121 research outputs found

    The Impact of Agricultural Knowledge Transfer Resources on Farm Level Profitability during the Economic Recession – A Quantitative Study

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    Purpose: The outcomes from agricultural knowledge transfer (KT) are dependent on the access to and the quality of services available, coupled with the motivation of prospective clients to implement new skills. Within this context, the allocation of resources particularly in terms of the location of KT offices and number of agricultural advisers are important considerations for understanding KT impact. This quantitative study evaluates the impact of the rationalisation of KT resources on farm profitability for KT clients in Ireland during the recessionary period 2008-2014. Design/Methodology: Teagasc, the public KT service provider in Ireland, experienced significant office closures (43%) and staff reduction (38%) during the economic crisis, yet client numbers declined only slightly (4.5%). Administrative data is merged with a panel data set on farm level performance to test the impact of KT through Random Effects estimation. Findings: The results show that annual contract holders gained a 12.3% benefit to their market gross margin per hectare over the period. However, there was a negative effect of 0.2% for each additional client assigned to the adviser which averaged at 9.6% per adviser. Practical Implications: The quantitative findings provide a measure of impact that represents the value for money for the KT service. The key implication is that the client ratio for advisers should be considered when allocating resources and lower ratios would positively impact client margins. Theoretical Implications: This article outlines the value of quantitative studies to estimate impact in a clear translatable manner which can aid the policy discussion around resource deployment particularly in a recessionary period. The employment of a Random Effects estimator on a panel data set provides a solid base for the analysis. Originality/Value: This study evaluates the impact of KT on farm level profitability during a recessionary period when resources were constrained, and uses spatial variables and client densities to examine the regional effects

    Quantum Holographic Encoding in a Two-dimensional Electron Gas

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    The advent of bottom-up atomic manipulation heralded a new horizon for attainable information density, as it allowed a bit of information to be represented by a single atom. The discrete spacing between atoms in condensed matter has thus set a rigid limit on the maximum possible information density. While modern technologies are still far from this scale, all theoretical downscaling of devices terminates at this spatial limit. Here, however, we break this barrier with electronic quantum encoding scaled to subatomic densities. We use atomic manipulation to first construct open nanostructures--"molecular holograms"--which in turn concentrate information into a medium free of lattice constraints: the quantum states of a two-dimensional degenerate Fermi gas of electrons. The information embedded in the holograms is transcoded at even smaller length scales into an atomically uniform area of a copper surface, where it is densely projected into both two spatial degrees of freedom and a third holographic dimension mapped to energy. In analogy to optical volume holography, this requires precise amplitude and phase engineering of electron wavefunctions to assemble pages of information volumetrically. This data is read out by mapping the energy-resolved electron density of states with a scanning tunnelling microscope. As the projection and readout are both extremely near-field, and because we use native quantum states rather than an external beam, we are not limited by lensing or collimation and can create electronically projected objects with features as small as ~0.3 nm. These techniques reach unprecedented densities exceeding 20 bits/nm2 and place tens of bits into a single fermionic state.Comment: Published online 25 January 2009 in Nature Nanotechnology; 12 page manuscript (including 4 figures) + 2 page supplement (including 1 figure); supplementary movie available at http://mota.stanford.ed

    Teagasc submission made in response to the Discussion document for the preparation of a National Policy Statement on the Bioeconomy

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    Teagasc SubmissionThis document is Teagasc’s response to the β€œDiscussion Document for the Preparation of a National Policy Statement on the Bioeconomy” issued by the Department of the Taoiseach’s Economic Division in July 2017. It recognises the potential significance of the bioeconomy to Ireland, offers some policy and strategic insights from other countries, and identifies Teagasc’s role in supporting the development of the bioeconomy in Ireland

    Worldviews about change: their structure and their implications for understanding responses to sustainability, technology, and political change

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    People hold different perspectives about how they think the world is changing or should change. We examined five of these β€œworldviews” about change: Progress, Golden Age, Endless Cycle, Maintenance, and Balance. In Studies 1–4 (total N = 2733) we established reliable measures of each change worldview, and showed how these help explain when people will support or oppose social change in contexts spanning sustainability, technological innovations, and political elections. In mapping out these relationships we identify how the importance of different change worldviews varies across contexts, with Balance most critical for understanding support for sustainability, Progress/Golden Age important for understanding responses to innovations, and Golden Age uniquely important for preferring Trump/Republicans in the 2016 US election. These relationships were independent of prominent individual differences (e.g., values, political orientation for elections) or context-specific factors (e.g., self-reported innovativeness for responses to innovations). Study 5 (N = 2140) examined generalizability in 10 countries/regions spanning five continents, establishing that these worldviews exhibited metric invariance, but with country/region differences in how change worldviews were related to support for sustainability. These findings show that change worldviews can act as a general β€œlens” people use to help determine whether to support or oppose social change

