347 research outputs found

    Ethnic Innovation and U.S. Multinational Firm Activity

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    This paper studies the impact that immigrant innovators have on the global activities of U.S. firms by analyzing detailed data on patent applications and on the operations of the foreign affiliates of U.S. multinational firms. The results indicate that increases in the share of a firm’s innovation performed by inventors of a particular ethnicity are associated with increases in the share of that firm’s affiliate activity in their native countries. Ethnic innovators also appear to facilitate the disintegration of innovative activity across borders and to allow U.S. multinationals to form new affiliates abroad without the support of local joint venture partners. Thus, this paper points out that immigration can enhance the competitiveness of multinational firms

    The influence of leg-to-body ratio, arm-to-body ratio and intra-limb ratio on male human attractiveness.

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    Human mate choice is influenced by limb proportions. Previous work has focused on leg-to-body ratio (LBR) as a determinant of male attractiveness and found a preference for limbs that are close to, or slightly above, the average. We investigated the influence of two other key aspects of limb morphology: arm-to-body ratio (ABR) and intra-limb ratio (IR). In three studies of heterosexual women from the USA, we tested the attractiveness of male physiques that varied in LBR, ABR and IR, using figures that ranged from -3 to +3 standard deviations from the population mean. We replicated previous work by finding that the optimally attractive LBR is approximately 0.5 standard deviations above the baseline. We also found a weak effect of IR, with evidence of a weak preference for the baseline proportions. In contrast, there was no effect of ABR on attractiveness, and no interactions between the effects of LBR, ABR and IR. Our results indicate that ABR is not an important determinant of human mate choice for this population, and that IR may exert some influence but that this is much smaller than the effects of LBR. We discuss possible reasons for these results, including the limited variability in upper limb proportions and the potentially weak fitness-signal provided by this aspect of morphology

    The Yield of Essential Oils in Melaleuca alternifolia (Myrtaceae) Is Regulated through Transcript Abundance of Genes in the MEP Pathway

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    Medicinal tea tree (Melaleuca alternifolia) leaves contain large amounts of an essential oil, dominated by monoterpenes. Several enzymes of the chloroplastic methylerythritol phosphate (MEP) pathway are hypothesised to act as bottlenecks to the production of monoterpenes. We investigated, whether transcript abundance of genes encoding for enzymes of the MEP pathway were correlated with foliar terpenes in M. alternifolia using a population of 48 individuals that ranged in their oil concentration from 39 -122 mg x g DM(-1). Our study shows that most genes in the MEP pathway are co-regulated and that the expression of multiple genes within the MEP pathway is correlated with oil yield. Using multiple regression analysis, variation in expression of MEP pathway genes explained 87% of variation in foliar monoterpene concentrations. The data also suggest that sesquiterpenes in M. alternifolia are synthesised, at least in part, from isopentenyl pyrophosphate originating from the plastid via the MEP pathway.The work was funded by an Australian Research Council Linkage grant to W.J.F. (LP110100184) with the active partnership of the Australian Tea Tree Industry Association (ATTIA) and a supplementary grant from the Rural Industries Research and Development Corporation. The funders had no role is study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Fulminant immune-mediated necrotising myopathy (IMNM) mimicking myocardial infarction with non-obstructive coronary arteries (MINOCA)

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    A 74-year-old man, with inflammatory arthritis, recently commenced on adalimumab, presented with a 4-week history of left-sided chest pain, malaise and shortness of breath. Admission ECG showed age-indeterminate left bundle branch block. Troponin T was 4444 ng/L (normal range <15 ng/L) and acute coronary syndrome treatment was commenced. Catheter angiogram revealed mild-burden non-obstructive coronary disease. Cardiac magnetic resonance (CMR) was performed to refine the differential diagnosis and demonstrated no myocardial oedema or late gadolinium enhancement. Extracardiac review highlighted oedema and enhancement of the left shoulder girdle muscles consistent with acute myositis. Creatine kinase was subsequently measured and significantly elevated at 7386 IU/L (normal range 30–200 IU/L in men). Electrophoresis clarified that this was of predominantly skeletal muscle origin. Myositis protocol MRI revealed florid skeletal muscle oedema. The MR findings, together with positive anti-Scl-70 antibodies, suggested fulminant immune-mediated necrotising myopathy presenting as a rare mimic of myocardial infarction with non-obstructive coronary arteries, diagnosed by careful extracardiac CMR review

    Anomalies in low-energy Gamma-Ray Burst spectra with the Fermi Gamma-Ray Burst Monitor

