Marek’s disease virus (MDV) vaccines were the first vaccines that protected against cancer. The avirulent turkey herpesvirus (HVT) was widely employed and protected billions of chickens from a deadly MDV infection. It is also among the most common vaccine vectors providing protection against a plethora of pathogens. HVT establishes latency in T-cells, allowing the vaccine virus to persist in the host for life. Intriguingly, the HVT genome contains telomeric repeat arrays (TMRs) at both ends; however, their role in the HVT life cycle remains elusive. We have previously shown that similar TMRs in the MDV genome facilitate its integration into host telomeres, which ensures efficient maintenance of the virus genome during latency and tumorigenesis. In this study, we investigated the role of the TMRs in HVT genome integration, latency, and reactivation in vitro and in vivo. Additionally, we examined HVT infection of feather follicles. We generated an HVT mutant lacking both TMRs (vΔTMR) that efficiently replicated in cell culture. We could demonstrate that wild type HVT integrates at the ends of chromosomes containing the telomeres in T-cells, while integration was severely impaired in the absence of the TMRs. To assess the role of TMRs in vivo, we infected one-day-old chickens with HVT or vΔTMR. vΔTMR loads were significantly reduced in the blood and hardly any virus was transported to the feather follicle epithelium where the virus is commonly shed. Strikingly, latency in the spleen and reactivation of the virus were severely impaired in the absence of the TMRs, indicating that the TMRs are crucial for the establishment of latency and reactivation of HVT. Our findings revealed that the TMRs facilitate integration of the HVT genome into host chromosomes, which ensures efficient persistence in the host, reactivation, and transport of the virus to the skin.
Weniger anzeigenPancreatic cancer is one of the deadliest cancers globally, with limited success from existing therapies, including chemotherapies and immunotherapies like checkpoint inhibitors for patients with advanced pancreatic ductal adenocarcinoma (PDAC). A promising new approach is the use of oncolytic viruses (OV), a form of immunotherapy that has been demonstrated clinical effectiveness in various cancers. Here we investigated the potential of the oncolytic coxsackievirus B3 strain (CVB3) PD-H as a new treatment for pancreatic cancer. In vitro, PD-H exhibited robust replication, as measured by plaque assays, and potent lytic activity, as assessed by XTT assays, in most pancreatic tumor cell lines, outperforming two other coxsackievirus strains tested, H3N-375/1TS and CVA21. Thus, H3N-375/1TS showed efficient replication and lytic efficiency in distinctly fewer tumor cell lines, while most tumor cells were resistant to CVA21. The oncolytic efficiency of the three OV largely correlated with mRNA expression levels of viral receptors and their ability to induce apoptosis, as measured by cleaved caspase 3/7 activity in the tumor cells. In a syngeneic mouse model with subcutaneous pancreatic tumors, intratumoral administration of PD-H significantly inhibited tumor growth but did not completely stop tumor progression. Importantly, no virus-related side effects were observed. Although pancreatic tumors respond to PD-H treatment, its therapeutic efficacy is limited. Combining PD-H with other treatments, such as those aiming at reducing the desmoplastic stroma which impedes viral infection and spread within the tumor, may enhance its efficacy.
Weniger anzeigenTo effectively mitigate anthropogenic air pollution, it is imperative to implement strategies aimed at reducing emissions from traffic-related sources. Achieving this objective can be facilitated by employing modeling techniques to elucidate the interplay between environmental impacts and traffic activities. This paper highlights the importance of combining traffic emission models with high-resolution turbulence and dispersion models in urban areas at street canyon level and presents the development and implementation of an interface between the mesoscopic traffic and emission model MATSim and PALM-4U, which is a set of urban climate application modules within the PALM model system. The proposed coupling mechanism converts MATSim output emissions into input emission flows for the PALM-4U chemistry module, which requires translating between the differing data models of both modeling systems. In an idealized case study, focusing on Berlin, the model successfully identified “hot spots” of pollutant concentrations near high-traffic roads and during rush hours. Results show good agreement between modeled and measured NOx concentrations, demonstrating the model’s capacity to accurately capture urban pollutant dispersion. Additionally, the presented coupling enables detailed assessments of traffic emissions but also offers potential for evaluating the effectiveness of traffic management policies and their impact on air quality in urban areas.
