6,564 research outputs found

    Control Charts for Mean for Non-Normally Correlated Data

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    Traditionally, quality control methodology is based on the assumption that serially-generated data are independent and normally distributed. On the basis of these assumptions the operating characteristic (OC) function of the control chart is derived after setting the control limits. But in practice, many of the basic industrial variables do not satisfy both the assumptions and hence one may doubt the validity of the inferences drawn from the control charts. In this paper the power of the control chart for the mean is examined when both the assumptions of independence and normality are not tenable. The OC function is calculated and compared with the normal population

    Academic stress and life satisfaction as social sustainability among university students

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    This study was conducted to determine the relationship between academic stress and life satisfaction among university students in Sabah, Malaysia. A total of 400 students were selected as respondents and data were collected using questionnaires. Academic stress was measured using the Perception of Academic Stress Scale (PAS), which has four subscales: i) Performance stress; ii) Workload perception of workload and examinations; iii) Academic self-perception; and iv) Time constraints. Meanwhile, the Satisfaction with Life Scale was used to study student’s life satisfaction. The data obtained were analyzed using Pearson correlation and t-test. The results showed that performance stress is negatively associated with life satisfaction, while academic self-perception is positively associated with life satisfaction. The result also showed that perception of workload and examinations and time constraints not associated with life satisfaction. All in all, academic self-perception and performance stress have an association with life satisfaction

    Differential microRNA expression and identification of putative miRNA targets and pathways in head and neck cancers.

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    MicroRNAs (miRNAs) are small noncoding RNAs that involved in various cancer-related cellular processes. Diverse studies on expression profiling of miRNAs have been performed and the data showed that some miRNAs are up-regulated or down-regulated in cancer. Until now, there are no data published on the miRNA expression in head and neck cancers from Malaysia. Hence, this study aimed to investigate potentially crucial miRNAs in head and neck cancer patients from Malaysian populations. A global miRNA profiling was performed on 12 samples of head and neck cancer tissue using microarray analysis followed by validation using real-time RT-PCR Microarray analysis identified 10 miRNAs that could distinguish malignant head and neck cancer lesions from normal tissues; 7 miRNAs (hsa-miR-181a-2*, hsa-miR-29b-1*, hsa-miR-181a, hsa-miR-181b, hsa-miR-744, hsa-miR-1271 and hsa-miR-221*) were up-regulated while 3 miRNAs (hsa-miR-141, hsa-miR-95 and hsa-miR-101) were down-regulated. These miRNAs may contribute in a simple profiling strategy to identify individuals at higher risk of developing head and neck cancers, thus helping in the elucidation of the molecular mechanisms involved in head and neck cancer pathogenesis

    IgE-Mediated Hypersensitivity Reactions to Cannabis in Laboratory Personnel

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    Background: There have been sporadic reports of hypersensitivity reactions to plants of the Cannabinaceae family (hemp and hops), but it has remained unclear whether these reactions are immunologic or nonimmunologic in nature. Objective: We examined the IgE-binding and histamine-releasing properties of hashish and marijuana extracts by CAP-FEIA and a basophil histamine release test. Methods: Two workers at a forensic laboratory suffered from nasal congestion, rbinitis, sneezing and asthmatic symptoms upon occupational contact with hashish or marijuana, which they had handled frequently for 25 and 16 years, respectively. Neither patient had a history of atopic disease. Serum was analyzed for specific IgE antibodies to hashish or marijuana extract by research prototype ImmunoCAP, and histamine release from basophils upon exposure to hashish or marijuana extracts was assessed. Results were matched to those of 4 nonatopic and 10 atopic control subjects with no known history of recreational or occupational exposure to marijuana or hashish. Results: Patient 1 had specific IgE to both hashish and marijuana (CAP class 2), and patient 2 to marijuana only (CAP class 2). Controls proved negative for specific IgE except for 2 atopic individuals with CAP class 1 to marijuana and 1 other atopic individual with CAP class 1 to hashish. Stimulation of basophils with hashish or marijuana extracts elicited histamine release from basophils of both patients and 4 atopic control subjects. Conclusions: Our results suggest an IgE-related pathomechanism for hypersensitivity reactions to marijuana or hashish. Copyright (C) 2011 S. Karger AG, Base

    Tumor cell nuclei soften during transendothelial migration

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    During cancer metastasis, tumor cells undergo significant deformation in order to traverse through endothelial cell junctions in the walls of blood vessels. As cells pass through narrow gaps, smaller than the nuclear diameter, the spatial configuration of chromatin must change along with the distribution of nuclear enzymes. Nuclear stiffness is an important determinant of the ability of cells to undergo transendothelial migration, yet no studies have been conducted to assess whether tumor cell cytoskeletal or nuclear stiffness changes during this critical process in order to facilitate passage. To address this question, we employed two non-contact methods, Brillouin confocal microscopy (BCM) and confocal reflectance quantitative phase microscopy (QPM), to track the changes in mechanical properties of live, transmigrating tumor cells in an in vitro collagen gel platform. Using these two imaging modalities to study transmigrating MDA-MB-231, A549, and A375 cells, we found that both the cells and their nuclei soften upon extravasation and that the nuclear membranes remain soft for at least 24 h. These new data suggest that tumor cells adjust their mechanical properties in order to facilitate extravasation

    Kesan kerjasama dalam aktiviti berkumpulan terhadap kualiti perhubungan pelajar berbilang etnik di Universiti Putra Malaysia

