243 research outputs found

    Light Scattering Characterization of Elastin-Like Polypeptide Trimer Micelles

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    Elastin-Like Polypeptides (ELP) can be used to form thermo-reversible vehicles for drug delivery systems. The ELP nanoparticles are composed of three-armed star polypeptides. Each of the three arms extending from the negatively charged foldon domain includes 20 repeats of the (GVGVP) amino acid sequence. The ELP polymer chains are soluble at room temperature and become insoluble at the transition temperature (close to 50 oC), forming micelles. The size and shape of the micelle is dependent on the temperature and the pH of solution, along with the concentration of the Phosphate Buffered Saline (PBS) solvent. The technique of Depolarized Dynamic Light Scattering (DDLS) was employed to study the structure and dynamics of micelles at 62 oC; the solution was maintained at an approximate pH level of 7.3 - 7.5, while varying the concentration of the solvent (PBS). At low salt concentrations (\u3c 15 mM), the micellar size is not very reproducible due to unstable pH levels, arising from low buffer concentration. At intermediate salt concentrations (15 - 60 mM), the system formed spherically-shaped micelles exhibiting a steady growth in the hydrodynamic radius (Rh) from 10 to 21 nm, with increasing PBS concentration. Interestingly, higher salt concentrations (\u3e 60 mM) displayed an apparent elongation of the micelles evident by a significant VH signal, along with a surge in the apparent Rh. A model of micelle growth (and potentially elongation) with increase in salt concentration is considered.https://engagedscholarship.csuohio.edu/u_poster_2016/1038/thumbnail.jp

    Light Scattering Study of Mixed Micelles Made from Elastin-Like Polypeptide Linear Chains and Trimers

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    Temperature sensitive nanoparticles (E20F) were generated from a construct of three chains of Elastin- Like Polypeptides (ELP) linked to a negatively charged foldon domain. This ELP system was mixed at different ratios with a single linear chain of ELP (H40L) which was deprived of the foldon domain. The mixed system is soluble at room temperature and at a transition temperature will form swollen micelles with the hydrophobic linear chains hidden inside. This system was studied using Depolarized Dynamic Light Scattering (DDLS) and Static Light Scattering (SLS) to model the size, shape, and internal structure of the mixed micelles. The mixed micelle in equal parts of E20F and H40L show a constant apparent hydrodynamic radius of 40-45 nm at the concentration window from 25:25 to 60:60 μM (1:1 ratio). At a fixed 50 μM concentration of the E20F with varying H40L concentrations from 5 to 80 μM, a linear growth in the hydrodynamic radius is seen from about 11 to about 62 nm, along with a 1000-fold increase in VH signal. A possible simple model explaining the growth of the mixed micelles is considered. Lastly, the VH signal can indicate elongation in the geometry of the particle or could possibly be a result from anisotropic properties from the core of the micelle. Static Light Scattering was used to study the molecular weight, and the radius of gyration of the micelle to help identify the structure and morphology of mixed micelles and the tangible cause of the VH signal.https://engagedscholarship.csuohio.edu/u_poster_2016/1039/thumbnail.jp

    Mainstreaming or retrenchment? Migration-related diversity in Dutch and Flemish education policies

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    This article analyses how states adapt generic policies to the increasing diversity that characterises contemporary European societies. More particularly, it zooms in on how migration-related diversity is mainstreamed into education policies in the Netherlands and Flanders and why we observe different policy trends in these two cases. We find that the focus on migration-related diversity largely faded in Dutch education policies in the period from 2000 to 2014. In Flanders, this trend towards ‘migration-related diversity retrenchment’ is less prevalent during this period, even though a similar evolution has started to take place more recently. These findings present a puzzle, as the most evident explanation for diversity retrenchment, namely the increasing politicisation of migration and diversity, cannot account for this difference since the Netherlands and Flanders are characterised by similar degrees of politicisation of migration-related diversity. Our findings thus call for an exploration of underemphasised explanations for diversity retrenchment. We show that the diverging degree of diversity retrenchment can be explained by the presence or absence of a sub-state nationalist project and diverging degrees of neoliberal retrenchment policies. Sub-state nationalism seems to have temporarily offered a buffer against the neoliberal retrenchment of migration-related diversity.</p

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    Novel applications for a noninvasive sampling method of the nasal mucosa

