Particle flux measurements from moorings and surface sediment studies of sediment cores in the SE Pacific Ocean

Flux of siliceous plankton and taxonomic composition of diatom and silicoflagellate assemblages were determined from sediment trap samples collected in coastal upwelling-influenced waters off northern Chile (30°S, CH site) under "normal" or non-El Niño (1993-94) and El Niño conditions (1997-98). In addition, concentration of biogenic opal and siliceous plankton, and diatom and silicoflagellate assemblages preserved in surface sediments are provided for a wide area between 27° and 43°S off Chile. Regardless of the year, winter upwelling determines the maximum production pattern of siliceous microorganisms, with diatoms numerically dominating the biogenic opal flux. During the El Niño year the export is markedly lower: on an annual basis, total mass flux diminished by 60%, and diatom and silicoflagellate export by 75%. Major components of the diatom flora maintain much of their regular seasonal cycle of flux maxima and minima during both sampling periods. Neritic resting spores (RS) of Chaetoceros dominate the diatom flux, mirroring the influence of coastal-upwelled waters at the CH trap site. Occurrence of pelagic diatoms species Fragilariopsis doliolus, members of the Rhizosoleniaceae, Azpeitia spp. and Nitzschia interruptestriata, secondary components of the assemblage, reflects the intermingling of warmer waters of the Subtropical Gyre. Dictyocha messanensis dominates the silicoflagellate association almost year-around, but Distephanus pulchra delivers ca. 60% of its annual production in less than three weeks during the winter peak. The siliceous thanatocoenosis is largely dominated by diatoms, whose assemblage shows significant qualitative and quantitative variations from north to south. Between 27° and 35°S, the dominance of RS Chaetoceros, Thalassionema nitzschioides var. nitzschioides and Skeletonema costatum reflects strong export production associated with occurrence of coastal upwelling. Both highest biogenic opal content and diatom concentration at 35° and 41°-43°S coincide with highest pigment concentrations along the Chilean coast. Predominance of the diatom species Thalassiosira pacifica and T. poro-irregulata, and higher relative contribution of the silicoflagellate Distephanus speculum at 41°-43°S suggest the influence of more nutrient-rich waters and low sea surface temperatures, probably associated with the Antarctic Circumpolar Water.

Making Abortion Services Accessible in the Wake of Legal Reforms: A Framework and Six Case Studies

Contiene Informe completo y resumen.

X. Riu, Dionysism and Comedy, Greek Studies: Interdisciplinary Approaches, Series Editor: G. Nagy, Harvard University, Rowman and Litkefield Publishers, Inc. Maryland, 1999, vii+294 pp.

Fil: Zecchin de Fasano, Graciela Cristina. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

X. Riu, Dionysism and Comedy, Greek Studies: Interdisciplinary Approaches, Series Editor: G. Nagy, Harvard University, Rowman and Litkefield Publishers, Inc. Maryland, 1999, vii+294 pp.

Fil: Zecchin de Fasano, Graciela Cristina. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

X. Riu, Dionysism and Comedy, Greek Studies: Interdisciplinary Approaches, Series Editor: G. Nagy, Harvard University, Rowman and Litkefield Publishers, Inc. Maryland, 1999, vii+294 pp.

Fil: Zecchin de Fasano, Graciela Cristina. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Benthic foraminiferal d18O and Mg/Ca studies of sediment cores off tropical NW Africa

Benthic foraminiferal d18O and Mg/Ca of sediment cores off tropical NW Africa are used to study the properties of Atlantic central waters during the Last Glacial Maximum (LGM) and Heinrich Stadial 1 (HS1). We combined our core top data with published results to develop a new Mg/Ca-temperature calibration for Planulina ariminensis, which shows a Mg/Ca-temperature sensitivity of 0.19 mmol/mol per °C. Estimates of the LGM and HS1 thermocline temperatures are comparable to the present-day values between 200 and 400 m water depth, but were 1.2-1.5°C warmer at 550-570 m depth. The HS1 thermocline waters (200-570 m depth) did not show any warming relative to the LGM. This is in contrast to previous climate model studies, which concluded that tropical Atlantic thermocline waters warmed significantly when Atlantic meridional overturning circulation was reduced. However, our results suggest that thermocline temperatures of the northeastern tropical Atlantic show no pronounced sensitivity to changes in the thermohaline circulation during glacial periods. In contrast, we find a significant increase in thermocline-water salinity during the LGM (200-550 m depth) and HS1 (200-400 m depth) with respect to the present-day, which we relate to changes in the wind-driven circulation. We infer that the LGM thermocline (200-550 m depth) and the HS1 upper thermocline (200-400 m depth) in the northeastern tropical Atlantic was ventilated by surface waters from the North Atlantic rather than the southern-sourced waters. This suggests that the frontal zone between the modern South Atlantic and North Atlantic Central Waters was probably shifted southward during the LGM and HS1.