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    Kepelbagaian dan kerencaman dari segi budaya, etnik dan agama sememangnya menjadi kebanggaan rakyat Malaysia. Namun begitu, Malaysia masih tidak lekang daripada isu-isu etnik dan agama yang sensitif. Contoh terkini adalah isu pergaduhan antara etnik di Plaza Low Yat pada tahun 2015. Kejadian ini telah menimbulkan persoalan samada hubungan antara etnik di Malaysia kian rapuh? Jika benar, apakah mekanisme untuk memperbaiki hubungan ini? Menurut Teori Perhubungan (Contact Theory) yang diperkenalkan oleh Gordon Allport (1954), hubungan antara etnik dapat diperbaiki sekiranya sesuatu perhubungan itu memenuhi empat syarat iaitu persamaan status, persamaan matlamat, keizinan pihak berkuasa dan interaksi yang melibatkan kerjasama. Justeru, kajian ini adalah satu percubaan untuk mengaplikasikan Teori Perhubungan ini dalam aktiviti berkumpulan pelajar di Universiti Putra Malaysia dengan memberikan tumpuan pada aspek kerjasama. Untuk tujuan ini, sebuah eksperimen telah dijalankan dalam kalangan pelajar yang mengambil kursus (Tamadun Islam dan Tamadun Asia) TITAS dan Hubungan Etnik. Pelajar telah dibahagikan kepada satu kumpulan eksperimen, satu kumpulan kawalan dan dua kumpulan perbandingan. Kumpulan eksperimen dan kumpulan perabandingan telah diberikan tugasan yang mempunyai sifat dan tahap kerjasama yang berbeza. Menurut hasil analisis ANOVA, tahap integrasi yang tinggi dan kerjasama antara pelajar yang berbilang etnik mempunyai kesan terhadap kualiti perhubungan. Hasil kajian ini menunjukkan bahawa sesuatu perhubungan yang berkualiti dan baik itu perlu disertai dengan empat elemen yang dicadangkan dan sebaliknya akan berlaku jika sesuatu perhubungan itu tidak disertai empat elemen tersebut

    Who is in charge? A review and a research agenda on the 'human side' of the circular economy

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    The adoption of the circular economy (CE) at the firm level has rarely intersected with human resource management (HRM) – here called 'the human side of organizations' – and these two fields remain largely separate areas of knowledge. While the literature on the CE is expanding, discussion of its implementation in organizations is, so far, rare, along with exploration of the necessary alignment of the CE with green human resource management (GHRM). In this article, we extend the state-of-the-art literature on CE business models through the inclusion of the ‘human side’ of such issues. This goal is met by offering an original integrative GHRM framework for organizations developing CE. The theoretical lenses of stakeholders' theory and the resource based view (RBV) form the foundation of this framework, which represents a 'middle range theory'. We underline the practices and dimensions of the links between GHRM and the 'ReSOLVE' CE model. Through an exploration of this integrative framework, we propose a future research agenda along with original research propositions. Furthermore, the middle-range integrated theoretical framework we propose can serve both academics and practitioners in developing understanding of the human resource management (HRM) and change management aspects of the CE

    Nishimori point in random-bond Ising and Potts models in 2D

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    We study the universality class of the fixed points of the 2D random bond q-state Potts model by means of numerical transfer matrix methods. In particular, we determine the critical exponents associated with the fixed point on the Nishimori line. Precise measurements show that the universality class of this fixed point is inconsistent with percolation on Potts clusters for q=2, corresponding to the Ising model, and q=3Comment: 11 pages, 3 figures. Contribution to the proceedings of the NATO Advanced Research Workshop on Statistical Field Theories, Como 18-23 June 200

    Electronic correlations in the iron pnictides

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    In correlated metals derived from Mott insulators, the motion of an electron is impeded by Coulomb repulsion due to other electrons. This phenomenon causes a substantial reduction in the electron's kinetic energy leading to remarkable experimental manifestations in optical spectroscopy. The high-Tc superconducting cuprates are perhaps the most studied examples of such correlated metals. The occurrence of high-Tc superconductivity in the iron pnictides puts a spotlight on the relevance of correlation effects in these materials. Here we present an infrared and optical study on single crystals of the iron pnictide superconductor LaFePO. We find clear evidence of electronic correlations in metallic LaFePO with the kinetic energy of the electrons reduced to half of that predicted by band theory of nearly free electrons. Hallmarks of strong electronic many-body effects reported here are important because the iron pnictides expose a new pathway towards a correlated electron state that does not explicitly involve the Mott transition.Comment: 10 page

    Exploring time and frequency linkages of green bond with renewable energy and crypto market

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    This paper examines the dynamic linkages of green bond with the energy and crypto market. The S&P green bond index (RSPGB) is used as a proxy for the green bond market; S&P global clean energy index and ISE global wind energy (RIGW) are used as proxies for the renewable energy market, and; Bitcoin and Ethereum (RETHER) are used as the proxies of the crypto market. The daily prices of these constituent series are collected using Bloomberg from October 3, 2016 to February 23, 2021. We undertake an empirical analysis through the application of three key tests, namely: dynamic conditional correlation (DCC), Diebold and Yilmaz (Int J Forecast 28(1):57–66, 2012. 10.1016/j.ijforecast.2011.02.006), Baruník and Křehlík (J Financ Econom 16(2):271–296, 2018. 10.1093/jjfinec/nby001) model. The DCC reveals no dynamic linkages of volatility from the green bond to the energy and crypto market in the short run. Referring to Diebold and Yilmaz (2012), it dictates that the green bond (RSPGB) is a net receiver while the energy market (RIGW) and cryptocurrency (RETHER) are the largest and least contributors to the transmission of the volatility. Additionally, the Baruník and Křehlík (2018) model confirmed that the magnitude of the total spillover is high in more prolonged than shorter periods, suggesting reduced diversification opportunities. Overall, the present study exemplifies the significance of the green bond market as protection against risk
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