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    Reliable methods for sampling the nasal mucosa provide clinical researchers with key information regarding respiratory biomarkers of exposure and disease. For quick and noninvasive sampling of the nasal mucosa, nasal lavage (NL) collection has been widely used as a clinical tool; however, limitations including volume variability, sample dilution, and storage prevent NL collection from being used in nonlaboratory settings and analysis of low abundance biomarkers. In this study, we optimize and validate a novel methodology using absorbent Leukosorb paper cut to fit the nasal passage to extract epithelial lining fluid (ELF) from the nasal mucosa. The ELF sampling method limits the dilution of soluble mediators, allowing quantification of both high- and low-abundance soluble biomarkers such as IL-1β, IL-8, IL-6, interferon gamma-induced protein 10 (IP-10), and neutrophil elastase. Additionally, we demonstrate that this method can successfully detect the presence of respiratory pathogens such as influenza virus and markers of antibiotic-resistant bacteria in the nasal mucosa. Efficacy of ELF collection by this method is not diminished in consecutive-day sampling, and percent recovery of both recombinant IL-8 and soluble mediators are not changed despite freezing or room temperature storage for 24 h. Our results indicate that ELF collection using Leukosorb paper sampling of ELF provides a sensitive, easy-to-use, and reproducible methodology to collect concentrated amounts of soluble biomarkers from the nasal mucosa. Moreover, the methodology described herein improves upon the standard NL collection method and provides researchers with a novel tool to assess changes in nasal mucosal host defense status

    Efektywność działań powiatowych urzędów pracy w zmniejszaniu bezrobocia w makroregionie centralnym Polski w 2021 roku

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    Z punktu widzenia rynku pracy i gospodarki w ogóle rok 2021 wyraźnie różni się od ostatnich kilku lat. Najważniejszym tego powodem jest zniesienie ograniczeń wprowadzonych w związku z pandemią wywołaną przez wirus SARS‑CoV–2. Jednym ze skutków serii obostrzeń było pogorszenie sytuacji na rynku pracy, który również powoli zaczął się odtwarzać. W niniejszym artykule postanowiliśmy przybliżyć sytuację na rynku pracy makroregionu centralnego w Polsce w 2021 roku oraz zbadać efektywność działań podejmowanych w celu ograniczenia bezrobocia przez powiatowe urzędy pracy na wspomnianym obszarze. Badanie efektywności zostało przeprowadzone za pomocą modelu DEA, uwzględniającego niekontrolowalne wyniki. Następnie oceniono istotność i siłę wpływu zmiennych opisujących regionalne uwarunkowania na wskaźnik efektywności z modelu DEA za pomocą modelu tobitowego. Dane pochodziły z wojewódzkich i powiatowych urzędów pracy, GUS‑u oraz Ministerstwa Rodziny i Polityki Społecznej. Przeprowadzone badanie wykazało, że w 2021 roku – w porównaniu z rokiem 2020 – sytuacja na rynku pracy się poprawiła. W makroregionie centralnym zaczęło spadać bezrobocie, choć zmiany te nie przebiegały jednakowo we wszystkich powiatach. Tylko jedna piąta powiatowych urzędów pracy w optymalny sposób przekształcała nakłady w wyniki. W pozostałych urzędach często występowała bardzo silna efektywność. Model tobitowy wskazał, które zmienne w istotny sposób wpływają na efektywność powiatowych urzędów pracy. Zdaniem autorów nieefektywność urzędów pracy nie wynika wyłącznie ze stosowanych przez nie rozwiązań. Po ustąpieniu pandemii na rynku pracy dały się zaobserwować niekorzystne zjawiska, na które urzędy mają znikomy lub wręcz żaden wpływ. Zaliczamy do nich duży wzrost udziału długotrwale bezrobotnych w ogólnej liczbie bezrobotnych oraz dużą liczbę osób, które wielokrotnie rejestrują się jako bezrobotni. Ta grupa dobrowolnie bezrobotnych rzadko jest zainteresowana skierowanymi do nich działaniami powiatowych urzędów pracy

    Systemic RNAi mediated gene silencing in the anhydrobiotic nematode Panagrolaimus superbus

