625 research outputs found

    Conservation and concealment in SpeciesBanking.com, USA: an analysis of neoliberal performance in the species offsetting industry

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    Market-based strategies are promoted as neoliberal governance solutions to environmental problems, from local to global scales. Tradable mitigation schemes are proliferating. These include species banking, which enables payments for the purchase of species credits awarded to conserved areas to offset development impacts on protected species elsewhere. An analysis of species banks in the USA through a survey of data from the website www.SpeciesBanking.com (established as a ‘clearing house’ for species banking information) was complemented by questionnaire material from USA bank managers. The number of USA species banks has increased rapidly, bank area ownership and management is consolidated in a small number of organizations, and public information on species credit price is limited. In interrogating the case material, the roles of specific economic policies associated with neoliberalism are considered, focusing on the extension of privatization, de- and re-regulation and marketization into the arena of environmental conservation, and commodification processes as manifested in species banking. Problematic ecological and distributive ‘concealments’ in species banking include the ‘development-led’ nature of conservation banking, tendencies towards net biodiversity loss, and an emphasis on supporting conservation-related wealth accumulation by larger landowners and investors

    Geochemical proxies of ocean circulation and weathering inputs: Radiogenic isotopes of Nd, Pb, Sr, Hf, and Os

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    Marine records of the radiogenic isotope composition of the elements neodymium (Nd), lead (Pb), hafnium (Hf), strontium (Sr), and osmium (Os) allow the reconstruction of past ontinental weathering inputs on different time scales as a function of their respective oceanic residence times. Sr and Os have oceanic residence times significantly longer than the global mixing time of the ocean and are efficiently mixed on a global scale. Their isotope composition changes on long time scales as a function of plate tectonics and major orogenies, which allows their use as precise stratigraphic tools for the entire Phanerozoic. In contrast, Hf, Pb, and in particular Nd, have residence times on the order of or shorter than the global mixing time of the ocean, which results in distinct isotopic signatures of water masses and allows the reconstruction of past water mass mixing and weathering inputs on both long and short time scales. Here applications of these isotopes systems with a focus on the shorter residence time tracers are reviewed (without claiming to be comprehensive) and problems and potential solutions are discussed. Keywords: Radiogenic isotopes, paleo-oceanography, ocean circulation, water mass mixing, continental weatherin

    Fungicidal effect of three plants extracts in control of four phytopathogenic fungi of tomato (Lycopersicum esculentum L.) fruit rot.

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    Fungicidal effect of leaf aqueous extracts of Azadirachta indica, Tithonia diversifolia and Chromolaena odorata were determined on rot causing fungi. In the study, the phytopathogenic fungi isolated from the infected tomato fruit parts and identified based on morphological and cultural characters were: Aspergillus Niger Van Tiegh, Fusarium oxysporum Schlecht, Geotrichum candidium Link and Rhizopus stolonifer Ehrenb. ex. Fr. as confirmed by pathogenicity tests. Leaf aqueous extracts of different concentrations (20, 40, 80, 60 and 100 % w/v) of A. indica, T. diversifolia and C. odorata were added to growth media prior to inoculation. All aqueous extracts of the tested plants significantly (p < 0.05) reduced mycelial growth of the fungal pathogens and this effect gradually increased with increasing concentration. Fungicidal activity was strongly exhibited by A. indica extract at 100% w/v against all the pathogenic fungi. In the case of T. diversifolia extracts inhibitiory effects at 20, 40, 60, 80 and 100% w/v were greater than those of C. odorata on A. Niger , F. oxysporum and G. candidium while for R. stolonifer inhibition, C. odorata produced the highest in the all five concentrations than T. diversifolia extracts. It could be emphatically concluded that the tested plant extracts can effectively control rot causing fungi disease of tomato. This makes them potential biocide in diseases management in that they are cheap and environmentally safe as they showed fungicidal and fungitoxic ability

