507 research outputs found
Emergence of individual behavioural traits and associated hippocampal plasticity in genetically identical mice
Die Erforschung der Zusammenhänge zwischen Gehirnplastizität und individuellem Verhalten gestaltet sich aufgrund ihrer Komplexität im Tiermodell schwierig. Die vorliegende Studie wurde im mit dem Ziel konzipiert, die Individualitätsentwicklung bei Mäusen mit den gleichen physiologischen und genetischen Voraussetzungen in einer komplexen räumlichen und sozialen Umgebung zu beschreiben. Ich untersuchte die Korrelation dieser Entwicklung mit der Neurogenese im adulten Hippokampus als Maß für Gehirnplastizität. Zu diesem Zweck wurden zwei je mit einem automatisierten RFID-Tracking-System ausgestattete Großgehege mit jeweils 40 Tieren besiedelt. Die Bewegungen der Tiere wurden kontinuierlich aufgezeichnet und es wurden zudem direkte Verhaltensbeobachtungen durchgeführt.
Die Tiere zeigten eine normale physiologische Entwicklung. Die Roaming Entropy (RE), ein Maß für die Gleichmäßigkeit, mit der die Tiere ihr Gehege nutzten, beschreibt das Erkundungsverhalten der einzelnen Mäuse. Die kumulativ erworbenen RE-Werte (cRE) in jedem der beiden Gehege wurden mit der Zeit zunehmend verschieden. Es war nicht möglich, aufgrund kleiner anfänglicher Unterschiede die Endwerte zu berechnen. Das bedeutet, dass die Tiere erst durch die andauernde Interaktion mit ihrer Umwelt und den Artgenossen unterschiedlicher wurden. Darüber hinaus sind die cRE-Werte am Endpunkt positiv mit den Neurogenesewerten korreliert. Dies beweist, dass während der Entwicklung auftretende Faktoren die Individualitätsentwicklung beeinflussen. Dieser Prozess benötigt plastische Hirnstrukturen und formt diese wiederum.
Die Verhaltensanalysen zeigten, dass Tiere, die viele Antennenkontakte sammelten („most active“, MA) nicht zwangsläufig auch hohe cRE-Werte hatten. MA-Mäuse waren häufiger an sozialen Interaktionen beteiligt als Tiere mit wenigen Antennenkontakten („least active“, LA), akkumulierten über die Zeit niedrigere cRE-Werte und standen vermutlich weiter unten in der sozialen Hierarchie.
Zusammenfassend kann man sagen, dass das Ausmaß der räumlichen Exploration und die allmähliche Erweiterung der Erfahrung mit einer gesteigerten Plastizität des Gehirns in Form von adulter Neurogenese verbunden war. Die Daten zeigen, dass Tiere mit den gleichen Voraussetzungen sich dennoch auf zunehmend divergierende, individuelle Art entwickeln. Dies ist zumindest teilweise durch leicht unterschiedliche epigenetische Voraussetzungen zu erklären, die durch das Wechselspiel mit dem komplexen Umfeld weiter auseinanderdriften. Auch scheint es, dass Individuation lebenden Organismen inhärent und Voraussetzung für evolutionäre Prozesse ist. Die Studie zeigt, dass die Unterschiede in individuellem Verhalten und Gehirnstruktur nicht allein durch Genen und Umweltbedingungen festgelegt sind, sondern auch durch Faktoren, die sich während der ontogenetischen Entwicklung entfalten, beeinflusst werden. Der beschriebene Versuchsaufbau stellt darüber hinaus ein Tiermodell für die Untersuchung von Mechanismen und modulierenden Faktoren auf die strukturellen Grundlagen der Plastizität als individuelle Reaktion auf die gemeinsam genutzte Umgebung dar.The complex nature of the relationship between brain plasticity and individual behaviour renders its investigation using animal models difficult. The present study was designed to describe the emergence of individuality in mice with the same physiological, environmental and genetic preconditions in response to complex environmental and social cues. I investigated the correlation of this development to brain plasticity, namely neurogenesis in the adult hippocampus. To this end, two large, multi-level enclosures fitted with and automated RFID tracking system were populated with 40 animals to each. The mice were continuously tracked and live behaviour observations were done.