Larval and post-larval stages of pacific oyster (Crassostrea gigas) are resistant to elevated CO2

Rising anthropogenic carbon dioxide (CO2) dissolving into coastal waters is decreasing the pH and carbonate ion concentration, thereby lowering the saturation state of calcium carbonate (CaCO3) minerals through a process named ocean acidification (OA). The unprecedented threats posed by such low pH on calcifying larvae of several edible oyster species have not yet been fully explored. Effects of low pH (7.9, 7.6, 7.4) on the early growth phase of Portuguese oyster (Crassostrea angulata) veliger larvae was examined at ambient salinity (34 ppt) and the low-salinity (27 ppt) treatment. Additionally, the combined effect of pH (8.1, 7.6), salinity (24 and 34 ppt) and temperature (24 °C and 30 °C) was examined using factorial experimental design. Surprisingly, the early growth phase from hatching to 5-day-old veliger stage showed high tolerance to pH 7.9 and pH 7.6 at both 34 ppt and 27 ppt. Larval shell area was significantly smaller at pH 7.4 only in low-salinity. In the 3-factor experiment, shell area was affected by salinity and the interaction between salinity and temperature but not by other combinations. Larvae produced the largest shell at the elevated temperature in low-salinity, regardless of pH. Thus the growth of the Portuguese oyster larvae appears to be robust to near-future pH level (> 7.6) when combined with projected elevated temperature and low-salinity in the coastal aquaculture zones of South China Sea.

Micropaleontological and geochemical proxy studies of sediment core GeoB7926-2

[1] The low-latitude upwelling regime off the Mauritanian coast in the subtropical NE Atlantic accounts for a significant part of global export production. Although productivity variations in coastal upwelling areas are usually attributed to changes in wind stress and upwelling intensity, productivity dynamics off Mauritania are less straightforward because of the complex atmospheric and hydrographic setting. Here we integrate micropaleontological (diatoms) and geochemical (bulk biogenic sediment components, X-ray fluorescence, and alkenones) proxies to examine on submillennial-to-millennial changes in diatom production that occurred off Mauritania, NW Africa, for the last 25 ka. During the Last Glacial Maximum (LGM, 19.0-23.0 ka B.P.), moderate silicate content of upwelled waters coupled with weakened NE trade winds determined moderate diatom productivity. No significant cooling is observed during the LGM, suggesting that our alkenone-based SST reconstruction represents a local, upwelling-related signal rather than a global insolation related one. Extraordinary increases in diatom and opal concentrations during Heinrich event 1 (H1, 15.5-18.0 ka B.P.) and the Younger Dryas (YD, 13.5-11.5 ka B.P.) are attributed to enhanced upwelling of silica-rich waters and an enlarged upwelling filament, due to more intense NE trade winds. The synchronous increase of CaCO3 and K intensity and the decreased opal and diatoms values mark the occurrence of the Bølling/Allerød (BA, 13.5-15.5 ka B.P.) due to weakened eolian input and more humid conditions on land. Although the high export of diatoms is inextricably linked to upwelling intensity off Mauritania, variability in the nutrient content of the thermocline also plays a decisive role.