    Evidence for intense REE scavenging at cold seeps from the Niger Delta margin

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    International audienceFor many trace elements, continental margins are the location of intense exchange processes between sediment and seawater, which control their distribution in the water column, but have yet to be fully understood. In this study, we have investigated the impact of fluid seepage at cold seeps on the marine cycle of neodymium. We determined dissolved and total dissolvable (TD) concentrations for REE and well-established tracers of fluid seepage (CH4, TDFe, TDMn), and Nd isotopic compositions in seawater samples collected above cold seeps and a reference site (i.e. away from any fluid venting area) from the Niger Delta margin. We also analyzed cold seep authigenic phases and various core-top sediment fractions (pore water, detrital component, easily leachable phases, uncleaned foraminifera) recovered near the hydrocast stations. Methane, TDFe and TDMn concentrations clearly indicate active fluid venting at the studied seeps, with plumes rising up to about 100 m above the seafloor. Depth profiles show pronounced REE enrichments in the non-filtered samples (TD concentrations) within plumes, whereas filtered samples (dissolved concentrations) exhibit slight REE depletion in plumes relative to the overlying water column and display typical seawater REE patterns. These results suggest that the net flux of REE emitted into seawater at cold seeps is controlled by the presence of particulate phases, most probably Fe-Mn oxyhydroxides associated to resuspended sediments. At the reference site, however, our data reveal significant enrichment for dissolved REE in bottom waters, that clearly relates to diffusive benthic fluxes from surface sediments. Neodymium isotopic ratios measured in the water column range from ΔNd ~−15.7 to − 10.4. Evidence that the ΔNd values for Antarctic Intermediate waters (AAIW) differed from those reported for the same water mass at open ocean settings shows that sediment/water interactions take place in the Gulf of Guinea. At each site, however, the bottom water ΔNd signature generally differs from that for cold seep minerals, easily leachable sediment phases, and detrital fractions from local sediments, ruling out the possibility that seepage of methane-rich fluids and sediment dissolution act as a substantial source of dissolved Nd to seawater in the Gulf of Guinea. Taken together, our data hence suggest that co-precipitation of Fe-Mn oxyhydroxide phases in sub-surface sediments leads to quantitative scavenging of dissolved REE at cold seeps, preventing their emission into bottom waters. Most probably, it is likely that diffusion from suboxic surface sediments dominates the exchange processes affecting the marine Nd cycle at the Niger Delta margin

    U-Pb zircon dating of the Gruf Complex: disclosing the late Variscan granulitic lower crust of Europe stranded in the Central Alps

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    Permian granulites associated with noritic intrusions and websterites are a common feature of the post-Variscan European crust. Such granulites are common in the Southern Alps (e.g. Ivrea Zone), but occur only in the Gruf Complex in the Central Alps. To understand the geotectonic significance of these granulites, in particular in the context of Alpine migmatisation, zircons from 15 high-grade samples have been U-Pb dated by SHRIMP II analysis. Oscillatory zoned zircons from charnockite sheets, interpreted as melts generated through granulite facies fluid-absent biotite melting at 920-940°C, yield ages of 282-260Ma. Some of these zircons contain inclusions of opx, unequivocally attributable to the granulite facies, thus confirming a Permian age for the charnockites and associated granulites. Two samples from an enclave-rich orthogneiss sheet yield Cambrian and Ordovician zircon cores. Two deformed leucogranites and six ortho- and augengneisses, which compose two-thirds of the Gruf Complex, give zircon ages of 290-260Ma. Most zircons have milky rims with ages of 34-29Ma. These rims date the Alpine amphibolite facies migmatisation, an interpretation confirmed by directly dating a leucosome pocket from upper amphibolite facies metapelites. The Gruf charnockites associated with metre-scale schlieren and boudins of opx-sapphirine-garnet-granulites, websterites and gabbronorites can thus be identified as part of the post-Variscan European lower crust. A geotectonic reconstruction reveals that this piece of lower crust stranded in the (European) North upon rifting of the Neotethys, such contrasting the widespread granulite units in the Southern Alps. Emplacement of the Gruf lower crust into its present-day position occurred during migmatisation and formation of the Bergell Pluton in the aftermath of the breakoff of the European sla

    Design and characterization of synthetic biodegradable films for musculoskeletal tissue engineering

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    To repair soft tissue, it is vital to ensure that the biomaterial is able to mimic the complex elasticity of the native tissue. It has been demonstrated that substrate stiffness has a huge influence on cellular growth, differentiation, motility and phenotype maintenance. The goal of the present study is to characterize extensively a set of polymeric films with variable mechanical profiles. A range of synthetic biodegradable polymers was selected according to the physico-chemical intrinsic properties of aliphatic polymers. They have similar chemistry (absorbable polyesters made from lactic acid, glycolic acid, trimethylene carbonate, dioxanone & ÎÂČ-caprolactone), however show different mechanical and degradation properties. The films were manufactured by thermal presser and then characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR). The mechanical properties of the films were assessed by uniaxial tensile tests in wet conditions and also by atomic force microscopy (AFM) to assess the material's stiffness at a micro-level. In vitro assays were performed to assess the cell cytocompatibility, proliferation and differentiation potential of the films. The mechanical properties of the materials are within the range intended for musculoskeletal tissue repair. Biological assays showed good cell adhesion, cell proliferation and cell viability. Stem cells were able to differentiate into adipogenic, osteogenic, chondrogenic and tenogenic lineages. Overall the selection of polymers gave good options for a potential tissue repair scaffold. In the future, the combined effect of stiffness and topography will be assessed on cell phenotype maintenance

    Combined pangenomics and transcriptomics reveals core and redundant virulence processes in a rapidly evolving fungal plant pathogen

