152 research outputs found
Studying the effect of manager’s Strategic Thinking on Corporate entrepreneurship
The purpose of this research is to explore the effect of managers' strategic thinking on corporate entrepreneurship. To this end, one main hypothesis and five secondary hypotheses were proposed. This study is descriptive-applicable and Lidka studies (1998) were employed to measure managers' strategic thinking and Robins and Kutler's questionnaire (1996) was used to measure corporate entrepreneurship. The statistical population included 118 managers and employees of a manufacturing company in Kermanshah industrial estate. The research sample was equal to 90 using Cochran formula. The results disclosed that managers' strategic thinking has a positive and significant effect on corporate entrepreneurship and all hypotheses were confirme
Effect of inadequate lap splice length on the seismic fragility of ground soft-story reinforced concrete frames
In this study, numerical analysis was used to derive seismic fragility curves for 3-, 6- and 9-story reinforced concrete (RC) frame with inadequate lap splice length and ground soft-story condition. The structural models were subjected to 15 far-field natural earthquake records. The peak ground acceleration (PGA) of the selected records was scaled in the range of 0.05g to 0.50g with an increment of 0.05g. Incremental dynamic analysis was employed to determine their inter-story drift demand and capacities. The obtained results indicated that the probability of severe damage to the RC frames increased as the number of stories decreased. It was also observed that the RC frames with inadequate lap splice length exhibited significantly higher probability of collapse when compared with RC frames with adequate lap splice length
Satisfying the Direct Laser Acceleration Resonance Condition in a Laser Wakefield Accelerator
In this proceeding, we show that when the drive laser pulse overlaps the
trapped electrons in a laser wakefield accelerator (LWFA), those electrons can
gain energy from direct laser acceleration (DLA) over extended distances
despite the evolution of both the laser and the wake. Through simulations, the
evolution of the properties of both the laser and the electron beam is
quantified, and then the resonance condition for DLA is examined in the context
of this change. We find that although the electrons produced from the LWFA
cannot continuously satisfy the DLA resonance condition, they nevertheless can
gain a significant amount of energy from DLA.Comment: 2014 Advanced Accelerator Concepts Worksho
Does relaxation education in anxious primigravid Iranian women influence adverse pregnancy outcomes? A randomized controlled trial
Context: Maternal anxiety and stress are found to be predictors of adverse pregnancy outcomes, including low birth weight and prematurity. OBJECTIVE: The aim of the study was to determine whether relaxation education in anxious pregnant Iranian women in their first pregnancy affects selected pregnancy outcomes, including birth weight, preterm birth, and surgical delivery rate. SUBJECTS: A total of 110 obstetrically and medically low-risk primigravid women in Iran with a high anxiety level demonstrated by Spielberger's State-Trait Anxiety Inventory were randomly assigned into experimental and control groups. METHOD: In this randomized controlled trial, the experimental group received routine prenatal care along with 7-week applied relaxation training sessions, while the control group received only routine prenatal care. Anxiety and perceived stress were measured by preeducational and posteducational intervention. Data related to pregnancy outcomes include birth weight, gestational age at birth, and type of delivery. RESULTS: Significant reductions in low birth weight, cesarean section, and/or instrumental extraction were found in the experimental group compared with the control group. No significant differences were found in the rate of preterm birth. CONCLUSION: The findings suggest beneficial effects of nurse-led relaxation education sessions during the prenatal period. This intervention could serve as a resource for improving pregnancy outcomes in women with high anxiety. © 2006 Lippincott Williams & Wilkins, Inc
Prediction of strain values in reinforcements and concrete of a RC frame using neural networks
The level of strain in structural elements is an important indicator for the presence of damage and its intensity. Considering this fact, often structural health monitoring systems employ strain gauges to measure strains in critical elements. However, because of their sensitivity to the magnetic fields, inadequate long-term durability especially in harsh environments, difficulties in installation on existing structures, and maintenance cost, installation of strain gauges is not always possible for all structural components. Therefore, a reliable method that can accurately estimate strain values in critical structural elements is necessary for damage identification. In this study, a full-scale test was conducted on a planar RC frame to investigate the capability of neural networks for predicting the strain values. Two neural networks each of which having a single hidden layer was trained to relate the measured rotations and vertical displacements of the frame to the strain values measured at different locations of the frame. Results of trained neural networks indicated that they accurately estimated the strain values both in reinforcements and concrete. In addition, the trained neural networks were capable of predicting strains for the unseen input data set
Expressions of TWIST1 and CD105 markers in colorectal cancer patients and their association with metastatic potential and prognosis
