394 research outputs found
A Generalization to the Rastall Theory and Cosmic Eras
A generalized version for the Rastall theory is proposed showing the
agreement with the cosmic accelerating expansion. In this regard, a coupling
between geometry and the pressureless matter fields is derived which may play
the role of dark energy responsible for the current accelerating expansion
phase. Moreover, our study also shows that the radiation field may not be
coupled to the geometry in a non-minimal way which represents that the ordinary
energy-momentum conservation law is respected by the radiation source. It is
also shown that the primary inflationary era may be justified by the ability of
the geometry to couple to the energy-momentum source in an empty flat FRW
universe. In fact, this ability is independent of the existence of the
energy-momentum source and may compel the empty flat FRW universe to expand
exponentially. Finally, we consider a flat FRW universe field by a spatially
homogeneous scalar field evolving in potential , and study
the results of applying the slow-roll approximation to the system which may
lead to an inflationary phase for the universe expansion.Comment: 11 page
Einstein and Rastall Theories of Gravitation in Comparison
We profit by a recent paper of Visser claiming that Rastall gravity is
equivalent to Einstein gravity to compare the two gravitational theories in a
general way. Our conclusions are different from Visser's ones. We indeed argue
that these two theories are not equivalent. In fact, Rastall theory of gravity
is an "open" theory when compared to Einstein general theory of relativity.
Thus, it is ready to accept the challenges of observational cosmology and
quantum gravity.Comment: 8 pages, comment on the paper arXiv:1711.11500, "Rastall gravity is
equivalent to Einstein gravity", by Matt Visser. Final version matching the
paper published in the European Physical Journal
Solar Powered Electric Vehicle Charger
This project will look into how to create an efficiently-operated solar powered electric vehicle charger. The solar panel will harvest energy from the sun that will be stored a battery pack to be readily available to charge an electric vehicle. These stations could be commercialized to be located along a highway, or personalized for a in-house installation
Validity of neutrophil gelatinase associated lipocaline as a biomarker for diagnosis of children with acute pyelonephritis
Purpose: Novel biomarkers have been investigated for various renal disorders, including urinary tract infection (UTI). The aim of this study was to assess whether urine neutrophil gelatinase associated lipocaline (NGAL), could represent a reliable biomarker for diagnosis and treatment of children with acute pyelonephritis (APN). Materials and Methods: A total of 37 children (32 females, 5 males) with APN were included in this prospective study. Urine NGAL was measured before and 5-7 days after antibiotic treatment in the UTI group, using ELISA kit and compared with 26 (8 females, 18 males) control group children admitted for other bacterial infections. Results: Mean age of the UTI group was 39 � 28 months, compared to 43.6 � 31.5 months for the control group with no statistically significant difference. Median urine NGAL level was significantly higher in patients with APN than the other subjects 0.48 (interquartile range (IQR): 0.15-0.72) vs. 0.065 (0.01-0.24), P = .001, and decreased significantly after antibiotic treatment (P = .002). Using a cutoff of 0.20 ng/mL, sensitivity and specificity of urine NGAL were 76% and 77% for prediction of APN, respectively. The area under the ROC curve (AUC) for urine NGAL was 0.75 (CI= 0.61-0.88), suggesting urine NGAL as a relatively good predictive biomarker of APN. Conclusion: Urine NGAL is a good biomarker for diagnosis and treatment monitoring of APN in children
Application of the World Health Organization Quality of Life Instrument, Short Form (WHOQOL-BREF) to patients with cataract
OBJECTIVES: Cataract is a prevalent disease in the elderly, and negatively influences patients' quality of life. This study was conducted to study the application of the World Health Organization Quality of Life Instrument, Short Form (WHOQOL-BREF) to patients with cataract. METHODS: In this cross-sectional study, 300 patients with cataract were studied in Neyshabur, Iran from July to October 2014. The Iranian version of the WHOQOL-BREF questionnaire was used to measure their quality of life. Cronbach's alpha coefficient, Pearson's correlation coefficient, the paired t-test, the independent t-test, and a linear regression model were used to analyze the data in SPSS version 16.0 (SPSS Inc., Chicago, IL, USA). RESULTS: The mean age of the participants was 68.11±11.98 years, and most were female (53). The overall observed Cronbach's alpha coefficient for the WHOQOL-BREF was 0.889, ranging from 0.714 to 0.810 in its four domains. The total mean score of the respondents on the WHOQOL-BREF was 13.19. The highest and lowest mean scores were observed in the social relationship domain (14.11) and the physical health domain (12.29), respectively. A backward multiple linear regression model found that duration of disease and marital status were associated with total WHOQOL scores, while age, duration of disease, marital status, and income level were associated with domains one through four, respectively (p<0.05). CONCLUSIONS: The reliability analysis conducted in this study indicated that the WHOQOL-BREF scale exhibited an acceptable degree of internal consistency in the measurement of the quality of life of patients with cataract. It was also found that the patients with cataract who were surveyed reported a relatively moderate quality of life
Estimating the completeness of lung cancer registry in Ardabil, Iran with a three-source capture-recapture method
Cancer registration is an important component of a comprehensive cancer control program, providing timely data and information for research and administrative use. Capture-recapture methods have been used as tools to investigate completeness of cancer registry data. This study aimed to estimate the completeness of lung cancer cases registered in Ardabil Population Based Cancer Registry (APBCR) with a three-source capture-recapture method. Data for all new cases of lung cancer reported by three sources (pathology reports, death certificates, and medical records) to APBCR for 2006 and 2008 were obtained. Duplicate cases shared among the three sources were identified based on similarity of first name, last name and father's names. A log-linear model was used to estimate number of missed cases and to control for dependency among sources. A total of 218 new cases of lung cancer was reported by three sources after removing duplicates. The estimated completeness calculated by log-linear method was 26.4 for 2006 and 27.1 for 2008. The completeness differed according to gender. In men, the completeness was 26.0 for 2006 and 28.1 for 2008. In women, the completeness was 36.5 for 2006 and 46.9 for 2008. In conclusion, none of the three sources can be considered as a reliable source for accurate cancer incidence estimation. © 2016, Asian Pacific Journal of Cancer Prevention
Microwave dielectric study of spin-Peierls and charge ordering transitions in (TMTTF)PF salts
We report a study of the 16.5 GHz dielectric function of hydrogenated and
deuterated organic salts (TMTTF)PF. The temperature behavior of the
dielectric function is consistent with short-range polar order whose relaxation
time decreases rapidly below the charge ordering temperature. If this
transition has more a relaxor character in the hydrogenated salt, charge
ordering is strengthened in the deuterated one where the transition temperature
has increased by more than thirty percent. Anomalies in the dielectric function
are also observed in the spin-Peierls ground state revealing some intricate
lattice effects in a temperature range where both phases coexist. The variation
of the spin-Peierls ordering temperature under magnetic field appears to follow
a mean-field prediction despite the presence of spin-Peierls fluctuations over
a very wide temperature range in the charge ordered state of these salts.Comment: 7 pages, 6 figure
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