| 41. |
|
|
| 42. |
- Andersson, Jonas, et al.
(author)
-
Optimal heparin surface concentration and antithrombin binding capacity as evaluated with human non-anticoagulated blood in vitro
- 2003
-
In: Journal of Biomedical Materials Research. - : Wiley. - 0021-9304 .- 1097-4636. ; 67:2, s. 458-466
-
Journal article (peer-reviewed)abstract
- Contact between blood and a biomaterial surface takes place in many applications and is known to activate the coagulation and complement systems. Heparin surface coatings have been shown to reduce blood activation upon contact with artificial surfaces. To establish the optimal heparin surface concentration, blood was incubated in a tubing loop model at 37 degrees C. The tubing was coated with different surface concentrations of heparin and rotated at three different velocities. We demonstrate that the blood compatibility of a surface with regard to coagulation, complement, and platelet activation can be improved by increasing the heparin surface concentration in the 6-12 pmol antithrombin/cm2 concentration interval. The binding of factor H is not influenced by the increased heparin surface concentration, suggesting that this factor is not the primary regulator of complement on heparin surfaces. In addition, the heparin coating has no effect on the complement activation that occurs on gas surfaces in extracorporeal circuits.
|
|
| 43. |
- Angelov, Nikolay, et al.
(author)
-
Testing for unit root against stationarity using the likelihood ratio test
- 2007
-
In: Communications in statistics. Simulation and computation. - : Informa UK Limited. - 0361-0918 .- 1532-4141. ; 36:2, s. 391-412
-
Journal article (peer-reviewed)abstract
- In a first order autoregressive model with drift, we derive the likelihood ratio test for a unit root against the stationary alternative. We also derive the test in a state space model with trend. Finite sample and asymptotic critical values are obtained by Monte Carlo simulations. A simulation study investigates the power performance of the likelihood ratio test and we also examine how a bias correction of the test affects the results.
|
|
| 44. |
- Aspegren, Henrik, et al.
(author)
-
Nationell styrning behövs för at förebygga översvämningar och vattenbrist
- 2018
-
In: Göteborgs-Posten. - 1103-9345.
-
Journal article (pop. science, debate, etc.)abstract
- DebattTillgången till vatten kan inte längre ses som en lokal fråga utan måste ses ur ett bredare perspektiv, som kräver en samordning som är ny för Sverige. Det behövs sammanhängande nationell styrning och en strategi med helhetssyn på vattenfrågan, skriver nio svenska vattenexperter som kommer att debattera detta ämne under politikerveckan i Almedalen.
|
|
| 45. |
- Baranowska, Izabella, et al.
(author)
-
Sensory ataxic neuropathy in golden retriever dogs is caused by a deletion in the mitochondrial tRNATyr gene
- 2009
-
In: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 5:5, s. e1000499-
-
Journal article (peer-reviewed)abstract
- Sensory ataxic neuropathy (SAN) is a recently identified neurological disorder in golden retrievers. Pedigree analysis revealed that all affected dogs belong to one maternal lineage, and a statistical analysis showed that the disorder has a mitochondrial origin. A one base pair deletion in the mitochondrial tRNA(Tyr) gene was identified at position 5304 in affected dogs after re-sequencing the complete mitochondrial genome of seven individuals. The deletion was not found among dogs representing 18 different breeds or in six wolves, ruling out this as a common polymorphism. The mutation could be traced back to a common ancestor of all affected dogs that lived in the 1970s. We used a quantitative oligonucleotide ligation assay to establish the degree of heteroplasmy in blood and tissue samples from affected dogs and controls. Affected dogs and their first to fourth degree relatives had 0-11% wild-type (wt) sequence, while more distant relatives ranged between 5% and 60% wt sequence and all unrelated golden retrievers had 100% wt sequence. Northern blot analysis showed that tRNA(Tyr) had a 10-fold lower steady-state level in affected dogs compared with controls. Four out of five affected dogs showed decreases in mitochondrial ATP production rates and respiratory chain enzyme activities together with morphological alterations in muscle tissue, resembling the changes reported in human mitochondrial pathology. Altogether, these results provide conclusive evidence that the deletion in the mitochondrial tRNA(Tyr) gene is the causative mutation for SAN.
|
|
| 46. |
- Belaghi, Reza, et al.
(author)
-
Improved shrinkage estimators in the beta regression model with application in econometric and educational data
- 2023
-
In: Statistical papers. - : Springer. - 0932-5026 .- 1613-9798. ; 64:6, s. 1891-1912
-
Journal article (peer-reviewed)abstract
- Although beta regression is a very useful tool to model the continuous bounded outcome variable with some explanatory variables, however, in the presence of multicollinearity, the performance of the maximum likelihood estimates for the estimation of the parameters is poor. In this paper, we propose improved shrinkage estimators via Liu estimator to obtain more efficient estimates. Therefore, we defined linear shrinkage, pretest, shrinkage pretest, Stein and positive part Stein estimators to estimate of the parameters in the beta regression model, when some of them have not a significant effect to predict the outcome variable so that a sub-model may be sufficient. We derived the asymptotic distributional biases, variances, and then we conducted extensive Monte Carlo simulation study to obtain the performance of the proposed estimation strategy. Our results showed a great benefit of the new methodologies for practitioners specifically in the applied sciences. We concluded the paper with two real data analysis from economics and education.
|
|
| 47. |
|
|
| 48. |
|
|
| 49. |
|
|
| 50. |
|
|
