1,170 research outputs found

    The Effects of Overseas Investment on Domestic Employment

    Get PDF
    In this paper, we study the effects of FDI on domestic employment by examining the data of Taiwan's manufacturing industry. Treating domestic production and overseas production as two distinctive outputs from a joint production function, we may estimate the effect of overseas production on the demand for domestic labor. We found that overseas production generally reduces the demand for domestic labor as overseas products serve as a substitute for primary inputs in domestic production (substitution effect). But overseas production also allows the investor to expand its domestic output through enhanced competitiveness. The expanded domestic output leads to more employment at home (output effect). The net effect of FDI on domestic employment is a combination of substitution and output effects. For Taiwan, the net effect is positive in most cases but it differs across the labor group. Technical workers tend to benefit most from FDI, followed by managerial workers, and blue-collar workers benefit the least; indeed they may even be adversely affected. This suggests that after FDI, a reconfiguration of division of labor within a firm tend to shift the domestic production toward technology and management intensive operations.

    Development of a Partial Proportional Odds Model for Pedestrian Injury Severity at Intersections

    Get PDF
    Pedestrian injury in crashes at intersections often results from complex interaction among various factors. The factor identification is a critical task for understanding the causes and improving the pedestrian safety. A total of 2,614 crash records at signalized and non-signalized intersections were applied. A Partial Proportional Odds (PPO) model was developed to examine the factors influencing Pedestrian Injury Severity (PIS) because it can accommodate the ordered response nature of injury severity. An elasticity analysis was conducted to quantify the marginal effects of contributing factors on the likelihood of PIS. For signalized intersections, seven explanatory variables significantly affect the likelihood of PIS, in which five explanatory variables violate the Proportional Odds Assumption (POA). Local driver, truck, holiday, clear weather, and hit-and-run lead to higher likelihood of severer PIS. For non-signalized intersections, six explanatory variables were found significant to the PIS, in which three explanatory variables violate the POA. Young and adult drivers, senior pedestrian, bus/van, divided road, holiday, and darkness tend to increase the likelihood of severer PIS. The vehicles of large size and heavy weight (e.g. truck, bus/van) are significant factors to the PIS at both signalized and non-signalized intersections. The proposed PPO model has demonstrated its effectiveness in identifying the effects of contributing factors on the PIS.</p

    Synthesis and characterization of hybrid organic-inorganic materials based on sulphonated polyamideimide and silica

    Get PDF
    The preparation of hybrid organicā€“inorganic membrane materials based on a sulphonated polyamideimide resin and silica filler has been studied. The method allows the solā€“gel process to proceed in the presence of a high molecular weight polyamideimide, resulting in well dispersed silica nanoparticles (<50 nm) within the polymer matrix with chemical bonding between the organic and inorganic phases. Tetraethoxysilane (TEOS) was used as the silica precursor and the organosilicate networks were bonded to the polymer matrix via a coupling agent aminopropyltriethoxysilane (APTrEOS). The structure and properties of these hybrid materials were characterized via a range of techniques including FTIR, TGA, DSC, SEM and contact angle analysis. It was found that the compatibility between organic and inorganic phases has been greatly enhanced by the incorporation of APTrEOS. The thermal stability and hydrophilic properties of hybrid materials have also been significantly improved

    Oosorption in the Endoparasitoid, Pteromalus puparum

    Get PDF
    Oosorption is the resorption of oocytes in the ovaries, and is usually induced by environmental stress. It has been demonstrated in some insect species, but overall the mechanisms of oosorption are poorly understood. In this study, the oosorption in the endoparasitic wasp, Pteromalus puparum L. (Hymenoptera: Pteromalidae), was observed in response to starvation. To explore the details of oosorption in P. puparum, both levels of hemolymph vitellogenin and ovarian vitellin were determined using sandwich ELISA. The results indicated that both levels of vitellin and total protein in the ovaries were significantly decreased 48 h after eclosion in starved P. puparum, while those of vitellogenin and total protein in the hemolymph were increased. In addition, observation of the ultrastructure of mature oocytes in the ovarioles revealed changes in yolk protein content. Those protein yolk spheres and lipid yolk spheres that had accumulated in the oocytes, were transferred out of the oocytes of starved females. It was assumed that once oosorption was induced in P. puparum, vitellin in the oocytes was transported outside and released into the hemolymph. This information helps to elucidate a mechanism of oosorption in insects

