264 research outputs found
Entwicklung eines kooperativen Seminarmoduls im Konferenzformat (Kosemko)
Proseminar- und Seminarmodule für Studierende
bilden das wissenschaftliche Arbeiten oftmals nicht
umfassend ab. Zudem besteht die Herausforderung,
dass Studierende heterogene Wissensstände aufweisen,
häufig geringes Interesse an ihren Seminarthemen
zeigen und gelernte Inhalte nach Abschluss
eines Seminars meist nicht mehr präsent sind. Daher
war es das Ziel des hochschulübergreifenden Projektes
KoSemKo, Studierenden mit dem Schwerpunkt
Marketing die Möglichkeit zu geben, interessante
Ergebnisse, die sie im Rahmen ihrer Seminararbeiten
selbst entwickeln, in einer professionellen Konferenz-
Atmosphäre zu präsentieren. Studierende
sammeln dadurch nicht nur Erfahrung im wissenschaftlichen
Schreiben, sondern schlüpfen gleichzeitig
bei der Durchführung eines Peer-Reviews in die
Rolle der Gutachter_innen und auf der Konferenz in
die Rollen der Vortragenden und Teilnehmer_innen.
Durch das Einnehmen dieser verschiedenen Perspektiven
setzen sich die Studierenden kritisch und tiefer
greifend mit ihren Themen auseinander. Dadurch
wird zudem die Motivation gesteigert und gleichzeitig
die inhaltliche sowie wissenschaftlich/methodische
Komponente der Proseminar- und Seminararbeiten
verbessert. Ein im Rahmen des Projektes entwickeltes
Online-Lernmodul zum wissenschaftlichen Arbeiten
unterstützt den Lernprozess der Studierenden
und dient im Nachgang der Verstetigung des Gelernten.
Das Projekt wurde von der Fachgruppe Marketing
der Westsächsischen Hochschule Zwickau sowie
der Professur Marketing und Internationaler Handel
der Technischen Universität Bergakademie Freiberg
realisiert
Inflammatory and cytotoxic responses of an alveolar-capillary coculture model to silica nanoparticles: Comparison with conventional monocultures
<p>Abstract</p> <p>Background</p> <p>To date silica nanoparticles (SNPs) play an important role in modern technology and nanomedicine. SNPs are present in various materials (tyres, electrical and thermal insulation material, photovoltaic facilities). They are also used in products that are directly exposed to humans such as cosmetics or toothpaste. For that reason it is of great concern to evaluate the possible hazards of these engineered particles for human health. Attention should primarily be focussed on SNP effects on biological barriers. Accidentally released SNP could, for example, encounter the alveolar-capillary barrier by inhalation. In this study we examined the inflammatory and cytotoxic responses of monodisperse amorphous silica nanoparticles (aSNPs) of 30 nm in size on an <it>in vitro </it>coculture model mimicking the alveolar-capillary barrier and compared these to conventional monocultures.</p> <p>Methods</p> <p>Thus, the epithelial cell line, H441, and the endothelial cell line, ISO-HAS-1, were used in monoculture and in coculture on opposite sides of a filter membrane. Cytotoxicity was evaluated by the MTS assay, detection of membrane integrity (LDH release), and TER (Transepithelial Electrical Resistance) measurement. Additionally, parameters of inflammation (sICAM-1, IL-6 and IL-8 release) and apoptosis markers were investigated.</p> <p>Results</p> <p>Regarding toxic effects (viability, membrane integrity, TER) the coculture model was less sensitive to apical aSNP exposure than the conventional monocultures of the appropriate cells. On the other hand, the <it>in vitro </it>coculture model responded with the release of inflammatory markers in a much more sensitive fashion than the conventional monoculture. At concentrations that were 10-100fold less than the toxic concentrations the apically exposed coculture showed a release of IL-6 and IL-8 to the basolateral side. This may mimic the early inflammatory events that take place in the pulmonary alveoli after aSNP inhalation. Furthermore, a number of apoptosis markers belonging to the intrinsic pathway were upregulated in the coculture following aSNP treatment. Analysis of the individual markers indicated that the cells suffered from DNA damage, hypoxia and ER-stress.</p> <p>Conclusion</p> <p>We present evidence that our <it>in vitro </it>coculture model of the alveolar-capillary barrier is clearly advantageous compared to conventional monocultures in evaluating the extent of damage caused by hazardous material encountering the principle biological barrier in the lower respiratory tract.</p
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Cytocompatibility Evaluation of PEG-Methylsulfone Hydrogels
Methylsulfone derivatized poly(ethylene) glycol (PEG) macromers can be biofunctionalized with thiolated ligands and cross-linked with thiol-based cross-linkers to obtain bioactive PEG hydrogels for in situ cell encapsulation. Methylsulfonyl-thiol (MS-SH) reactions present several advantages for this purpose when compared to other thiol-based cross-linking systems. They proceed with adequate and tunable kinetics for encapsulation, they reach a high conversion degree with good selectivity, and they generate stable reaction products. Our previous work demonstrated the cytocompatibility of cross-linked PEG-MS/thiol hydrogels in contact with fibroblasts. However, the cytocompatibility of the in situ MS-SH cross-linking reaction itself, which generates methylsulfinic acid as byproduct at the cross-linked site, remains to be evaluated. These studies are necessary to evaluate the potential of these systems for in vivo applications. Here we perform an extensive cytocompatibility