The Influence of Leadership Style and Organizational Citizenship Behaviour (OCB) on Organizational Performance: A Case of ICT Firm in Saudi Arabia

The purpose of this quantitative study was to examine the influence of leadership style and organizational citizenship behaviour (OCB) on organizational behaviour. This study arises from the need to know the factors that can increase the organizational performance in the MOBAILI telecommunication company which located in Saudi Arabia. It is argued in this thesis that very limited number of studies have been conducted on the relationship between leadership style and OCB in the perspective of developing countries in general, so this study aimed at investigating whether leadership style and OCB have a positive impact on organizational performance in one of telecommunication company called MOBAILI located in Saudi Arabia. To this end, 86 respondents working in MOBAILI telecommunication company located in Saudi Arabia were selected to participate in the study. Organizational performance was measured by the 10-item developed by Steele (1987). Leadership style was measured by the 20-items and OCB was measured by 12-items developed by Podsakoff and Mackenzie(as cited in Niehoff & Moorman, 1993). The instruments for in this study were measured by using the 5-item questionnaire. The findings revealed that leadership style and organizational citizenship behaviour (OCB) were statistically and significantly related to organizational performance. OCB was found to be the best predictor of organizational performance. The limitations of this study and the recommendations for future research are also discussed

Reliability of Early Fetal Echocardiography for Congenital Heart Disease Detection: A Preliminary Experience and Outcome Analysis of 102 Fetuses to Demonstrate the Value of a Clinical Flow-Chart Designed for At-Risk Pregnancy Management

Early fetal echocardiography (EFEC) is a fetal cardiac ultrasound analysis performed between the 12th and 16th week of pregnancy (compared with the usual 18-22 weeks). In the last 10 years, the introduction of “aneuploidy sonographic markers” in screening for cardiac defects has led to a shift from late second to end of the first trimester or beginning of the second trimester of pregnancy for specialist fetal echocardiography. In this prospective study, early obstetric screening was performed between January 2014 and October 2015, using “aneuploidy sonographic markers” following SIEOG Guidelines 2014. These parameters were then collected and strategically combined in an evaluation score to select the group of pregnancies for performing EFEC, in accordance with the American Society of Echocardiography guidelines for fetal Echocardiography. All second-level examinations were performed transabdominally using a 3D convex volumetric probe with frequency range of 4-8 MHz (Accuvix – Samsung). The outcome data included transabdominal fetal echocardiography from 18 weeks to term and after birth. Overall, 99 pregnant women in the first trimester underwent EFEC (95 singleton and 4 twin pregnancies). Specifically, 30 fetuses were evaluated for extra-cardiac anomalies evidenced by obstetric screening (30%), 25 for family history of congenital heart diseases (25%), 8 for family history of genetic-linked diseases (8%), 4 for heart diseases suspected by obstetric screening (4%) and 19 by normal screening (19%). Was detected 11 (10.7%) CHD, when EFEC detected CHD, were compared to those performed later in pregnancy (18 weeks GA-term), a high degree of diagnosis correspondence was evidenced. The higher sensitivity value of EFEC vs late-FE, in comparison with the post-natal value, coupled with the high EFEC specificity shown vs both the end points, enabled us to consider it as a really reliable diagnostic technology, at least in perienced hands. The introduction of a key combination of the more sensitive obstetric and cardiologic variables should facilitate the formulation of a possible flow-chart as a guide for CHD at-risk pregnancies

Elevated hepatocyte growth factor levels in osteoarthritis osteoblasts contribute to their altered response to bone morphogenetic protein-2 and reduced mineralization capacity

