Dissolved Iron, Aluminium, and Dissolved Inorganic Phosphorus in the (Sub-)Tropical Atlantic Surface Ocean

Inorganic nitrogen depletion restricts productivity in much of the low-latitude oceans, generating a selective advantage for diazotrophic organisms capable of fixing atmospheric dinitrogen (N2). However, the abundance and activity of diazotrophs can in turn be controlled by the availability of other potentially limiting nutrients, including phosphorus (P) and iron (Fe). Here we present high-resolution data (~0.3°) for dissolved iron, aluminum, and inorganic phosphorus that confirm the existence of a sharp north-south biogeochemical boundary in the surface nutrient concentrations of the (sub)tropical Atlantic Ocean. Combining satellite-based precipitation data with results from a previous study, we here demonstrate that wet deposition in the region of the intertropical convergence zone acts as the major dissolved iron source to surface waters. Moreover, corresponding observations of N2 fixation and the distribution of diazotrophic Trichodesmium spp. indicate that movement in the region of elevated dissolved iron as a result of the seasonal migration of the intertropical convergence zone drives a shift in the latitudinal distribution of diazotrophy and corresponding dissolved inorganic phosphorus depletion. These conclusions are consistent with the results of an idealized numerical model of the system. The boundary between the distinct biogeochemical systems of the (sub)tropical Atlantic thus appears to be defined by the diazotrophic response to spatial-temporal variability in external Fe inputs. Consequently, in addition to demonstrating a unique seasonal cycle forced by atmospheric nutrient inputs, we suggest that the underlying biogeochemical mechanisms would likely characterize the response of oligotrophic systems to altered environmental forcing over longer timescales.

Pore water chemistry of samples near the sediment-water interface

Rhizon samplers were originally designed as micro-tensiometers for soil science to sample seepage water in the unsaturated zone. This study shows applications of Rhizons for porewater sampling from sediments in aquatic systems and presents a newly developed Rhizon in situ sampler (RISS). With the inexpensive Rhizon sampling technique, porewater profiles can be sampled with minimum disturbance of both the sediment structure and possible flow fields. Field experiments, tracer studies, and numerical modeling were combined to assess the suitability of Rhizons for porewater sampling. It is shown that the low effort and simple application makes Rhizons a powerful tool for porewater sampling and an alternative to classical methods. Our investigations show that Rhizons are well suited for sampling porewater on board a ship, in a laboratory, and also for in situ sampling. The results revealed that horizontally aligned Rhizons can sample porewater with a vertical resolution of 1 cm. Combined with an in situ benthic chamber system, the RISS allows studies of benthic fluxes and porewater profiles at the same location on the seafloor with negligible effect on the incubated sediment water interface. Results derived by porewater sampling of sediment cores from the Southern Ocean (Atlantic sector) and by in situ sampling of tidal flat sediments of the Wadden Sea (Sahlenburg/Cuxhaven, Germany) are presented.

The 2011 student movement on the Chilean press: What Pluralism in the digital press?

This article presents results of two research projects that explored the coverage of the Student Movement 2011 carried out by two chains of newspaper of Chile: El Mercurio S.A.P and Diarios Mi Voz, in three regions of the country. These press chains correspond to paper and digital press, respectively. In this research, we analyze information and photographs allowed to establish changes in journalistic practices as well as similarities in the ways of representing the student movement.

Time beyond clock: time use-surveys revisited

Time use surveys -despite having represented a turning point in the study of inequalities between women and men- continue hiding care times and subtracting relevance to the qualitative dimensions of time. This due both, to the ideological conception that lies behind this type of studies that consider more relevant market process as to surveys methodology. This article analyzes the theoretical model that lies behind time use surveys and, consequently, the study of the conceptual aspects, the methodology and the potential of these surveys as an analytical instrument. The aim is to unraveling the limitations presented by the surveys to take in account the subjective dimensions of time related to the wellbeing of  people.

