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
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
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
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
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
EFSA Panel on Food Contact Material, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 47, Revision 1: Bi- and tricyclic secondary, ketones and related esters from chemical groups 7 and 8
Environmental risk assessment of genetically modified plants - concepts and controversies
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
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.
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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