Upstream process optimization to support efficient HEK293 cell growth and adenovirus production

Development of effective vaccines against emerging and re-emerging pathogens is a worldwide public health priority. In response to the current pandemic, global vaccine manufacturers have developed several types of SARS-CoV-2 vaccines, including adenovirus (AdV)-vector based vaccines. Production of viral vector vaccines requires optimization of several cell culture parameters. Using wildtype AdV type 5 infection with suspension HEK293 cells as a model system, we evaluated various conditions (including time of harvest, multiplicity of infection (MOI), cell density, insulin supplementation, and temperature shift) to optimize adenovirus production. In addition, we evaluated cell growth and AdV5 production in different chemically defined media and feeds. Viral titers were quantified by qPCR, TCID50 and Focus Forming Assay (FFA). While GibcoTM CD 293TM Medium supports comparable cell density to other commercially available media, cell density attained in GibcoTM DynamisTM Medium was \u3e2-fold higher. Predictably, upon AdV5 infection, cell density and cell viability decreased for all infected cultures from 2 to 7 days post infection (dpi). Addition of feed on 0 and 2dpi (with temperature downshift on 3dpi), resulted in peak AdV titers on 4 or 5 dpi for DynamisTM Medium and CD 293TM Medium, respectively. The AdV5 titers in both DynamisTM Medium and CD 293TM Medium showed comparable or better peak titers than other commercially available media. Furthermore, peak virus titers were not dependent on insulin in either DynamisTM Medium or CD 293TM Medium. Finally, infectivity assays (TCID50 assays and FFA) confirmed the AdV5 titers obtained with qPCR. Overall, these results demonstrate DynamisTM Medium and CD 293TM Medium can effectively support HEK293 cell growth and high adenovirus production

Scintillated microlensing: measuring cosmic distances with fast radio bursts

We propose a novel means of directly measuring cosmological distances using scintillated microlensing of fast radio bursts (FRBs). In standard strong lensing measurements of cosmic expansion, the main source of systematic uncertainty lies in modeling the mass profile of galactic halos. Using extra-galactic stellar microlensing to measure the Hubble constant avoids this systematic uncertainty as the lens potential of microlenses depends only on a single parameter: the mass of the lens. FRBs, which may achieve nanosecond precision on lensing time delays, are well-suited to precision measurements of stellar microlensing, for which the time delays are on the order of milliseconds. However, typical angular separations between the microlensed images on the order of microarcseconds make the individual images impossible to spatially resolve with ground-based telescopes. We propose leveraging scintillation in the ISM to resolve the microlensed images, effectively turning the ISM into an astrophysical-scale interferometer. Using this technique, we estimate a 6\% uncertainty on $H_0$ from a single observed scintillated microlensing event, with a sub-percent uncertainty on $H_0$ achievable with only 30 such events. With an optical depth for stellar microlensing of $10^{-3}$, this may be achievable in the near future with upcoming FRB telescopes

Transactional Associations Between Supportive Family Climate and Young Children’s Heritage Language Proficiency in Immigrant Families

Heritage language (HL) proficiency confers developmental benefits; however, the onset of HL loss is observed among many young children from immigrant families. In this longitudinal study, transactional associations between children’s HL proficiency and supportive family climate were examined in Chinese immigrant families with pre-school-aged children. Parental warmth, cultural maintenance values, and use of HL support were investigated as aspects of family climate. Measures included observable parent–child interactions and performance-based language proficiency assessments. While parental cultural maintenance values appeared influential, parental behavioral support of HL showed more robust prospective associations with children’s HL development. Concurrently, children’s earlier HL proficiency predicted subsequent parental behavior; parents whose children had limited HL proficiency decreased their use of HL support 1 later. Implications of the findings are discussed for immigrant parents with young children

Transactional Associations Between Supportive Family Climate and Young Children’s Heritage Language Proficiency in Immigrant Families

Heritage language (HL) proficiency confers developmental benefits; however, the onset of HL loss is observed among many young children from immigrant families. In this longitudinal study, transactional associations between children’s HL proficiency and supportive family climate were examined in Chinese immigrant families with pre-school-aged children. Parental warmth, cultural maintenance values, and use of HL support were investigated as aspects of family climate. Measures included observable parent–child interactions and performance-based language proficiency assessments. While parental cultural maintenance values appeared influential, parental behavioral support of HL showed more robust prospective associations with children’s HL development. Concurrently, children’s earlier HL proficiency predicted subsequent parental behavior; parents whose children had limited HL proficiency decreased their use of HL support 1 later. Implications of the findings are discussed for immigrant parents with young children

Perspective of monochromatic gamma-ray line detection with the High Energy cosmic-Radiation Detection (HERD) facility onboard China's Space Station

