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Anders Björklund

Bio: Anders Björklund is an academic researcher from Lund University. The author has contributed to research in topics: Transplantation & Dopamine. The author has an hindex of 165, co-authored 769 publications receiving 84268 citations. Previous affiliations of Anders Björklund include University of Washington & Institute for the Study of Labor.


Papers
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Book ChapterDOI
01 Jan 1986
TL;DR: These critical experiments continue, revealing more information about the limits and potentials for graft survival and integration with the host brain.
Abstract: The experimental use of intracerebral neuronal grafting has expanded greatly in the last 10 years, as compared to any other time in history, though the basic methodology has been available for centuries. Early experiments focused on determining whether intracerebral grafting was possible (see, e.g., Saltykow 1905, Thompson 1890, Del Conte 1907, Dunn 1917). Subsequently, the parameters for optimal grafting were sought for a variety of approaches, focusing on issues such as age of donor (Olson et al. 1982, Kromer et al. 1983, Das et al. 1980), age of host (Hallas et al. 1980, Azmitia et al. 1981), cross-species compatibility (Bjorklund et al. 1982, Freed 1983, Low et al. 1983), host-graft interconnections (Bjorklund et al. 1976, 1979a, McLoon and Lund 1980a,b), target specificity (Lund et al. 1982), and vascularization (Stenevi et al. 1976). These critical experiments continue, revealing more information about the limits and potentials for graft survival and integration with the host brain.

5 citations

Journal Article
TL;DR: Although, as it has been described earlier, dopamine transmission is necessary for mediation of behavioural functions of the prefrontal system, it does not change quantitatively in the system during specific activity.
Abstract: Dopamine, norepinephrine and DOPAC were measured in two cortical areas (the medial prefrontal and the posterolateral, Te2) and in the anterior and posterior neostriatum in rats which were exposed to three different experiences for three different lengths of time. One group learned delayed alternation and the two others served as controls. Throughout the training period all animals were housed in single cages. There was no significant effect of the kind of experience on any measure, but the length of exposure did affect some values: the amount of non-precursor dopamine was decreased significantly in both neostriatal samples. A significant increase of dopamine turnover and amount of norepinephrine was found in the Te2 area and in the posterior neostriatal sample. The observed changes are attributed to isolation stress. We conclude that although, as it has been described earlier, dopamine transmission is necessary for mediation of behavioural functions of the prefrontal system, it does not change quantitatively in the system during specific activity.

5 citations

Journal ArticleDOI
M.H. Bassant, M. Joly, Ola Nilsson1, Anders Björklund1, Yvon Lamour 
TL;DR: Electrophysiological and pharmacological properties of neurons within solid basal forebrain transplants were studied in adult rats anesthetized with urethane in order to evaluate the responses of grafted neurons to glutamate, gamma-aminobutyric acid, acetylcholine, serotonin and norepinephrine.

4 citations

Journal ArticleDOI
TL;DR: 'Transplants of embryonic septal tissue in rats given fimbria-fornix (Ffx) lesions can either restore maze performance or lead to greater impairments than lesions alone.
Abstract: Transplants of embryonic septal tissue in rats given fimbria-fornix (Ffx) lesions can either restore maze performance or lead to greater impairments than lesions alone.' The patterns of innervation produced in these two cases are not now distinguishable histologically. The present study investigated the effects of transplants of embryonic septal tissue upon single unit activity in the hippocampus of four groups of rats: normal rats, those given Ffx lesions, those given Ffx lesions and transplants that improved performance on spatial memory tests (trans/smart), and those given Ffx lesions and transplants that impaired maze performance (trans/impaired). Rats were given either sham operations, aspiration lesions of the Ffx, or Ffx lesions and transplants (solid grafts) of embryonic septal tissue into the lesion cavity. Three months after surgery the rats were tested on a water maze that required spatial memory.* Performance on this task distinguished between trans/smart and trans/ impaired rats. Electrodes for single unit recording were implanted surgically after behavioral testing, and recording began one week after surgery. Theta unit activity was recorded from the CA-1 layer of the dorsal hippocampus during two behaviors: an appetitive behavior in which rats walked on an elevated track during recording and a consummatory behavior in which rats drank chocolate milk from a drinking tube. Theta unit activity is characterized by changes in firing frequency and periodicity that vary with behavioral class. In normal rats, high frequency theta unit activity was organized into 7 Hz spike trains during walking, whereas low frequency activity was not organized into periodic spike trains during drinking. In rats given Ffx lesions, firing frequency increased during walking relative to drinking, whereas theta unit activity was never organized into periodic spike trains. In trans/smart rats, overall firing frequency increased during walking relative to drinking, and theta unit activity was somewhat organized into periodic spike trains. In trans/impaired rats, high frequency firing appeared during both behaviors, and theta unit activity did not appear to be organized normally during either behavior. The modulation of theta unit activity was correlated with recovery of performance on the water maze. Unit activity recorded from trans/smart rats resembled that from normal rats, since both frequency and periodicity of theta units were correlated with behavioral class. Only one component of unit activity recorded from Ffx rats were correlated with behavior, since firing frequency, but not periodicity, increased during appetitive behavior. Unit activity recorded from trans/impaired rats was not correlated with behavioral class a t all.

