54 research outputs found
International Trade and Inter-Industry Wage Structure in Swedish Manufacturing - Evidence from matched employer-employee data
This study examines the inter-industry wage structure in Swedish manufacturing by using matched employer-employee data for the period 1996 to 2000. First, we use detailed individual and job characteristics to estimate industry-specific and time-varying wage premiums. Second, we investigate the impact of international trade on wage premiums, after controlling for effects of domestic competition and technical progress. Our results indicate that industries that face intensive import competition from low-income countries have lower wage premiums. Surprisingly, the wage premiums are not related to export intensities. Furthermore, technical progress, measured by investment in R&D activity, appears to enhance inter-industry wage premiums.Inter-industry wage structure; International trade; Matched employer- employee data
On isolation of singular zeros of multivariate analytic systems
We give a separation bound for an isolated multiple root of a square
multivariate analytic system satisfying that an operator deduced by adding
and a projection of in a direction of the kernel of
is invertible. We prove that the deflation process applied on and this kind
of roots terminates after only one iteration. When is only given
approximately, we give a numerical criterion for isolating a cluster of zeros
of near . We also propose a lower bound of the number of roots in the
cluster.Comment: 17 page
Verified Error Bounds for Isolated Singular Solutions of Polynomial Systems: Case of Breadth One
In this paper we describe how to improve the performance of the
symbolic-numeric method in (Li and Zhi,2009, 2011) for computing the
multiplicity structure and refining approximate isolated singular solutions in
the breadth one case. By introducing a parameterized and deflated system with
smoothing parameters, we generalize the algorithm in (Rump and Graillat, 2009)
to compute verified error bounds such that a slightly perturbed polynomial
system is guaranteed to have a breadth-one multiple root within the computed
bounds.Comment: 20 page
An efficient optimal design methodology for abnormal noise control of automobile transmission in the neutral idle condition
The modal analysis of the automobile transmission housing assembly is formulated using 3D graphics software Pro/E together with Finite Element Method in order to reduce the noise and vibration by accurately identifying the noise source of the transmission in the neutral idle condition. Besides, the calculation of meshing frequency of gear pair is conducted. After comparing model analysis results with the calculation results, we can intuitively analysis the dynamic characteristics of the transmission housing assembly and find out sensitive parts of the housing vibration. In order to enhance the structural stiffness of the transmission housing assembly and allow intentionally the natural frequency of the transmission to avoid the gear meshing frequency, we increase the thickness of thin plate or add the strengthening rib on the weak parts of the transmission housing assembly. The results of the above modified modal reanalysis show that low mode frequencies of the transmission housing assembly are greatly improved after optimization, and avoid the gear meshing excitation frequency effectively. The probability of resonance for the transmission housing assembly in use will be greatly reduced, which can well achieve the purpose of enhancing the dynamic characteristics of the transmission housing assembly
Genome-wide identification and characterization of a superfamily of bacterial extracellular contractile injection systems
Effects of Gualou Guizhi Decoction Aqueous Extract on Axonal Regeneration in Organotypic Cortical Slice Culture after Oxygen-Glucose Deprivation
Gualou Guizhi decoction (GLGZD) is effective for the clinical treatment of limb spasms caused by ischemic stroke, but its underlying mechanism is unclear. Propidium iodide (PI) fluorescence staining, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), immunohistochemistry, western blot, and real-time qPCR were used to observe the axonal regeneration and neuroprotective effects of GLGZD aqueous extract on organotypic cortical slices exposed to oxygen-glucose deprivation (OGD) and further elucidate the potential mechanisms. Compared with the OGD group, the GLGZD aqueous extract decreased the red PI fluorescence intensity; inhibited neuronal apoptosis; improved the growth of slice axons; upregulated the protein expression of tau and growth-associated protein-43; and decreased protein and mRNA expression of neurite outgrowth inhibitor protein-A (Nogo-A), Nogo receptor 1 (NgR1), ras homolog gene family A (RhoA), rho-associated coiled-coil-containing protein kinase (ROCK), and phosphorylation of collapsin response mediator protein 2 (CRMP2). Our study found that GLGZD had a strong neuroprotective effect on brain slices after OGD injury. GLGZD plays a vital role in promoting axonal remodeling and functional remodeling, which may be related to regulation of the expression of Nogo-A and its receptor NgR1, near the injured axons, inhibition of the Rho-ROCK pathway, and reduction of CRMP2 phosphorylation
HIV-1 capsid is involved in post-nuclear entry steps
BACKGROUND: HIV-1 capsid influences viral uncoating and nuclear import. Some capsid is detected in the nucleus but it is unclear if it has any function. We reported that the antibiotic Coumermycin-A1 (C-A1) inhibits HIV-1 integration and that a capsid mutation confers resistance to C-A1, suggesting that capsid might affect post-nuclear entry steps.
