| 1. |
- Davies, G., et al.
(författare)
-
Study of 300,486 individuals identifies 148 independent genetic loci influencing general cognitive function
- 2018
-
Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 9:1
-
Tidskriftsartikel (refereegranskat)abstract
- General cognitive function is a prominent and relatively stable human trait that is associated with many important life outcomes. We combine cognitive and genetic data from the CHARGE and COGENT consortia, and UK Biobank (total N = 300,486; age 16-102) and find 148 genome-wide significant independent loci (P < 5 × 10-8) associated with general cognitive function. Within the novel genetic loci are variants associated with neurodegenerative and neurodevelopmental disorders, physical and psychiatric illnesses, and brain structure. Gene-based analyses find 709 genes associated with general cognitive function. Expression levels across the cortex are associated with general cognitive function. Using polygenic scores, up to 4.3% of variance in general cognitive function is predicted in independent samples. We detect significant genetic overlap between general cognitive function, reaction time, and many health variables including eyesight, hypertension, and longevity. In conclusion we identify novel genetic loci and pathways contributing to the heritability of general cognitive function.
|
|
| 2. |
- Komatsu, Kimberly J., et al.
(författare)
-
Global change effects on plant communities are magnified by time and the number of global change factors imposed
- 2019
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 116:36, s. 17867-17873
-
Tidskriftsartikel (refereegranskat)abstract
- Accurate prediction of community responses to global change drivers (GCDs) is critical given the effects of biodiversity on ecosystem services. There is consensus that human activities are driving species extinctions at the global scale, but debate remains over whether GCDs are systematically altering local communities worldwide. Across 105 experiments that included over 400 experimental manipulations, we found evidence for a lagged response of herbaceous plant communities to GCDs caused by shifts in the identities and relative abundances of species, often without a corresponding difference in species richness. These results provide evidence that community responses are pervasive across a wide variety of GCDs on long-term temporal scales and that these responses increase in strength when multiple GCDs are simultaneously imposed.Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.
|
|
| 3. |
- Shrestha, Sarita, 1991-, et al.
(författare)
-
The use of ICD codes to identify IBD subtypes and phenotypes of the Montreal classification in the Swedish National Patient Register
- 2020
-
Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 55:4, s. 430-435
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Whether data on International Classification of Diseases (ICD)-codes from the Swedish National Patient Register (NPR) correctly correspond to subtypes of inflammatory bowel disease (IBD) and phenotypes of the Montreal classification scheme among patients with prevalent disease is unknown. Materials and methods: We obtained information on IBD subtypes and phenotypes from the medical records of 1403 patients with known IBD who underwent biological treatment at ten Swedish hospitals and retrieved information on their IBD-associated diagnostic codes from the NPR. We used previously described algorithms to define IBD subtypes and phenotypes. Finally, we compared these register-generated subtypes and phenotypes with the corresponding information from the medical records and calculated positive predictive values (PPV) with 95% confidence intervals. Results: Among patients with clinically confirmed disease and diagnostic listings of IBD in the NPR (N = 1401), the PPV was 97 (96-99)% for Crohn's disease, 98 (97-100)% for ulcerative colitis, and 8 (4-11)% for IBD-unclassified. The overall accuracy for age at diagnosis was 95% (when defined as A1, A2, or A3). Examining the validity of codes representing disease phenotype, the PPV was 36 (32-40)% for colonic Crohn's disease (L2), 61 (56-65)% for non-stricturing/non-penetrating Crohn's disease behaviour (B1) and 83 (78-87)% for perianal disease. Correspondingly, the PPV was 80 (71-89)% for proctitis (E1)/left-sided colitis (E2) in ulcerative colitis. Conclusions: Among people with known IBD, the NPR is a reliable source of data to classify most subtypes of prevalent IBD, even though misclassification commonly occurred in Crohn's disease location and behaviour and also among IBD-unclassified patients.
|
|
| 4. |
- Dobson, Roy Thomas, et al.
(författare)
-
A quality improvement activity to promote interprofessional collaboration among health professions students
- 2009
-
Ingår i: American Journal of Pharmaceutical Education. - 0002-9459 .- 1553-6467. ; 73:4, s. 1-7
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To develop and evaluate a classroom-based curriculum designed to promote interprofessional competencies by having undergraduate students from various health professions work together on system-based problems using quality improvement (QI) methods and tools to improve patient-centered care.DESIGN: Students from 4 health care programs (nursing, nutrition, pharmacy, and physical therapy) participated in an interprofessional QI activity. In groups of 6 or 7, students completed pre-intervention and post-intervention reflection tools on attitudes relating to interprofessio nal teams, and a tool designed to evaluate group process.ASSESSMENT: One hundred thirty-four students (76.6%) completed both self-reflection instruments, and 132 (74.2%) completed the post-course group evaluation instrument. Although already high prior to the activity, students' mean post-intervention reflection scores increased for 12 of 16 items. Post-intervention group evaluation scores reflected a high level of satisfaction with the experience.CONCLUSION: Use of a quality-based case study and QI methodology were an effective approach to enhancing interprofessional experiences among students.
|
|
| 5. |
- Hacker,, R Scott, 1964-, et al.
(författare)
-
A Bootstrap Test for Causality with Endogenous Lag Length Choice : theory and application in finance
- 2010
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Granger causality tests have become among the most popular empirical applications with time series data. Several new tests have been developed in the literature that can deal with different data generating processes. In all existing theoretical papers it is assumed that the lag length is known a priori. However, in applied research the lag length has to be selected before testing for causality. This paper suggests that in investigating the effectiveness of various Granger causality testing methodologies, including those using bootstrapping, the lag length choice should be endogenized, by which we mean the data-driven preselection of lag length should be taken into account. We provide and accordingly evaluate a Granger-causality bootstrap test which may be used with data that may or may not be integrated, and compare the performance of this test to that for the analogous asymptotic test. The suggested bootstrap test performs well and appears to be also robust to ARCH effects that usually characterize the financial data. This test is applied to testing the causal impact of the US financial market on the market of the United Arab Emirates.
|
|
| 6. |
- Hacker, R. Scott, et al.
