Physical oceanography from the northwestern Weddell Sea

We analyzed hydrographic data from the northwestern Weddell Sea continental shelf of the three austral winters 1989, 1997, and 2006 and two summers following the last winter cruise. During summer a thermal front exists at ~64° S separating cold southern waters from warm northern waters that have similar characteristics as the deep waters of the central basin of the Bransfield Strait. In winter, the whole continental shelf exhibits southern characteristics with high Neon (Ne) concentrations, indicating a significant input of glacial melt water. The comparison of the winter data from the shallow shelf off the tip of the Antarctic Peninsula, spanning a period of 17 yr, shows a salinity decrease of 0.09 for the whole water column, which has a residence time of <1 yr. We interpret this freshening as being caused by a combination of reduced salt input due to a southward sea ice retreat and higher precipitation during the late 20th century on the western Weddell Sea continental shelf. However, less salinification might also result from a delicate interplay between enhanced salt input due to sea ice formation in coastal areas formerly occupied by Larsen A and B ice shelves and increased Larsen C ice loss.

Sea-floor images from ROV transects during POLARSTERN cruise ANT-XVII/3 (EASIZ III) to the Weddell Sea, Antarctica

Transects of a Remotely Operated Vehicle (ROV) providing sea-bed videos and photographs were carried out during POLARSTERN expedition ANT-XVII/3 focussing on the ecology of benthic assemblages on the Antarctic shelf in the South-Eastern Weddell Sea. The ROV-system sprint 103 was equiped with two video- and one still camera, lights, flash-lights, compass, and parallel lasers providing a scale in the images, a tether-management system (TMS), a winch, and the board units. All cameras used the same main lense and could be tilted. Videos were recorded in Betacam-format and (film-)slides were made by decision of the scientific pilot. The latter were mainly made under the aspect to improve the identification of organisms depicted in the videos because the still photographs have a much higher optical resolution than the videos. In the photographs species larger than 3 mm, in the videos larger than 1 cm are recognisable and countable. Under optimum conditions the transects were strait; the speed and direction of the ROV were determined by the drift of the ship in the coastal current, since both, the ship and the ROV were used as a drifting system; the option to operate the vehicle actively was only used to avoide obstacles and to reach at best a distance of only approximately 30 cm to the sea-floor. As a consequence the width of the photographs in the foreground is approximately 50 cm. Deviations from this strategy resulted mainly from difficult ice- and weather conditions but also from high current velocity and local up-welling close to the sea-bed. The sea-bed images provide insights into the general composition of key species, higher systematic groups and ecological guilds. Within interdisciplinary approaches distributions of assemblages can be attributed to environmental conditions such as bathymetry, sediment characteristics, water masses and current regimes. The images also contain valuable information on how benthic species are associated to each other. Along the transects, small- to intermediate-scaled disturbances, e.g. by grounding icebergs were analysed and further impact to the entire benthic system by local succession of recolonisation was studied. This information can be used for models predicting the impact of climate change to benthic life in the Southern Ocean. All these approaches contribute to a better understanding of the fiunctioning of the benthic system and related components of the entire Antarctic marine ecosystem. Despite their scientific value the imaging methods meet concerns about the protection of sensitive Antarctic benthic systems since they are non-invasive and they also provide valuable material for education and outreach purposes.

CFC, and noble gas measurements during POLARSTERN cruise ANT-XXIX/3

During the austral summer expedition PS81, ANT-XXIX/3 with the German research ice breaker Polarstern in 2013, research was carried out to investigate the role of environmental factors on the distribution of benthic communities and marine mammal and krill densities around the northern tip of the Antarctic Peninsula. For these studies collated in this special issue and studies in this area, we present a collection of environmental parameters with probable influence on the marine ecosystems around the Antarctic Peninsula.