PURPOSE: Clinical and in vitro studies suggest that subchondral bone sclerosis due to abnormal osteoblasts is involved in the progression of osteoarthritis (OA). Human osteoblasts isolated from sclerotic subchondral OA bone tissue show an altered phenotype, a decreased canonical Wnt/ß-catenin pathway, and a reduced mineralization in vitro as well as in vivo. These alterations were linked with an abnormal response to BMP-2. OA osteoblasts release factors such as the hepatocyte growth factor (HGF) that contribute to cartilage loss whereas chondrocytes do not express HGF. HGF can stimulate BMP-2 expression in human osteoblasts, however, the role of HGF and its effect in OA osteoblasts remains unknown. Here we investigated whether elevated endogenous HGF levels in OA osteoblasts are responsible for their altered response to BMP-2. METHODS: We prepared primary human subchondral osteoblasts using the sclerotic medial portion of the tibial plateaus of OA patients undergoing total knee arthroplasty, or from tibial plateaus of normal individuals obtained at autopsy. The expression of HGF was evaluated by qRT-PCR and the protein production by western blot analysis. HGF expression was reduced with siRNA technique whereas its activity was inhibited using the selective inhibitor PHA665752. Alkaline phosphatase activity (ALPase) and osteocalcin release were measured by substrate hydrolysis and EIA respectively. Canonical Wnt/β-catenin signaling (cWnt) was evaluated both by target gene expression using the TOPflash TCF/lef luciferase reporter assay and western blot analysis of β-catenin levels in response to Wnt3a stimulation. Mineralization in response to BMP-2 was evaluated by alizarin red staining. RESULTS: The expression of HGF was increased in OA osteoblasts compared to normal osteoblasts and was maintained during their in vitro differentiation. OA osteoblasts released more HGF than normal osteoblasts as assessed by western blot analysis. HGF stimulated the expression of TGF-β1. BMP-2 dose-dependently (1 to 100ng/ml) stimulated both ALPase and osteocalcin in normal osteoblasts whereas, it inhibited them in OA osteoblasts. HGF-siRNA treatments reversed this response in OA osteoblasts and restored the BMP-2 response. cWnt is reduced in OA osteoblasts compared to normal, and HGF-siRNA treatments increased cWnt in OA osteoblasts almost to normal. Smad1/5/8 phosphorylation in response to BMP-2, which is reduced in OA osteoblasts, was corrected when these cells were treated with PHA665752. The BMP-2-dependent mineralization of OA osteoblasts, which is also reduced compared to normal, was only partially restored by PHA665752 treatment whereas 28days treatment with HGF reduced the mineralization of normal osteoblasts. CONCLUSION: OA osteoblasts expressed more HGF than normal osteoblasts. Increased endogenous HGF production in OA osteoblasts stimulated the expression of TGF-β1 and reduced their response to BMP-2. Inhibiting HGF expression or HGF signaling restored the response to BMP-2 and Smad1/5/8 signaling. In addition, decreased HGF signaling partly corrects the abnormal mineralization of OA osteoblasts while increased HGF prevents the normal mineralization of normal osteoblasts. In summary, we hypothesize that sustained elevated HGF levels in OA osteoblasts drive their abnormal phenotype and is implicated in OA pathophysiology

COMPLEXITY REDUCTION OF CYCLOSTATIONARY SENSING TECHNIQUE USING IMPROVED HYBRID SENSING METHOD

In cognitive radio system, the spectrum sensing has a major challenge in needing a sensing method, which has a high detection capability with reduced complexity. In this paper, a low-cost hybrid spectrum sensing method with an optimized detection performance based on energy and cyclostationary detectors is proposed. The method is designed such that at high signal-to-noise ratio SNR values, energy detector is used alone to perform the detection. At low SNR values, cyclostationary detector with reduced complexity may be employed to support the accurate detection. The complexity reduction is done in two ways: through reducing the number of sensing samples used in the autocorrelation process in the time domain and through using the Sliding Discrete Fourier Transform (SDFT) instead of the Fast Fourier Transform (FFT). To evaluate the performance, two versions of the proposed hybrid method are implemented, one with the FFT and the other with the SDFT. The proposed method is simulated for cooperative and non-cooperative scenarios and investigated under a multipath fading channel. Obtained results are evaluated by comparing them with other methods including: cyclostationary feature detection (CFD), energy detector and traditional hybrid. The simulation results show that the proposed method with the FFT and the SDFT successfully reduced the complexity by 20% and 40% respectively, when 60 sensing samples are used with an acceptable degradation in the detection performance. For instance, when Eb/N0 is 0 dB , the probability of the detection of Pd is decreased by 20 % and 10% by the proposed method with the FFT and the SDFT respectively, as compared with the hybrid method existing in the literature