Background: TWIST1 and CD105, which contribute to tumor malignancy, are overexpressed in cancers. Accordingly, TWIST1 enhances epithelial-to-mesenchymal transition (EMT) and promotes the formation of cancer stem cells (CSCs). Also, CD105 is a neoangiogenesis marker in endothelial cells, which is introduced as a CSC marker in tumoral epithelial cells in several types of cancers. The present study was aimed to investigate expressions of TWIST1 and CD105 in colorectal cancer (CRC) patients. Methods: Expressions of TWIST1 and CD105 in 250 CRC tissue samples were evaluated using immunohistochemistry on tissue microarrays (TMAs). In this regard, TWIST1 expression was investigated in the subcellular locations (cytoplasm and nucleus), while CD105 was mapped in endothelial cells and cytoplasmic tumor cells of CRC tissues. The association between the expression of these markers and clinicopathological parameters, as well as survival outcomes were analyzed. Results: Results indicate a statistically significant association between higher nuclear expression levels of TWIST1 and distant metastases in CRC (P = 0.040) patients. In addition, it was shown that the increased nuclear expression of TWIST1 had a poor prognostic value for disease-specific survival (DSS) and progression-free survival (PFS) (P = 0.042, P = 0.043, respectively) in patients with CRC. Moreover, analysis of CD105 expression level has revealed that there is a statistically significant association between the increased expression of CD105 in tumoral epithelial cells and more advanced TNM stage (P = 0.050). Conclusions: Our results demonstrate that nuclear TWIST1 and cytoplasmic CD105 expressions in tumor cells had associations with more aggressive tumor behavior and more advanced diseases in CRC cases. © 2021, The Author(s)
Benign prostatic hyperplasia treatment using plasmonic nanoparticles irradiated by laser in a rat model
Objective: In the current study we have stimulated the efficacy of plasmonic nanoparticles (NPs) by laser hyperthermia to achieve a less invasive method for tumor photothermal therapy of benign prostatic hyperplasia (BPH). Methods: The levels of apoptosis on induced BPH in rats were assessed after treatment and revealed and recorded by various assayed. Moreover, the expression of caspases was considered to demonstrate the apoptotic pathways due to laser induced plasmonic NPs. Results: In the Laser + NPs group prostate size of induced BPH decreased. Laser + NPs also decreased prostate specific antigen in comparison with the BPH groups. Furthermore, Laser + NPs attenuated BPH histopathologic indices in the rats. Laser + NPs induced apoptosis in prostatic epithelial cells via caspase-1 pathway. Conclusions: Altogether, the approach and findings from this study can be applied to introduce the laser irritated NPs method as a novel and less invasive therapy for patients suffering from BP
Low expression of Talin1 is associated with advanced pathological features in colorectal cancer patients
To explore the proper prognostic markers for the likelihood of metastasis in CRC patients. Seventy-seven fresh CRC samples were collected to evaluate the mRNA level of the selected marker using Real-time PCR. Moreover, 648 formalin-fixed paraffin-embedded CRC tissues were gathered to evaluate protein expression by immunohistochemistry (IHC) on tissue microarrays. The results of Real-Time PCR showed that low expression of Talin1 was significantly associated with advanced TNM stage (p = 0.034) as well as gender (p = 0.029) in mRNA levels. Similarly, IHC results indicated that a low level of cytoplasmic expression of Talin1 was significantly associated with advanced TNM stage (p = 0.028) as well as gender (p = 0.009) in CRC patients. Moreover, decreased expression of cytoplasmic Talin1 protein was found to be a significant predictor of worse disease-specific survival (DSS) (p = 0.011) in the univariate analysis. In addition, a significant difference was achieved (p = 0.039) in 5-year survival rates of DSS: 65 for low, 72 for moderate, and 88 for high Talin1 protein expression. Observations showed that lower expression of Talin1 at both the gene and protein level may drive the disparity of CRC patients� outcomes via worse DSS and provide new insights into the development of progression indicators because of its correlation with increased tumor aggressiveness. © 2020, The Author(s)
Evidence for the accelerated expansion of the Universe from weak lensing tomography with COSMOS
We present a tomographic cosmological weak lensing analysis of the HST COSMOS
Survey. Applying our lensing-optimized data reduction, principal component
interpolation for the ACS PSF, and improved modelling of charge-transfer
inefficiency, we measure a lensing signal which is consistent with pure
gravitational modes and no significant shape systematics. We carefully estimate
the statistical uncertainty from simulated COSMOS-like fields obtained from
ray-tracing through the Millennium Simulation. We test our pipeline on
simulated space-based data, recalibrate non-linear power spectrum corrections
using the ray-tracing, employ photometric redshifts to reduce potential
contamination by intrinsic galaxy alignments, and marginalize over systematic
uncertainties. We find that the lensing signal scales with redshift as expected
from General Relativity for a concordance LCDM cosmology, including the full
cross-correlations between different redshift bins. For a flat LCDM cosmology,
we measure sigma_8(Omega_m/0.3)^0.51=0.75+-0.08 from lensing, in perfect
agreement with WMAP-5, yielding joint constraints Omega_m=0.266+0.025-0.023,
sigma_8=0.802+0.028-0.029 (all 68% conf.). Dropping the assumption of flatness
and using HST Key Project and BBN priors only, we find a negative deceleration
parameter q_0 at 94.3% conf. from the tomographic lensing analysis, providing
independent evidence for the accelerated expansion of the Universe. For a flat
wCDM cosmology and prior w in [-2,0], we obtain w<-0.41 (90% conf.). Our dark
energy constraints are still relatively weak solely due to the limited area of
COSMOS. However, they provide an important demonstration for the usefulness of
tomographic weak lensing measurements from space. (abridged)Comment: 26 pages, 25 figures, matches version accepted for publication by
Astronomy and Astrophysic
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