467 research outputs found

    Distinctive features of spatial planning nearby estuaries – an exploratory analysis of water-related rules in municipal master plans in Portugal

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    Land-use types and related intensities are often associated with pressures and disturbances on estuarine envi- ronmental values and ecosystem services provided by water. Although with varied legal frameworks across countries, broadly, spatial planning has been expected to contribute to the protection of environmentally sen- sitive areas, such as estuaries. Among the various planning tools are the plan’s land-use control rules. This article studies the incorporation of water-related terms in the regulations of municipal master plans to assess if land-use rules established on estuarine areas are significantly different from others, such as in upstream areas. It does so by developing a content analysis of a set of plans’ regulations located in estuarine and upstream areas of two river basins of Mainland Portugal. The results show greater incorporation of water-related terms in plans’ reg- ulations located in estuarine areas. Moreover, they show a greater diversity of water-related topics, types, and focus of rules on estuarine areas, whereas on upstream areas the regulatory approaches look poorer. Although the incorporation of water-related terms is globally higher in younger plans, and to a certain extent, in more arti- ficialized and dense territories, a clear distinctiveness of water-related concerns in land-use regulations of municipal plans on estuarine areas remains visible. Surprisingly, the results bring to the fore fragilities of land- use regulations on upstream areas worthy of attention in future studies. The methodology used for content analysis disclosed a valuable path for future research as it is easily expandable to take into consideration different land-uses or to be applied to different regions, to further refine if the distinctive features are explicitly related with estuarine areas or with other types of water problems.publishe

    Lactate Produced by Glycogenolysis in Astrocytes Regulates Memory Processing

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    When administered either systemically or centrally, glucose is a potent enhancer of memory processes. Measures of glucose levels in extracellular fluid in the rat hippocampus during memory tests reveal that these levels are dynamic, decreasing in response to memory tasks and loads; exogenous glucose blocks these decreases and enhances memory. The present experiments test the hypothesis that glucose enhancement of memory is mediated by glycogen storage and then metabolism to lactate in astrocytes, which provide lactate to neurons as an energy substrate. Sensitive bioprobes were used to measure brain glucose and lactate levels in 1-sec samples. Extracellular glucose decreased and lactate increased while rats performed a spatial working memory task. Intrahippocampal infusions of lactate enhanced memory in this task. In addition, pharmacological inhibition of astrocytic glycogenolysis impaired memory and this impairment was reversed by administration of lactate or glucose, both of which can provide lactate to neurons in the absence of glycogenolysis. Pharmacological block of the monocarboxylate transporter responsible for lactate uptake into neurons also impaired memory and this impairment was not reversed by either glucose or lactate. These findings support the view that astrocytes regulate memory formation by controlling the provision of lactate to support neuronal functions

    Variations on a theme: diversification of cuticular hydrocarbons in a clade of cactophilic Drosophila

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    <p>Abstract</p> <p>Background</p> <p>We characterized variation and chemical composition of epicuticular hydrocarbons (CHCs) in the seven species of the <it>Drosophila buzzatii </it>cluster with gas chromatography/mass spectrometry. Despite the critical role of CHCs in providing resistance to desiccation and involvement in communication, such as courtship behavior, mating, and aggregation, few studies have investigated how CHC profiles evolve within and between species in a phylogenetic context. We analyzed quantitative differences in CHC profiles in populations of the <it>D. buzzatii </it>species cluster in order to assess the concordance of CHC differentiation with species divergence.</p> <p>Results</p> <p>Thirty-six CHC components were scored in single fly extracts with carbon chain lengths ranging from C<sub>29 </sub>to C<sub>39</sub>, including methyl-branched alkanes, <it>n</it>-alkenes, and alkadienes. Multivariate analysis of variance revealed that CHC amounts were significantly different among all species and canonical discriminant function (CDF) analysis resolved all species into distinct, non-overlapping groups. Significant intraspecific variation was found in different populations of <it>D. serido </it>suggesting that this taxon is comprised of at least two species. We summarized CHC variation using CDF analysis and mapped the first five CHC canonical variates (CVs) onto an independently derived <it>period </it>(<it>per</it>) gene + chromosome inversion + mtDNA COI gene for each sex. We found that the COI sequences were not phylogenetically informative due to introgression between some species, so only <it>per </it>+ inversion data were used. Positive phylogenetic signal was observed mainly for CV1 when parsimony methods and the test for serial independence (TFSI) were used. These results changed when no outgroup species were included in the analysis and phylogenetic signal was then observed for female CV3 and/or CV4 and male CV4 and CV5. Finally, removal of divergent populations of <it>D. serido </it>significantly increased the amount of phylogenetic signal as up to four out of five CVs then displayed positive phylogenetic signal.</p> <p>Conclusions</p> <p>CHCs were conserved among species while quantitative differences in CHC profiles between populations and species were statistically significant. Most CHCs were species-, population-, and sex-specific. Mapping CHCs onto an independently derived phylogeny revealed that a significant portion of CHC variation was explained by species' systematic affinities indicating phylogenetic conservatism in the evolution of these hydrocarbon arrays, presumptive waterproofing compounds and courtship signals as in many other drosophilid species.</p

