Hispanic Oral Tradition: Form and Content

The nineteenth-century humanist Johann Gottfried von Herder distinguished "art poetry" from "natural poetry," and he discovered in the latter "the heart and soul of a people" (Bluestein). Scholars aligned with the nationbuilding process all around the v\/orld have frequently turned to the traditions that issue directly from the life of human communities in the effort to capture their true character, to establish their authentic identities. Oral tradition emerges from the fabric of everyday existence; it responds to the immediate and ultimate problems posed by life in human societies. Its insights and artistry derive from individual genius tempered by collective assent. More than any other expressive product, oral literature provides access to the wisdom and resolve of a people acting within and sometimes against the confines of their historical destiny

A set-based approach for coordination of multi-level collaborative design studies

Presented in this paper is a framework for design coordination of hierarchical (multi-level) design studies. The proposed framework utilizes margin management and set-based design principles for handling the challenges associated with vertical and horizontal design coordination. The former is based on flexible constraints/margins, while the latter is handled by intersecting feasible design spaces across different teams. The framework is demonstrated with an industrial test-case from the UK ATI APPROCONE (Advanced PROduct CONcept analysis Environment) project

Stronger diversity effects with increased environmental stress : a study of multitrophic interactions between oak, powdery mildew and ladybirds

Recent research has suggested that increasing neighbourhood tree species diversity may mitigate the impact of pests or pathogens by supporting the activities of their natural enemies and/or reducing the density of available hosts. In this study, we attempted to assess these mechanisms in a multitrophic study system of young oak (Quercus), oak powdery mildew (PM, caused by Erysiphe spp.) and a mycophagous ladybird (Psyllobora vigintiduo-punctata). We assessed ladybird mycophagy on oak PM in function of different neighbourhood tree species compositions. We also evaluated whether these species interactions were modulated by environmental conditions as suggested by the Stress Gradient Hypothesis. We adopted a complementary approach of a field experiment where we monitored oak saplings subjected to a reduced rainfall gradient in a young planted forest consisting of different tree species mixtures, as well as a lab experiment where we independently evaluated the effect of different watering treatments on PM infections and ladybird mycophagy. In the field experiment, we found effects of neighbourhood tree species richness on ladybird mycophagy becoming more positive as the target trees received less water. This effect was only found as weather conditions grew drier. In the lab experiment, we found a preference of ladybirds to graze on infected leaves from trees that received less water. We discuss potential mechanisms that might explain this preference, such as emissions of volatile leaf chemicals. Our results are in line with the expectations of the Natural Enemies Hypothesis and support the hypothesis that biodiversity effects become stronger with increased environmental stress

Efficient characterization of multiple binding sites of small molecule imaging ligands on amyloid-beta, tau and alpha-synuclein

PURPOSE: There is an unmet need for compounds to detect fibrillar forms of alpha-synuclein (αSyn) and 4-repeat tau, which are critical in many neurodegenerative diseases. Here, we aim to develop an efficient surface plasmon resonance (SPR)-based assay to facilitate the characterization of small molecules that can bind these fibrils. METHODS: SPR measurements were conducted to characterize the binding properties of fluorescent ligands/compounds toward recombinant amyloid-beta (Aβ)$_{42}$, K18-tau, full-length 2N4R-tau and αSyn fibrils. In silico modeling was performed to examine the binding pockets of ligands on αSyn fibrils. Immunofluorescence staining of postmortem brain tissue slices from Parkinson's disease patients and mouse models was performed with fluorescence ligands and specific antibodies. RESULTS: We optimized the protocol for the immobilization of Aβ$_{42}$, K18-tau, full-length 2N4R-tau and αSyn fibrils in a controlled aggregation state on SPR-sensor chips and for assessing their binding to ligands. The SPR results from the analysis of binding kinetics suggested the presence of at least two binding sites for all fibrils, including luminescent conjugated oligothiophenes, benzothiazole derivatives, nonfluorescent methylene blue and lansoprazole. In silico modeling studies for αSyn (6H6B) revealed four binding sites with a preference for one site on the surface. Immunofluorescence staining validated the detection of pS129-αSyn positivity in the brains of Parkinson's disease patients and αSyn preformed-fibril injected mice, 6E10-positive Aβ in arcAβ mice, and AT-8/AT-100-positivity in pR5 mice. CONCLUSION: SPR measurements of small molecules binding to Aβ$_{42}$, K18/full-length 2N4R-tau and αSyn fibrils suggested the existence of multiple binding sites. This approach may provide efficient characterization of compounds for neurodegenerative disease-relevant proteinopathies

