Migraciones temporarias, ciclos laborales y estrategias de reproducción social : El caso de las unidades domésticas del área rural de Bernardo de Irigoyen (Misiones, Argentina) participes del empleo forestal

Este artículo versa sobre un conjunto de unidades domésticas ubicadas en el área rural de Bernardo de Irigoyen (Misiones), en las que algunos de sus integrantes migran temporalmente al empleo forestal de otras provincias. El objetivo es comprender la práctica migratoria y su peso con relación a los demás mecanismos de reproducción social en las unidades domésticas. La metodología es de tipo cualitativa mediante la realización de entrevistas a trabajadores migrantes y sus parientes. El trabajo concluye que la movilidad espacial es un recurso al cual los trabajadores y sus familias acceden de modo desigual para lograr su reproducción social

Reflexiones metodológicas sobre algunas contribuciones de la terapia familiar sistémica a un estudio antropológico de la familia

El fenómeno migratorio ha sido tratado a partir de diferentes estudios históricos, sociológicos, demográficos y antropológicos. Muchas veces estos abordajes solo ofrecen respuestas parciales a las problemáticas que conforman la migración. Nuestras investigaciones se centraron en el estudio de grupos de inmigrantes caboverdeanos en Argentina, aportando modelos sobre la organización e interacción de esos grupos, con el fin de explorar temas críticos, como inmigración y familia, identidad y etnicidad, entre otros. Luego de años de trabajo hemos ajustado metodologías, sobre todo las derivadas de la antropología tradicional, buscando alternativas, "reciclando" premisas, pautas y técnicas de otras disciplinas como la psicología (en particular la terapia familiar de orientación sistémica). En este trabajo reflexionamos sobre algunas cuestiones metodológicas, particularmente el uso de genogramas puestos en práctica en el estudio del parentesco y de la familia caboverdeana en un contexto migratorio, cuyo análisis fue uno de los objetivos planteados en el proyecto de investigación sobre el mencionado grupo en la Argentina

La lírica popular-tradicional argentina : Límites difusos

La sociedad argentina puede caracterizarse como "nueva", producto de proyectos poblacionales y migraciones internas y externas. Esta condición determinó que la cultura popular, y la poesía en particular, se manifestaran en distintas tradiciones superpuestas. Una tradición hispánica procedente del período colonial se asentó en el noroeste del país, área de población más antigua en la que fueron documentados romances y coplas tradicionales. Paralelamente, una tradición criolla heredera de la hispánica tuvo expresiones autóctonas en relación con los movimientos independentistas (romancero criollo, pero también décimas y coplas). Por último, una tradición europea se incorporó entre fines del siglo xix y principios del xx con el denominado aluvión inmigratorio. Esta última corriente impregnó todo lo anterior con nuevos temas procedentes especialmente de España, pero en contacto con diversas formas populares de otros países como Italia, Francia y Portugal. El propósito de este artículo es ofrecer un panorama de la superposición de estos distintos estratos culturales tal como se manifiesta en las coplas que se cantaron y se imprimieron en la primera mitad del Siglo xx

La educación de los descendientes de inmigrantes japoneses en la Colonia Justo José de Urquiza

Este trabajo es el resultado de un estudio sobre la evolución de la visión que sobre la educación tiene un grupo de inmigrantes japoneses y sus descendientes, los nikkei, radicados en la Colonia Justo José de Urquiza. El caso es analizado desde un marco teórico que abarca el concepto de cultura y sus variables, donde la interculturalidad es la resultante. Desde este marco teórico, es posible visualizar cómo se manifiesta esta comunidad, en relación con la sociedad receptora, en este caso la platense y las características propias educativas. Para ello, se realiza una síntesis de la educación en Japón, en especial de posguerra, ya que los padres de la generación que nace en Argentina traen consigo, con la emigración, un bagaje cultural y educacional de su país de origen correspondiente a la etapa anterior al movimiento migratorio. Al instalarse en una colonia agrícola en Argentina esta visión perdura y forma parte de sus comportamientos, por lo tanto construyen el imaginario de la comunidad en un lugar propicio para reproducirlo, manteniendo rasgos particulares. No sólo se analiza el ámbito rural, también se contempla su relación con el ámbito urbano, sus influencias o no dentro de ese espacio geográfico. Para establecer parámetros se realiza un apartado comparativo con otra comunidad que arribó al país al mismo tiempo y en las mismas condiciones que el caso abordado en este trabajo, algunos exponentes de la colectividad italiana, con el fin de observar diferencias o similitudes en la educación de los hijos, los proyectos, los logros o las deserciones

Ni crisol de razas, ni pluralismo cultural : Pluralismo social. Migraciones y pautas matrimoniales en una ciudad patagónica (Neuquén, 1960-1990)

