| 1. |
- Meech, K. J., et al.
(författare)
-
EPOXI: Comet 103P/Hartley 2 Observations from a Worldwide Campaign
- 2011
-
Ingår i: Astrophysical Journal Letters. - London : IOP. - 2041-8213 .- 2041-8205. ; 734:L1, s. 1-9
-
Tidskriftsartikel (refereegranskat)abstract
- Earth- and space-based observations provide synergistic information for space mission encounters by providing data over longer timescales, at different wavelengths and using techniques that are impossible with an in situ flyby. We report here such observations in support of the EPOXI spacecraft flyby of comet 103P/Hartley 2. The nucleus is small and dark, and exhibited a very rapidly changing rotation period. Prior to the onset of activity, the period was ~16.4?hr. Starting in 2010 August the period changed from 16.6?hr to near 19?hr in December. With respect to dust composition, most volatiles and carbon and nitrogen isotope ratios, the comet is similar to other Jupiter-family comets. What is unusual is the dominance of CO 2 -driven activity near perihelion, which likely persists out to aphelion. Near perihelion the comet nucleus was surrounded by a large halo of water-ice grains that contributed significantly to the total water production.
|
|
| 2. |
- Nazemi, L., et al.
(författare)
-
Depression, Prevalence and Some Risk Factors in Elderly Nursing Homes in Tehran, Iran
- 2013
-
Ingår i: Iranian Journal of Public Health. - 2251-6085. ; 42:6, s. 559-569
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The most common geriatric psychiatric disorder is depression, known to be a multi factorial disorder. However, the influence of common preventable factors is yet to be discovered. This study was designed to evaluate the prevalence of depression and some possible risk factors in elderly residents of nursing homes in Iran. Methods: Data on demographic characteristics, nutritional and health status of 244 residents aged 60 years or older were collected from seventeen nursing homes in Tehran, Iran, during 2010 to 2012. Depression was assessed and classified according to the 15-item GDS. Univariate and then multivariate complex sample survey ordinal regression analysis was performed to investigate the association between depression and the risk factors. Results: The average age of the 244 cases studied was 75.8 (+/- 8.7) years, 53.3% were female (of whom 74.2% were housewives), 43.4% illiterate, and 32.0% were divorced or were living separately. The percentages of non-depressed, mild, moderate and severe depression were 9.8%, 50.0%, 29.5% and 10.7%, respectively. Multivariate analysis showed that dissatisfaction with personnel of nursing homes and food quality had odds ratios of 2.91 (1.33-6.36) and 2.64 (1.44-4.87), corresponding to greater odds of having a higher grade depression. Moreover, those who rested or walked had significantly higher risk of a more severe depression in comparison with those who did not (OR of 2.25 (1.50-3.38) and 1.98 (1.24-3.18), respectively), however, studying had a protective odds ratio of 0.17 (0.13-0.22). Conclusion: Depression was very common in our sample and their lifestyle influenced its prevalence.
|
|
| 3. |
|
|
| 4. |
- Sandholm, Niina, et al.