4 citations

Posted Content
TL;DR: In this article, the authors compare the relationship between family structure and children's outcomes in terms of educational attainment and earnings using data from Sweden and the United States and find that living in a non-intact family is correlated with lower educational attainment.
Abstract: It is well known that children reared in non-intact families on average have less favorable educational outcomes than children reared in two-parent families. Evidence from the United States and Sweden indicates that living in a non-intact family is correlated with lower educational attainment. In this paper we compare the relationships between family structure and children’s outcomes in terms of educational attainment and earnings using data from Sweden and the United States. Comparing the United States and Sweden is interesting because both family structure and public policy environments in the two countries differ significantly. Family structure could potentially have a less negative effect in Sweden than in the United States because of the extensive social safety net provided by that country. We find, however, the associations between family structure and children’s outcomes to be remarkably similar in the United States and Sweden even though the policy and social environments differ between the two countries; living in a non-intact family is negatively related to child outcomes. This relationship is weakened when we control for other family characteristics, such as time lived with full and half siblings. In addition, when we use siblingdifference models to take account of unobserved family characteristics, the relationship is no longer statistically significant. Taken together, our results suggest that the true effect of family structure is more complex than the biological relationship of parents to children in both Sweden and the United States.

4 citations


Cited by
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Book
01 Jan 2001
TL;DR: This is the essential companion to Jeffrey Wooldridge's widely-used graduate text Econometric Analysis of Cross Section and Panel Data (MIT Press, 2001).
Abstract: The second edition of this acclaimed graduate text provides a unified treatment of two methods used in contemporary econometric research, cross section and data panel methods. By focusing on assumptions that can be given behavioral content, the book maintains an appropriate level of rigor while emphasizing intuitive thinking. The analysis covers both linear and nonlinear models, including models with dynamics and/or individual heterogeneity. In addition to general estimation frameworks (particular methods of moments and maximum likelihood), specific linear and nonlinear methods are covered in detail, including probit and logit models and their multivariate, Tobit models, models for count data, censored and missing data schemes, causal (or treatment) effects, and duration analysis. Econometric Analysis of Cross Section and Panel Data was the first graduate econometrics text to focus on microeconomic data structures, allowing assumptions to be separated into population and sampling assumptions. This second edition has been substantially updated and revised. Improvements include a broader class of models for missing data problems; more detailed treatment of cluster problems, an important topic for empirical researchers; expanded discussion of "generalized instrumental variables" (GIV) estimation; new coverage (based on the author's own recent research) of inverse probability weighting; a more complete framework for estimating treatment effects with panel data, and a firmly established link between econometric approaches to nonlinear panel data and the "generalized estimating equation" literature popular in statistics and other fields. New attention is given to explaining when particular econometric methods can be applied; the goal is not only to tell readers what does work, but why certain "obvious" procedures do not. The numerous included exercises, both theoretical and computer-based, allow the reader to extend methods covered in the text and discover new insights.