The animals showed normal physiological development. The Roaming Entropy (RE), a measure for the evenness of their usage of the enclosure, describes the exploration behaviour of each animal. Cumulatively acquired RE scores (cRE) within an enclosure increasingly diverged with time. Small differences at the beginning were not predictive of the end values. Thus, the animals became different through the continued interaction with environment and conspecifics. Moreover, the cRE values at the end point positively correlated with the amount of hippocampal neurogenesis. This proves that factors emerging during development contribute to individuality development. These factors at the same time shape and rely on plastic brain structures.
Behavioural analyses showed that animals with a high amount of antenna contacts (most active, MA mice) were not necessarily those with high cRE values. MA mice were more often involved in social interactions than the least active mice (least active, LA), accumulated lower cRE scores over time and seemed to be lower in the social hierarchy.
In conclusion, the amount of spatial exploration and gradual broadening of experience was linked to brain plasticity in the form of elevated levels of hippocampal neurogenesis. The data shows that animals with same preconditions still develop along increasingly divergent, individual paths. This is probably partly given through slightly different epigenetic preconditions, drifting further apart by interaction with the complex environment. Also, individuation seems to be inherent in living organisms and necessary for evolutionary processes. The study shows firstly that differences in individual behaviour and brain structure are defined not only by genes and the environment but also modulated by factors unfolding or emerging during ontogenetic development. The present paradigm moreover introduces an animal model for studying mechanisms and influences on the structural basis of plasticity as an individual response to the nonshared environment
Digital Agency
In diesem Artikel wird das Konzept der Digital Agency (en) / digitaler Handlungsmacht (de) vorgestellt. Digital Agency (DA) behandelt neben Wissen und Fertigkeiten auch die Dimensionen Selbstvertrauen und Verantwortlichkeit im Umgang mit digitalen Artefakten. Digitale Handlungsmacht wird als die Fähigkeit beschrieben, digitale Kontexte zu kontrollieren und sich ihnen anzupassen. Der Artikel würdigt die Erweiterung des Konzepts von digitalen Kompetenzen und stellt gleichzeitig zwei zentrale Lücken zur Diskussion. Erstens zeigen wir, dass die grundlagentheoretische Fundierung und Verortung des Konzepts noch nicht hinreichend ausgeführt und begründet ist. Zweitens wird klar, dass feministische und intersektionale Dimensionen im DA-Konzept bislang keine Beachtung finden. Auf Basis dieser kritischen Würdigung stellen wir abschließend mögliche theoretische Anknüpfungspunkte und weitere Forschungs- und Entwicklungsfragen vor
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Physical plasma-treated saline promotes an immunogenic phenotype in CT26 colon cancer cells in vitro and in vivo
Metastatic colorectal cancer is the fourth most common cause of cancer death. Current options in palliation such as hyperthermic intraperitoneal chemotherapy (HIPEC) present severe side effects. Recent research efforts suggested the therapeutic use of oxidant-enriched liquid using cold physical plasma. To investigate a clinically accepted treatment regimen, we assessed the antitumor capacity of plasma-treated saline solution. In response to such liquid, CT26 murine colon cancer cells were readily oxidized and showed cell growth with subsequent apoptosis, cell cycle arrest, and upregulation of immunogenic cell death (ICD) markers in vitro. This was accompanied by marked morphological changes with re-arrangement of actin fibers and reduced motility. Induction of an epithelial-to-mesenchymal transition phenotype was not observed. Key results were confirmed in MC38 colon and PDA6606 pancreatic cancer cells. Compared to plasma-treated saline, hydrogen peroxide was inferiorly toxic in 3D tumor spheroids but of similar efficacy in 2D models. In vivo, plasma-treated saline decreased tumor burden in Balb/C mice. This was concomitant with elevated numbers of intratumoral macrophages and increased T cell activation following incubation with CT26 cells ex vivo. Being a potential adjuvant for HIPEC therapy, our results suggest oxidizing saline solutions to inactivate colon cancer cells while potentially stimulating antitumor immune responses
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Murine Macrophages Modulate Their Inflammatory Profile in Response to Gas Plasma-Inactivated Pancreatic Cancer Cells