International Delegations and the Values of Federalism

Inland water sediments receive large quantities of terrestrial organic matter(1-5) and are globally important sites for organic carbon preservation(5,6). Sediment organic matter mineralization is positively related to temperature across a wide range of high-latitude ecosystems(6-10), but the situation in the tropics remains unclear. Here we assessed temperature effects on the biological production of CO2 and CH4 in anaerobic sediments of tropical lakes in the Amazon and boreal lakes in Sweden. On the basis of conservative regional warming projections until 2100 (ref. 11), we estimate that sediment CO2 and CH4 production will increase 9-61% above present rates. Combining the CO2 and CH4 as CO2 equivalents (CO(2)eq; ref. 11), the predicted increase is 2.4-4.5 times higher in tropical than boreal sediments. Although the estimated lake area in low latitudes is 3.2 times smaller than that of the boreal zone, we estimate that the increase in gas production from tropical lake sediments would be on average 2.4 times higher for CO2 and 2.8 times higher for CH4. The exponential temperature response of organic matter mineralization, coupled with higher increases in the proportion of CH4 relative to CO2 on warming, suggests that the production of greenhouse gases in tropical sediments will increase substantially. This represents a potential large-scale positive feedback to climate change

Efficient use of water for irrigation in the upper midwest

The objectives of this multidisciplinary interinstitutional regional study on the efficient use of water for irrigation in the upper Midwest were: (1) to determine parameters needed for existing or improved models of crop response; (2) to relate yield response to costs and revenues by assessing the water demand for irrigation; and (3) to study the demand for irrigation, present and projected, and its availability as related to public allocation decisions. From this series of studies it was concluded that: (1) There are many areas of the Midwest with sufficient groundwater and surface water resources to support the development of irrigation. (2) Soil moisture models indicate that only moderate yield response to irrigation can be expected on high moisture soils; on lighter soils and claypan soils, yield response is significant, even in regions with relatively high precipitation. (3) Irrigation and drainage on claypan soils can dramatically increase corn yields. (4) It appears economically worthwhile for the individual farmer operating on moderate soils or on claypan soils to evaluate capital investments in irrigation along with other capital investments. (5) Increases in yields and persistence of alfalfa due to irrigation appear to be insignificant when compared to conventional management practices; further research is needed. A potential, however, appears to exist for improving adaptation of a1 fa1 fa varieties to soil water deficits.U.S. Geological SurveyU.S. Department of the InteriorOpe

Biogeochemical functioning of the Baltic Sea

Location, specific topography, and hydrographic setting together with climate change and strong anthropogenic pressure are the main factors shaping the biogeochemical functioning and thus also the ecological status of the Baltic Sea. The recent decades have brought significant changes in the Baltic Sea. First, the rising nutrient loads from land in the second half of the 20th century led to eutrophication and spreading of hypoxic and anoxic areas, for which permanent stratification of the water column and limited ventilation of deep-water layers made favourable conditions. Since the 1980s the nutrient loads to the Baltic Sea have been continuously decreasing. This, however, has so far not resulted in significant improvements in oxygen availability in the deep regions, which has revealed a slow response time of the system to the reduction of the land-derived nutrient loads. Responsible for that is the low burial efficiency of phosphorus at anoxic conditions and its remobilization from sediments when conditions change from oxic to anoxic. This results in a stoichiometric excess of phosphorus available for organic-matter production, which promotes the growth of N2-fixing cyanobacteria and in turn supports eutrophication. This assessment reviews the available and published knowledge on the biogeochemical functioning of the Baltic Sea. In its content, the paper covers the aspects related to changes in carbon, nitrogen, and phosphorus (C, N, and P) external loads, their transformations in the coastal zone, changes in organic-matter production (eutrophication) and remineralization (oxygen availability), and the role of sediments in burial and turnover of C, N, and P. In addition to that, this paper focuses also on changes in the marine CO2 system, the structure and functioning of the microbial community, and the role of contaminants for biogeochemical processes. This comprehensive assessment allowed also for identifying knowledge gaps and future research needs in the field of marine biogeochemistry in the Baltic Sea.Peer reviewe

Dust inputs and bacteria influence dissolved organic matter in clear alpine lakes

Remote lakes are usually unaffected by direct human influence, yet they receive inputs of atmospheric pollutants, dust, and other aerosols, both inorganic and organic. In remote, alpine lakes, these atmospheric inputs may influence the pool of dissolved organic matter, a critical constituent for the biogeochemical functioning of aquatic ecosystems. Here, to assess this influence, we evaluate factors related to aerosol deposition, climate, catchment properties, and microbial constituents in a global dataset of 86 alpine and polar lakes. We show significant latitudinal trends in dissolved organic matter quantity and quality, and uncover new evidence that this geographic pattern is influenced by dust deposition, flux of incident ultraviolet radiation, and bacterial processing. Our results suggest that changes in land use and climate that result in increasing dust flux, ultraviolet radiation, and air temperature may act to shift the optical quality of dissolved organic matter in clear, alpine lakes