263 research outputs found

    The radiation problem from a vertical short dipole antenna above flat and lossy ground. Novel formulation in the spectral domain with closed form analytical solution in the high frequency regime

    Get PDF
    In this paper we consider the problem of radiation from a vertical short Hertzian dipole above flat lossy ground, which represents the well known in the literature Sommerfeld radiation problem. The problem is formulated in a novel spectral domain approach, and by inverse three dimensional Fourier transformation the expressions for the received electric and magnetic field in the physical space are derived as one dimensional integrals over the radial component of wavevector, in cylindrical coordinates. Subsequent use of the Stationary Phase Method in the high frequency regime yields closed form analytical solutions for the received EM field vectors, which coincide with the corresponding reflected EM field originating from the image point. In this way, we conclude that the so called in the literature space wave, i.e. line of sight plus reflected EM field, represents the total solution of the Sommerfeld problem in the high frequency regime, in which case the surface wave can be ignored. Finally, numerical results in the high frequency regime are presented in this paper, in comparison with corresponding numerical results based on Norton solution of the problem, i.e. space and surface waves

    Structural empowerment is a strong predictor of organizational commitment in nurses: A systematic review and meta-analysis

    Get PDF
    AIMS: The aim of this systematic review and meta-analysis is to explore the relationship between structural empowerment and organizational commitment and to examine a theoretical model under which empowerment could potentially affect organizational performance. DESIGN: PRISMA guidelines for systematic reviews and meta-analyses were used and quality assessment of articles was performed. DATA SOURCES: Electronic database searches were conducted in Google Scholar, PubMed/Medline, CINAHL, Scopus, and EMBASE from January 1950–1 January 2019, which resulted in 204 retrieved studies, published between 1994–2018. REVIEW METHODS: A random effects model was used to produce a pooled estimate of effect sizes (correlation coefficient, Cronbach's alpha), with analysis of heterogeneity and publication bias. A meta-analytic structural equation model of the constructs analysed was also performed. RESULTS: The final review included 22 studies. The meta-analytic means of structural empowerment, organizational commitment, job satisfaction, and psychological empowerment alpha reliabilities were 0.87, 0.84, 0.85, and 0.87, respectively. Heterogeneity but no publication bias was present in these outcomes. Structural empowerment was strongly correlated with organizational commitment (r = 0.43). The meta-analytic correlation coefficients of organizational commitment with psychological empowerment and job satisfaction were 0.53 and 0.47, respectively. Structural empowerment was correlated with job satisfaction and psychological empowerment with correlation coefficients of 0.57 and 0.44, respectively. Finally, job satisfaction was correlated with psychological empowerment with a correlation coefficient of 0.53. A meta-analytic structural equation model was tested with good fit which predicted performance (commitment and job satisfaction) from empowerment (structural and psychological). CONCLUSION: Structural empowerment is strongly correlated to organizational commitment and with psychological empowerment, they increase organizational performance. Organizations should attempt to make structural empowerment as widespread as possible to create an effective workplace culture. IMPACT: Structural empowerment in nurses is important to help deliver an effective workplace culture where nurses can be committed and have reduced intention-to-leave. Structural empowerment was strongly correlated with organizational commitment. Organizational commitment was significantly correlated with psychological empowerment and job satisfaction. Structural empowerment was correlated with job satisfaction and psychological empowerment as well. A meta-analytic structural equation model with good fit predicted performance. These results will affect nursing researchers and practitioners. Results indicate a need for organizational restructuring that promotes empowerment and formation of theoretical models that connect empowerment to performance

    Clinical Studies of Nonpharmacological Methods to Minimize Salivary Gland Damage after Radioiodine Therapy of Differentiated Thyroid Carcinoma: Systematic Review

    Get PDF
    Purpose. To systematically review clinical studies examining the effectiveness of nonpharmacological methods to prevent/minimize salivary gland damage due to radioiodine treatment of differentiated thyroid carcinoma (DTC). Methods. Reports on relevant trials were identified by searching the PubMed, CINHAL, Cochrane, and Scopus electronic databases covering the period 01/2000-10/2015. Inclusion/exclusion criteria were prespecified. Search yielded eight studies that were reviewed by four of the present authors. Results. Nonpharmacological methods used in trials may reduce salivary gland damage induced by radioiodine. Sialogogues such as lemon candy, vitamin E, lemon juice, and lemon slice reduced such damage significantly (p < 0.0001, p < 0.05, p < 0.10, and p < 0.05, resp.). Parotid gland massage also reduced the salivary damage significantly (p < 0.001). Additionally, vitamin C had some limited effect (p = 0.37), whereas no effect was present in the case of chewing gum(p = 0.99). Conclusion. The review showed that, among nonpharmacological interventions, sialogogues and parotid gland massage had the greatest impact on reducing salivary damage induced by radioiodine therapy of DTC. However, the studies retrieved were limited in number, sample size, strength of evidence, and generalizability. More randomized controlled trials of these methods with multicenter scope and larger sample sizes will provide more systematic and reliable results allowing more definitive conclusions

    Essential oils as antibacterial agents against food-borne pathogens: are they really as useful as they are claimed to be ?

