71 research outputs found

    From selling goods to selling services: firm responses to trade liberalization

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    In the face of trade liberalization domestic firms are often forced out of the market, whereas others adapt and survive. In this paper we focus on a new channel of adaptation, namely the shift toward increased provision of services in lieu of goods production. We exploit variation in EU trade policy to show that lower manufacturing tariffs cause firms to shift into services provision and out of goods production. Additionally, we find that a successful transition is strongly associated with higher firm-level R&D stocks whereas higher physical capital stocks slow the shift into services provision

    Biotic Resistance to Invasion: Native Predator Limits Abundance and Distribution of an Introduced Crab

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    Introduced species frequently escape the natural enemies (predators, competitors, and parasites) that limit their distribution and abundance in the native range. This reduction in native predators, competitors, and parasites may result in ecological release in the introduced range. However, biological interactions also can limit the establishment and spread of nonnative populations. The extent to which such biotic resistance occurs is poorly resolved, especially for marine ecosystems. Here we test whether a native predator, the blue crab Callinectes sapidus, affects the abundance and geographic range of the introduced European green crab Carcinus maenas in eastern North America. Both crab species occur in shallow, soft-sediment habitats of bays and estuaries, and their ranges overlap in eastern North America. First, we tested for a negative relationship in the abundances of the two species from trap samples across a 640-km (5.78° latitude) coastal transect. Second, we estimated variation in predation pressure on tethered Carcinus maenas across latitude and as a function of Callinectes sapidus abundance. Third, we measured predation rates on Carcinus maenas by Callinectes sapidus in field and laboratory experiments. Our results support the hypothesis that the native predator Callinectes sapidus provides biotic resistance to invasion and prevents the southward spread and establishment of Carcinus maenas. Within and across bays, Carcinus maenas were significantly less abundant at sites and depths with Callinectes sapidus compared with areas lacking Callinectes sapidus. Moreover, no Carcinus maenas were found in Chesapeake Bay, where Callinectes sapidus were most abundant. Predation of tethered Carcinus maenas increased with Callinectes sapidus abundance. In laboratory and field experiments, Callinectes sapidus preyed readily on Carcinus maenas. Thus, we conclude the predation by Callinectes sapidus, alone or in combination with other factors, limits the abundance and geographic range of an invasive marine species

    From selling goods to selling services: firm responses to trade liberalization

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    In this paper we focus on a new channel of adaptation to trade liberalization, namely the shift toward increased provision of services in lieu of goods production. We exploit variation in European Union trade policy to show that lower manufacturing tariffs lead firms to shift into services provision and out of goods production. We also find that a successful transition is associated with higher firm-level R&D stocks

    Influence of an audience on conscious motor processing and performance during a go-only and stop-signal soccer penalty shooting task

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    The Theory of Reinvestment predicts that perceived pressure to perform well can negatively impact the perceptual-motor skills of experts, by promoting conscious reinvestment of explicit knowledge about how the skills should be performed (i.e., “conscious motor processing”). This study sought to investigate the influence of pressure on conscious motor processing and performance in a soccer (football) penalty shooting task. Performance was compared in an “execution-only” and “dynamic” task context, in which fifteen experienced soccer players were required to accurately shoot on target (execution-only) or, if the goalkeeper moved to intercept, inhibit their shot (dynamic). Pressure was manipulated by means of a small audience. Manipulation checks of conscious motor processing were taken, and performance measures included movement time, reaction time, inhibition success, and penalty shooting accuracy. Analyses indicated that penalty shooting accuracy was lower in the dynamic than in the execution-only task context (p = .01). Presence of an audience did not increase perceived anxiety, nor did it result in significant effects on conscious motor processing or penalty shooting performance. Covariate analyses identified trait reinvestment as a significant covariate. Whilst in general, presence of an audience had no significant effects on conscious motor processing or penalty shooting performance, high (trait) reinvestors were found to engage more in conscious motor processing, initiated their responses earlier (allowing more time for execution), and showed improved response inhibition in the presence of an audience. Future studies are required to further evaluate the influence of trait reinvestment on conscious motor processing and performance under pressure

    Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

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    Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

    Projecting Range Expansion of Invasive European Green Crabs (Carcinus maenas) to Alaska: Temperature and Salinity Tolerance of Larvae

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    The European Green Crab (Carcinus maenas) is a global invader, successfully colonizing many world regions and having significant ecological and economic impacts. The Green Crab colonized western North America in the late 1980s, spreading primarily northward from the initial establishment in San Francisco Bay to several other bays in northern California, Oregon, and Washington. Initial analysis, based largely upon temperature tolerance of postlarval crabs, suggests Green Crabs will continue to spread and become established throughout much of Alaska. However, establishment of self-sustaining populations in Alaska may be restricted by environmental conditions for reproduction and larval development, instead of the broad tolerances of postlarval crabs. Using laboratory experiments, we tested conditions required for successful development of Green Crab larvae. We collected ovigerous Green Crabs from California and Maine, and cultured larval stages under various temperature and salinity conditions, measuring conditions necessary for survival and the length of time required for successful development (i.e., metamorphosis to postlarval crab stage). Our laboratory experiments indicate poor larval survivorship and development at temperatures below 10oC and salinities below 20 ppt. Based upon temperature-specific development rates, several sites within Prince William Sound and elsewhere in Alaska appear warm enough to support self-sustaining Green Crab populations, even though larval tolerances are more restrictive than those for adult crabs. Coupled with northward natural dispersal and ship-mediated transfer in ballast water, our data indicate Alaska is at risk to invasion by Green Crabs. The extent to which biotic interactions (e.g., competition, predation, etc.) may affect colonization success and population sizes remain unresolved

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    Effects of Moment of Inertia on Simple Reaction Time

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