    Expression of Distal-less, dachshund, and optomotor blind in Neanthes arenaceodentata (Annelida, Nereididae) does not support homology of appendage-forming mechanisms across the Bilateria

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    The similarity in the genetic regulation of arthropod and vertebrate appendage formation has been interpreted as the product of a plesiomorphic gene network that was primitively involved in bilaterian appendage development and co-opted to build appendages (in modern phyla) that are not historically related as structures. Data from lophotrochozoans are needed to clarify the pervasiveness of plesiomorphic appendage forming mechanisms. We assayed the expression of three arthropod and vertebrate limb gene orthologs, Distal-less (Dll), dachshund (dac), and optomotor blind (omb), in direct-developing juveniles of the polychaete Neanthes arenaceodentata. Parapodial Dll expression marks premorphogenetic notopodia and neuropodia, becoming restricted to the bases of notopodial cirri and to ventral portions of neuropodia. In outgrowing cephalic appendages, Dll activity is primarily restricted to proximal domains. Dll expression is also prominent in the brain. dac expression occurs in the brain, nerve cord ganglia, a pair of pharyngeal ganglia, presumed interneurons linking a pair of segmental nerves, and in newly differentiating mesoderm. Domains of omb expression include the brain, nerve cord ganglia, one pair of anterior cirri, presumed precursors of dorsal musculature, and the same pharyngeal ganglia and presumed interneurons that express dac. Contrary to their roles in outgrowing arthropod and vertebrate appendages, Dll, dac, and omb lack comparable expression in Neanthes appendages, implying independent evolution of annelid appendage development. We infer that parapodia and arthropodia are not structurally or mechanistically homologous (but their primordia might be), that Dll’s ancestral bilaterian function was in sensory and central nervous system differentiation, and that locomotory appendages possibly evolved from sensory outgrowths

    Non-Redundant Selector and Growth-Promoting Functions of Two Sister Genes, buttonhead and Sp1, in Drosophila Leg Development

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    The radically distinct morphologies of arthropod and tetrapod legs argue that these appendages do not share a common evolutionary origin. Yet, despite dramatic differences in morphology, it has been known for some time that transcription factors encoded by the Distalless (Dll)/Dlx gene family play a critical role in the development of both structures. Here we show that a second transcription factor family encoded by the Sp8 gene family, previously implicated in vertebrate limb development, also plays an early and fundamental role in arthropod leg development. By simultaneously removing the function of two Sp8 orthologs, buttonhead (btd) and Sp1, during Drosophila embryogenesis, we find that adult leg development is completely abolished. Remarkably, in the absence of these factors, transformations from ventral to dorsal appendage identities are observed, suggesting that adult dorsal fates become derepressed when ventral fates are eliminated. Further, we show that Sp1 plays a much more important role in ventral appendage specification than btd and that Sp1 lies genetically upstream of Dll. In addition to these selector-like gene functions, Sp1 and btd are also required during larval stages for the growth of the leg. Vertebrate Sp8 can rescue many of the functions of the Drosophila genes, arguing that these activities have been conserved, despite more than 500 million years of independent evolution. These observations suggest that an ancient Sp8/Dlx gene cassette was used in an early metazoan for primitive limb-like outgrowths and that this cassette was co-opted multiple times for appendage formation in multiple animal phyla

    Genetic Background Strongly Modifies the Severity of Symptoms of Hirschsprung Disease, but Not Hearing Loss in Rats Carrying Ednrbsl Mutations

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    Hirschsprung disease (HSCR) is thought to result as a consequence of multiple gene interactions that modulate the ability of enteric neural crest cells to populate the developing gut. However, it remains unknown whether the single complete deletion of important HSCR-associated genes is sufficient to result in HSCR disease. In this study, we found that the null mutation of the Ednrb gene, thought indispensable for enteric neuron development, is insufficient to result in HSCR disease when bred onto a different genetic background in rats carrying Ednrbsl mutations. Moreover, we found that this mutation results in serious congenital sensorineural deafness, and these strains may be used as ideal models of Waardenburg Syndrome Type 4 (WS4). Furthermore, we evaluated how the same changed genetic background modifies three features of WS4 syndrome, aganglionosis, hearing loss, and pigment disorder in these congenic strains. We found that the same genetic background markedly changed the aganglionosis, but resulted in only slight changes to hearing loss and pigment disorder. This provided the important evidence, in support of previous studies, that different lineages of neural crest-derived cells migrating along with various pathways are regulated by different signal molecules. This study will help us to better understand complicated diseases such as HSCR and WS4 syndrome