Macrophages and immuno-modulation play a dominant role in the pathology of pancreatic cancer. Gas plasma is a technology recently suggested to demonstrate anticancer efficacy. To this end, two murine cell lines were employed to analyze the inflammatory consequences of plasma-treated pancreatic cancer cells (PDA) on macrophages using the kINPen plasma jet. Plasma treatment decreased the metabolic activity, viability, and migratory activity in an ROS- and treatment time-dependent manner in PDA cells in vitro. These results were confirmed in pancreatic tumors grown on chicken embryos in the TUM-CAM model (in ovo). PDA cells promote tumor-supporting M2 macrophage polarization and cluster formation. Plasma treatment of PDA cells abrogated this cluster formation with a mixed M1/M2 phenotype observed in such co-cultured macrophages. Multiplex chemokine and cytokine quantification showed a marked decrease of the neutrophil chemoattractant CXCL1, IL6, and the tumor growth supporting TGFβ and VEGF in plasma-treated compared to untreated co-culture settings. At the same time, macrophage-attractant CCL4 and MCP1 release were profoundly enhanced. These cellular and secretome data suggest that the plasma-inactivated PDA6606 cells modulate the inflammatory profile of murine RAW 264.7 macrophages favorably, which may support plasma cancer therapy
Continuous Adaptive Evolution of a Fast-Growing Corynebacterium glutamicum Strain Independent of Protocatechuate
Graf M, Haas T, Mueller F, et al. Continuous Adaptive Evolution of a Fast-Growing Corynebacterium glutamicum Strain Independent of Protocatechuate. Frontiers in Microbiology . 2019;10: 1648.Corynebacterium glutamicum is a commonly applied host for the industrial production of amino acids. While valued for its robustness, it is somewhat inferior to competing strains such as Escherichia coli because of the relatively low growth rate of 0.40 h(-1) in synthetic, industrial media. Accordingly, adaptive laboratory evolution (ALE) experiments were performed in continuous cultivation mode to select for a growth-improved host. To ensure industrial attractiveness, this ALE study aimed at a reduction of dependency on costly growth-boosting additives such as protocatechuate (RCA) or complex media supplements. Consequently, double selection pressures were installed consisting of a steady increase in growth rate demands and a parallel reduction of complex medium fractions. Selection yielded C. glutamicum EVO5 achieving 0.54 h(-1) and 1.03g(Glc) g(CDW)(-1) h(-1) in minimal medium without above mentioned supplements. Sequencing revealed 10 prominent mutations, three of them in key regulator genes
Using the community psychology competencies to address sexual assault on a college campus
Sexual assault on college campuses is a national issue, with a recent report from the White House estimating that 20% of women will experience a sexual assault during college. Students at Wichita State University formed a campus organization to bring visibility to both community psychology and address this important problem. The Community Psychology Association is comprised of both graduate and undergraduate students, and members utilized three community psychology competencies: ecological perspectives, information dissemination/building public awareness, and community organizing and community advocacy in their work to improve resources and campus support for this issue. Community Psychology Association members utilized focus groups with campus students, faculty, and staff to facilitate discussions on sexual assault, campus safety, and university and administrative accountability. Content analysis revealed multiple themes that were used to generate a larger campus discussion and promote change in campus policies. As a result of these activities, major changes occurred at Wichita State, including data driven programming for interventions regarding sexual assault, changes in leadership in the offices of Title IX and Student Affairs, support for a CDC grant, and overall increased organizational awareness for sexual assault survivors. This study highlights the importance of applying community psychology principles and concepts to research and action to ultimately have a positive and tangible impact on the local community
Using the community psychology competencies to address sexual assault on a college campus
Sexual assault on college campuses is a national issue, with a recent report from the White House estimating that 20% of women will experience a sexual assault during college. Students at Wichita State University formed a campus organization to bring visibility to both community psychology and address this important problem. The Community Psychology Association is comprised of both graduate and undergraduate students, and members utilized three community psychology competencies: ecological perspectives, information dissemination/building public awareness, and community organizing and community advocacy in their work to improve resources and campus support for this issue. Community Psychology Association members utilized focus groups with campus students, faculty, and staff to facilitate discussions on sexual assault, campus safety, and university and administrative accountability. Content analysis revealed multiple themes that were used to generate a larger campus discussion and promote change in campus policies. As a result of these activities, major changes occurred at Wichita State, including data driven programming for interventions regarding sexual assault, changes in leadership in the offices of Title IX and Student Affairs, support for a CDC grant, and overall increased organizational awareness for sexual assault survivors. This study highlights the importance of applying community psychology principles and concepts to research and action to ultimately have a positive and tangible impact on the local community
