31 research outputs found
Nogo-A Expression in the Brain of Mice with Cerebral Malaria
Cerebral malaria (CM) is associated with a high rate of transient or persistent neurological sequelae. Nogo-A, a protein that is highly expressed in the endoplasmic reticulum (ER) of the mammalian central nervous system (CNS), is involved in neuronal regeneration and synaptic plasticity in the injured CNS. The current study investigates the role of Nogo-A in the course of experimental CM. C57BL/6J mice were infected with Plasmodium berghei ANKA blood stages. Brain homogenates of mice with different clinical severity levels of CM, infected animals without CM and control animals were analyzed for Nogo-A up-regulation by Western blotting and immunohistochemistry. Brain regions with Nogo-A upregulation were evaluated by transmission electron microscopy. Densitometric analysis of Western blots yielded a statistically significant upregulation of Nogo-A in mice showing moderate to severe CM. The number of neurons and oligodendrocytes positive for Nogo-A did not differ significantly between the studied groups. However, mice with severe CM showed a significantly higher number of cells with intense Nogo-A staining in the brain stem. In this region ultrastructural alterations of the ER were regularly observed. Nogo-A is upregulated during the early course of experimental CM. In the brain stem of severely affected animals increased Nogo-A expression and ultrastructural changes of the ER were observed. These data indicate a role of Nogo-A in neuronal stress response during experimental CM
Localism in Finland : The changing role and current crisis of the Finnish municipal system
Peer reviewe
Exploring the role of individual level and firm level dynamic capabilities in SMEs’ internationalization
This paper presents a multi-level model that examines the impact of dynamic capabilities on the internationalization of SMEs while taking into account the interactions among them. The purpose of the research is to understand the applicability of dynamic capabilities at the individual and the firm level to the SME internationalization process in developing country context and to assess to what extent a firm’s asset position and individual level dynamic capabilities influence the generation of firm level dynamic capabilities in SMEs. First, the dynamic capabilities theory was theoretically linked to the internationalization phenomenon. The relationships among firm-level dynamic capabilities, individual-level dynamic capabilities (owner specific dynamic capabilities), and internationalization were identified. The research framework and hypotheses were developed and empirically tested with 197 SMEs. The findings established that owner-specific dynamic capabilities have a positive influence on both firm dynamic capabilities and internationalization, and firm dynamic capabilities positively influence internationalization. It was also found that the market assets position measured as perceptual environmental dynamism positively influenced firm dynamic capabilities but structural and reputational asset positions of SMEs did not influence generation of firm dynamic capabilities. Moreover, firm dynamic capabilities had a mediation effect in the relationship between owner-specific dynamic capabilities and internationalization. Theoretically, this confirms the relevance of dynamic capability theory to internationalization and the possibility of integrating existing internationalization theories. Entrepreneurs, SME managers, and policy-makers could gain valuable insights on how entrepreneur and firm capabilities lead to better international prospects from this outcome
Functional and Histological Outcome after Focal Traumatic Brain Injury Is Not Improved in Conditional EphA4 Knockout Mice
We investigated the role of the axon guidance molecule EphA4 following traumatic brain injury (TBI) in mice. Neutralization of EphA4 improved motor function and axonal regeneration following experimental spinal cord injury (SCI). We hypothesized that genetic absence of EphA4 could improve functional and histological outcome following TBI. Using qRT-PCR in wild-type (WT) mice, we evaluated the EphA4 mRNA levels following controlled cortical impact (CCI) TBI or sham injury and found it to be downregulated in the hippocampus (p < 0.05) but not the cortex ipsilateral to the injury at 24 h post-injury. Next, we evaluated the behavioral and histological outcome following CCI using WT mice and Emx1-Cre-driven conditional knockout (cKO) mice. In cKO mice, EphA4 was completely absent in the hippocampus and markedly reduced in the cortical regions from embryonic day 16, which was confirmed using Western blot analysis. EphA4 cKO mice had similar learning and memory abilities at 3 weeks post-TBI compared to WT controls, although brain-injured animals performed worse than sham-injured controls (p < 0.05). EphA4 cKO mice performed similarly to WT mice in the rotarod and cylinder tests of motor function up to 29 days post-injury. TBI increased cortical and hippocampal astrocytosis (GFAP immunohistochemistry, p < 0.05) and hippocampal sprouting (Timm stain, p < 0.05) and induced a marked loss of hemispheric tissue (p < 0.05). EphA4 cKO did not alter the histological outcome. Although our results may argue against a beneficial role for EphA4 in the recovery process following TBI, further studies including post-injury pharmacological neutralization of EphA4 are needed to define the role for EphA4 following TBI
The center of olfactory bulb‐seeded α‐synucleinopathy is the limbic system and the ensuing pathology is higher in male than in female mice
Can Migration Decisions be Affected by Income Policy Interventions? Evidence from Finland