Media web sites interactivity: Searching new ways to dialog with their users

Currently the media have made many new tools on their websites in order to broaden the dialogue with its users, a feature that has been called interactivity. The objective of this research is to describe the interactive resources of Chilean media websites. The analysis was conducted at 20 sites using a pattern of six dimensions with interactive forms which are today using identified. The findings indicate that digital media Chileans are expanding the possibilities of dialogue with users on social media, especially Twitter and Facebook, and the mediauser interaction is monological, that is to say, from the media to the user, but with very low feedback.

Peruanos y bolivianos en la sátira chilena de la Guerra del Pacífico (1879 - 1884)

A partir de los grabados publicados en las páginas de los periódicos que incluyeron humor gráfico en sus ediciones durante la Guerra del Pacífico (1879 - 1883), los caricaturistas chilenos desplegaron un discurso visual agresivo en clave patriótica y belicista, donde presentaron a sus lectores una imagen crítica y despectiva respecto de los adversarios de Chile. Recalcaron la supuesta falta de ánimo y valor combativo, ante la sola presencia de los efectivos militares chilenos tanto en el mar como en tierra. Así, la tinta y el papel, se transformaron en otra de las armas que intervinieron en el conflicto de Chile contra el Perú y Bolivia por la posesión de los ricos territorios salitreros de Tarapacá y Antofagasta. Las imágenes fueron interpretadas a partir de los postulados de la Escuela de Warburg, en especial los de Erwin Panofsky, que propone tres niveles de estudio del significado de cada obra, a saber, la “descripción preiconográfica”, luego el “estudio iconográfico” en cuanto tal y, finalmente, la “interpretación iconológica”.

Perspectives on gender, migration and transnational work: joint work of social reproduction and care in Southern Europe

This paper presents the "state of the art" and some of the main issues discussed in relation to the topic of transnational migration and reproductive work in southern Europe. We start doing a genealogy of the complex theoretical development leading to the consolidation of the research program, linking consideration of gender with transnational migration and transformation of work and ways of survival, thus making the production aspects as reproductive, in a context of globalization. The analysis of the process of multiscale reconfiguration of social reproduction and care, with particular attention to its present global dimension is presented, pointing to the turning point of this line of research that would have taken place with the beginning of this century, with the rise notions such as "global care chains" (Hochschild, 2001), or "care drain" (Ehrenreich and Hochschild, 2013). Also, the role of this new agency, now composed in many cases women who migrate to other countries or continents, precisely to address these reproductive activities, is recognized. Finally, reference is made to some of the new conceptual and theoretical developments in this area.

Estados Unidos y la guerra por el desarrollo: el control de la natalidad en Chile, 1960-1970

Bajo el paradigma de modernización y desarrollo norteamericano -y en un contexto de Guerra Fría-, durante la década de 1960 se adecuaron a la realidad chilena programas de control de natalidad que no sólo buscaron disminuir las altas tasas de mortalidad materno infantil, sino que además respondieron al proyecto de seguridad hemisférica norteamericana de contención a posibles revoluciones populares en países del Tercer Mundo.

Civic Humanism and the Classical Tradition in the Early Republic of Chile

The first decades of the 19th century constituted a period of profound change for Chile, the principal results of which were to be seen in the consolidation of the process of independence from Spanish dominion in 1818. The consequences were not limited to a revolution of military and political nature; they also included a renovation of the cultural panorama -at least among the educated patriots who made an effort to distance themselves ideologically from the Monarchy-, with the implicit challenge of establishing a new order for Chile, based on legitimate and universally recognizable foundations. The inspirational framework for these efforts is usually associated with other revolutionary examples -France and the United States- that preceded the emancipation processes in Spanish America, as well as with the discourses of illustrated liberalism. As we will attempt to demonstrate in this study, a new reading of the texts written by the Creoles that lead the Chilean independence process may, nonetheless, also reveal the relevance of the classical tradition as a model for the configuration and legitimization of the first Republican projects that especially admired the ideals of Republicanism.