study of PEG hydrogels during in situ cross-linking by the methylsulfonyl-thiol reaction. We compare these results with maleimide-thiol cross-linked PEGs which are well established for cell culture and in vivo experiments and do not involve the release of a byproduct. We show that fibroblasts and endothelial cells remain viable after in situ polymerization of methylsulfonyl-thiol gels on the top of the cell layers. Cell viability seems better than after in situ cross-linking hydrogels with maleimide-thiol chemistry. The endothelial cell proinflammatory phenotype is low and similar to the one obtained by the maleimide-thiol reaction. Finally, no activation of monocytes is observed. All in all, these results demonstrate that the methylsulfonyl-thiol chemistry is cytocompatible and does not trigger high pro-inflammatory responses in endothelial cells and monocytes. These results make methylsulfonyl-thiol chemistries eligible for in vivo testing and eventually clinical application in the future
Demographic variation in space and time : implications for conservation targeting
The dynamics of wild populations are governed by demographic rates which vary spatially and/or temporally in response to environmental conditions. Conservation actions for widespread but declining populations could potentially exploit this variation to target locations (or years) in which rates are low, but only if consistent spatial or temporal variation in demographic rates occurs. Using long-term demographic data for wild birds across Europe, we show that productivity tends to vary between sites (consistently across years), while survival rates tend to vary between years (consistently across sites), and that spatial synchrony is more common in survival than productivity. Identifying the conditions associated with low demographic rates could therefore facilitate spatially targeted actions to improve productivity or (less feasibly) forecasting and temporally targeting actions to boost survival. Decomposing spatio-temporal variation in demography can thus be a powerful tool for informing conservation policy and for revealing appropriate scales for actions to influence demographic rates.Peer reviewe
TOI-1685 b Is a Hot Rocky Super-Earth: Updates to the Stellar and Planet Parameters of a Popular JWST Cycle 2 Target
We present an updated characterization of the TOI-1685 planetary system, which consists of a P b = 0.69 day ultra-short-period super-Earth planet orbiting a nearby (d = 37.6 pc) M2.5V star (TIC 28900646, 2MASS J04342248+4302148). This planet was previously featured in two contemporaneous discovery papers, but the best-fit planet mass, radius, and bulk density values were discrepant, allowing it to be interpreted either as a hot, bare rock or a 50% H2O/50% MgSiO3 water world. TOI-1685 b will be observed in three independent JWST Cycle 2 programs, two of which assume the planet is a water world, while the third assumes that it is a hot rocky planet. Here we include a refined stellar classification with a focus on addressing the host star’s metallicity, an updated planet radius measurement that includes two sectors of TESS data and multicolor photometry from a variety of ground-based facilities, and a more accurate dynamical mass measurement from a combined CARMENES, InfraRed Doppler, and MAROON-X radial velocity data set. We find that the star is very metal-rich ([Fe/H] ≃ +0.3) and that the planet is systematically smaller, lower mass, and higher density than initially reported, with new best-fit parameters of R pl = 1.468 −0.051+0.050 R ⊕ and M pl = 3.03−0.32+0.33 M ⊕. These results fall in between the previously derived values and suggest that TOI-1685 b is a hot rocky planet with an Earth-like density (ρ pl = 5.3 ± 0.8 g cm−3, or 0.96 ρ ⊕), high equilibrium temperature (T eq = 1062 ± 27 K), and negligible volatiles, rather than a water world
Synthesizing plausible futures for biodiversity and ecosystem services in Europe and Central Asia using scenario archetypes
Scenarios are a useful tool to explore possible futures of social-ecological systems. The number of scenarios has increased dramatically over recent decades, with a large diversity in temporal and spatial scales, purposes, themes, development methods, and content. Scenario archetypes generically describe future developments and can be useful in meaningfully classifying scenarios, structuring and summarizing the overwhelming amount of information, and enabling scientific outputs to more effectively interface with decision-making frameworks. The Intergovernmental Platform for Biodiversity and Ecosystem Services (IPBES) faced this challenge and used scenario archetypes in its assessment of future interactions between nature and society. We describe the use of scenario archetypes in the IPBES Regional Assessment of Europe and Central Asia. Six scenario archetypes for the region are described in terms of their driver assumptions and impacts on nature (including biodiversity) and its contributions to people (including ecosystem services): business-as-usual, economic optimism, regional competition, regional sustainability, global sustainable development, and inequality. The analysis shows that trade-offs between nature’s contributions to people are projected under different scenario archetypes. However, the means of resolving these trade-offs depend on differing political and societal value judgements within each scenario archetype. Scenarios that include proactive decision making on environmental issues, environmental management approaches that support multifunctionality, and mainstreaming environmental issues across sectors, are generally more successful in mitigating trade-offs than isolated environmental policies. Furthermore, those scenario archetypes that focus on achieving a balanced supply of nature’s contributions to people and that incorporate a diversity of values are estimated to achieve more policy goals and targets, such as the UN Sustainable Development Goals and the Convention on Biological Diversity Aichi targets. The scenario archetypes approach is shown to be helpful in supporting science-policy dialogue for proactive decision making that anticipates change, mitigates undesirable trade-offs, and fosters societal transformation in pursuit of sustainable development
