Optimal conditions for primary production in a polymictic tropical lake (Lake Xolotl´an, Nicaragua)

From 1987 to 1993we assessed the variation of phytoplankton biomass, underwater irradiance and primary production in Lake Xolotlán (L. Managua, Nicaragua). Chlorophyll-a averaged 65 mg m−3 and maximum and minimum concentrationswere 120 and 30mg m−3, respectively. The variability over depths and weeks was low (CV< 20%). There were strong correlations between particulate carbon and chlorophyll-a (the ratio = 100: 1) and between particulate carbon and particulate nitrogen and phosphorus (the ratio � 100: 11: 1). Gross primary production averaged 6.8 g C m−2 d−1 and was stable over the years (CV�10%). Algal cell growth was approximately 4–5 g C m−2 d−1. Productivity was limited only by the availability of underwater light and the depth of the photic zone was mainly regulated by the chlorophyll-a concentration. Therefore, areal photic zone chlorophyll-a was the only factor directly correlated to the integral photosynthetic activity but, contrary to theoretical models, the production did not increase in proportion to chlorophyll-a. Data from African lakes show a similar pattern

A Flourishing Brain in the 21st Century: A Scoping Review of the Impact of Developing Good Habits for Mind, Brain, Well-Being, and Learning

Emerging scientific knowledge such as the role of epigenetics and neuroplasticity—the brain\u27s capability to constantly rewire with every action, experience, and thought—is fundamentally changing our understanding of the potential impact we can have on our brain. Our brain is formed by our habits in interaction with our body, the environment, influenced by our lifestyle, successes, failures, and traumas. Neuroplasticity proves that every student\u27s brain is a work in progress, and it is never too late to take better care of one\u27s cognitive fitness. This review presents a repertoire of good habits (GHs). Combined, we suggest that these GHs provide conditions for optimal brain health, by acting as a “Mental Vaccine” which enhances the brain\u27s resilience to brain health-degrading challenges. We argue that schools have a crucial role to play in empowering students to increase their own stress resilience, well-being, and learning by developing their own GHs profile

Producción primaria y la estimación del rendimiento potencial pesquero en el Lago Cocibolca, Nicaragua

Once mediciones de la producción primaria utilizando el método de C14 se realizaron entre los años 1990 y 1998 en el Lago Cocibolca. La producción primaria varió entre 0.5 y 3.1 g C m-2 d-1, registrando los valores promedios más altos durante la estación seca, en comparación con la época de lluvias, con 2.4 y 1.2 g C m-2 d-1, respectivamente. Estas diferencias probablemente se deban a las variaciones en las condiciones hidrográficas, especialmente las relacionadas con el régimen de lluvias de la región. Las diatomeas dominaron durante la estación seca, mientras que, las cianófitas y clorófitas abundaron en número y biomasa durante los meses de mayor precipitación y estabilidad en la columna de agua. La fracción de la Radiación Fotosintéticamente Activa (PAR), absorbida por el fitoplancton fue muy similar en ambas estaciones. Los valores de producción primaria en el Lago Cocibolca y considerando además, el limitado número de datos de nutrientes, lo ubican como un lago eutrófico en la escala trófica. El rendimiento potencial pesquero, estimado por métodos indirectos, es de 50-70 kg ha-1 a-1

Comparison of organic and conventional food and food production. Part II: Animal health and welfare in Norway

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Reversal of gender differences in Educational Attainment – historical analysis of the West German Case

Background information: During the late 1970s and the early 1980s, West Germany witnessed a reversal of gender differences in educational attainment, as females began to outperform males. Purpose: The main objective was to analyse which processes were behind the reversal of gender differences in educational attainment after 1945. The theoretical reflections and empirical evidence presented for the US context by DiPrete and Buchmann (Gender-specific trends in the value of education and the emerging gender gap in college completion, Demography 43: 1–24, 2006) and Buchmann, DiPrete, and McDaniel (Gender inequalities in education, Annual Review of Sociology 34: 319–37, 2008) are considered and applied to the West German context. It is suggested that the reversal of gender differences is a consequence of the change in female educational decisions, which are mainly related to labour market opportunities and not, as sometimes assumed, a consequence of a ‘boy’s crisis’. Sample: Several databases, such as the German General Social Survey, the German Socio-economic Panel and the German Life History Study, are employed for the longitudinal analysis of the educational and occupational careers of birth cohorts born in the twentieth century. Design and methods: Changing patterns of eligibility for university studies are analysed for successive birth cohorts and gender. Binary logistic regressions are employed for the statistical modelling of the individuals’ achievement, educational decision and likelihood for social mobility – reporting average marginal effects (AME). Results: The empirical results suggest that women’s better school achievement being constant across cohorts does not contribute to the explanation of the reversal of gender differences in higher education attainment, but the increase of benefits for higher education explains the changing educational decisions of women regarding their transition to higher education. Conclusions: The outperformance of females compared with males in higher education might have been initialised by several social changes, including the expansion of public employment, the growing demand for highly qualified female workers in welfare and service areas, the increasing returns of women’s increased education and training, and the improved opportunities for combining family and work outside the home. The historical data show that, in terms of (married) women’s increased labour market opportunities and female life-cycle labour force participation, the raising rates of women’s enrolment in higher education were – among other reasons – partly explained by their rising access to service class positions across birth cohorts, and the rise of their educational returns in terms of wages and long-term employment

Invented communities and social vulnerability : The local post-disaster dynamics of extreme environmental events

This paper investigates post-disaster dynamics at the local level, in particular how local identity and social cohesion are affected after an extreme event. A particular case is investigated: the largest forest fire in modern Swedish history, which took place in 2014. The empirical material consists of interviews with forest professionals and organizations involved with the fire or the postfire work and a postal survey to all people directly affected by the wildfire. The analysis finds that the experience of the wildfire and its social interpretation led to the invention of a particular community identity, one that strengthened the self-understanding of the community. Thus, the post-disaster dynamics are pivotal for what social practices that emerge and what local identities are invented and thus may greatly affect the capacity of a community to handle extreme events