(författare)
-
New susceptibility loci associated with kidney disease in type 1 diabetes
- 2012
-
Ingår i: PLOS Genetics. - San Francisco, USA : Public Library of Science, PLOS. - 1553-7390 .- 1553-7404. ; 8:9, s. e1002921-
-
Tidskriftsartikel (refereegranskat)abstract
- Diabetic kidney disease, or diabetic nephropathy (DN), is a major complication of diabetes and the leading cause of end-stage renal disease (ESRD) that requires dialysis treatment or kidney transplantation. In addition to the decrease in the quality of life, DN accounts for a large proportion of the excess mortality associated with type 1 diabetes (T1D). Whereas the degree of glycemia plays a pivotal role in DN, a subset of individuals with poorly controlled T1D do not develop DN. Furthermore, strong familial aggregation supports genetic susceptibility to DN. However, the genes and the molecular mechanisms behind the disease remain poorly understood, and current therapeutic strategies rarely result in reversal of DN. In the GEnetics of Nephropathy: an International Effort (GENIE) consortium, we have undertaken a meta-analysis of genomewide association studies (GWAS) of T1D DN comprising similar to 2.4 million single nucleotide polymorphisms (SNPs) imputed in 6,691 individuals. After additional genotyping of 41 top ranked SNPs representing 24 independent signals in 5,873 individuals, combined meta-analysis revealed association of two SNPs with ESRD: rs7583877 in the AFF3 gene (P = 1.2 x 10(-8)) and an intergenic SNP on chromosome 15q26 between the genes RGMA and MCTP2, rs12437854 (P = 2.0 x 10(-9)). Functional data suggest that AFF3 influences renal tubule fibrosis via the transforming growth factor-beta (TGF-beta 1) pathway. The strongest association with DN as a primary phenotype was seen for an intronic SNP in the ERBB4 gene (rs7588550, P = 2.1 x 10(-7)), a gene with type 2 diabetes DN differential expression and in the same intron as a variant with cis-eQTL expression of ERBB4. All these detected associations represent new signals in the pathogenesis of DN.
|
|
| 5. |
- Hosseini, S. M. Hassan, et al.
(författare)
-
Modeling of Partial Discharge in Transformer Winding by Multi-Conductor Transmission Line Model
- 2012
-
Ingår i: International Review of Electrical Engineering. - 1827-6660 .- 2533-2244. ; 7:2, s. 3926-3934
-
Tidskriftsartikel (refereegranskat)abstract
- To locate accurately the occurrence of a partial discharge in a power transformer winding, a wide frequency band model of the winding is required. In this paper a wide frequency band Multi Conductor Transmission Line model (MTL) is employed to simulate the propagation of PD signal in transformer windings. The MTL model is briefly reviewed and the related equations of the model are reformulated to easily simulate occurrence of a PD signal along the winding. Software is developed in Matlab to calculate the windings resonance frequencies and the magnitudes of over-voltages occurring between different disks along the winding. Then propagation of PD signal in a power transformer (900MVA, 525kV), is simulated using the (MTL) model with frequency dependent parameters. Also this method is employed to model the laboratory transformer winding.
|
|
| 6. |
- Baudoin, Eric, et al.
(författare)
-
Effect of partial premixing on stabilization and local extinction of turbulent methane/air flames
- 2013
-
Ingår i: Flow, Turbulence and Combustion. - : Springer Science and Business Media LLC. - 1573-1987 .- 1386-6184. ; 90:2, s. 269-284
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedThe stabilization characteristics and local extinction structures of partially premixed methane/air flames were studied using simultaneous OH-PLIF/PIV techniques, and large eddy simulations employing a two-scalar flamelet model. Partial premixing was made in a mixing chamber comprised of two concentric tubes, where the degree of partial premixing of fuel and air was controlled by varying the mixing length of the chamber. At the exit of the mixing chamber a cone was mounted to stabilize the flames at high turbulence intensities. The stability regime of flames was determined for different degree of partial premixing and Reynolds numbers. It was found that in general partially premixed flames at low Reynolds numbers become more stable when the level of partial premixing of air to the fuel stream decreases. At high Reynolds numbers, for the presently studied burner configuration there is an optimal partial premixing level of air to the fuel stream at which the flame is most stable. OH-PLIF images revealed that for the stable flames not very close to the blowout regime, significant local extinction holes appear already. By increasing premixing air to fuel stream successively, local extinction holes grow in size leading to eventual flame blowout. Local flame extinction was found to frequently attain to locations where locally high velocity flows impinging to the flame. The local flame extinction poses a future challenge for model simulations and the present flames provide a possible test case for such study.
|
|
| 7. |
- Baudoin, Eric, et al.