Dévaluation et commerce international : une étude sur quelques pays de la zone CFA

Le travail examine le rôle des prix dans le processus d’ajustement de la balance commerciale des pays de la zone CFA et vérifie la pertinence de la condition Marshall Lerner. Nous avons dérivé des fonctions d'importation et d'exportation à partir d'un problème d'optimisation dynamique puisé dans l'article de Reinhart (1994). Nous nous sommes servis des tests de cointégration. L'étude est calibrée sur le Cameroun, la Côte d'Ivoire, le Gabon et le Togo. Les résultats laissent croire qu'il n'existe pas de relation de long terme entre les prix, les exportations et les importations. La condition Marshall Lerner s'est révélée non valable à court terme. La révision des hypothèses sous-jacentes à cette condition a mis en exergue les élasticités des importations dans les possibilités de réussite de cette dévaluation.

Comportamiento metabólico, fisiológico y electrocardiográfico en trabajadores expuestos a altas temperaturas en una empresa líder en la explotación y coquización del carbón en Boyacá, Colombia, 2016

Objetivo: Establecer la relación entre la exposición ocupacional a altas temperaturas o sobrecarga térmica con el comportamiento fisiológico, metabólico y electrocardiográfico. Métodos: estudio de corte transversal, donde se incluyeron dos grupos (expuesto y no expuesto a altas temperaturas) en una empresa minera, en el departamento de Boyacá, Colombia, en el año 2016. El número de participantes fue de 160 trabajadores del género masculino, grupo expuesto (n=86) y grupo no expuesto (n=74). La exposición ocupacional a sobrecarga térmica se evaluó con el índice de temperatura de globo y bulbo húmedo (TGBH), el comportamiento fisiológico con el índice de costo cardiaco relativo (ICCR) con mediciones de frecuencia cardiaca (FC), el comportamiento metabólico con la determinación del colesterol total (CT), colesterol de alta densidad (C-HDL), colesterol de baja densidad (C-LDL), triglicéridos (TG) y glicemia basal (GL). Las alteraciones electrocardiográficas con la toma de Electrocardiograma de 12 derivaciones. También fueron evaluadas variables antropométricas, tensión arterial, hábitos y antecedentes de enfermedad cardiovascular en ambos grupos. Resultados: incrementos significativos del ICCR (p<0.001) y la carga física (p<0.001) fueron encontrados en los trabajadores expuestos a altas temperaturas. Los índices lipídicos y glicemia, así como los antecedentes personales cardiovasculares, IMC, consumo de cigarrillo y consumo de alcohol, no mostraron significancia. El antecedente familiar de ACV (p=0.043) y el EKG alterado (p=0.011) mostraron una asociación significativa con la exposición a altas temperaturas. El modelo de regresión lineal múltiple explicó la relación entre el incremento del ICCR y la exposición a altas temperaturas (β=4,213, IC 95%: 1.57,6.85) ajustado por variables fisiológicas y electrocardiográficas. Conclusiones: La exposición ocupacional a altas temperaturas, presenta asociación con las alteraciones cardiovasculares a nivel fisiológico y electrocardiográfico, aumentando el ICCR y la carga física de trabajo (GE trabajo).

La importancia del proceso de desarme desmovilización y reinserción (DDR) para las mujeres soldado de sierra leona durante el post-conflicto

El presente estudio de caso tiene como objetivo analizar los procesos de Desarme, Desmovilización y Reintegración para las mujeres excombatientes en Sierra leona, desarrollados por los mecanismos internacionales, tales como la ONU y su misión en este país UNAMSIL, teniendo en cuenta que la Reintegración es el momento más importante para lograr el mantenimiento de la paz que se firmo en el Acuerdo de Lomé. Este trabajo muestra la importancia de una intervención apropiada de acuerdo a las necesidades de cada Estado y teniendo en cuenta las características del conflicto y sus minorías participativas.