The Sandinista Revolution and Post-Conflict Development--Key Issues

Following Daniel Ortega's victory in the presidential election held in November 2006, Nicaragua has been undergoing a transition from a democratic to authoritarian system. In the 1980s, Ortega served as President of the Sandinista government and implemented a Cuban-type socialist system, but the system failed and democracy was established during 1990-2007. Considering this failure, why did Ortega succeed in taking power again? This paper provides a brief history of modern Nicaragua and gives some insights into the twists of Latin American politics. The paper was prepared for the international seminar on Helping Failed States Recover: The Role of Business in Promoting Stability and Development, organized by the University of Kansas Center for International Business Education and Research (CIBER), held on April 4-6, 2007 in Lawrence. The opinions and views expressed herein are those of the author. All mistakes and/or errors are entirely the author's responsibility.

Ethnicity and Elections under Authoritarianism: The Case of Kazakhstan

Despite the ethnicisation of power since independence in 1991, Kazakhstan has managed to maintain political stability without experiencing large-scale mobilisation to oppose Kazakh domination. This paper examines government strategy to avoid ethnic voting in an attempt to explain why ethnic divisions were rarely reflected in the struggle for power in the republic. While the arbitrary use of legal provisions considerably limited participation in elections by ethnic leaders, powerful pro-president parties that exhibited a cross-ethnic character were created to curtail ethnically based movements. The control strategy in elections aimed not simply at ethnicising the parliament in favour of Kazakhs, but at having loyal Russians and other minorities represented in the legislature through nomination by the president and catch-all pro-regime parties, or through the presidential consultative body—Assembly of the People of Kazakhstan. This well-controlled representation of minorities served not only to placate non-Kazakhs but also to provide legitimacy for the Kazakh-dominated leadership by projecting the image of cross-ethnic support for the president and some degree of power-sharing.

Depth dependent lattice disorder and strain in Mn-implanted and post-annealed InAs thin films

The lattice order degree and the strain in as-grown, Mn-implanted and post-implantedannealedInAsthinfilms were investigated with depth resolution by means of Rutherford backscattering spectrometry in channeling conditions (RBS/C). Three main crystallographic axes were analyzed for both In and As sublattices. The behaviour of the induced defects was evaluated in two regions with different native defects: the interface and the surface. The results show that Mn implantation and post-implantation annealing are anisotropic processes, affecting in a different way the In and As sublattices. The mechanisms influencing the enhancement and deterioration of the crystal quality during the implantation are discussed in relation to the as-grown defects and the segregation of the elements

Survey and brain storming studies about machines, constructions, human and environmental risk consideration in the careers of the Universidad Politécnica of Madrid

The Universidad Politécnica of Madrid (UPM) includes schools and faculties that were for engineering degrees, architecture and computer science, that are now in a quick EEES Bolonia Plan metamorphosis getting into degrees, masters and doctorate structures. They are focused towards action in machines, constructions, enterprises, that are subjected to machines, human and environment created risks. These are present in actions such as use loads, wind, snow, waves, flows, earthquakes, forces and effects in machines, vehicles behavior, chemical effects, and other environmental factors including effects of crops, cattle and beasts, forests, and varied essential economic and social disturbances. Emphasis is for authors in this session more about risks of natural origin, such as for hail, winds, snow or waves that are not exactly known a priori, but that are often considered with statistical expected distributions giving extreme values for convenient return periods. These distributions are known from measures in time, statistic of extremes and models about hazard scenarios and about responses of man made constructions or devices. In each engineering field theories were built about hazards scenarios and how to cover for important risks. Engineers must get that the systems they handle, such as vehicles, machines, firms or agro lands or forests, obtain production with enough safety for persons and with decent economic results in spite of risks. For that risks must be considered in planning, in realization and in operation, and safety margins must be taken but at a reasonable cost. That is a small level of risks will often remain, due to limitations in costs or because of due to strange hazards, and maybe they will be covered by insurance in cases such as in transport with cars, ships or aircrafts, in agro for hail, or for fire in houses or in forests. These and other decisions about quality, security for men or about business financial risks are sometimes considered with Decision Theories models, using often tools from Statistics or operational Research. The authors have done and are following field surveys about risk consideration in the careers in UPM, making deep analysis of curricula taking into account the new structures of degrees in the EEES Bolonia Plan, and they have considered the risk structures offered by diverse schools of Decision theories. That gives an aspect of the needs and uses, and recommendations about improving in the teaching about risk, that may include special subjects especially oriented for each career, school or faculty, so as to be recommended to be included into the curricula, including an elaboration and presentation format using a multi-criteria decision model.