2,137 research outputs found

    Why Has the Fraction of Contingent Workers Increased? A case study of Japan

    Get PDF
    The fraction of contingent workers among all workers in Japan increased from 17% in 1986 to some 34% in 2008. This paper investigates the reason for this secular trend. Both demand and supply increases of contingent workers relative to regular workers are important, as evidenced by the stable relative wage to regular workers. The increase of female labor-force participation explains the supply increase, and the change of industrial composition explains the demand increase. These compositional changes explain about one quarter of the increase of contingent workers. Uncertainty surrounding product demand and the introduction of information and communication technologies increase firms' usage of contingent workers, but its quantitative effect is limited. These findings suggest that the declining importance of firm-specific human capital is a probable cause for the increase of contingent workers.

    Enhanced Expression of Integrin αvβ3 Induced by TGF-β Is Required for the Enhancing Effect of Fibroblast Growth Factor 1 (FGF1) in TGF-β-Induced Epithelial-Mesenchymal Transition (EMT) in Mammary Epithelial Cells.

    Get PDF
    Epithelial-to-mesenchymal transition (EMT) plays a critical role in cancer metastasis, and is regulated by growth factors such as transforming growth factor β (TGF-β) and fibroblast growth factors (FGF) secreted from the stromal and tumor cells. However, the role of growth factors in EMT has not been fully established. Several integrins are upregulated by TGF-β1 during EMT. Integrins are involved in growth factor signaling through integrin-growth factor receptor crosstalk. We previously reported that FGF1 directly binds to integrin αvβ3 and the interaction was required for FGF1 functions such as cell proliferation and migration. We studied the role of αvβ3 induced by TGF-β on TGF-β-induced EMT. Here, we describe that FGF1 augmented EMT induced by TGF-β1 in MCF10A and MCF12A mammary epithelial cells. TGF-β1 markedly amplified integrin αvβ3 and FGFR1 (but not FGFR2). We studied if the enhancing effect of FGF1 on TGF-β1-induced EMT requires enhanced levels of both integrin αvβ3 expression and FGFR1. Knockdown of β3 suppressed the enhancement by FGF1 of TGF-β1-induced EMT in MCF10A cells. Antagonists to FGFR suppressed the enhancing effect of FGF1 on EMT. Integrin-binding defective FGF1 mutant did not augment TGF-β1-induced EMT in MCF10A cells. These findings suggest that enhanced integrin αvβ3 expression in addition to enhanced FGFR1 expression is critical for FGF1 to augment TGF-β1-induced EMT in mammary epithelial cells

    Why Has the Fraction of Contingent Workers Increased? A Case Study of Japan

    Get PDF
    This paper explains the secular increase of contingent workers in Japan whose share of employment increased from 17 to 34 percent between 1986 and 2008. Changes in labor-forceand industrial compositions explain about one quarter of the increase of contingent workers. The uncertainty of product demand and the introduction of information and communication technologies increased firms' usage of contingent workers. The increase of contingent workers was concentrated among new entrants to the labor market, male workers of younger cohorts, and female workers of all cohorts, suggesting that the declining importance of the long-term employment relationship is a major cause for the increase of contingent workers.Contingent Workers, Female Labor Supply, Uncertainty, ICT, Japan