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    <p>Abstract</p> <p>Background</p> <p>Gene silencing by RNA interference (RNAi) is a powerful tool for functional genomics. Although RNAi was first described in <it>Caenorhabditis elegans</it>, several nematode species are unable to mount an RNAi response when exposed to exogenous double stranded RNA (dsRNA). These include the satellite model organisms <it>Pristionchus pacificus </it>and <it>Oscheius tipulae</it>. Available data also suggest that the RNAi pathway targeting exogenous dsRNA may not be fully functional in some animal parasitic nematodes. The genus <it>Panagrolaimus </it>contains bacterial feeding nematodes which occupy a diversity of niches ranging from polar, temperate and semi-arid soils to terrestrial mosses. Thus many <it>Panagrolaimus </it>species are adapted to tolerate freezing and desiccation and are excellent systems to study the molecular basis of environmental stress tolerance. We investigated whether <it>Panagrolaimus </it>is susceptible to RNAi to determine whether this nematode could be used in large scale RNAi studies in functional genomics.</p> <p>Results</p> <p>We studied two species: <it>Panagrolaimus </it>sp. PS1159 and <it>Panagrolaimus superbus</it>. Both nematode species displayed embryonic lethal RNAi phenotypes following ingestion of <it>Escherichia coli </it>expressing dsRNA for the <it>C. elegans </it>embryonic lethal genes <it>Ce-lmn-1 </it>and <it>Ce-ran-4</it>. Embryonic lethal RNAi phenotypes were also obtained in both species upon ingestion of dsRNA for the <it>Panagrolaimus </it>genes <it>ef1b </it>and <it>rps-2</it>. Single nematode RT-PCR showed that a significant reduction in mRNA transcript levels occurred for the target <it>ef1b </it>and <it>rps-2 </it>genes in RNAi treated <it>Panagrolaimus </it>sp. 1159 nematodes. Visible RNAi phenotypes were also observed when <it>P. superbus </it>was exposed to dsRNA for structural genes encoding contractile proteins. All RNAi phenotypes were highly penetrant, particularly in <it>P. superbus</it>.</p> <p>Conclusion</p> <p>This demonstration that <it>Panagrolaimus </it>is amenable to RNAi by feeding will allow the development of high throughput methods of RNAi screening for <it>P. superbus</it>. This greatly enhances the utility of this nematode as a model system for the study of the molecular biology of anhydrobiosis and cryobiosis and as a possible satellite model nematode for comparative and functional genomics. Our data also identify another nematode infraorder which is amenable to RNAi and provide additional information on the diversity of RNAi phenotypes in nematodes.</p

    Digitalisierung als Störung?

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    Asymmetrische Praktiken der schulischen Kommunikation werden durch den Einsatz etwa von Tablets, die digitales Lehrmaterial beinhalten, neu strukturiert. In unserer empirisch-ethnografischen Studie von digital vermitteltem Religionsunterricht via Tablets werden Episoden sichtbar, in denen die Schüler:innenschaft zumindest zeitweise zur Lehrkraft symmetrisiert wird. Lehrpersonen reagieren hierauf mit einer veränderten Selbstbeschreibung von Rollenkonstellationen zwischen sich sowie den Schüler:innen. Die Umsetzung der digitalen Unterrichtssituation verläuft allerdings nicht reibungslos: Dabei zeigt sich, dass die herkömmliche Unterrichtssituation derart strukturiert ist, dass sie den Einsatz digitaler Medien zunächst eher behindert als befördert. Wir kommen deshalb in unserer empirisch-qualitativen Analyse auch zu dem Schluss: Es ist der (asymmetrisch organisierte) Unterricht, der den reibungsfreien Vollzug digitaler Medien stört

    Probabilistic sequence learning in mild cognitive impairment

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    Mild Cognitive Impairment (MCI) causes slight but noticeable disruption in cognitive systems, primarily executive and memory functions. However, it is not clear if the development of sequence learning is affected by an impaired cognitive system and, if so, how. The goal of our study was to investigate the development of probabilistic sequence learning, from the initial acquisition to consolidation, in MCI and healthy elderly control groups. We used the Alternating Serial Reaction Time task (ASRT) to measure probabilistic sequence learning. Individuals with MCI showed weaker learning performance than the healthy elderly group. However, using the reaction times only from the second half of each learning block – after the reactivation phase - we found intact learning in MCI. Based on the assumption that the first part of each learning block is related to reactivation/recall processes, we suggest that these processes are affected in MCI. The 24-hour offline period showed no effect on sequence-specific learning in either group but did on general skill learning: the healthy elderly group showed offline improvement in general reaction times while individuals with MCI did not. Our findings deepen our understanding regarding the underlying mechanisms and time course of sequence acquisition and consolidation

    Machine Learning and Computer Vision Techniques in Bee Monitoring Applications

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    Machine learning and computer vision are dynamically growing fields, which have proven to be able to solve very complex tasks. They could also be used for the monitoring of the honeybee colonies and for the inspection of their health state, which could identify potentially dangerous states before the situation is critical, or to better plan periodic bee colony inspections and therefore save significant costs. In this paper, we present an overview of the state-of-the-art computer vision and machine learning applications used for bee monitoring. We also demonstrate the potential of those methods as an example of an automated bee counter algorithm. The paper is aimed at veterinary and apidology professionals and experts, who might not be familiar with machine learning to introduce to them its possibilities, therefore each family of applications is opened by a brief theoretical introduction and motivation related to its base method. We hope that this paper will inspire other scientists to use the machine learning techniques for other applications in bee monitoring
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