1,499 research outputs found

    Investigating the mix of strategic choices and performance of transaction platforms: Evidence from the crowdfunding setting

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    Research Summary: The platform literature offers keen insights on the pricing and non-pricing strategies that transaction platforms undertake. We supplement this work by studying how platforms mix together their strategic choices and the association with platforms’ performance. To that end, we focus on crowdfunding platforms; a prominent setting of transaction platforms. We present an inductive large-N study of the population of 788 crowdfunding platforms that operated in EU-15 countries up to 2018. Our contribution is threefold: (a) identifying common mixes of strategic choices; (b) tracking deviations from these mixes; and (c) associating these with platforms’ survival and growth. We discuss our findings and how they advance knowledge at the intersection of the platform and strategic management literatures. Managerial Summary: Notable transaction-platforms such as eBay, LinkedIn, and Tencent have an aggregate market-value in the hundreds of billions of dollars. We know that platforms’ success is driven by the strategic choices they undertake. Yet, we know less about how they mix together these choices and the association with platforms’ performance. Our study addresses this gap by focusing on a prominent setting: crowdfunding. Using data on the population of 788 crowdfunding platforms in EU-15 countries, we show that these platforms cluster around three common mixes of strategic choices. Moreover, crowdfunding platforms do not strictly adhere to the strategy mix they are affiliated with. Interestingly, there is a positive association between the degree to which a platform's choices differentiate from its strategy mix and platform's subsequent performance

    Componential coding in the condition monitoring of electrical machines Part 2: application to a conventional machine and a novel machine

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    This paper (Part 2) presents the practical application of componential coding, the principles of which were described in the accompanying Part 1 paper. Four major issues are addressed, including optimization of the neural network, assessment of the anomaly detection results, development of diagnostic approaches (based on the reconstruction error) and also benchmarking of componential coding with other techniques (including waveform measures, Fourier-based signal reconstruction and principal component analysis). This is achieved by applying componential coding to the data monitored from both a conventional induction motor and from a novel transverse flux motor. The results reveal that machine condition monitoring using componential coding is not only capable of detecting and then diagnosing anomalies but it also outperforms other conventional techniques in that it is able to separate very small and localized anomalies

    In Situ Hybridization and Monoclonal Antibody Analysis of Plasma Membrane Ca-Pump mRNA and Protein in Submandibular Glands of Rabbit, Rat and Man

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    The degree of supersaturation of saliva with calcium (Ca) is related to the mineral phase of enamel in erupted teeth, the incidence of caries, and the formation of calculus. The mechanisms for regulating salivary Ca concentration are therefore of relevance to dentistry. Sections of rabbit, rat and human submandibular gland (SMG) were processed for immuno-histochemistry with a specific anti-plasma membrane Ca-pump antibody, 5F10. Western blots confirm that the molecular weight of the proteins identified by our antibody (135 kDa) is consistent with an appropriate molecular weight for PMCA antigen (135-150 kDa). Tissue sections were also processed for in situ hybridization to study the distribution of the PMCA mRNA isoforms. In mammals, the PMCAl gene is reported to code for a PMCA protein with a role in maintaining the intracellular Ca levels in both epithelial and non-epithelial cells. Other genes including the PMCA2 and PMCA4 genes may code for PMCA proteins specific to Ca transporting tissues. Our studies demonstrate cytoplasmic labeling of PMCA mRNA with hPMCA-1 and hPMCA-4 specific cDNA probes in humans, and rPMCA-1 and rPMCA-2 specific oligonucleotide probes in rats. Labeling of PMCA protein and all mRNA isoforms was found in the cytoplasm of the interlobular and intralobular ducts (except for intercalated ducts). The demonstrated presence of PMCA in SMGs of rabbit, rat, and man, may suggest a role for PMCA in the regulation of intracellular Ca and in a mechanism for regulating and maintaining the high concentration of Ca in saliva