A source of entangled photons based on a cavity-enhanced and strain-tuned GaAs quantum dot
A quantum-light source that delivers photons with a high brightness and a
high degree of entanglement is fundamental for the development of efficient
entanglement-based quantum-key distribution systems. Among all possible
candidates, epitaxial quantum dots are currently emerging as one of the
brightest sources of highly entangled photons. However, the optimization of
both brightness and entanglement currently requires different technologies that
are difficult to combine in a scalable manner. In this work, we overcome this
challenge by developing a novel device consisting of a quantum dot embedded in
a circular Bragg resonator, in turn, integrated onto a micromachined
piezoelectric actuator. The resonator engineers the light-matter interaction to
empower extraction efficiencies up to 0.69(4). Simultaneously, the actuator
manipulates strain fields that tune the quantum dot for the generation of
entangled photons with fidelities up to 0.96(1). This hybrid technology has the
potential to overcome the limitations of the key rates that plague current
approaches to entanglement-based quantum key distribution and
entanglement-based quantum networks. Introductio
Superstring Cosmology
Aspects of superstring cosmology are reviewed with an emphasis on the
cosmological implications of duality symmetries in the theory. The string
effective actions are summarized and toroidal compactification to four
dimensions reviewed. Global symmetries that arise in the compactification are
discussed and the duality relationships between the string effective actions
are then highlighted. Higher-dimensional Kasner cosmologies are presented and
interpreted in both string and Einstein frames, and then given in dimensionally
reduced forms. String cosmologies containing both non-trivial
Neveu-Schwarz/Neveu-Schwarz and Ramond-Ramond fields are derived by employing
the global symmetries of the effective actions. Anisotropic and inhomogeneous
cosmologies in four-dimensions are also developed. The review concludes with a
detailed analysis of the pre-big bang inflationary scenario. The generation of
primordial spectra of cosmological perturbations in such a scenario is
discussed. Possible future directions offered in the Horava-Witten theory are
outlined.Comment: 161 pages, latex with epsf, 15 figures. Minor changes, additional
references and figures. Version to appear in Physics Report
Genomic analyses of hair from Ludwig van Beethoven
Ludwig van Beethoven (1770–1827) remains among the most influential and popular classical music composers. Health problems significantly impacted his career as a composer and pianist, including progressive hearing loss, recurring gastrointestinal complaints, and liver disease. In 1802, Beethoven requested that following his death, his disease be described and made public. Medical biographers have since proposed numerous hypotheses, including many substantially heritable conditions. Here we attempt a genomic analysis of Beethoven in order to elucidate potential underlying genetic and infectious causes of his illnesses. We incorporated improvements in ancient DNA methods into existing protocols for ancient hair samples, enabling the sequencing of high-coverage genomes from small quantities of historical hair. We analyzed eight independently sourced locks of hair attributed to Beethoven, five of which originated from a single European male. We deemed these matching samples to be almost certainly authentic and sequenced Beethoven\u27s genome to 24-fold genomic coverage. Although we could not identify a genetic explanation for Beethoven\u27s hearing disorder or gastrointestinal problems, we found that Beethoven had a genetic predisposition for liver disease. Metagenomic analyses revealed furthermore that Beethoven had a hepatitis B infection during at least the months prior to his death. Together with the genetic predisposition and his broadly accepted alcohol consumption, these present plausible explanations for Beethoven\u27s severe liver disease, which culminated in his death. Unexpectedly, an analysis of Y chromosomes sequenced from five living members of the Van Beethoven patrilineage revealed the occurrence of an extra-pair paternity event in Ludwig van Beethoven\u27s patrilineal ancestry
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