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    Background Studying genomic variation in rapidly evolving pathogens potentially enables identification of genes supporting their “core biology”, being present, functional and expressed by all strains or “flexible biology”, varying between strains. Genes supporting flexible biology may be considered to be “accessory”, whilst the “core” gene set is likely to be important for common features of a pathogen species biology, including virulence on all host genotypes. The wheat-pathogenic fungus Zymoseptoria tritici represents one of the most rapidly evolving threats to global food security and was the focus of this study. Results We constructed a pangenome of 18 European field isolates, with 12 also subjected to RNAseq transcription profiling during infection. Combining this data, we predicted a “core” gene set comprising 9807 sequences which were; (1) present in all isolates; (2) lacking inactivating polymorphisms; and (3) expressed by all isolates. A large accessory genome, consisting of 45% of the total genes was also defined. We classified genetic and genomic polymorphism at both chromosomal and individual gene scales. Proteins required for essential functions including virulence, had lower-than average sequence variability amongst core genes. Both core and accessory genomes encoded many small, secreted candidate effector proteins that likely interact with plant immunity. Viral vector-mediated transient in planta overexpression of 88 candidates failed to identify any which induced leaf necrosis characteristic of disease. However, functional complementation of a non-pathogenic deletion mutant lacking five core genes, demonstrated that full virulence was restored by re-introduction of the single gene exhibiting least sequence polymorphism and highest expression. Conclusions These data support the combined use of pangenomics and transcriptomics for defining genes which represent core, and potentially exploitable, weaknesses in rapidly evolving pathogens

    Hormone-regulated defense and stress response networks contribute to heterosis in Arabidopsis F1 hybrids

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    Plant hybrids are extensively used in agriculture to deliver increases in yields, yet the molecular basis of their superior performance (heterosis) is not well understood. Our transcriptome analysis of a number of Arabidopsis F1 hybrids identified changes to defense and stress response gene expression consistent with a reduction in basal defense levels. Given the reported antagonism between plant immunity and growth, we suggest that these altered patterns of expression contribute to the greater growth of the hybrids. The altered patterns of expression in the hybrids indicate decreases to the salicylic acid (SA) biosynthesis pathway and increases in the auxin [indole-3-acetic acid (IAA)] biosynthesis pathway. SA and IAA are hormones known to control stress and defense responses as well as plant growth. We found that IAA-targeted gene activity is frequently increased in hybrids, correlating with a common heterotic phenotype of greater leaf cell numbers. Reduced SA concentration and target gene responses occur in the larger hybrids and promote increased leaf cell size. We demonstrated the importance of SA action to the hybrid phenotype by manipulating endogenous SA concentrations. Increasing SA diminished heterosis in SA-reduced hybrids, whereas decreasing SA promoted growth in some hybrids and phenocopied aspects of hybrid vigor in parental lines. Pseudomonas syringae infection of hybrids demonstrated that the reductions in basal defense gene activity in these hybrids does not necessarily compromise their ability to mount a defense response comparable to the parents

    Assessing the combined effect of surface topography and substrate rigidity in human bone marrow stem cell cultures

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    The combined effect of surface topography and substrate rigidity in stem cell cultures is still under-investigated, especially when biodegradable polymers are used. Herein, we assessed human bone marrow stem cell response on aliphatic polyester substrates as a function of anisotropic grooved topography and rigidity (7 and 12 kPa). Planar tissue culture plastic (TCP, 3 GPa) and aliphatic polyester substrates were used as controls. Cell morphology analysis revealed that grooved substrates caused nuclei orientation/alignment in the direction of the grooves. After 21 days in osteogenic and chondrogenic media, the 3 GPa TCP and the grooved 12 kPa substrate induced significantly higher calcium deposition and alkaline phosphatase (ALP) activity and glycosaminoglycan (GAG) deposition, respectively, than the other groups. After 14 days in tenogenic media, the 3 GPa TCP upregulated four and downregulated four genes; the planar 7 kPa substrate upregulated seven genes and downregulated one gene; and the grooved 12 kPa substrate upregulated seven genes and downregulated one gene. After 21 days in adipogenic media, the softest (7 kPa) substrates induced significantly higher oil droplet deposition than the other substrates and the grooved substrate induced significantly higher droplet deposition than the planar. Our data pave the way for more rational design of bioinspired constructs.This work has also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie SkƂodowska-Curie, grant agreement No. 676338, the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme, grant agreement No. 866126 and the European Union’s Horizon 2020 research and innova tion Widespread: Twinning programme, grant agreement No. 810850. This publication has emanated from research supported in part by grants from Science Foundation Ireland (SFI) under Grant numbers 15/CDA/3629 and 19/FFP/6982 and Science Foundation Ireland (SFI) and European Regional Development Fund (ERDF) under grant number 13/RC/2073_2. E.M.F. acknowledges to the project TERM RES Hub – Infraestrutura Científica para a Engenharia de Tecidos e Medicina Regenerativa, Ref Num ber NORTE-01-0145-FEDER-02219015. The authors would like to acknowledge the significant contribution of Dr Oonagh Dwane in the writing and management of all grants. Open access funding provided by IReL
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