HERD is the High Energy cosmic-Radiation Detection instrument proposed to operate onboard China's space station in the 2020s. It is designed to detect energetic cosmic ray nuclei, leptons and photons with a high energy resolution ($\sim1\%$ for electrons and photons and $20\%$ for nuclei) and a large geometry factor ($>3\,{ m^2\,sr}$ for electrons and diffuse photons and $>2\,{ m^2\,sr}$ for nuclei). In this work we discuss the capability of HERD to detect monochromatic $\gamma$-ray lines, based on simulations of the detector performance. It is shown that HERD will be one of the most sensitive instruments for monochromatic $\gamma$-ray searches at energies between $\sim10$ to a few hundred GeV. Above hundreds of GeV, Cherenkov telescopes will be more sensitive due to their large effective area. As a specific example, we show that a good portion of the parameter space of a supersymmetric dark matter model can be probed with HERD.Comment: 9 pages, 7 figures, matches version published in Astropart.Phy

Sustainable AI : An inventory of the state of knowledge of ethical, social, and legal challenges related to artificial intelligence

This report is an inventory of the state of knowledge of ethical, social, and legal challenges related to artificial intelligence conducted within the Swedish Vinnova-funded project “Hållbar AI – AI Ethics and Sustainability”, led by Anna Felländer. Based on a review and mapping of reports and studies, a quantitative and bibliometric analysis, and in-depth analyses of the healt- care sector, the telecom sector, and digital platforms, the report proposes three recommendations. Sustainable AI requires: 1. a broad focus on AI governance and regulation issues, 2. promoting multi-disciplinary collaboration, and 3. building trust in AI applications and applied machine-learning, which is a matter of key importance and requires further study of the relationship between transparency and accountability

Promoting tau secretion and propagation by hyperactive p300/CBP via autophagy-lysosomal pathway in tauopathy.

BackgroundThe trans-neuronal propagation of tau has been implicated in the progression of tau-mediated neurodegeneration. There is critical knowledge gap in understanding how tau is released and transmitted, and how that is dysregulated in diseases. Previously, we reported that lysine acetyltransferase p300/CBP acetylates tau and regulates its degradation and toxicity. However, whether p300/CBP is involved in regulation of tau secretion and propagation is unknown.MethodWe investigated the relationship between p300/CBP activity, the autophagy-lysosomal pathway (ALP) and tau secretion in mouse models of tauopathy and in cultured rodent and human neurons. Through a high-through-put compound screen, we identified a new p300 inhibitor that promotes autophagic flux and reduces tau secretion. Using fibril-induced tau spreading models in vitro and in vivo, we examined how p300/CBP regulates tau propagation.ResultsIncreased p300/CBP activity was associated with aberrant accumulation of ALP markers in a tau transgenic mouse model. p300/CBP hyperactivation blocked autophagic flux and increased tau secretion in neurons. Conversely, inhibiting p300/CBP promoted autophagic flux, reduced tau secretion, and reduced tau propagation in fibril-induced tau spreading models in vitro and in vivo.ConclusionsWe report that p300/CBP, a lysine acetyltransferase aberrantly activated in tauopathies, causes impairment in ALP, leading to excess tau secretion. This effect, together with increased intracellular tau accumulation, contributes to enhanced spreading of tau. Our findings suggest that inhibition of p300/CBP as a novel approach to correct ALP dysfunction and block disease progression in tauopathy

Star formation and dust obscuration in the tidally distorted galaxy NGC 2442

Abridged: We present a detailed investigation of the morphological distribution and level of star formation and dust obscuration in the nearby tidally distorted galaxy NGC2442. Spitzer images in the IR at 3.6, 4.5, 5.8, 8.0um, and 24um and GALEX images at 1500\AA{} and 2300\AA{} allow us to resolve the galaxy on scales between 240-600pc. We supplement these with archival data in the B, J, H, and K bands. We use the 8um, 24um and FUV (1500\AA) emission to study the star formation rate (SFR). We find that globally, these tracers of star formation give a range of results of ~6-11\msun/yr, with the dust-corrected FUV giving the highest value of SFR. We can reconcile the UV and IR-based estimates by adopting a steeper UV extinction curve that lies in between the starburst (Calzetti) and SMC extinction curves. However, the regions of highest SFR intensity along the spiral arms are consistent with a starburst-like extinction. Overall, the level of star-formation we find is higher than previously published for this galaxy, by about a factor of two, which, contrary to previous conclusions, implies that the interaction that caused the distorted morphology of NGC2442 likely also triggered increased levels of star-formation activity. Outside of the spiral arms, we discover what appears to be a superbubble, ~1.7kpc across in the IRAC images. Significant H{\alpha}, UV and IR emission in the area also suggest vigorous ongoing star-formation. A known, recent supernova (SN1999ga) is located at the edge of this superbubble. Although speculative at this stage, this area suggests a large star-forming region with a morphology shaped by generations of supernovae. Lastly, we discover an 8um (PAH) circumnuclear ring with an ~0.8kpc radius. The H{\alpha} emission is largely concentrated inside that ring and shows a vague spiral structure in the rest of the galaxy.Comment: 16 pages, 13 figures, accepted for publication in Ap

Animal-origin free peptones enhance adenovirus production

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