    14-3-3Ļƒ Regulates Ī²-Catenin-Mediated Mouse Embryonic Stem Cell Proliferation by Sequestering GSK-3Ī²

    Get PDF
    [[abstract]]Background: Pluripotent embryonic stem cells are considered to be an unlimited cell source for tissue regeneration and cell-based therapy. Investigating the molecular mechanism underlying the regulation of embryonic stem cell expansion is thus important. 14-3-3 proteins are implicated in controlling cell division, signaling transduction and survival by interacting with various regulatory proteins. However, the function of 14-3-3 in embryonic stem cell proliferation remains unclear. Methodology and Principal Findings: In this study, we show that all seven 14-3-3 isoforms were detected in mouse embryonic stem cells. Retinoid acid suppressed selectively the expression of 14-3-3Ļƒ isoform. Knockdown of 14-3-3Ļƒ with siRNA reduced embryonic stem cell proliferation, while only 14-3-3Ļƒ transfection increased cell growth and partially rescued retinoid acid-induced growth arrest. Since the growth-enhancing action of 14-3-3Ļƒ was abrogated by Ī²-catenin knockdown, we investigated the influence of 14-3-3Ļƒ overexpression on Ī²-catenin/GSK-3Ī². 14-3-3Ļƒ bound GSK-3Ī² and increased GSK-3Ī² phosphorylation in a PI-3K/Akt-dependent manner. It disrupted Ī²-catenin binding by the multiprotein destruction complex. 14-3-3Ļƒ overexpression attenuated Ī²-catenin phosphorylation and rescued the decline of Ī²-catenin induced by retinoid acid. Furthermore, 14-3-3Ļƒ enhanced Wnt3a-induced Ī²-catenin level and GSK-3Ī² phosphorylation. DKK, an inhibitor of Wnt signaling, abolished Wnt3a-induced effect but did not interfere GSK-3Ī²/14-3-3Ļƒ binding. Significance:Our findings show for the first time that 14-3-3Ļƒ plays an important role in regulating mouse embryonic stem cell proliferation by binding and sequestering phosphorylated GSK-3Ī² and enhancing Wnt-signaled GSK-3Ī² inactivation. 14-3-3Ļƒ is a novel target for embryonic stem cell expansion

    TRAPPC4-ERK2 Interaction Activates ERK1/2, Modulates Its Nuclear Localization and Regulates Proliferation and Apoptosis of Colorectal Cancer Cells

    Get PDF
    The trafficking protein particle complex 4 (TRAPPC4) is implicated in vesicle-mediated transport, but its association with disease has rarely been reported. We explored its potential interaction with ERK2, part of the ERK1/2 complex in the Extracellular Signal-regulated Kinase/ Mitogen-activated Protein Kinase (ERK-MAPK) pathway, by a yeast two-hybrid screen and confirmed by co-immunoprecipitation (Co-IP) and glutathione S-transferase (GST) pull-down. Further investigation found that when TRAPPC4 was depleted, activated ERK1/2 specifically decreased in the nucleus, which was accompanied with cell growth suppression and apoptosis in colorectal cancer (CRC) cells. Overexpression of TRAPPC4 promoted cell viability and caused activated ERK1/2 to increase overall, but especially in the nucleus. TRAPPC4 was expressed more highly in the nucleus of CRC cells than in normal colonic epithelium or adenoma which corresponded with nuclear staining of pERK1/2. We demonstrate here that TRAPPC4 may regulate cell proliferation and apoptosis in CRC by interaction with ERK2 and subsequently phosphorylating ERK1/2 as well as modulating the subcellular location of pERK1/2 to activate the relevant signaling pathway
    • ā€¦
    corecore