3,385 research outputs found

    The natural history observations and collections made during Furneaux's visit to Tasmania (Van Diemen's Land) in 1773 with special reference to botany

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    During the visit of H.M.S. ADVENTURE to Tasmania in March 1773 a number of animals and birds were caught or observed; several of the birds were later drawn. As well, Tobias Furneaux, captain of ADVENTURE, collected seeds of at least two plants, Eucalyptus obliqua and Leptospermum lanigerum, and herbarium specimens of the latter, which were brought back to England. The seeds were germinated and plants were growing in London gardens in the late 1770's. The possible existence of other herbarium specimens is discussed, and the reasons for the small amount of scientific collection by ADVENTURE's complement are discussed

    The locations of collection and collectors of specimens described by Labillardierc in 'Novae Hollandiae Plantarum Specimen' - additional notes

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    Several plants described by Labillardire and indicated to have been collected in Tasmania are shown to be species endemic to Western Australia. The locations are corrected and collectors are indicated if the original specimens could not have been collected by Labillardiere. The reasons for these errors are discussed and it is concluded that caution is required in accepting Labillardiere's type locations

    Controlled interfacial assembly of 2D curved colloidal crystals and jammed shells

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    Assembly of colloidal particles on fluid interfaces is a promising technique for synthesizing two-dimensional micro-crystalline materials useful in fields as diverse as biomedicine1, materials science2, mineral flotation3 and food processing4. Current approaches rely on bulk emulsification methods, require further chemical and thermal treatments, and are restrictive with respect to the materials employed5-9. The development of methods that exploit the great potential of interfacial assembly for producing tailored materials have been hampered by the lack of understanding of the assembly process. Here we report a microfluidic method that allows direct visualization and understanding of the dynamics of colloidal crystal growth on curved interfaces. The crystals are periodically ejected to form stable jammed shells, which we refer to as colloidal armour. We propose that the energetic barriers to interfacial crystal growth and organization can be overcome by targeted delivery of colloidal particles through hydrodynamic flows. Our method allows an unprecedented degree of control over armour composition, size and stability.Comment: 18 pages, 5 figure

    Scientific Opinion on the safety and efficacy of disodium 5?-ribonucleotides, disodium 5?-guanylate, disodium 5?-inosinate for all animal species and categories

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    The flavours included in this assessment are widely present in nature as the building blocks of DNA and RNA. In the absence of any information on the microbial strains or substrates used for the production of the additives, and with little information on the manufacturing process, the FEEDAP Panel is unable to ascertain whether the manufacturing process introduces any safety concerns. Disodium 5′-guanylate and disodium 5′-inosinate and their mixture are considered to be safe for the target animals and the consumer. However, considering the lack of information on the production process, these conclusions apply only to the compounds ‘per se’ and their extrapolation to any feed additive containing these compounds is not possible. In the absence of any data related to hazard to the user, it would be prudent to regard disodium 5′-guanylate and disodium 5′-inosinate and their mixture as potentially hazardous to workers by skin or inhalation exposure. The compounds under assessment are naturally present in feed materials; therefore, no risk to the safety for the environment is foreseen. Since these compounds are used in food as flavourings, and their function in feed is essentially the same as that in food, no further demonstration of efficacy is necessary

    Environmental risk assessment of genetically modified plants - concepts and controversies

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    Background and purpose: In Europe, the EU Directive 2001/18/EC lays out the main provisions of environmental risk assessment (ERA) of genetically modified (GM) organisms that are interpreted very differently by different stakeholders. The purpose of this paper is to: (a) describe the current implementation of ERA of GM plants in the EU and its scientific shortcomings, (b) present an improved ERA concept through the integration of a previously developed selection procedure for identification of non-target testing organisms into the ERA framework as laid out in the EU Directive 2001/18/EC and its supplement material (Commission Decision 2002/623/EC), (c) describe the activities to be carried out in each component of the ERA and (d) propose a hierarchical testing scheme. Lastly, we illustrate the outcomes for three different crop case examples. Main features: Implementation of the current ERA concept of GM crops in the EU is based on an interpretation of the EU regulations that focuses almost exclusively on the isolated bacteria-produced novel proteins with little consideration of the whole plant. Therefore, testing procedures for the effect assessment of GM plants on non-target organisms largely follow the ecotoxicological testing strategy developed for pesticides. This presumes that any potential adverse effect of the whole GM plant and the plant-produced novel compound can be extrapolated from testing of the isolated bacteriaproduced novel compound or can be detected in agronomic field trials. This has led to persisting scientific criticism. Results: Based on the EU ERA framework, we present an improved ERA concept that is system oriented with the GM plant at the centre and integrates a procedure for selection of testing organisms that do occur in the receiving environment. We also propose a hierarchical testing scheme from laboratory studies to field trials and we illustrate the outcomes for three different crop case examples. Conclusions and recommendations: Our proposed concept can alleviate a number of deficits identified in the current approach to ERA of GM plants. It allows the ERA to be tailored to the GM plant case and the receiving environment

    Decaying Dark Matter can explain the electron/positron excesses

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    PAMELA and ATIC recently reported excesses in e+ e- cosmic rays. Since the interpretation in terms of DM annihilations was found to be not easily compatible with constraints from photon observations, we consider the DM decay hypothesis and find that it can explain the e+ e- excesses compatibly with all constraints, and can be tested by dedicated HESS observations of the Galactic Ridge. ATIC data indicate a DM mass of about 2 TeV: this mass naturally implies the observed DM abundance relative to ordinary matter if DM is a quasi-stable composite particle with a baryon-like matter asymmetry. Technicolor naturally yields these type of candidates.Comment: 20 pages, 7 figure

    Genome-wide association study identifies loci associated with liability to alcohol and drug dependence that is associated with variability in reward-related ventral striatum activity in African- and European-Americans.

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    Genetic influences on alcohol and drug dependence partially overlap, however, specific loci underlying this overlap remain unclear. We conducted a genome-wide association study (GWAS) of a phenotype representing alcohol or illicit drug dependence (ANYDEP) among 7291 European-Americans (EA; 2927 cases) and 3132 African-Americans (AA: 1315 cases) participating in the family-based Collaborative Study on the Genetics of Alcoholism. ANYDEP was heritable (h 2 in EA = 0.60, AA = 0.37). The AA GWAS identified three regions with genome-wide significant (GWS; P < 5E-08) single nucleotide polymorphisms (SNPs) on chromosomes 3 (rs34066662, rs58801820) and 13 (rs75168521, rs78886294), and an insertion-deletion on chromosome 5 (chr5:141988181). No polymorphisms reached GWS in the EA. One GWS region (chromosome 1: rs1890881) emerged from a trans-ancestral meta-analysis (EA + AA) of ANYDEP, and was attributable to alcohol dependence in both samples. Four genes (AA: CRKL, DZIP3, SBK3; EA: P2RX6) and four sets of genes were significantly enriched within biological pathways for hemostasis and signal transduction. GWS signals did not replicate in two independent samples but there was weak evidence for association between rs1890881 and alcohol intake in the UK Biobank. Among 118 AA and 481 EA individuals from the Duke Neurogenetics Study, rs75168521 and rs1890881 genotypes were associated with variability in reward-related ventral striatum activation. This study identified novel loci for substance dependence and provides preliminary evidence that these variants are also associated with individual differences in neural reward reactivity. Gene discovery efforts in non-European samples with distinct patterns of substance use may lead to the identification of novel ancestry-specific genetic markers of risk
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