(författare)
-
Effect of partial premixing on stabilization and local extinction of turbulent methane/air flames
- 2011
-
Ingår i: Proceedings of the 17th Mediterranean Combustion symposium, MCS 7. - 9788888104126
-
Konferensbidrag (refereegranskat)abstract
- The stabilization characteristics and local extinction structures of partially premixed methane/air flames were studied using simultaneous OH-PLIF/PIV techniques, and large eddy simulations employing a two-scalar flamelet model. Partial premixing was made in a mixing chamber comprised of two concentric tubes, where the degree of partial premixing of fuel and air was controlled by varying the mixing length of the chamber. At the exit of the mixing chamber a cone was mounted to stabilize the flames at high turbulence intensities. The stability regime of flames was determined for different degree of partial premixing and Reynolds numbers. It was found that in general partially premixed flames at low Reynolds numbers become more stable when the level of partial premixing of air to the fuel stream decreases. At high Reynolds numbers, for the presently studied burner configuration there is an optimal partial premixing level of air to the fuel stream at which the flame is most stable. OH-PLIF images revealed that for the stable flames not very close to the blowout regime,significant local extinction holes appear already. By increasing premixing air to fuel stream successively, local extinction holes grow in size leading to eventual flame blowout. Local flame extinction was found to frequently attain to locations where locally high velocity flows impinging to the flame. The local flame extinction poses a future challenge for model simulations and the present flames provide a possible test case for such study.
|
|
| 8. |
- Hosseini-Hashemi, Sh., et al.
(författare)
-
Free vibration analysis of functionally graded elliptical plates
- 2012
-
Ingår i: International journal of Maritime Technology. - 2345-6000. ; 8:15, s. 43-60
-
Tidskriftsartikel (refereegranskat)abstract
- This paper deals with a free vibration analysis of functionally graded elliptical plates with different classical boundary conditions on the basis of polynomial-Ritz method and classical plate theory. The proposed admissible function is capable to obtain accurate natural frequencies of various classical boundary conditions namely, clamped, free and simply supported edges. The mechanical properties of the FG plate are assumed to vary continuously through the thickness of the plate and obey a power law distribution of the volume fraction of the constituents. The convergency of applied polynomial-Ritz method is investigated. In order to verify the accuracy of the present solution, a comprehensive comparison study is performed with the available results in the literature for homogeneous elliptical plate and FG circular plate. Also, the numerical results of the present solution for FG elliptical plate are compared with those of the finite element method (FEM). Finally, the effects of the plate geometry and inhomogeneity on the natural frequencies are investigated and some vibrational mode shapes related to symmetric-symmetric, symmetric-antisymmetric, antisymmetric- symmetric and antisymmetric- antisymmetric states are presented.
|
|
| 9. |
- Meijer, A., et al.
(författare)
-
Adjusted prognostic association of depression following myocardial infarction with mortality and cardiovascular events: individual patient data meta-analysis
- 2013
-
Ingår i: British Journal of Psychiatry. - : Royal College of Psychiatrists. - 0007-1250 .- 1472-1465. ; 203:2, s. 90-102
-
Tidskriftsartikel (refereegranskat)abstract
- Background The association between depression after myocardial infarction and increased risk of mortality and cardiac morbidity may be due to cardiac disease severity. To combine original data from studies on the association between post-infarction depression and prognosis into one database, and to investigate to what extent such depression predicts prognosis independently of disease severity. An individual patient data meta-analysis of studies was conducted using multilevel, multivariable Cox regression analyses. Sixteen studies participated, creating a database of 10 175 post-infarction cases. Hazard ratios for post-infarction depression were 1.32 (95% CI 1.26-1.38, P<0.001) for all-cause mortality and 1.19 (95% CI 1.14-1.24, P<0.001) for cardiovascular events. Hazard ratios adjusted for disease severity were attenuated by 28% and 25% respectively. The association between depression following myocardial infarction and prognosis is attenuated after adjustment for cardiac disease severity. Still, depression remains independently associated with prognosis, with a 22% increased risk of all-cause mortality and a 13% increased risk of cardiovascular events per standard deviation in depression z-score.
|
|
| 10. |
|
|