    Fine mapping of the 9q31 Hirschsprung’s disease locus

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    Hirschsprung’s disease (HSCR) is a congenital disorder characterised by the absence of ganglia along variable lengths of the intestine. The RET gene is the major HSCR gene. Reduced penetrance of RET mutations and phenotypic variability suggest the involvement of additional modifying genes in the disease. A RET-dependent modifier locus was mapped to 9q31 in families bearing no coding sequence (CDS) RET mutations. Yet, the 9q31 causative locus is to be identified. To fine-map the 9q31 region, we genotyped 301 tag-SNPs spanning 7Β Mb on 137 HSCR Dutch trios. This revealed two HSCR-associated regions that were further investigated in 173 Chinese HSCR patients and 436 controls using the genotype data obtained from a genome-wide association study recently conducted. Within one of the two identified regions SVEP1 SNPs were found associated with Dutch HSCR patients in the absence of RET mutations. This ratifies the reported linkage to the 9q31 region in HSCR families with no RET CDS mutations. However, this finding could not be replicated. In Chinese, HSCR was found associated with IKBKAP. In contrast, this association was stronger in patients carrying RET CDS mutations with pΒ =Β 5.10Β Γ—Β 10βˆ’6 [ORΒ =Β 3.32 (1.99, 5.59)] after replication. The HSCR-association found for IKBKAP in Chinese suggests population specificity and implies that RET mutation carriers may have an additional risk. Our finding is supported by the role of IKBKAP in the development of the nervous system

    Coe Genes Are Expressed in Differentiating Neurons in the Central Nervous System of Protostomes

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    Genes of the coe (collier/olfactory/early B-cell factor) family encode Helix-Loop-Helix transcription factors that are widely conserved in metazoans and involved in many developmental processes, neurogenesis in particular. Whereas their functions during vertebrate neural tube formation have been well documented, very little is known about their expression and role during central nervous system (CNS) development in protostomes. Here we characterized the CNS expression of coe genes in the insect Drosophila melanogaster and the polychaete annelid Platynereis dumerilii, which belong to different subgroups of protostomes and show strikingly different modes of development. In the Drosophila ventral nerve cord, we found that the Collier-expressing cells form a subpopulation of interneurons with diverse molecular identities and neurotransmitter phenotypes. We also demonstrate that collier is required for the proper differentiation of some interneurons belonging to the Eve-Lateral cluster. In Platynereis dumerilii, we cloned a single coe gene, Pdu-coe, and found that it is exclusively expressed in post mitotic neural cells. Using an original technique of in silico 3D registration, we show that Pdu-coe is co-expressed with many different neuronal markers and therefore that, like in Drosophila, its expression defines a heterogeneous population of neurons with diverse molecular identities. Our detailed characterization and comparison of coe gene expression in the CNS of two distantly-related protostomes suggest conserved roles of coe genes in neuronal differentiation in this clade. As similar roles have also been observed in vertebrates, this function was probably already established in the last common ancestor of all bilaterians

    Ancient Origin of the New Developmental Superfamily DANGER

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    Developmental proteins play a pivotal role in the origin of animal complexity and diversity. We report here the identification of a highly divergent developmental protein superfamily (DANGER), which originated before the emergence of animals (∼850 million years ago) and experienced major expansion-contraction events during metazoan evolution. Sequence analysis demonstrates that DANGER proteins diverged via multiple mechanisms, including amino acid substitution, intron gain and/or loss, and recombination. Divergence for DANGER proteins is substantially greater than for the prototypic member of the superfamily (Mab-21 family) and other developmental protein families (e.g., WNT proteins). DANGER proteins are widely expressed and display species-dependent tissue expression patterns, with many members having roles in development. DANGER1A, which regulates the inositol trisphosphate receptor, promotes the differentiation and outgrowth of neuronal processes. Regulation of development may be a universal function of DANGER family members. This family provides a model system to investigate how rapid protein divergence contributes to morphological complexity
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