    Spontaneous Activation of Event Details in Episodic Future Simulation

    Get PDF
    Episodic future simulation is supported by both the retrieval and recombination of episodic details. It remains unclear, however, how individuals retrieve episodic details from memory to construct possible future scenarios; for this people must use details related to the planned future events appropriately. A potentially relevant cognitive process is the spontaneous activation of intention observed in prospective memory (i.e., the intention superiority effect). Previous studies on prospective memory have shown that the approximation of retrieval opportunities for future intentions activate related information, suggesting that the intention superiority effect is context-sensitive. We hypothesized that the same cognitive process underlies future simulation—that is, details related to future events should spontaneously become activated at the appropriate moment of future simulation to make that simulation plausible. In Experiment 1, participants took part in future experiments and formed intentions to perform particular actions for the next experiments. Subsequently, they imagined events that could occur up until they arrived at the experimental room on the day of the next experiment. During this exercise, they did not imagine engaging in the required experimental task. We measured the conceptual activation of intention-related information via a recognition task using intended action words as targets. The results showed the intention superiority effect—concepts related to participants’ future intentions became active when envisioning future events approaching the next experiment. In Experiments 2 and 3, we ensured that the intention superiority effect in future simulation was context-sensitive by adding a control condition that required participants to imagine events other than the approaching future experiments. These results indicated that concepts related to the intended actions were spontaneously activated when imagined future events became both temporally and spatially close to the future simulation. Our finding suggests that spontaneous activation of details approaching the context of a future simulation helps in constructing plausible future scenarios

    Ultrasound therapy for a week promotes regeneration and reduces pro-inflammatory macrophages in a rat sciatic nerve autograft model

    Get PDF
    Peripheral nerve injury causes long-term motor dysfunction. Ultrasound (US) therapy is expected to accelerate peripheral nerve regeneration. However, its optimal usage and effects on macrophage phenotypes during peripheral nerve regeneration remain unknown. In this study, we investigated the optimal duration of US therapy and its effects on macrophage phenotype. Twenty-seven rats with autologous sciatic nerve grafting were divided into three groups: two received US therapy (1 MHz frequency, intensity of 140 mW/cm2, 20% duty cycle, 5 min/day) for one (US1) or 4 weeks (US4), and one group received sham stimulation. Immunohistochemistry was performed 3 and 7 days after injury in another set of 12 rats. Eight weeks after the injury, the compound muscle action potential amplitude of the gastrocnemius in the US1 and US4 groups was significantly higher than that in the sham group. The toe-spreading test showed functional recovery, whereas the gait pattern during treadmill walking did not recover. There were no significant differences in motor function, histomorphometry, or muscle weight between groups. Immunohistochemistry showed that US therapy decreased the number of pro-inflammatory macrophages seven days after injury. Therefore, US therapy for both one or 4 weeks can similarly promote reinnervation and reduce proinflammatory macrophages in autograft model rats

    Why Has the Fraction of Contingent Workers Increased?: A case study of Japan (Japanese)

    Get PDF
    The fraction of contingent workers among all workers in Japan increased from 17% in 1986 to some 34% in 2008. This paper investigates the reason for this secular trend. Both demand and supply increases of contingent workers relative to regular workers are important, as evidenced by the stable relative wage to regular workers. The increase of female labor-force participation explains the supply increase, and the change of industrial composition explains the demand increase. These compositional changes explain about one quarter of the increase of contingent workers. Uncertainty surrounding product demand and the introduction of information and communication technologies increase firms' usage of contingent workers, but its quantitative effect is limited. These findings suggest that the declining importance of firm-specific human capital is a probable cause for the increase of contingent workers.

    The Deacetylase HDAC6 Regulates Aggresome Formation and Cell Viability in Response to Misfolded Protein Stress

    Get PDF
    AbstractThe efficient clearance of cytotoxic misfolded protein aggregates is critical for cell survival. Misfolded protein aggregates are transported and removed from the cytoplasm by dynein motors via the microtubule network to a novel organelle termed the aggresome where they are processed. However, the means by which dynein motors recognize misfolded protein cargo, and the cellular factors that regulate aggresome formation, remain unknown. We have discovered that HDAC6, a microtubule-associated deacetylase, is a component of the aggresome. We demonstrate that HDAC6 has the capacity to bind both polyubiquitinated misfolded proteins and dynein motors, thereby acting to recruit misfolded protein cargo to dynein motors for transport to aggresomes. Indeed, cells deficient in HDAC6 fail to clear misfolded protein aggregates from the cytoplasm, cannot form aggresomes properly, and are hypersensitive to the accumulation of misfolded proteins. These findings identify HDAC6 as a crucial player in the cellular management of misfolded protein-induced stress
    corecore