    Get PDF
    Original articleMost studies evaluating the use of essential oils (EO) as antibacterial agents focus mainly on minimal inhibitory concentrations (MIC) rather than minimal bactericidal concentrations (MBC). In this work, we compared MICs and MBCs of EO from condiment plants commonly used in Mediterranean Europe, namely Origanum vulgare, Salvia lavandulaefolia, Salvia officinalis, Salvia sclarea and Rosmarinus officinalis, aiming to evaluate their application as disinfecting agents in minimally processed produce. Outbreaks-related pathogens such as Listeria monocytogenes, Pseudomonas aeruginosa and Yarrowia lipolytica were used. Results showed that all EO were able to reduce bacterial growth in all bacterial strains tested, particularly O. vulgare. However, fewer EO exhibited bactericidal activities, and were only effective against one or two bacterial strains, hence eliminating the possibility to use them as broad range disinfectants. Furthermore, the necessary concentrations were too high for food application. Hence, our work suggests the need to evaluate MBC rather than MIC and questions EO usefulness in controlling undesired microorganisms. Overall, and despite the large volume of data published on EO, results obtained were not very encouraging for a realistic application on produce and question the viability of EOs as disinfecting agents in foodinfo:eu-repo/semantics/publishedVersio

    GDF15 promotes weight loss by enhancing energy expenditure in muscle

    Get PDF
    Funding Information: We thank R. Seeley for sharing GFRAL-null mice; B. Lowell for sharing β-less mice; and J. Wu for shipping β-less mice to us. G.R.S. was supported by a Diabetes Canada Investigator Award (DI-5-17-5302-GS), a Canadian Institutes of Health Research Foundation Grant (201709FDN-CEBA-116200), a Tier 1 Canada Research Chair in Metabolic Diseases and a J. Bruce Duncan Endowed Chair in Metabolic Diseases; D.W. by Fellowship Grants from the McMaster Institute for Research on Aging (MIRA) at McMaster University; S.R. by a postdoctoral fellowship supported by MITACS and Novo Nordisk; L.K.T. by a CIHR Post-Doctoral Fellowship Award and Michael DeGroote Fellowship Award in Basic Biomedical Science; E.M.D. by a Vanier Canada Graduate Scholarship; G.P.H. by the Natural Sciences and Engineering Research Council of Canada (NSERC: 400362); G.J.D. and S.M.F. by NSERC-CGSM scholarships; L.D. by the Fonds de Recherche du Québec-Santé doctoral training award; D.P.B. by the GSK Chair in Diabetes of Université de Sherbrooke and a FRQS J1 salary award. The Genotype-Tissue Expression (GTEx) Project was supported by the Common Fund of the Office of the Director of the National Institutes of Health, and by the NCI, NHGRI, NHLBI, NIDA, NIMH and NINDS. Funding Information: S.B.J. and R.E.K. are employees of Novo Nordisk, a pharmaceutical company producing and selling medicine for the treatment of diabetes and obesity. G.R.S. is a co-founder and shareholder of Espervita Therapeutics. McMaster University has received funding from Espervita Therapeutics, Esperion Therapeutics, Poxel Pharmaceuticals and Nestle for research conducted in the laboratory of G.R.S. S.R. is supported by a MITACS postdoctoral fellowship sponsored by Novo Nordisk. H.C.G. holds the McMaster-Sanofi Population Health Institute Chair in Diabetes Research and Care. G.R.S., G.P. and H.C.G. are inventors listed on a patent for identifying GDF15 as a biomarker for metformin. G.R.S. has received consulting/speaking fees from Astra Zeneca, Eli Lilly, Esperion Therapeutics, Merck, Poxel Pharmaceuticals and Cambrian Biosciences. The other authors declare no competing interests. Publisher Copyright: © 2023, The Author(s).Peer reviewedPublisher PD

    Dyadic adjustment, family coping, body image, quality of life and psychological morbidity in patients with psoriasis and their partners

    Get PDF
    Background Psoriasis is an incurable and chronic disease that includes unpredictable periods of remission and relapse requiring long-term therapy. Purpose This paper focuses on the relationship among family coping, psychological morbidity, body image, dyadic adjustment and quality of life in psoriatic patients and their partners. Method One hundred and one patients with psoriasis and 78 partners comprised the sample. They were regular users of the Dermatology Service of a Central Northern hospital in Portugal and a private dermatology clinic. Patients with psoriasis were assessed on anxiety, depression, body image, quality of life, dyadic adjustment and family coping. Partners were assessed on the same measures except body image and quality of life. Results A positive relationship among dyadic adjustment, psychological morbidity and family coping in patients and their partners was found. Also, patients with lower levels of quality of life had partners with higher levels of depressive and anxious symptoms. Better dyadic adjustment predicted family coping in the psoriatic patient. High levels of dyadic adjustment in patients and low partners’ trait anxiety predicted better dyadic adjustment in partners. Conclusion The results highlight the importance of incorporating family variables in psychological interventions in psoriasis’ care, particularly family coping and dyadic adjustment as well as the need for psychological intervention to focus both on patients and partners
    corecore