Dinoflagellate cysts counts of sediment core MD95-2042

Dinoflagellate cysts were analysed from IMAGES core MD952042 (37°48?N; 10°01?W) retrieved from the Tagus Abyssal Plain. Previous results of stable isotope and magnetic susceptibility measurements as well as of planktonic foraminiferal temperature reconstruction from this core, suggest the occurrence of "Heinrich-like events" (i.e. large ice-sheet decay) during Marine Isotopic Stage 5 (MIS 5). Dinoflagellate assemblages of this time period have revealed six dinocyst events that are characterised by peaks in Bitectatodinium tepikiense percentages. These events occur synchronously with "Heinrich-like events" previously identified. They are coeval with major retreats of the forest on land, indicating, therefore, drastic changes in the regional climate. However, results from the Ice-Rafted Detritus (IRD) analysis of the >150 ?m lithic fraction shows that MIS 5 of MD952042 has only recorded one significant input of iceberg discharge, located at the MIS 6/MIS 5 transition. It seems therefore that it is the only event that could be called a "true Heinrich event".

Fabricando falsas verdades: la prensa italiana de izquierdas y la construcción de la imagen de palestinos e israelíes (1947-1957)

El objetivo del presente estudio es analizar la forma en la que la prensa italiana de izquierdas construyó la imagen de palestinos e israelíes entre 1947 y 1957. La investigación se ha centrado en el estudio de los artículos publicados por algunos destacados periódicos de la época, con la finalidad de comprender cómo ha ido cambiando el lenguaje empleado por dichos órganos de prensa a la hora de referirse a los moradores de la tierra de Palestina. La tesis de este artículo es que dichos periódicos construyeron múltiples y contradictorias representaciones de judíos y palestinos, representaciones que no tenían nada que ver con la realidad de Oriente Medio, sino que obedecían a cuestiones ideológicas de carácter nacional e internacional (relaciones entre los partidos italianos y evolución de las dinámicas de la guerra fría).

Morphological characterization of two new species of Dicontophrya (Ciliophora: Astomatia: Contophryidae) commensal of earthworms (Oligochaeta: Annelida) of ebebda and nkolbikogo (Cameroon)

Article

Parasitos metazoários de duas populações de Leporinus friderici (Characiformes, anostomidae) do sistema do Rio Amazonas no Brasil.

Leporinus friderici Bloch, 1794 é um Anostomidae com ampla distribuição nas bacias dos rios Amazonas, Paraná e Araguaia-Tocantins. Tem hábito alimentar onívoro, alimentando-se de insetos, material vegetal, detritos, frutos, sementes, camarão e pequenos peixes, bem como hábitos diurnos e sedentárias. No sistema Rio Amazonas, esse peixe se reproduz no período de abril a outubro, e tem desova total. Este estudo comparou a estrutura das comunidades de parasitos metazoários em duas populações de Leporinus friderici de diferentes bacias do sistema do Rio Amazonas, no Brasil. Em julho de 2012, 47 espécimes de L. friderici (22.1 ± 3.8 cm e 171.1 ± 86.3 g) foram coletados na bacia do Rio Jari, município de Vitória do Jari, Estado do Amapá (Brasil), e de julho a dezembro de 2012, 50 espécimes de L. friderici (15.1 ± 3.6 cm e 57.4 ± 42.8 g) foram coletadas na bacia Igarapé Fortaleza, próximo à cidade de Macapá, estado do Amapá (Brasil), para análise parasitológica. Métodos usuais de coleta, fixação, conservação e identificação dos parasitos foram usados neste estudo. Os termos ecológicos usados foram os recomendados na literatura. O índice de diversidade de Shannon (H) e uniformidade (E), riqueza de espécies e frequência de dominância (FD%) foram calculados para avaliar a comunidade componente de parasitos. O índice de dispersão e índice de discrepância foram calculados, para detectar o padrão de distribuição das infracomunidades de parasitos para espécies com prevalência >10%. As duas populações de L. friderici estavam parasitadas por Jainus leporini, Urocleidoides paradoxus, Urocleidoides sp., Tereancistrum parvus, Tereancistrum sp., Clinostomum marginatum, Procamallanus (Spirocamallanus) inopinatus, Contracaecum sp., Octospiniferoides incognita e Ergasilus sp. Houve diferença na riqueza de espécies de parasitos, índice de Shannon e equitabilidade entre ambas as populações de L. friderici, pois a comunidade de parasitos mostrou similaridade de apenas 33%. Somente os monogenoideas, C. marginatum e P. (S.) inopinatus foram as espécies de parasitos compartilhadas por ambas as populações de L. friderici examinados. Os parasitos apresentaram padrão dispersão agregada, exceto Contracaecum sp., que mostrou padrão de dispersão randômica. Diferenças no tamanho dos hospedeiros foi um dos fatores que contribuiram para as diferenças nos níveis de parasitos encontradas entre as populações estudadas. O hábito alimentar contribui para ocorrência de endoparasitos em L. friderici, hospedeiro intermediário para tais esses parasitos como ciclo de vida complexo. Este é primeiro registro de O. incognita, C. marginatum e Ergasilus para L. friderici.