(författare)
-
A bootstrap test for causality with endogenous lag length choice : theory and application in finance
- 2012
-
Ingår i: Journal of economic studies. - : Emerald. - 0144-3585 .- 1758-7387. ; 39:2, s. 144-160
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose – In all existing theoretical papers on causality it is assumed that the lag length is known a priori. However, in applied research the lag length has to be selected before testing for causality. The purpose of this paper is to suggest that in investigating the effectiveness of various Granger causality testing methodologies, including those using bootstrapping, the lag length choice should be endogenized, by which we mean the data-driven preselection of lag length should be taken into account.Design/methodology/approach – The size and power of a bootstrap test with endogenized lag-length choice are investigated by simulation methods. A statistical software component is produced to implement the test, which is available online.Findings – The simulation results show that this test performs well. An application of the test provides empirical support for the hypothesis that the UAE financial market is integrated with the US market.Social implications – The empirical results based on this test are expected to be more precise.Originality/value – This paper considers a bootstrap test for causality with endogenous lag order. This test has superior properties compared to existing causality tests in terms of size, with similar if not better power and it is robust to ARCH effects that usually characterize financial data. Practitioners interested in causal inference based on time series data might find the test valuable.
|
|
| 7. |
- Hacker, R Scott, et al.
(författare)
-
A Test for Multivariate ARCH Effects
- 2005
-
Ingår i: Applied Economics Letters. - : Informa UK Limited. - 1350-4851 .- 1466-4291. ; 12:7, s. 411-417
-
Tidskriftsartikel (refereegranskat)abstract
- This paper extends Engle's LM test for ARCH affects to multivariate cases. The size and power properties of this multivariate test for ARCH effects in VAR models are investigated based on asymptotic and bootstrap distributions. Using the asymptotic distribution, deviations of actual size from nominal size do not appear to be very excessive. Nevertheless, there is a tendency for the actual size to overreject the null hypothesis when the nominal size is 1% and underreject the null when the nominal size is 5% or 10%. It is found that using a bootstrap distribution for the multivariate LM test is generally superior in achieving the appropriate size to using the asymptotic distribution when (1) the nominal size is 5%; (2) the sample size is small (40 observations) and/or the VAR system is stable. With a small sample, the power of the test using the bootstrap distribution also appears better at the 5% nominal size.
|
|
| 8. |
- Hacker, R Scott, et al.
(författare)
-
An Alternative Method to Test for Contagion with an Application to the Asian Financial Crisis
- 2005
-
Ingår i: Applied Financial Economics Letters. - : Informa UK Limited. - 1744-6546 .- 1744-6554. ; 1:6, s. 343-347
-
Tidskriftsartikel (refereegranskat)abstract
- This paper investigates the size properties of a test for contagion based on an asymptotic t -distribution. The simulations show that this asymptotic test does not have correct size properties. An alternative test method based on case-resampling bootstrapping is introduced to improve on the correctness of inference. The simulations show that this new test has much better size properties. It also has quite high power properties and it is robust to ARCH effects. The method is applied to testing for contagion from Thailand to Indonesia during the Asian financial crisis.
|
|
| 9. |
- Hacker, R Scott, et al.
(författare)
-
Capital Mobility in Sweden : A Time Varying Parameter Approach
- 2007
-
Ingår i: Applied Economics Letters. - : Informa UK Limited. - 1350-4851 .- 1466-4291. ; 14:15, s. 1115-1118
-
Tidskriftsartikel (refereegranskat)abstract
- This article investigates the degree of capital mobility in Sweden during 1993 to 2004 using quarterly data. A time varying parameter model is estimated by the Kalman filter, and it shows that the relationship between investment as share in gross domestic product (GDP) and saving as share in GDP is much less than one (within the interval of 0.25–0.35), indicating substantial capital mobility. However, since the coefficient in each period is statistically different from zero, capital is still not perfectly mobile. Nevertheless, capital mobility seems to have increased until 1995 when Sweden became a member of EU and after membership there seems to be no significant increase in capital mobility.
|
|
| 10. |
- Hacker, R Scott, et al.
(författare)
-
How Productivity and Domestic Output Are Related to Exports and Foreign Output in the Case of Sweden
- 2003
-
Ingår i: Empirical Economics. - : Springer Science and Business Media LLC. - 0377-7332 .- 1435-8921. ; 28:4, s. 767-782
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper we examine the relationships between two sets of three variables: Swedish real exports, Swedish real GDP, and foreign real GDP in one set; and Swedish real exports, Swedish total factor productivity, and foreign real GDP in the other set. The foreign real GDP facing Sweden is proxied by total OECD real GDP minus Sweden's real GDP. Multivariate tests for integration and cointegration show that the variables in each model are cointegrated. We also perform Granger causality tests on these variables in our examination using the Toda-Yamamoto procedure. We discover bi-directional causality between Swedish real exports and Swedish real GDP (or Swedish total factor productivity). Foreign real GDP is shown to Granger cause Swedish real exports, but no significant causation of foreign real GDP on either domestic GDP or total factor productivity was found. A change in foreign real GDP thus appears to affect Swedish output and productivity only indirectly, through changes in Swedish exports.
|
|