28,298 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Book
28 Apr 2021
TL;DR: In this article, the authors proposed a two-way error component regression model for estimating the likelihood of a particular item in a set of data points in a single-dimensional graph.
Abstract: Preface.1. Introduction.1.1 Panel Data: Some Examples.1.2 Why Should We Use Panel Data? Their Benefits and Limitations.Note.2. The One-way Error Component Regression Model.2.1 Introduction.2.2 The Fixed Effects Model.2.3 The Random Effects Model.2.4 Maximum Likelihood Estimation.2.5 Prediction.2.6 Examples.2.7 Selected Applications.2.8 Computational Note.Notes.Problems.3. The Two-way Error Component Regression Model.3.1 Introduction.3.2 The Fixed Effects Model.3.3 The Random Effects Model.3.4 Maximum Likelihood Estimation.3.5 Prediction.3.6 Examples.3.7 Selected Applications.Notes.Problems.4. Test of Hypotheses with Panel Data.4.1 Tests for Poolability of the Data.4.2 Tests for Individual and Time Effects.4.3 Hausman's Specification Test.4.4 Further Reading.Notes.Problems.5. Heteroskedasticity and Serial Correlation in the Error Component Model.5.1 Heteroskedasticity.5.2 Serial Correlation.Notes.Problems.6. Seemingly Unrelated Regressions with Error Components.6.1 The One-way Model.6.2 The Two-way Model.6.3 Applications and Extensions.Problems.7. Simultaneous Equations with Error Components.7.1 Single Equation Estimation.7.2 Empirical Example: Crime in North Carolina.7.3 System Estimation.7.4 The Hausman and Taylor Estimator.7.5 Empirical Example: Earnings Equation Using PSID Data.7.6 Extensions.Notes.Problems.8. Dynamic Panel Data Models.8.1 Introduction.8.2 The Arellano and Bond Estimator.8.3 The Arellano and Bover Estimator.8.4 The Ahn and Schmidt Moment Conditions.8.5 The Blundell and Bond System GMM Estimator.8.6 The Keane and Runkle Estimator.8.7 Further Developments.8.8 Empirical Example: Dynamic Demand for Cigarettes.8.9 Further Reading.Notes.Problems.9. Unbalanced Panel Data Models.9.1 Introduction.9.2 The Unbalanced One-way Error Component Model.9.3 Empirical Example: Hedonic Housing.9.4 The Unbalanced Two-way Error Component Model.9.5 Testing for Individual and Time Effects Using Unbalanced Panel Data.9.6 The Unbalanced Nested Error Component Model.Notes.Problems.10. Special Topics.10.1 Measurement Error and Panel Data.10.2 Rotating Panels.10.3 Pseudo-panels.10.4 Alternative Methods of Pooling Time Series of Cross-section Data.10.5 Spatial Panels.10.6 Short-run vs Long-run Estimates in Pooled Models.10.7 Heterogeneous Panels.Notes.Problems.11. Limited Dependent Variables and Panel Data.11.1 Fixed and Random Logit and Probit Models.11.2 Simulation Estimation of Limited Dependent Variable Models with Panel Data.11.3 Dynamic Panel Data Limited Dependent Variable Models.11.4 Selection Bias in Panel Data.11.5 Censored and Truncated Panel Data Models.11.6 Empirical Applications.11.7 Empirical Example: Nurses' Labor Supply.11.8 Further Reading.Notes.Problems.12. Nonstationary Panels.12.1 Introduction.12.2 Panel Unit Roots Tests Assuming Cross-sectional Independence.12.3 Panel Unit Roots Tests Allowing for Cross-sectional Dependence.12.4 Spurious Regression in Panel Data.12.5 Panel Cointegration Tests.12.6 Estimation and Inference in Panel Cointegration Models.12.7 Empirical Example: Purchasing Power Parity.12.8 Further Reading.Notes.Problems.References.Index.

10,363 citations

Journal ArticleDOI
11 Sep 2003-Neuron
TL;DR: PD models based on the manipulation of PD genes should prove valuable in elucidating important aspects of the disease, such as selective vulnerability of substantia nigra dopaminergic neurons to the degenerative process.

4,872 citations