Spatial Updating Depends on Gravity

As we move through an environment the positions of surrounding objects relative to our body constantly change. Maintaining orientation requires spatial updating, the continuous monitoring of self-motion cues to update external locations. This ability critically depends on the integration of visual, proprioceptive, kinesthetic, and vestibular information. During weightlessness gravity no longer acts as an essential reference, creating a discrepancy between vestibular, visual and sensorimotor signals. Here, we explore the effects of repeated bouts of microgravity and hypergravity on spatial updating performance during parabolic flight. Ten healthy participants (four women, six men) took part in a parabolic flight campaign that comprised a total of 31 parabolas. Each parabola created about 20-25 s of 0 g, preceded and followed by about 20 s of hypergravity (1.8 g). Participants performed a visual-spatial updating task in seated position during 15 parabolas. The task included two updating conditions simulating virtual forward movements of different lengths (short and long), and a static condition with no movement that served as a control condition. Two trials were performed during each phase of the parabola, i.e., at 1 g before the start of the parabola, at 1.8 g during the acceleration phase of the parabola, and during 0 g. Our data demonstrate that 0 g and 1.8 g impaired pointing performance for long updating trials as indicated by increased variability of pointing errors compared to 1 g. In contrast, we found no support for any changes for short updating and static conditions, suggesting that a certain degree of task complexity is required to affect pointing errors. These findings are important for operational requirements during spaceflight because spatial updating is pivotal for navigation when vision is poor or unreliable and objects go out of sight, for example during extravehicular activities in space or the exploration of unfamiliar environments. Future studies should compare the effects on spatial updating during seated and free-floating conditions, and determine at which g-threshold decrements in spatial updating performance emerge

Asymmetric thinning of the cerebral cortex across the adult lifespan is accelerated in Alzheimer’s disease

© 2021, The Author(s). Aging and Alzheimer’s disease (AD) are associated with progressive brain disorganization. Although structural asymmetry is an organizing feature of the cerebral cortex it is unknown whether continuous age- and AD-related cortical degradation alters cortical asymmetry. Here, in multiple longitudinal adult lifespan cohorts we show that higher-order cortical regions exhibiting pronounced asymmetry at age ~20 also show progressive asymmetry-loss across the adult lifespan. Hence, accelerated thinning of the (previously) thicker homotopic hemisphere is a feature of aging. This organizational principle showed high consistency across cohorts in the Lifebrain consortium, and both the topological patterns and temporal dynamics of asymmetry-loss were markedly similar across replicating samples. Asymmetry-change was further accelerated in AD. Results suggest a system-wide dedifferentiation of the adaptive asymmetric organization of heteromodal cortex in aging and AD

Grundwasser - Altlasten - Boden aktuell

Zehn Fachbeiträge dokumentieren die Ergebnisse der aktuellen Projekt- und Forschungsarbeit des Landesamtes in den Themenbereichen Grundwasser, Altlasten und Boden

Grundwasser - Altlasten - Boden aktuell

Neun Fachbeiträge dokumentieren die Ergebnisse der aktuellen Projekt- und Forschungsarbeit des Landesamtes in den Themenbereichen Grundwasser, Altlasten und Boden

Grundwasser - Altlasten - Boden aktuell

Neun Fachbeiträge dokumentieren Ergebnisse der aktuellen Projekt- und Forschungsarbeit des Landesamtes in den Themenbereichen Grundwasser, Altlasten und Boden. Die Inhalte reichen vom Interesse aus Namibia für diese Themenbereiche über verschiedene Auswertungen von Hintergrundwerten und Hochwasser 2013 bis hin zu Planungen im Bereich Bodendauerbeobachtung in Sachsen. Einzelerkenntnisse zu Wülknitz bzw. zum Tagebau Witznitz werden in dem Heft fortgeführt

Asymmetric thinning of the cerebral cortex across the adult lifespan is accelerated in Alzheimer's disease.

Aging and Alzheimer's disease (AD) are associated with progressive brain disorganization. Although structural asymmetry is an organizing feature of the cerebral cortex it is unknown whether continuous age- and AD-related cortical degradation alters cortical asymmetry. Here, in multiple longitudinal adult lifespan cohorts we show that higher-order cortical regions exhibiting pronounced asymmetry at age ~20 also show progressive asymmetry-loss across the adult lifespan. Hence, accelerated thinning of the (previously) thicker homotopic hemisphere is a feature of aging. This organizational principle showed high consistency across cohorts in the Lifebrain consortium, and both the topological patterns and temporal dynamics of asymmetry-loss were markedly similar across replicating samples. Asymmetry-change was further accelerated in AD. Results suggest a system-wide dedifferentiation of the adaptive asymmetric organization of heteromodal cortex in aging and AD

The IRX1/HOXA connection : insights into a novel t(4;11)- specific cancer mechanism

One hallmark of MLL-r leukemia is the highly specific gene expression signature indicative for commonly deregulated target genes. An usual read-out for this transcriptional deregulation is the HOXA gene cluster, where upregulated HOXA genes are detected in MLL-r AML and ALL patients. In case of t(4;11) leukemia, this simple picture becomes challenged, because these patients separate into HOXAhi- and HOXAlo-patients. HOXAlo-patients showed a reduced HOXA gene transcription, but instead overexpressed the homeobox gene IRX1. This transcriptional pattern was associated with a higher relapse rate and worse outcome. Here, we demonstrate that IRX1 binds to the MLL-AF4 complex at target gene promotors and counteract its promotor activating function. In addition, IRX1 induces transcription of HOXB4 and EGR family members. HOXB4 is usually a downstream target of c-KIT, WNT and TPO signaling pathways and necessary for maintaining and expanding in hematopoietic stem cells. EGR proteins control a p21-dependent quiescence program for hematopoietic stem cells. Both IRX1-dependend actions may help t(4;11) leukemia cells to establish a stem cell compartment. We also demonstrate that HDACi administration is functionally interfering with IRX1 and MLL-AF4, a finding which could help to improve new treatment options for t(4;11) patients

Resistance in the context of school development. Exploring a yet neglected field

Widerstand gilt als konstitutives Moment von Schulentwicklung, ist jedoch in der deutschsprachigen Schulentwicklungsforschung bislang kaum systematisch betrachtet worden. Der vorliegende Beitrag hat daher das Ziel, die bisherige themenbezogene Auseinandersetzung mittels eines Literaturüberblicks zu explorieren und Widerstand als multidimensionales Phänomen kategoriengeleitet zu strukturieren. Eine Diskussion der Befunde und die Explizierung wesentlicher Forschungsdesiderata runden den Beitrag ab. (DIPF/Orig.)Resistance emerges as a constitutive aspect of school development. Yet, the systematic examination of resistance in the field of German school development research proves limited. Thus, this article aims to explore the previous examination of the subject by means of a literature review and to structure resistance as a multidimensional phenomenon along different categories. The article closes with a discussion of the findings and the formulation of essential research desiderata. (DIPF/Orig.