    Construct validity of a continuous metabolic syndrome score in children

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    <p>Abstract</p> <p>Objective</p> <p>The primary purpose of this study was to examine the construct validity of a continuous metabolic syndrome score (cMetS) in children. The secondary purpose was to identify a cutpoint value(s) for an adverse cMetS based on receiver operating characteristic (ROC) curve analysis.</p> <p>Methods</p> <p>378 children aged 7 to 9 years were assessed for the metabolic syndrome which was determined by age-modified cutpoints. High-density-lipoprotein cholesterol, triglycerides, the homeostasis assessment model of insulin resistance, mean arterial pressure, and waist circumference were used to create a cMetS for each subject.</p> <p>Results</p> <p>About half of the subjects did not possess any risk factors while about 5% possessed the metabolic syndrome. There was a graded relationship between the cMetS and the number of adverse risk factors. The cMetS was lowest in the group with no adverse risk factors (-1.59 ± 1.76) and highest in those possessing the metabolic syndrome (≥3 risk factors) (7.05 ± 2.73). The cutoff level yielding the maximal sensitivity and specificity for predicting the presence of the metabolic syndrome was a cMetS of 3.72 (sensitivity = 100%, specificity = 93.9%, and the area of the curve = 0.978 (0.957-0.990, 95% confidence intervals).</p> <p>Conclusion</p> <p>The results demonstrate the construct validity for the cMetS in children. Since there are several drawbacks to identifying a single cut-point value for the cMetS based on this sample, we urge researchers to use the approach herein to validate and create a cMetS that is specific to their study population.</p

    Inhibition of the glycaemic response by onion : a comparison between lactose-tolerant and lactose-intolerant adults

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    This document is the Accepted Manuscript of the following article: R Hoffman, G Ranjbar and A M Madden, ‘Inhibition of the glycaemic response by onion: a comparison between lactose-tolerant and lactose-intolerant adults’, European Journal of Clinical Nutritin, (2016), 70: 1089-1091. The Version of Record is available online at doi: 10.1038/ejcn.2016.44.This pilot study compared inhibition of the glycaemic response to glucose by a dietary source of quercetin glucosides (onion) in lactose-tolerant adults (n = 12) and lactose-intolerant adults (n = 12). We hypothesised that lactose-intolerant people (who do not express lactase) will retain intact quercetin glucosides that can inhibit glucose uptake via the glucose transporter SGLT1 whereas lactose-tolerant people (who do express lactase) will hydrolyse quercetin glucosides to free quercetin which does not inhibit glucose uptake. In a glucose tolerance test, reduction of peak glucose levels by an onion meal was higher in lactose-intolerant people than lactose-tolerant people (44.2% versus 19.3%, p = 0.04). Incremental area under the blood glucose curve was reduced more in lactose-intolerant people, but was not statistically significantly (54.5% versus 42.1%, p = 0.42). A diet containing quercetin glucosides may be of greater benefit for glycaemic control in lactose-intolerant people than in lactose-tolerant people.Peer reviewedFinal Accepted Versio

    Growing with the market : how changing conditions during market growth affect formation and evolution of interfirm ties