RESULTS: Here we report that C-A1 inhibits HIV-1 integration in a capsid-dependent way. Using molecular docking, we identify an extended binding pocket delimited by two adjacent capsid monomers where C-A1 is predicted to bind. Isothermal titration calorimetry confirmed that C-A1 binds to hexameric capsid. Cyclosporine washout assays in Jurkat CD4+ T cells expressing engineered human TRIMCyp showed that C-A1 causes faster and greater escape from TRIMCyp restriction. Sub-cellular fractionation showed that small amounts of capsid accumulated in the nuclei of infected cells and C-A1 reduced the nuclear capsid. A105S and N74D capsid mutant viruses did not accumulate capsid in the nucleus, irrespective of C-A1 treatment. Depletion of Nup153, a nucleoporin located at the nuclear side of the nuclear pore that binds to HIV-1 capsid, made the virus less susceptible to TRIMCyp restriction, suggesting that Nup153 may help maintain some integrity of the viral core in the nucleus. Furthermore C-A1 increased binding of CPSF6, a nuclear protein, to capsid.
CONCLUSIONS: Our results indicate that capsid is involved in post-nuclear entry steps preceding integration
Early detection of lung cancer in a real-world cohort via tumor-associated immune autoantibody and imaging combination
BackgroundEfficient early detection methods for lung cancer can significantly decrease patient mortality. One promising approach is the use of tumor-associated autoantibodies (TAABs) as a diagnostic tool. In this study, the researchers aimed to evaluate the potential of seven TAABs in detecting lung cancer within a population undergoing routine health examinations. The results of this study could provide valuable insights into the utility of TAABs for lung cancer screening and diagnosis.MethodsIn this study, the serum concentrations of specific antibodies were measured using enzyme-linked immunosorbent assay (ELISA) in a cohort of 15,430 subjects. The efficacy of both a 7-TAAB panel and LDCT for lung cancer detection were evaluated through receiver operating characteristic (ROC) analyses, with sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) being assessed and compared. These results could have significant implications for the development of improved screening methods for lung cancer.ResultsOver the 12-month observation period, 26 individuals were diagnosed with lung cancer. The 7-TAAB panel demonstrated promising sensitivity (61.5%) and a high degree of specificity (88.5%). The panelās area under the receiver operating characteristic (ROC) curve was 0.8062, which was superior to that of any individual TAAB. In stage I patients, the sensitivity of the panel was 50%. In our cohort, there was no gender or age bias observed. This 7-TAAB panel showed a sensitivity of approximately 60% in detecting lung cancer, regardless of histological subtype or lesion size. Notably, ground-glass nodules had a higher diagnostic rate than solid nodules (83.3% vs. 36.4%, P = 0.021). The ROC analyses further revealed that the combination of LDCT with the 7-TAAB assay exhibited a significantly superior diagnostic efficacy than LDCT alone.ConclusionIn the context of the study, it was demonstrated that the 7-TAAB panel showed improved detective efficacy of LDCT, thus serving as an effective aid for the detection of lung cancer in real-world scenarios
Effect of dendrobium mixture in alleviating diabetic cognitive impairment associated with regulating gut microbiota
Dendrobium mixture (DM) is a patent Chinese herbal formulation consisting of Dendrobii Caulis, Astragali Radix, Rehmanniae Radix as the main ingredients. DM has been shown to alleviate diabetic related symptoms attributed to its anti-hyperglycaemic and anti-inflammatory activities. However, the effect on diabetic induced cognitive dysfunction has not been investigated. This study aims to investigate the effect of DM in improving diabetic cognitive impairment and associated mechanisms. Our study confirmed the anti-hyperglycaemic effect of DM and showed its capacity to restore the cognitive and memory function in high fat/high glucose and streptozotocin-induced diabetic rats. The neuroprotective effect was manifested as improved learning and memory behaviours, restored blood-brain barrier tight junction, and enhanced expressions of neuronal survival related biomarkers. DM protected the colon tight junction, and
effectively lowered the circulated proinflammatory mediators including tumour necrosis factor-Ī±, interleukin-6 and lipopolysaccharides. In the gut microbiota, DM corrected the increase in the abundance of Firmicutes, the increase in the ratio of Firmicutes/Bacteroidetes, and the decrease in the abundance of Bacteroidetes in diabetic rats. It also reversed the abundance of Lactobacillus, Ruminococcus and Allobaculum genera. Short chain fatty acids, isobutyric acid and ethylmethylacetic acid, were negatively and significantly correlated to Ruminococcus and Allobaculum. Isovaleric acid was positively and significantly correlated with Lactobacillus, which all contributing to the improvement in glucose level, systemic inflammation and cognitive function in diabetic rats.
Our results demonstrated the potential of DM as a promising therapeutic agent in treating diabetic cognitive impairment and the underlying mechanism may be associated with regulating gut microbiota
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