    Governing and accelerating transformative entrepreneurship: exploring the potential for small business innovation on urban sustainability transitions

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    The alluring yet nebulous concept of transformative change is increasingly gaining traction in conversations about pathways to more sustainable futures. As such, new conceptual tools are needed to illuminate variety of actors, interests, and capacities at play in potentially radical experiments. This paper draws upon multi-level governance theory, sustainability transitions scholarship, and sustainability entrepreneurship literature, to interrogate the transformative potential of small and medium-sized enterprises (SMEs). We (1) identify characteristics of SMEs that might make them relatively more able to produce radical innovations, (2) explore dimensions of the broader socio-political context that influence the likelihood of this potential to be translated into action in urban spaces, and (3) discuss implications of these dynamics for transformative sustainability governance

    Recombination in West Nile Virus: minimal contribution to genomic diversity

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    Recombination is known to play a role in the ability of various viruses to acquire sequence diversity. We consequently examined all available West Nile virus (WNV) whole genome sequences both phylogenetically and with a variety of computational recombination detection algorithms. We found that the number of distinct lineages present on a phylogenetic tree reconstruction to be identical to the 6 previously reported. Statistically-significant evidence for recombination was only observed in one whole genome sequence. This recombination event was within the NS5 polymerase coding region. All three viruses contributing to the recombination event were originally isolated in Africa at various times, with the major parent (SPU116_89_B), minor parent (KN3829), and recombinant sequence (AnMg798) belonging to WNV taxonomic lineages 2, 1a, and 2 respectively. This one isolated recombinant genome was out of a total of 154 sequences analyzed. It therefore does not seem likely that recombination contributes in any significant manner to the overall sequence variation within the WNV genome

    PB1-F2 Proteins from H5N1 and 20th Century Pandemic Influenza Viruses Cause Immunopathology

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    With the recent emergence of a novel pandemic strain, there is presently intense interest in understanding the molecular signatures of virulence of influenza viruses. PB1-F2 proteins from epidemiologically important influenza A virus strains were studied to determine their function and contribution to virulence. Using 27-mer peptides derived from the C-terminal sequence of PB1-F2 and chimeric viruses engineered on a common background, we demonstrated that induction of cell death through PB1-F2 is dependent upon BAK/BAX mediated cytochrome c release from mitochondria. This function was specific for the PB1-F2 protein of A/Puerto Rico/8/34 and was not seen using PB1-F2 peptides derived from past pandemic strains. However, PB1-F2 proteins from the three pandemic strains of the 20th century and a highly pathogenic strain of the H5N1 subtype were shown to enhance the lung inflammatory response resulting in increased pathology. Recently circulating seasonal influenza A strains were not capable of this pro-inflammatory function, having lost the PB1-F2 protein's immunostimulatory activity through truncation or mutation during adaptation in humans. These data suggest that the PB1-F2 protein contributes to the virulence of pandemic strains when the PB1 gene segment is recently derived from the avian reservoir

    Governing and accelerating transformative entrepreneurship: exploring the potential for small business innovation on urban sustainability transitions

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    The alluring yet nebulous concept of transformative change is increasingly gaining traction in conversations about pathways to more sustainable futures. As such, new conceptual tools are needed to illuminate variety of actors, interests, and capacities at play in potentially radical experiments. This paper draws upon multi-level governance theory, sustainability transitions scholarship, and sustainability entrepreneurship literature, to interrogate the transformative potential of small and medium-sized enterprises (SMEs). We (1) identify characteristics of SMEs that might make them relatively more able to produce radical innovations, (2) explore dimensions of the broader socio-political context that influence the likelihood of this potential to be translated into action in urban spaces, and (3) discuss implications of these dynamics for transformative sustainability governance