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    Research Summary: Market conditions are known to matter for firm performance and growth. This study explores how changing levels of uncertainty and competition affect interfirm ties of entrepreneurial firms as markets transition from nascent to growth stage. Tracing 6 entrepreneurial game publishers during the growth stage of the US wireless gaming market, the findings reveal that in a growth stage market, as uncertainty decreases, certain ties of entrepreneurial firms are terminated. First, existing partners may cut ties and become competitors after entering the market directly. This is a “winner's curse” as more successful firms are more likely to entice their partners to enter the market directly. Second, ties may be terminated as prominent firms that are “overwhelmed” with too many partners cut ties with low to mediocre performance while their remaining partners enter a positive spiral of tie strength and performance. Finally, as uncertainty decreases, new firms may enter the market as competitors to prominent firms. While entrepreneurial firms with high and low performing ties to prominent partners may find ties with these new entrants attractive, those with mediocre ties to few prominent partners find this move too risky and wait for a first mover to legitimate it. Overall, the findings show that changing levels of uncertainty and competition in growth stage markets can have different consequences for firms due to heterogeneity in their ties and power relative to partners. The findings provide several contributions to literature regarding the relationship between interfirm ties, firm performance, and market evolution. Managerial Summary: Based on interviews at 6 entrepreneurial game publishers in the US and their partners, this study shows how changing levels of uncertainty and competition in growing markets can have different consequences for firms based on the different types of alliances in their portfolio and their power relative to partners. The findings highlight the importance of managing partners differently based on alliance type and goal of the partner. They advocate remaining flexible in alliance management as information asymmetries, intentions and bargaining power of partners can change and lead to abrupt alliance dissolution. They show that alliance portfolio management goes beyond a firm's capability of managing individual alliances, and provide a tool for managers to evaluate their alliance portfolios and take the necessary precautions

    Understanding signaling cascades in melanoma

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    Understanding regulatory pathways involved in melanoma development and progression has advanced significantly in recent years. It is now appreciated that melanoma is the result of complex changes in multiple signaling pathways that affect growth control, metabolism, motility and the ability to escape cell death programs. Here we review the major signaling pathways currently known to be deregulated in melanoma with an implication to its development and progression. Among these pathways are Ras, B-Raf, MEK, PTEN, phosphatidylinositol-3 kinase (PI3Ks) and Akt which are constitutively activated in a significant number of melanoma tumors, in most cases due to genomic change. Other pathways discussed in this review include the [Janus kinase/signal transducer and activator of transcription (JAK/STAT), transforming growth factor-beta pathways which are also activated in melanoma, although the underlying mechanism is not yet clear. As a paradigm for remodeled signaling pathways, melanoma also offers a unique opportunity for targeted drug development.Fil: Lopez Bergami, Pablo Roberto. Sanford-burnham Medical Research Institute; Estados Unidos. Consejo Nacional de Investigaciones Científicas y TÊcnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Fitchmann, B. Sanford-burnham Medical Research Institute; Estados UnidosFil: Ronai, Ze´ev. Sanford-burnham Medical Research Institute; Estados Unido

    Field assessment of guar gum stabilized microscale zerovalent iron particles for in-situ remediation of 1,1,1-trichloroethane

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    A pilot injection test with guar gum stabilized microscale zerovalent iron (mZVI) particles was performed at test site V (Belgium) where different chlorinated aliphatic hydrocarbons (CAHs) were present as pollutants in the subsurface. One hundred kilograms of 56 Îźm-diameter mZVI (~ 70 g/L) was suspended in 1.5 m3 of guar gum (~ 7 g/L) solution and injected into the test area. In order to deliver the guar gum stabilized mZVI slurry, one direct push bottom-up injection (Geoprobe) was performed with injections at 5 depths between 10.5 and 8.5 m bgs. The direct push technique was preferred above others (e.g. injection at low flow rate via screened wells) because of the limited hydraulic conductivity of the aquifer, and to the large size of the mZVI particles. A final heterogeneous distribution of the mZVI in the porous medium was observed explicable by preferential flow paths created during the high pressure injection. The maximum observed delivery distance was 2.5 m. A significant decrease in 1,1,1-TCA concentrations was observed in close vicinity of spots where the highest concentration of mZVI was observed. Carbon stable isotope analysis (CSIA) yielded information on the success of the abiotic degradation of 1,1,1-TCA and indicated a heterogeneous spatio-temporal pattern of degradation. Finally, the obtained results show that mZVI slurries stabilized by guar gum can be prepared at pilot scale and directly injected into low permeable aquifers, indicating a significant removal of 1,1,1-TCA
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