296 research outputs found
Die Wirkungsanalyse staatlicher Förderprogramme durch den Einsatz von Matching- und Selektionsmodellen am Beispiel der Fertigungstechnik
Mit dem Ziel die technologische Wettbewerbsfähigkeit zu steigern, investieren die Staaten der OECD jährlich beträchtliche Summen in die Förderung von Forschungs- und Entwicklungsaktivitäten (FuE). Angesichts knapper öffentlicher Budgets ist der Effektivität und Effizienz dieser Förderung eine hohe Bedeutung beizumessen. Neuere Methoden der Wirkungsanalyse tragen dazu bei, begründete Zweifel, die mit dieser Förderung einhergehen, auszuräumen oder zu bekräftigen. Diese Studie widmet sich zwei neueren quantitativen Methoden zur Wirkungsanalyse am Beispiel des deutschen Förderprogramms "Fertigungstechnik". Den Ergebnissen der Selektions- und Matchingansätze zufolge investieren Unternehmen der Fertigungstechnik im Durchschnitt zwischen 67 und 75 Prozent mehr in FuE, wenn sie gefördert werden
Rapid Bursts of \u3ci\u3eAndrogen-Binding Protein (Abp)\u3c/i\u3e Gene Duplication Occurred Independently in Diverse Mammals
Background
The draft mouse (Mus musculus) genome sequence revealed an unexpected proliferation of gene duplicates encoding a family of secretoglobin proteins including the androgen-binding protein (ABP) α, β and γ subunits. Further investigation of 14 α-like (Abpa) and 13 β- or γ-like (Abpbg) undisrupted gene sequences revealed a rich diversity of developmental stage-, sex- and tissue-specific expression. Despite these studies, our understanding of the evolution of this gene family remains incomplete. Questions arise from imperfections in the initial mouse genome assembly and a dearth of information about the gene family structure in other rodents and mammals. Results
Here, we interrogate the latest \u27finished\u27 mouse (Mus musculus) genome sequence assembly to show that the Abp gene repertoire is, in fact, twice as large as reported previously, with 30 Abpa and 34 Abpbg genes and pseudogenes. All of these have arisen since the last common ancestor with rat (Rattus norvegicus). We then demonstrate, by sequencing homologs from species within the Mus genus, that this burst of gene duplication occurred very recently, within the past seven million years. Finally, we survey Abp orthologs in genomes from across the mammalian clade and show that bursts of Abp gene duplications are not specific to the murid rodents; they also occurred recently in the lagomorph (rabbit, Oryctolagus cuniculus) and ruminant (cattle, Bos taurus) lineages, although not in other mammalian taxa. Conclusion
We conclude that Abp genes have undergone repeated bursts of gene duplication and adaptive sequence diversification driven by these genes\u27 participation in chemosensation and/or sexual identification
Die Wirkungsanalyse staatlicher Förderprogramme durch den Einsatz von Matching- und Selektionsmodellen am Beispiel der Fertigungstechnik
Mit dem Ziel die technologische Wettbewerbsfähigkeit zu steigern, investieren die Staaten der OECD jährlich beträchtliche Summen in die Förderung von Forschungs- und Entwicklungsaktivitäten (FuE). Angesichts knapper öffentlicher Budgets ist der Effektivität und Effizienz dieser Förderung eine hohe Bedeutung beizumessen. Neuere Methoden der Wirkungsanalyse tragen dazu bei, begründete Zweifel, die mit dieser Förderung einhergehen, auszuräumen oder zu bekräftigen. Diese Studie widmet sich zwei neueren quantitativen Methoden zur Wirkungsanalyse am Beispiel des deutschen Förderprogramms ?Fertigungstechnik?. Den Ergebnissen der Selektions- und Matchingansätze zufolge investieren Unternehmen der Fertigungstechnik im Durchschnitt zwischen 67 und 75 Prozent mehr in FuE, wenn sie gefördert werden. --Innovation,Public R&D Subsidies,Policy Evaluation,Parametric and Semiparametric Models
Revisiting the Flowers-Ruderman instability of magnetic stars
In 1977, Flowers and Ruderman described a perturbation that destabilises a
purely dipolar magnetic field in a fluid star. They considered the effect of
cutting the star in half along a plane containing the symmetry axis and
rotating each half by 90\degr in opposite directions, which would cause the
energy of the magnetic field in the exterior of the star to be greatly reduced,
just as it happens with a pair of aligned magnets. We formally solve for the
energy of the external magnetic field and check that it decreases monotonously
along the entire rotation. We also describe the instability using perturbation
theory, and see that it happens due to the work done by the interaction of the
magnetic field with surface currents. Finally, we consider the stabilising
effect of adding a toroidal field by studying the potential energy perturbation
when the rotation is not done along a sharp cut, but with a continuous
displacement field that switches the direction of rotation across a region of
small but finite width. Using these results, we estimate the relative strengths
of the toroidal and poloidal field needed to make the star stable to this
displacement and see that the energy of the toroidal field required for
stabilisation is much smaller than the energy of the poloidal field. We also
show that, contrary to a common argument, the Flowers-Ruderman instability
cannot be applied many times in a row to reduce the external magnetic energy
indefinitely.Comment: Uploaded complete version with corrections from the MNRAS refere
Microscale <i>In Vitro</i> Assays for the Investigation of Neutral Red Retention and Ethoxyresorufin-<i>O</i>-Deethylase of Biofuels and Fossil Fuels