HISTORIA Y EVOLUCIÓN DE LOS SISTEMAS DE INFORMACIÓN GEOGRÁFICA EN COSTA RICA

Este trabajo presenta un estudio retrospectivo de los orígenes y evolución de la aplicación de Sistemas de  Información Geográfca  (SIG) y Teledetección  (TD) en nuestro país. Se  inicia por el  rol desempeñado del Profesor Merrill Lyew dentro de  la Escuela de Ciencias Geográfcas de la Universidad Nacional, pasando luego por una breve descripción del proceso de implementación de SIG y TD en los centros de enseñanza superior estatales.En esta breve descripción se analiza cómo diferentes unidades académicas han ido incorporando la tecnología SIG y TD en sus planes de estudio.Posteriormente, se presenta una aproximación de la situación actual SIG y TD en las instituciones públicas y privadas y cómo ellas han venido incorporando estas tecnologías en su quehacer diario. Se hace alusión a diferentes eventos que se han llevado en Costa Rica con el objetivo de compartir experiencias en las más diversas aplicaciones.De la misma manera se citan algunas de las principales empresas privadas que se dedican a la venta de insumos, aplicaciones, capacitaciones y software en el campo SIG y TD. En el camino óptimo se visualizan dos opciones por seguir:  la consolidación ofcial de un organismo, comisión o secretaría que tenga bajo su responsabilidad la organización de la Infraestructura Nacional de Datos Geoespaciales. La segunda versa sobre el esfuerzo realizado por las Escuelas de Geografía de la Universidad de Costa Rica y Universidad Nacional para ofrecer a partir del 2008 el Programa de Maestría Profesional en Sistemas de Información Geográfca y Teledetección. Palabras claves: Sistemas de Información Geográfca (SIG), Teledetección, Evolución, Historia, Costa Rica.Abstract This work is a retrospective study of the origins and evolution of the applications of Geographic Information Systems (GIS) and Remote Sensing in our country. It begins with the work of Prof. Merryl Lyew of the School of Geographic Sciences at Universidad Nacional and continues with a brief description of the GIS and Remote Sensing implementation process at state centers of higher education.It  also  analyzes  how  different  academic  departments  have  incorporated GIS  and Remote Sensing technology in their courses of study.Subsequently, this work presents an approximation of the actual situation regarding GIS and remote sensing  in public and private  institutions and how  these  technologies have become incorporated in their daily work. It also refers to the different events that have been carried on in Costa Rica with the objective of sharing experiences in the most diverse applications. In the same way, this work cites some of the principal private businesses dedicated to the sale of supplies, applications, training and software in the feld of GIS and remote sensing. Two options are seen as the best way to pursue the offcial consolidation of an agency, commission  or  administrative  department  to  have  under  its  responsibility  organization  of  the National Infrastructure of Geospatial Data. The second deals with the successful effort by the School of Geographic Sciences at Universidad Nacional of Costa Rica as of 2008 to offer the Professional Master’s program in Geographic Information Systems and Remote Sensing.KEyWordS: Geographic Information Systems (GIS), Remote Sensing, Origin, Evolution, Costa Rica, Universidad Nacional