Experimental investigation in improving thermal performance of passive heat removal system using mist assisted evaporative cooling

Demands to increase the safety and reliability of the modern nuclear reactors are constantly being made. Typical demands include the increases the thermal performance of the passive heat removal system PHRS by removing larger amounts of energy and applied a technique that leads to reduce size and weight of the PHRS unit. This article presents an experimental investigation on the natural convection based on alternative cooling approach using water mist. The results obtained from the related experimental work indicated that the heat transfer rate was enhanced over that for the airflow as a result of water mist evaporation on the surface of the tubes. The Nu number increases by about 148%, 144%, and 128% respectively for all tube rows compared with airflow. The experimental results of the thermal performance factor values obtained by suspended water mist were correlated as functions of Rayleigh number (Ra) and Weber number (We). Subsequently, the predicted thermal performance factor from the correlation was plotted to compare with the experimental data. It was found that the thermal performance factor was within ±11%. © 2020 PENERBIT AKADEMIA BARU

Nerium oleander L. as a Phytoremediation of Heavy Metals in Diyala Governorate – Iraq

The study samples were collected during the months of April and May 2022, samples were collected from different regions in Diyala Governorate – Iraq. The study aimed to assess the role of oleander plant in the phytoremediation  of heavy metals (lead , cadmium , arsenic and selenium)  within Diyala Governorate by estimating their concentration in the leaves of the plant and the soil on which it grows as well as calculating the bioaccumulation factor (BAF). Al-Muqdadiyah Industrial area was one of the most polluted areas with lead,  the highest concentration of lead appeared in the leaves of the oleander plant grown in this area, as well as the soil on which it grows (2.452 and 0.904 ) ppm respectively. The highest concentration of cadmium was recorded for oleander leaves in the old city of Baqubah (2.208ppm), while the highest concentration appeared in the soil on which it grows in the Al-Muqdadiyah Industrial area (0.363ppm). The Al-Muqdadiya industrial area also recorded the highest concentration of arsenic in the leaves of the oleander plant ( 0.559 ppm) ,but the highest concentration in the soil on which it grows was in the central city of Al-Muqdadiyah (0.218ppm) , followed by the industrial city off Al-Muqdadiyah.( 0.132ppm) . The highest concentration of selenium appeared in the industrial city of Al-Muqdadiya in both the leaves of the oleander plant and the soil on which it grows (0.441 and 0.104) ppm. The value of the bioaccumulation factor (BAF) shows the efficiency of the oleander plant in the phytoremediation of cadmium, followed by lead, arsenic and selenium in varying proportions. Keywords : Phytoremediation , Neium oleander , Heavy metals DOI: 10.7176/JEES/12-9-04 Publication date:September 30th 202

Correction to: Exploring the biological functional mechanism of the HMGB1/TLR4/MD-2 complex by surface plasmon resonance.

After publication of this article (He et al., 2018), the corresponding authors recognised an error in Scheme 1, in particular to section A. HMGB1/TLR4/MD-2 complex formation . Above Step 2: B box binding to MD-2 , the text incorrectly read: Low affinity / extremely slow off . In addition, some text was omitted below TLR4/MD-2 . The correct version of Scheme 1 is included in this Correction article. The original article (He et al., 2018) has been corrected

Structure Determination of Ba\u3csub\u3e8\u3c/sub\u3eCoRh\u3csub\u3e6\u3c/sub\u3eO\u3csub\u3e21\u3c/sub\u3e, a New Member of the 2H-Perovskite Related Oxides

Single crystals of Ba8CoRh6O21 were grown out of a potassium carbonate flux. The structure was solved by a general method using the superspace group approach. The superspace group employed was R3m(00γ)0s with a = 10.0431(1) Å, c1 = 2.5946(1) Å and c2 = 4.5405(1) Å, V = 226.60(1) Å3. Ba8CoRh6O21 represents the first example of an m = 5, n = 3 member of the A3n+3mA\u27nB3m+nO9m+6n family of 2H hexagonal perovskite related oxides and contains chains consisting of six consecutive RhO6 octahedra followed by one distorted CoO6 trigonal prism. These chains in turn are separated from each other by [Ba]∞ chains