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Job Stress and Nurses Well-Being: Prayer and Age as Moderators
No full textThere is increasing popularity among researchers, scholars, and policymakers concerning the efficacy of prayer as a coping strategy for job stress. This study examines the moderating effects of prayer and age on the relationship between job stress and nurses’ well-being in UMMC. Three hundred (300) Muslim nursing staff working at the University of Malaya Medical Centre were sampled. Data were collected via questionnaires. The findings of this study show that the effect of job stress on well-being is significant for nurses and that prayer of nurses contributed to alleviating job stress and enhancing well-being. This study is limited to nurses in one public hospital in a developing country. Thus, it would be more interesting if the study could be extended to other public and private institutions in a Muslim country, and a comparison could be done between other religions as well. © 2019, Springer Science+Business Media, LLC, part of Springer Nature
Image denoising using combined higher order non-convex total variation with overlapping group sparsity
No full textIt is widely known that the total variation image restoration suffers from the stair casing artifacts which results in blocky restored images. In this paper, we address this problem by proposing a combined non-convex higher order total variation with overlapping group sparse regularizer. The hybrid scheme of both the overlapping group sparse and the non-convex higher order total variation for blocky artifact removal is complementary. The overlapping group sparse term tends to smoothen out blockiness in the restored image more globally, while the non-convex higher order term tends to smoothen parts that are more local to texture while preserving sharp edges. To solve the proposed image restoration model, we develop an iteratively re-weighted ℓ1 based alternating direction method of multipliers algorithm to deal with the constraints and subproblems. In this study, the images are degraded with different levels of Gaussian noise. A comparative analysis of the proposed method with the overlapping group sparse total variation, the Lysaker, Lundervold and Tai model, the total generalized variation and the non-convex higher order total variation, was carried out for image denoising. The results in terms of peak signal-to-noise ratio and structure similarity index measure show that the proposed method gave better performance than the compared algorithms. © 2018, Springer Science+Business Media, LLC, part of Springer Nature
Influence of wood surface chemistry on the tensile and flexural properties of heat-treated mangrove/high-density polyethylene composites
No full textMangrove wood fiber (MF) was treated at four different temperatures (120 °C, 140 °C, 160 °C and 180 °C) in order to improve its compatibility with polymer matrix. The chemo-structural, thermal and morphological characteristics of untreated and treated MF were analyzed. The chemical composition of the treated MF showed an increase in cellulose content from 46 to 56% at 120 °C, which decreased at further heating. The non-cellulosic constituents of the fiber were removed as indicated by the reduction in magnitude of absorbance peaks mainly at 3343 cm−1 and 1027 cm−1 in Fourier transform infrared spectroscopy. The X-ray diffraction depicted increased crystallinity with increased temperature due to the conversion of amorphous cellulose and some hemicelluloses to crystalline structures. Color spectroscopy showed higher values of lightness (L*) at 120 °C and 140 °C, with a corresponding increase in chroma coordinate a* and decrease in b* due to the chemical changes that occurred during the heat treatment. Surface morphology by field emission scanning electron microscopy revealed that heat treatment exposed the inner fibrillar feature of fiber, thereby increasing the roughness of the fiber surface. Thermogravimetry analysis further indicated that heat-treated MFs are more stable. Heat treatment improved the tensile strength and modulus of composites as fiber loading increased, while the flexural strength and modulus also showed the same trend. SEM images of tensile fractured surface indicated that the interfacial interaction between the matrix and untreated MF is weaker than the heat-treated specimens. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature
A compact linear-cavity multi-wavelength Brillouin/thulium fiber laser in S/S+-band
No full textA compact Brillouin thulium-doped fluoride fiber (TDFF)multi-wavelength fiber lasers (MWFLs)operating in the S/S+ band region is proposed and demonstrated. The system is based on a linear design and utilizes two Faraday mirrors at both ends of the cavity to enable bi-directional oscillation. An 11.5 m long TDFF with an absorption rate of 0.15 dB/m at 1400 nm is used as the gain medium. A stable output laser comb with 28 Stokes lines is obtained at the maximum pump power of 250 mW at the wavelength of 1488 nm. The multi-wavelength Brillouin fiber laser can also be tuned, covering a total tuning range of 55 nm from 1460 nm to 1515 nm. The proposed system is highly stable, and would have significant practical applications. © 201
Nickel phosphate as a C-band optical pulse modulator
No full textThis work discusses the fabrication of a nickel phosphate [Ni3(PO4)2]-polyvinyl alcohol (PVA) thin film and its application as an optical modulator for the generation of Q-switched pulses in the C-band region. A 50 cm long erbium-doped fiber with absorption coefficients of 250 dB/m and 16 dB/m at 980 nm and 1530 nm respectively was used as the gain medium. The modulation depth, saturable intensity and non-saturable loss were measured to be 56.43%, 0.15 kW/cm2 and 43.57%, respectively. Stable self-starting Q-switched pulses were observed at 1561.1 nm at an output power of 2.34 mW, a pulse width of 1.08 μs, and a repetition rate of 86.21 kHz, at the maximum pump power of 280.50 mW. The generated output was highly stable with a signal-to-noise ratio of 54.57 dB. The work undertaken has demonstrated the potential of Ni3(PO4)2 nanoparticles as an optically active material due to its excellent nonlinear saturable absorption characteristics, which translates to good laser performance. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature
Mode-locked near-infrared thulium doped fibre laser using evanescent field effect with Bi2O3 saturable absorber