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    A Band function has become the standard spectral function used to describe the prompt emission spectra of gamma-ray bursts (GRBs). However, deviations from this function have previously been observed in GRBs detected by BATSE and in individual GRBs from the \textit{Fermi} era. We present a systematic and rigorous search for spectral deviations from a Band function at low energies in a sample of the first two years of high fluence, long bursts detected by the \textit{Fermi} Gamma-Ray Burst Monitor (GBM). The sample contains 45 bursts with a fluence greater than 2×105\times10^{-5} erg / cm2^{2} (10 - 1000 keV). An extrapolated fit method is used to search for low-energy spectral anomalies, whereby a Band function is fit above a variable low-energy threshold and then the best fit function is extrapolated to lower energy data. Deviations are quantified by examining residuals derived from the extrapolated function and the data and their significance is determined via comprehensive simulations which account for the instrument response. This method was employed for both time-integrated burst spectra and time-resolved bins defined by a signal to noise ratio of 25 σ\sigma and 50 σ\sigma. Significant deviations are evident in 3 bursts (GRB\,081215A, GRB\,090424 and GRB\,090902B) in the time-integrated sample (\sim 7%) and 5 bursts (GRB\,090323, GRB\,090424, GRB\,090820, GRB\,090902B and GRB\,090926A) in the time-resolved sample (\sim 11%).} The advantage of the systematic, blind search analysis is that it can demonstrate the requirement for an additional spectral component without any prior knowledge of the nature of that extra component. Deviations are found in a large fraction of high fluence GRBs; fainter GRBs may not have sufficient statistics for deviations to be found using this method

    CfAIR2: Near Infrared Light Curves of 94 Type Ia Supernovae

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    CfAIR2 is a large homogeneously reduced set of near-infrared (NIR) light curves for Type Ia supernovae (SN Ia) obtained with the 1.3m Peters Automated InfraRed Imaging TELescope (PAIRITEL). This data set includes 4607 measurements of 94 SN Ia and 4 additional SN Iax observed from 2005-2011 at the Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona. CfAIR2 includes JHKs photometric measurements for 88 normal and 6 spectroscopically peculiar SN Ia in the nearby universe, with a median redshift of z~0.021 for the normal SN Ia. CfAIR2 data span the range from -13 days to +127 days from B-band maximum. More than half of the light curves begin before the time of maximum and the coverage typically contains ~13-18 epochs of observation, depending on the filter. We present extensive tests that verify the fidelity of the CfAIR2 data pipeline, including comparison to the excellent data of the Carnegie Supernova Project. CfAIR2 contributes to a firm local anchor for supernova cosmology studies in the NIR. Because SN Ia are more nearly standard candles in the NIR and are less vulnerable to the vexing problems of extinction by dust, CfAIR2 will help the supernova cosmology community develop more precise and accurate extragalactic distance probes to improve our knowledge of cosmological parameters, including dark energy and its potential time variation.Comment: 31 pages, 15 figures, 10 tables. Accepted to ApJS. v2 modified to more closely match journal versio

    A phylogenomic approach reveals a low somatic mutation rate in a long-lived plant.

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    Somatic mutations can have important effects on the life history, ecology, and evolution of plants, but the rate at which they accumulate is poorly understood and difficult to measure directly. Here, we develop a method to measure somatic mutations in individual plants and use it to estimate the somatic mutation rate in a large, long-lived, phenotypically mosaic Eucalyptus melliodora tree. Despite being 100 times larger than Arabidopsis, this tree has a per-generation mutation rate only ten times greater, which suggests that this species may have evolved mechanisms to reduce the mutation rate per unit of growth. This adds to a growing body of evidence that illuminates the correlated evolutionary shifts in mutation rate and life history in plants

    An Observed Correlation Between Thermal and Non-Thermal Emission in Gamma-Ray Bursts

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    Recent observations by the FermiFermi Gamma-ray Space Telescope have confirmed the existence of thermal and non-thermal components in the prompt photon spectra of some Gamma-ray bursts (GRBs). Through an analysis of six bright Fermi GRBs, we have discovered a correlation between the observed photospheric and non-thermal γ\gamma-ray emission components of several GRBs using a physical model that has previously been shown to be a good fit to the Fermi data. From the spectral parameters of these fits we find that the characteristic energies, EpE_{\rm p} and kTkT, of these two components are correlated via the relation EpTαE_{\rm p} \propto T^{\alpha} which varies from GRB to GRB. We present an interpretation in which the value of index α\alpha indicates whether the jet is dominated by kinetic or magnetic energy. To date, this jet composition parameter has been assumed in the modeling of GRB outflows rather than derived from the data
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