Este trabajo pretende aproximarse al problema de la integración de los migrantes en sociedades de crecimiento explosivo. Para ello, centra sus reflexiones en un caso particular: la ciudad de Neuquén (Patagonia, Argentina) en el periodo comprendido entre 1960 y 1990. Tomando en consideración los comportamientos matrimoniales de migrantes de diferentes orígenes, tanto intra e interprovinciales como trasandinos, el texto intentará discutir los alcances de categorías como las de melting pot, pluralismo cultural y pluralismo social. El trabajo analiza un corpus documental compuesto por cerca de tres millares de actas matrimoniales extraídas del Archivo de la Dirección Provincial de Registro Civil de Neuquén

Geochemical and biogeochemical parameters of bottom sediments from the area of the Spitsbergen (Svalbard) Archipelago

Quantitative characteristics for rates of diagenetic processes in the upper (0-30 cm) layer of sedimentary deposits in the area of the Spitsbergen (Svalbard) Archipelago (78°-80°N) were obtained by lithologo-geochemical, radioisotope (35S, 14C), and stable isotope (d34S, d13C) studies. It was proved that rates of diagenetic processes in polar deposits at 123-395 m depth affected by the East Spitsbergen ''warm'' current are mostly determined by bioproductivity and are commensurate with rates of processes in shelf deposits of temperate latitudes. High contents of migratory methane (up to 263 ml/dm**3) and isotopically-light organic carbon (Corg, d13C = -30 per mil PDB) were found in the 1 m layer of shelf deposits (at 123 m sea depth) with low bacterial in situ production of methane. It was shown that methane is not utilized in the deposits by the methanotrophic bacterial community and it may be supplied to the water mass and, probably, to the atmosphere.

Rates of seropositivity for Toxoplasma gondii antibodies in polar bears and marine mammals around Svalbard

Little is known about the prevalence of the parasite Toxoplasma gondii in the arctic marine food chain of Svalbard, Norway. In this study, plasma samples were analyzed for T. gondii antibodies using a direct agglutination test. Antibody prevalence was 45.6% among polar bears (Ursus maritimus), 18.7% among ringed seals (Pusa hispida) and 66.7% among adult bearded seals (Erignathus barbatus) from Svalbard, but no sign of antibodies were found in bearded seal pups, harbour seals (Phoca vitulina), white whales (Delphinapterus leucas) or narwhals (Monodon monoceros) from the same area. Prevalence was significantly higher in male polar bears (52.3%) compared with females (39.3%), likely due to dietary differences between the sexes. Compared to an earlier study, T. gondii prevalence in polar bears has doubled in the past decade. Consistently, an earlier study on ringed seals did not detect T. gondii. The high recent prevalence in polar bears, ringed seals and bearded seals could be caused by an increase in the number or survivorship of oocysts being transported via the North Atlantic Current to Svalbard from southern latitudes. Warmer water temperatures have led to influxes of temperate marine invertebrate filter-feeders that could be vectors for oocysts and warmer water is also likely to favour higher survivorship of oocycts. However, a more diverse than normal array of migratory birds in the Archipelago recently, as well as a marked increase in cruise-ship and other human traffic are also potential sources of T. gondii.

(Table 3) Soil temperatures at 10 cm depth after different treatments of wet sedge meadows on Ellesmere Island

Wet sedge tundra communities in the High Arctic are valuable sources of forage for several resident and migratory herbivores; however, the effects of grazing on these systems have been rarely studied. We simulated grazing in two wet sedge meadows at a site on Ellesmere Island that has not been affected by grazing. Over two summers, we clipped plots at four different frequencies and removed litter to assess effects on aboveground net primary production, availability of soil nitrogen, shoot concentrations of carbon and nitrogen, and soil temperature and moisture regimes. Available soil nitrate and ammonium were highest in plots with intermediate clipping frequencies. Shoot nitrogen concentrations were also greater at intermediate clipping frequencies in two of the four species studied. Aboveground net primary production decreased after clipping, regardless of frequency. Litter removal resulted in slightly increased soil moisture, but had no effect on aboveground net primary production. Soil temperature was not affected by any of our treatments. These results suggest that nitrogen cycling is stimulated by intermediate frequencies of simulated grazing, but clipping decreased aboveground net primary production in ungrazed high arctic wet sedge tundra.

Distribution of macrozooplankton at time series station MIGZOO-1

Vertical distributions and diel migrations of the main species of micronekton, four euphausiids, one mysid, one decapod and three fishes, were described in detail in the 0-1000 m water column on a fixed station in the Northwestern Mediterranean Sea. The euphausiids Euphausia krohni and Thysanopoda aequalis, the decapod Gennadas elegans and, to a lesser extent, the fish Argyropelecus hemigymnus were shown to perform clear diel vertical migrations. Results of horizontal hauls at a given depth around sunrise and sunset showed a marked diurnal symmetry of the migratory cycles, particularly for E.krohni, T.aequalis and G.elegans. The behaviour of the euphausiid Nematoscelis megalops was more complex: it presented a repetitive bimodal day distribution and only part of its population migrated. As very weak or non-migrators we found the euphausiid Stylocheiron longicorne and the bathypelagic mysid Eucopia unguiculata, for which migration concerned only some of the older individuals. The fishes Cyclothone braueri and Cyclothone pygmaea appeared to be non-migrants. As depth increased, C.braueri was replaced by C.pygmaea, with maximum concentrations at 350-550 and 550-700 m depth, respectively.