No full textUsing the evanescent field effect, a high power passively mode-locked laser with a pulse duration of 1.85 ps and the pulse energy of 13.15 pJ is demonstrated. A Bi2O3 solution is used as a saturable absorber (SA) on a side polished fibre incorporated into a thulium doped fibre laser cavity for operation in the mid-infrared range. The 37.61% SA has a modulation depth and creates a highly stable mode-locked pulse output with a short pulse duration. The calculated net cavity dispersion at central wavelength is -1.4 ps2, indicating operation is in the anomalous dispersion regime and confirmed by the presence of Kelly's side-bands observed in the generated optical spectrum. Radio frequency analysis reveals a high signal to noise ratio, making this laser stable for use in telecommunication systems. © 2019 Astro Ltd
Oncogenic Signaling in Tumorigenesis and Applications of siRNA Nanotherapeutics in Breast Cancer
No full textOverexpression of oncogenes and cross-talks of the oncoproteins-regulated signaling cascades with other intracellular pathways in breast cancer could lead to massive abnormal signaling with the consequence of tumorigenesis. The ability to identify the genes having vital roles in cancer development would give a promising therapeutics strategy in combating the disease. Genetic manipulations through siRNAs targeting the complementary sequence of the oncogenic mRNA in breast cancer is one of the promising approaches that can be harnessed to develop more efficient treatments for breast cancer. In this review, we highlighted the effects of major signaling pathways stimulated by oncogene products on breast tumorigenesis and discussed the potential therapeutic strategies for targeted delivery of siRNAs with nanoparticles in suppressing the stimulated signaling pathways. © 2019, MDPI AG. All rights reserved
Multi-Reservoir System Optimization Based on Hybrid Gravitational Algorithm to Minimize Water-Supply Deficiencies
No full textThe growing prevalence of droughts and water scarcity have increased the importance of operating dam and reservoir systems efficiently. Several methods based on algorithms have been developed in recent years in a bid to optimize water release operation policy, in order to overcome or minimize the impact of droughts. However, all of these algorithms suffer from some weaknesses or drawbacks – notably early convergence, a low rate of convergence, or trapping in local optimizations – that limit their effectiveness and efficiency in seeking to determine the global optima for the operation of water systems. Against this background, the present study seeks to introduce and test a Hybrid Algorithm (HA) which integrates the Gravitational Search Algorithm (GSA) with the Particle Swarm Optimization Algorithm (PSOA) with the goal of minimizing irrigation deficiencies in a multi-reservoir system. The proposed algorithm was tested for a specific important multi-reservoir system in Iran: namely the Golestan Dam and Voshmgir Dam system. The results showed that applying the HA could reduce average irrigation deficiencies for the Golestan Dam substantially, to only 2 million cubic meters (MCM), compared to deficiency values for the Genetic Algorithm (GA), PSOA and GSA of 15.1, 6.7 and 5.8 MCM respectively. In addition, the HA performed very efficiently, reducing substantially the computational time needed to achieve the global optimal when compared with the other algorithms tested. Furthermore, the HA showed itself capable of assuring a high volumetric reliability index (VRI) to meet the pattern of water demand downstream from the dams, as well as clearly outperforming the other algorithms on other important indices. In conclusion, the proposed HA seems to offer considerable potential as an optimizer for dam and reservoir operations world-wide. © 2019, Springer Nature B.V
A Study on the Factors Influencing Social Entrepreneurial Intention Among Undergraduates
No full textThis paper provides an insight on factors affecting the social entrepreneurial intention among undergraduates in Malaysia. Specifically, this paper emphasizes on external factors in influencing the Malaysian undergraduates' intention on becoming a social entrepreneur. The Theory of Planned Behaviour (TPB) was used as an underpinning theory to support the proposed conceptual model. Quantitative research method was used in this study. The sample consisted of 600 respondents, which comprises of undergraduates of Malaysian private universities. Likert scale questionnaire were distributed to the respondents to complete. The collected data were analysed using SPSS software and Partial Least Squares Structural Equation Modelling (PLS-SEM). Based on the research findings within this paper, some of the external factors greatly affect an undergraduate's intention on becoming a social entrepreneur in the future. The stated external factors are opportunity recognition and access to finance. However, the other factor, social capital, was found that it did not influence an undergraduate's intention to become a social entrepreneur
High-quality RNA isolation from pigment-rich Dendrobium flowers
No full textIsolation of high-quality RNA from Dendrobium flowers is challenging because of the high levels of pigment, polysaccharides, and polyphenols. In the present study, an efficient CTAB method for RNA extraction from the pigment-rich flowers of Dendrobium was optimised. The optimised method yielded high quantities of RNA (10.1–12.9 µg/g). Spectrophotometric values of A260/280 in the range of 2.2 to 2.4 and A260/230 values of 2.0 suggested that the isolated RNA was free of polyphenols, polysaccharides, and protein contaminants. RNA integrity numbers determined by microfluidics were in the range of 7.9–8.9 indicative of intact RNA. In the improved method, the addition of 3 M NaCl and 3% PVP-10 in the extraction buffer, followed by an incubation period of 45 min at 65 °C, eliminated most of the polysaccharides, polyphenolic compounds, and denatured protein. Extraction with phenol:chloroform:isoamyl alcohol (125:24:1) effectively removed pigments from the aqueous phase, while the precipitation of RNA with lithium chloride minimised the co-precipitation of protein, DNA, and polysaccharide and resulted in the extraction of high quality of RNA. The suitability of the RNA for downstream processing was confirmed via RT-PCR amplification of Chalcone synthase gene from cDNA prepared from RNA isolated from different developmental stages of the flower of a Dendrobium hybrid. The present method will be highly useful for the isolation of RNA from pigment, polyphenol, and polysaccharide-rich plant tissues. © 2019, King Abdulaziz City for Science and Technology