Benzisothiazolinone Derivatives as Potent Allosteric Monoacylglycerol Lipase Inhibitors That Functionally Mimic Sulfenylation of Regulatory Cysteines
We describe a set of benzisothiazolinone (BTZ) derivatives that are potent inhibitors of monoacylglycerol lipase (MGL), the primary degrading enzyme for the endocannabinoid 2-arachidonoyl-sn-glycerol (2-AG). Structure-activity relationship studies evaluated various substitutions on the nitrogen atom and the benzene ring of the BTZ nucleus. Optimized derivatives with nanomolar potency allowed us to investigate the mechanism of MGL inhibition. Site-directed mutagenesis and mass spectrometry experiments showed that BTZs interact in a covalent reversible manner with regulatory cysteines, Cys201 and Cys208, causing a reversible sulfenylation known to modulate MGL activity. Metadynamics simulations revealed that BTZ adducts favor a closed conformation of MGL that occludes substrate recruitment. The BTZ derivative 13 protected neuronal cells from oxidative stimuli and increased 2-AG levels in the mouse brain. The results identify Cys201 and Cys208 as key regulators of MGL function and point to the BTZ scaffold as a useful starting point for the discovery of allosteric MGL inhibitors
Writing in London. Home and Languaging in the Work of London Poets of Chinese Descent
This essay discusses literary works produced in London by poets of Chinese descent who are foreign-born or London native. Some of these works are written in English, and some in Chinese. The aim is to discuss poetry that has emphatically or reluctantly embraced the identity narrative, talking of home and belonging in substantially different ways from each other, according to each poet’s individual relationship with movement, migration, and stability. Therefore, through the use of the phrase ‘London poets of Chinese descent’, I do not aim at tracing a shared sense of identity, but instead I am interested in using London as a method for an oblique reading that recognises the variety of angles and approaches in these poets’ individual experience, history and circumstances that can range from occasional travel to political exile
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Synthesizing plausible futures for biodiversity and ecosystem services in europe and central asia using scenario archetypes
Scenarios are a useful tool to explore possible futures of social-ecological systems. The number of scenarios has increased dramatically over recent decades, with a large diversity in temporal and spatial scales, purposes, themes, development methods, and content. Scenario archetypes generically describe future developments and can be useful in meaningfully classifying scenarios, structuring and summarizing the overwhelming amount of information, and enabling scientific outputs to more effectively interface with decision-making frameworks. The Intergovernmental Platform for Biodiversity and Ecosystem Services (IPBES) faced this challenge and used scenario archetypes in its assessment of future interactions between nature and society. We describe the use of scenario archetypes in the IPBES Regional Assessment of Europe and Central Asia. Six scenario archetypes for the region are described in terms of their driver assumptions and impacts on nature (including biodiversity) and its contributions to people (including ecosystem services): Business-as-usual, economic optimism, regional competition, regional sustainability, global sustainable development, and inequality. The analysis shows that trade-offs between nature’s contributions to people are projected under different scenario archetypes. However, the means of resolving these trade-offs depend on differing political and societal value judgements within each scenario archetype. Scenarios that include proactive decision making on environmental issues, environmental management approaches that support multifunctionality, and mainstreaming environmental issues across sectors, are generally more successful in mitigating tradeoffs than isolated environmental policies. Furthermore, those scenario archetypes that focus on achieving a balanced supply of nature’s contributions to people and that incorporate a diversity of values are estimated to achieve more policy goals and targets, such as the UN Sustainable Development Goals and the Convention on Biological Diversity Aichi targets. The scenario archetypes approach is shown to be helpful in supporting science-policy dialogue for proactive decision making that anticipates change, mitigates undesirable trade-offs, and fosters societal transformation in pursuit of sustainable development. © 2019 by the author(s)
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