    Suriname: Reconciling agricultural development and conservation of unique natural wealth

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    National and transboundary adverse effects of competition for land are being increasingly recognized by researchers and decision-makers, however the consideration of these impacts within national planning strategies is not yet commonplace. To estimate how increasing agricultural production can be conciliated with protection of natural resources at the national scale, we analyzed current land use in Suriname, and investigated opportunities for, and constraints to developing a sustainable agricultural sector. Suriname is a remarkable case study. To date, Suriname has retained most of its natural resources with forest areas covering over 90% of the country. Surinamese forests combine extremely high levels of both biodiversity and carbon, making them top priority from a global ecosystem services perspective. Among other national and international pressures from increased demand for agricultural products, the country is also considering significant expansion of agricultural output to both diminish imports and become a ‘bread basket’ for the Caribbean region, which collectively may pose risks to natural resources. In this study, combining locally-obtained primary data, expert consultation and secondary data from the Food and Agriculture Organization we analyzed a range of scenarios, we show the complexities associated with current land management and we discuss alternatives for developing a sustainable agricultural sector in Suriname. We show that Suriname can increase the production of rice, which is the most important agricultural activity in the country, without expanding rice area. Rather, future increase in rice production could be promoted through an increase in rice productivity, and the employment of more environmentally-favorable management methods, in order to both diminish pollution and avoid encroachment of the agriculture into pristine areas. Further, we show a potential to both contribute to greening of the agricultural sector and to higher economic returns through expanding the production of ‘safe food’ and through possible development of organic agriculture in Suriname. If Suriname develops a ‘greener’ agricultural sector, it may both increase economic returns from the agricultural sector and benefit from continuing protection of natural resources. Because most of Suriname forests present top levels of carbon and biodiversity, the country could benefit from so-called ‘early-action’ Reducing Emissions from Deforestation and Forest Degradation (REDD) finance, which is already being paid mostly through bilateral agreements. Further, by adopting land-use planning that protects natural resources, Suriname may be in extraordinary position to benefit from both improved-quality agricultural production and from incentives to conserve forest carbon and biodiversity, such as payments for ecosystem services. Given the high stakes and the severe lack of both primary data and applied analyses in Suriname, further research focused on better informing land-use policies would be a valuable investment for the country. Although this analysis was performed for Suriname, conclusions drawn here are transferrable and may assist formulation of policy recommendations for land use elsewhere

    Discharge–calcium concentration relationships in streams of the Amazon and Cerrado of Brazil : soil or land use controlled

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    Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of springer for personal use, not for redistribution. The definitive version was published in Biogeochemistry 105 (2011): 19-35, doi:10.1007/s10533-011-9574-2.Stream discharge-concentration relationships are indicators of terrestrial ecosystem function. Throughout the Amazon and Cerrado regions of Brazil rapid changes in land use and land cover may be altering these hydrochemical relationships. The current analysis focuses on factors controlling the discharge-calcium (Ca) concentration relationship since previous research in these regions has demonstrated both positive and negative slopes in linear log10discharge-log10Ca concentration regressions. The objective of the current study was to evaluate factors controlling stream discharge-Ca concentration relationships including year, season, stream order, vegetation cover, land use, and soil classification. It was hypothesized that land use and soil class are the most critical attributes controlling discharge-Ca concentration relationships. A multilevel, linear regression approach was utilized with data from 28 streams throughout Brazil. These streams come from three distinct regions and varied broadly in watershed size (106 ha) and discharge (10-5.7 to 103.2 m3 sec-1). Linear regressions of log10Ca versus log10discharge in 13 streams have a preponderance of negative slopes with only two streams having significant positive slopes. An ANOVA decomposition suggests the effect of discharge on Ca concentration is large but variable. Vegetation cover, which incorporates aspects of land use, explains the largest proportion of the variance in the effect of discharge on Ca followed by season and year. In contrast, stream order, land use, and soil class explain most of the variation in stream Ca concentration. In the current data set, soil class, which is related to lithology, has an important effect on Ca concentration but land use, likely through its effect on runoff concentration and hydrology, has a greater effect on discharge-concentration relationships.This research was supported by grant #’s NCC5-686 and NNG06GE88A of NASA’s Terrestrial Ecology Program as part of the Large-scale Biosphere-Atmosphere Experiment in Amazonia (LBA-ECO) project
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