Haapanen M. and Ritsila J. (2007) Can migration decisions be affected by income policy interventions? Evidence from Finland, Regional Studies 41, 339-348. Using Finnish micro-level data, this paper maps out whether migration decisions can be affected by income policy interventions. The analysis focuses on individuals living in peripheral regions and distinguishes peripheral migration from growth-centre migration. In support of the human capital hypothesis, the estimation results imply that migration decisions can be affected by income policy interventions. For example, an intervention that would increase an individual's expected disposable income by 10%, given that he/she does not move to a growth-centre region, would decrease his/her probability of growth-centre migration by approximately 12%. However, the impact appears to be modest compared, for example, with the impact of education on migration. Haapanen M. et Ritsila J. (2007) La decision de migrer, est-elle influee par des politiques des revenus ponctuelles? Des preuves finlandaises, Regional Studies 41, 339-348. A partir des donnees microeconomiques finlandaises, cet article cherche a elaborer si, oui ou non, la decision de migrer est influee par des politiques des revenus ponctuelles. L'analyse porte sur les individus qui habitent les regions a la peripherie et distingue la migration a la peripherie de la migration aux poles de croissance. Pour soutenir l'hypothese du capital humain, les estimations laissent supposer que la decision de migrer peut etre influee par des politiques des revenus ponctuelles. Par exemple, une politique ponctuelle qui augmenterait de 10% le revenu disponible individuel escompte, donne que l'individu n'est pas oblige de migrer a un pole de croissance regional, diminuerait d'environ 12% la probabilite qu'il migrerait a un pole de croissance regional. Cependant, l'impact semble faible par comparaison a l'impact de l'education sur la migration, par exemple. Migration Revenu Politique ponctuelle Choix de destination Haapanen M. und Ritsila J. (2007) Lassen sich Migrationsentscheidungen durch politische Massnahmen hinsichtlich des Einkommens beeinflussen? Belege aus Finnland, Regional Studies 41, 339-348. In diesem Beitrag wird mit Hilfe finnischer Daten auf Mikroebene untersucht, ob sich Migrationsentscheidungen durch politische Massnahmen hinsichtlich des Einkommens beeinflussen lassen. Die Analyse konzentriert sich auf Personen in peripheren Regionen, wobei zwischen einer peripheren Migration und einer Migration zu Wachstumszentren unterschieden wird. Aus den Ergebnissen der Schatzung geht hervor, dass sich Migrationsentscheidungen durch politische Massnahmen hinsichtlich des Einkommens beeinflussen lassen, was die Hypothese des Humankapitals unterstutzt. Wenn sich zum Beispiel durch eine Massnahme das voraussichtliche verfugbare Einkommen einer Person um 10% erhoht, sofern diese Person nicht in ein Wachstumszentrum zieht, sinkt die Wahrscheinlichkeit einer Migration dieser Person in ein Wachstumszentrum um ca. 12%. Allerdings mutet die Auswirkung auf die Migration beispielsweise im Vergleich zur Auswirkung von Bildung eher bescheiden an. Migration Einkommen Politische Massnahmen Wahl des Zielorts Haapanen M. y Ritsila J. (2007) �Se puede influenciar en las decisiones de migracion mediante medidas politicas sobre ingresos? El ejemplo de Finlandia, Regional Studies 41, 339-348. Con ayuda de datos de Finlandia a nivel micro, en este estudio analizamos si las politicas sobre ingresos pueden influir en las decisiones sobre emigracion. Este analisis se centra en individuos que viven en regiones perifericas y hace una distincion entre la migracion periferica y la migracion hacia centros de crecimiento. Respaldando la hipotesis de capital humano, los resultados de las estimaciones indican que las medidas politicas sobre ingresos pueden influir en las decisiones sobre migracion. Si, por ejemplo, mediante una medida politica los ingresos previstos y disponibles de una persona aumentaran un 10%, a condicion de que esta persona no se trasladase a un centro de crecimiento, su probabilidad de migracion a un centro de crecimiento disminuiria aproximadamente un 12%. Sin embargo, este impacto parece ser modesto si lo comparamos por ejemplo con el impacto de la educacion en migracion. Migracion Ingresos Medidas politicas Eleccion del destinoMigration, Income, Policy interventions, Choice of destination,
Co-learning in a Digital Community : Information Literacy and Views on Learning in Pre-school Teacher Education
Through analysing how different views on learning enable pre-school teacher students to distinguish and use affordances offered by digital tools and the learning environment, this paper seeks to connect modes of appropriation, identity positions and information activities to types of information literacy. Identity, particularly views on learning, is analysed to find out how a Facebook group to some students remains a sustainable digital community throughout teacher education. The paper reports results from a netnographical study conducted between 2012 and 2015. The material used in the analysis consists primarily of 12 semi-structured student interviews and 6 teacher interviews. In the thematic analysis, a socio-cultural perspective on identity is applied. The concept affordance is used to analyse how identity is connected to use of digital tools and the learning environment. The findings show how the appropriation of the Facebook group is connected to identity positions and views on learning in two types of information literacy: a relational information literacy and a pragmatic information literacy. The normative function of co-learning is found to be an important aspect of the learning environment of pre-school teacher education that explains why the digital community can be experienced as either including or excluding