<div><p>Only few information on the potential toxic effectiveness of biofuels are available. Due to increasing worldwide demand for energy and fuels during the past decades, biofuels are considered as a promising alternative for fossil fuels in the transport sector. Hence, more information on their hazard potentials are required to understand the toxicological impact of biofuels on the environment. In the German Cluster of Excellence “Tailor-made Fuels from Biomass” design processes for economical, sustainable and environmentally friendly biofuels are investigated. In an unique and interdisciplinary approach, ecotoxicological methods are applied to gain information on potential adverse environmental effects of biofuels at an early phase of their development. In the present study, three potential biofuels, ethyl levulinate, 2-methyltetrahydrofuran and 2-methylfuran were tested. Furthermore, we investigated a fossil gasoline fuel, a fossil diesel fuel and an established biodiesel. Two <i>in vitro</i> bioassays, one for assessing cytotoxicity and one for aryl hydrocarbon receptor agonism, so called dioxin-like activity, as measured by Ethoxyresorufin-<i>O</i>-Deethylase, were applied using the permanent fish liver cell line RTL-W1 (<i>Oncorhynchus mykiss</i>). The special properties of these fuel samples required modifications of the test design. Points that had to be addressed were high substance volatility, material compatibility and low solubility. For testing of gasoline, diesel and biodiesel, water accommodated fractions and a passive dosing approach were tested to address the high hydrophobicity and low solubility of these complex mixtures. Further work has to focus on an improvement of the chemical analyses of the fuel samples to allow a better comparison of any effects of fossil fuels and biofuels.</p></div
ADDA: a domain database with global coverage of the protein universe
We used the Automatic Domain Decomposition Algorithm (ADDA) to generate a database of protein domain families with complete coverage of all protein sequences. Sequences are split into domains and domains are grouped into protein domain families in a completely automated process. The current database contains domains for more than 1.5 million sequences in more than 40 000 domain families. In particular, there are 3828 novel domain families that do not overlap with the curated domain databases Pfam, SCOP and InterPro. The data are freely available for downloading and querying via a web interface (http://ekhidna.biocenter.helsinki.fi:9801/sqgraph/pairsdb)
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Insights into the evolution of Darwin’s finches from comparative analysis of the Geospiza magnirostris genome sequence
Background: A classical example of repeated speciation coupled with ecological diversification is the evolution of 14 closely related species of Darwin’s (Galápagos) finches (Thraupidae, Passeriformes). Their adaptive radiation in the Galápagos archipelago took place in the last 2–3 million years and some of the molecular mechanisms that led to their diversification are now being elucidated. Here we report evolutionary analyses of genome of the large ground finch, Geospiza magnirostris. Results: 13,291 protein-coding genes were predicted from a 991.0 Mb G. magnirostris genome assembly. We then defined gene orthology relationships and constructed whole genome alignments between the G. magnirostris and other vertebrate genomes. We estimate that 15% of genomic sequence is functionally constrained between G. magnirostris and zebra finch. Genic evolutionary rate comparisons indicate that similar selective pressures acted along the G. magnirostris and zebra finch lineages suggesting that historical effective population size values have been similar in both lineages. 21 otherwise highly conserved genes were identified that each show evidence for positive selection on amino acid changes in the Darwin's finch lineage. Two of these genes (Igf2r and Pou1f1) have been implicated in beak morphology changes in Darwin’s finches. Five of 47 genes showing evidence of positive selection in early passerine evolution have cilia related functions, and may be examples of adaptively evolving reproductive proteins. Conclusions: These results provide insights into past evolutionary processes that have shaped G. magnirostris genes and its genome, and provide the necessary foundation upon which to build population genomics resources that will shed light on more contemporaneous adaptive and non-adaptive processes that have contributed to the evolution of the Darwin’s finches.Organismic and Evolutionary Biolog
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Catching Element Formation In The Act
Gamma-ray astronomy explores the most energetic photons in nature to address
some of the most pressing puzzles in contemporary astrophysics. It encompasses
a wide range of objects and phenomena: stars, supernovae, novae, neutron stars,
stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays
and relativistic-particle acceleration, and the evolution of galaxies. MeV
gamma-rays provide a unique probe of nuclear processes in astronomy, directly
measuring radioactive decay, nuclear de-excitation, and positron annihilation.
The substantial information carried by gamma-ray photons allows us to see
deeper into these objects, the bulk of the power is often emitted at gamma-ray
energies, and radioactivity provides a natural physical clock that adds unique
information. New science will be driven by time-domain population studies at
gamma-ray energies. This science is enabled by next-generation gamma-ray
instruments with one to two orders of magnitude better sensitivity, larger sky
coverage, and faster cadence than all previous gamma-ray instruments. This
transformative capability permits: (a) the accurate identification of the
gamma-ray emitting objects and correlations with observations taken at other
wavelengths and with other messengers; (b) construction of new gamma-ray maps
of the Milky Way and other nearby galaxies where extended regions are
distinguished from point sources; and (c) considerable serendipitous science of
scarce events -- nearby neutron star mergers, for example. Advances in
technology push the performance of new gamma-ray instruments to address a wide
set of astrophysical questions
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