given culture of organization or question it and develop a self way, so that the school comes to a standstill or develops autonomously into pacific coexistence backgrounds. There are different strategies and styles for conflict dealing, more or less appropriate according to the moment of application. As far as mediation and arbitration are concerned, they are complementary processes, though different ones, that contribute their own communicative and educational values.María Carme Boqué Torremorell Profesora de la Facultad de Psicología, Ciencias de la Educación y del Deporte Formadora y colaboradora del Departament d'Ensenyament en los programas de Mediación y Convivencia en los centros docentes de Educación Secundaria Universidad de Alicante Los procesos de gestión positiva de conflictos en la escuela tienen su razón de ser en su potencial para la transformación de un sistema educativo inmerso en la complejidad. Así pues, el enfoque que adopta un centro frente al conflicto es indicador de su capacidad para cuestionar o reproducir la propia cultura organizativa, estancándose o avanzando autónomamente hacia un clima de convivencia pacífica. Existen diversas estrategias y estilos de administración de los conflictos cuyas características los hacen más o menos apropiados con respecto al momento de intervención. Por su parte, mediación y arbitraje constituyen procesos complementarios, aunque bien diferenciados, que aportan valores comunicativos y educativos propios

Metodologies per a la coresponsabilitat en l’aprenentatge universitari

L’Espai Europeu d’Educació Superior ha propiciat un replantejament metodològic basat en el desenvolupament de competències que permet formular noves propostes d’estil docent universitari. En aquest article plantegem un model metodològic pròxim als principis del constructivisme social i del pensament complex, aplicable a un mòdul dels estudis de grau en Educació Infantil i en Educació Primària, analitzant diferents estratègies didàctiques utilitzades per a facilitar l’aprenentatge dels estudiants. Les diverses propostes metodològiques tenen, com a denominador comú,les particularitats següents: totes elles estan centrades en l’alumne, dinamitzen diferents àmbits competencials i afavoreixen la coresponsabilitat entre professor i estudiant en el procés d’aprenentatge. Els resultats d’un estudi fet durant el curs 2008-2009 sobre la percepció dels estudiants en relació a metodologies afins a les proposades,ens ha servit per a ratificar la pertinença de la majoria d’estratègies i incorporar-les al Pla docent del mòdul Societat, Família i Escola I

Vaccination of influenza a virus decreases transmission rates in pigs

Limited information is available on the transmission and spread of influenza virus in pig populations with differing immune statuses. In this study we assessed differences in transmission patterns and quantified the spread of a triple reassortant H1N1 influenza virus in naïve and vaccinated pig populations by estimating the reproduction ratio (R) of infection (i.e. the number of secondary infections caused by an infectious individual) using a deterministic Susceptible-Infectious-Recovered (SIR) model, fitted on experimental data. One hundred and ten pigs were distributed in ten isolated rooms as follows: (i) non-vaccinated (NV), (ii) vaccinated with a heterologous vaccine (HE), and (iii) vaccinated with a homologous inactivated vaccine (HO). The study was run with multiple replicates and for each replicate, an infected non-vaccinated pig was placed with 10 contact pigs for two weeks and transmission of influenza evaluated daily by analyzing individual nasal swabs by RT-PCR. A statistically significant difference between R estimates was observed between vaccinated and non-vaccinated pigs (p < 0.05). A statistically significant reduction in transmission was observed in the vaccinated groups where R (95%CI) was 1 (0.39-2.09) and 0 for the HE and the HO groups respectively, compared to an Ro value of 10.66 (6.57-16.46) in NV pigs (p < 0.05). Transmission in the HE group was delayed and variable when compared to the NV group and transmission could not be detected in the HO group. Results from this study indicate that influenza vaccines can be used to decrease susceptibility to influenza infection and decrease influenza transmission

School administrators' perceptions of democratic coexistence in Catalan schools: An analytical study

In democratic societies, education should help build a participative, critical and responsible citizenry and therefore promote the role of schools as settings where students learn democratic coexistence. With the study reported on here we aimed to analyse how coexistence is fostered in classrooms and schools, as well as the possible synergy between schools' efforts to educate in democratic coexistence, and the children's social participation in their setting. To do so, we focused on the perspective of 476 school administrators at schools in Catalonia (Spain) based on an ad-hoc questionnaire comprised of 22 items on a Likert scale. The results reflect settings that value democratic coexistence at school and in society, although when we delved a bit deeper, we found aspects that still required more work. Actions that should be the focal point in the immediate future include developing more innovative educational strategies, training the administrators and enlisting students' participation in running the schools

Microalgas y su uso como bioindicadoras en la laguna lobos y cuatro arroyos (Buenos Aires, Argentina): Microalgae and their use as bioindicators in lobos shallow lake and four streams (Buenos Aires, Argentina)

Los sistemas lóticos pampeanos constituyen una unidad única de paisaje, siendo la baja velocidad de corriente, la ausencia de plantas leñosas y el escaso sustrato rocoso principales características que regulan el desarrollo de los productores primarios, permitiendo el crecimiento del fitoplancton. Esta comunidad, cobra relevancia y llega a ser vital para sostener e integrar las tramas tróficas acuáticas. Para estudiarla estudio se establecieron 10 sitios de muestreo en verano entre la laguna de Lobos y sus afluentes, los arroyos Salgado, Las Garzas y Salvador María y el arroyo el Toro efluente de la laguna (Provincia de Buenos Aires-Argentina). En estos sitios se tomaron muestras de agua para los análisis fisicoquímicos, peso seco y clorofila y muestras de&nbsp; plancton para análisis cualitativo y cuantitativo. Se determinaron&nbsp; 110 morfoespecies de algas fitoplanctónicas en total, distribuidas en 8 clases y 21 órdenes. Los grupos taxonómicos más abundantes fueron Cyanophyceae y Bacillariophyceae siendo Cylindrospermopsis raciborskii, Phormidium sp.,&nbsp; Cyclotella meneghiniana y Nitzschia palea, las especies dominantes. La presencia de estos organismos, el análisis de los valores de la biomasa algal y la concentración de clorofila y nutrientes, indican un cambio en el estado trófico incrementándose de eutrófico a hipeurtrófico, por lo que se recomiendan monitoreos periódicos