Distribution of macrozooplankton at time series station MIGZOO-4

A large population of the colonial pelagic tunicate Pyrosoma atlanticum occurred in April 1991 in offshore waters of the Ligurian Sea (Northwestern Mediterranean). The high numbers of colonies caught allowed their vertical distribution and diel migration in the 0-965 m water column to be described as a function of their size. Daytime depths and amplitudes of the migration were correlated with colony size. The amplitude of the migration ranged from 90 m for 3-mm-length colonies to 760 m for 51-mm-length colonies, with a mean amplitude of 410 m for the whole population, all sizes pooled. The results of horizontal hauls at a given depth around sunrise and sunset showed a marked diurnal symmetry of the migratory cycle relative to noon, and that migration of the population was not cohesive. For example, the larger the colonies, the later after sunset they reached the upper layers during their upward migration.

Feeding of Sagitta setosa in the Black Sea

Gut dissection of fixed individuals from samples collected during Cruise 6 of R/V Vityaz-2 in April-May 1984 was used to study feeding of Sagitta setosa in the layers of daytime plankton accumulation at the lower boundary of the oxycline. The principal food was copepodite stage V of Calanus and females of Calanus and Pseudocalanus. Analysis of daytime and night data with reference to length of migratory alterations of Sagitta populations and gut passage time indicates that they feed actively in the layers of day¬time plankton accumulations. Total food consumption during time spent in the subsurface layers ranged from 0.025-0.097 cal/indiv. in 12 h, equivalent to 37-143% of their metabolic energy expenditure. Over the course of 12 h Sagitta population consumes 0.3-5% and 0.5-6% of population of stage V copepodites and females of Calanus and Pseudocalanus females, respectively.

(Table 1) Date, deployment location, tag longevity, and satellite data of humpback whales (Megaptera novaeangliae) off New Caledonia

Knowledge of the local and migratory movements of humpback whales (Megaptera novaeangliae) from New Caledonia is very limited. To investigate this topic, we attached satellite-monitored tags to 12 whales off southern New Caledonia. Tag longevity ranged from 1 to 52 days (X = 22.5 days). Tagged whales generally moved to the south or southeast, with several spending time in a previously unknown seamount habitat named Antigonia before resuming movement, generally toward Norfolk Island or New Zealand. However, 1 female with a calf traveled the entire length of the western coast of New Caledonia (~450 km) and then west in the direction of the Chesterfield Reefs, a 19th century American (''Yankee'') whaling ground. None of the New Caledonia whales traveled to or toward eastern Australia, which is broadly consistent with the low rate of interchange observed from photo-identification comparisons between these 2 areas. The connections between New Caledonia and New Zealand, together with the relatively low numbers of whales seen in these places generally, support the idea that whales from these 2 areas constitute a single population that remains small and unrecovered.

(Table 1) Concentrations of organic pollutants in soil samples from Adélie penguin (Pygoscelis adeliae) colonies and reference sites, Hop Island, Antarctica

Although long-range atmospheric transport has been described as the predominant mechanism for exposing polar regions to persistent organic pollutants (POPs), recent studies have suggested that bird activity can also contribute substantially to contaminant levels in some environments. However, because the species so far reported have all been migratory, it has not been demonstrated conclusively whether locally elevated contamination represents transport from lower latitudes by the migrating birds or, alternatively, redistribution and concentration of contaminants that were already present in the high-latitude environments. The present study demonstrates, for the first time, that several POPs are present in elevated concentrations in an environment frequented by a non-migratory species (Adelie penguins) that spends its entire life in the Antarctic. Levels of POPs, such as p,p'-DDE, hexachlorobenzene (HCB), chlordanes (CHLs) and polychlorinated biphenyls (PCBs), were 10 to 100-fold higher in soil samples from penguin colonies than from reference areas. This significant difference is likely related to local penguin activity, such as a higher abundance of guano and the presence of bird carcasses. This hypothesis is also supported by a higher percentage of persistent congeners (PCB 99, 118, 138 and 153) in the soil from the colonies compared to the reference areas. This profile of PCB congeners closely matched profiles seen in penguin eggs or penguin blood.

Migration forms of hydrocarbons in waters and bottom sediments of the Gulf of Riga

It is found that hydrocarbons are constantly accumulated on the main geochemical barriers: water-atmosphere, river-sea, water-suspended matter, and water-bottom sediment interfaces. Degree of hydrocarbon accumulation reaches 13.5-17.6 in the surface microlayer and exceeds 1000 in bottom sediments. Hydrocarbon composition changes in this process. Local pollutant loads result in accumulation of polycyclic aromatic hydrocarbons by bottom sediments and benzo(a)pyrene concentration sometimes exceeds MPC. Content of hydrocarbon migratory forms is calculated.