Weniger anzeigenBackground: The sand flea, Tunga penetrans, is the cause of a severely neglected parasitic skin disease (tungiasis) in the tropics and has received little attention from entomologists to understand its transmission ecology. Like all fleas, T. penetrans has environmental off-host stages presenting a constant source of reinfection. We adapted the Berlese-Tullgren funnel method using heat from light bulbs to extract off-host stages from soil samples to identify the major development sites within rural households in Kenya and Uganda.
Methods and findings: Simple, low-cost units of multiple funnels were designed to allow the extraction of >60 soil samples in parallel. We calibrated the method by investigating the impact of different bulb wattage and extraction time on resulting abundance and quality of off-host stages. A cross-sectional field survey was conducted in 49 tungiasis affected households. A total of 238 soil samples from indoor and outdoor living spaces were collected and extracted. Associations between environmental factors, household member infection status and the presence and abundance of off-host stages in the soil samples were explored using generalized models. The impact of heat (bulb wattage) and time (hours) on the efficiency of extraction was demonstrated and, through a stepwise approach, standard operating conditions defined that consistently resulted in the recovery of 75% (95% CI 63–85%) of all present off-host stages from any given soil sample. To extract off-host stages alive, potentially for consecutive laboratory bioassays, a low wattage (15–25 W) and short extraction time (4 h) will be required. The odds of finding off-host stages in indoor samples were 3.7-fold higher than in outdoor samples (95% CI 1.8–7.7). For every one larva outdoors, four (95% CI 1.3–12.7) larvae were found indoors. We collected 67% of all off-host specimen from indoor sleeping locations and the presence of off-host stages in these locations was strongly associated with an infected person sleeping in the room (OR 10.5 95% CI 3.6–28.4).
Conclusion: The indoor sleeping areas are the transmission hotspots for tungiasis in rural homes in Kenya and Uganda and can be targeted for disease control and prevention measures. The soil extraction methods can be used as a simple tool for monitoring direct impact of such interventions.
Weniger anzeigenIntroduction: Angiogenic behaviour has been shown as highly versatile among Endothelial cells (ECs) causing problems of in vitro assays of angiogenesis considering their reproducibility. It is indispensable to investigate influencing factors of the angiogenic potency of ECs.
Objective: The present study aimed to analyse the impact of knocking down triosephosphate isomerase (TPI) on in vitro angiogenesis and simultaneously on vimentin (VIM) and adenosylmethionine synthetase isoform type 2 (MAT2A) expression. Furthermore, native expression profiles of TPI, VIM and MAT2A in the course of angiogenesis in vitro were examined.
Methods: Two batches of human dermal microvascular ECs were cultivated over 50 days and stimulated to undergo angiogenesis. A shRNA-mediated knockdown of TPI was performed. During cultivation, time-dependant morphological changes were detected and applied for EC-staging as prerequisite for quantifying in vitro angiogenesis. Additionally, mRNA and protein levels of all proteins were monitored.
Results: Opposed to native cells, knockdown cells were not able to enter late stages of angiogenesis and primarily displayed a downregulation of VIM and an uprise in MAT2A expression. Native cells increased their TPI expression and decreased their VIM expression during the course of angiogenesis in vitro. For MAT2A, highest expression was observed to be in the beginning and at the end of angiogenesis.
Conclusion: Knocking down TPI provoked expressional changes in VIM and MAT2A and a deceleration of in vitro angiogenesis, indicating that TPI represents an angiogenic protein. Native expression profiles lead to the assumption of VIM being predominantly relevant in beginning stages, MAT2A in beginning and late stages and TPI during the whole course of angiogenesis in vitro.
Weniger anzeigenAnnual maxima of daily precipitation sums can be typically described well with a stationary generalized extreme value (GEV) distribution. In many regions of the world, such a description does also work well for monthly maxima for a given month of the year. However, the description of seasonal and interannual variations requires the use of non-stationary models. Therefore, in this paper we propose a non-stationary modeling strategy applied to long time series from rain gauges in Germany. Seasonal variations in the GEV parameters are modeled with a series of harmonic functions and interannual variations with higher-order orthogonal polynomials. By including interactions between the terms, we allow for the seasonal cycle to change with time. Frequently, the shape parameter ξ of the GEV is estimated as a constant value also in otherwise instationary models. Here, we allow for seasonal–interannual variations and find that this is beneficial. A suitable model for each time series is selected with a stepwise forward regression method using the Bayesian information criterion (BIC). A cross-validated verification with the quantile skill score (QSS) and its decomposition reveals a performance gain of seasonally–interannually varying return levels with respect to a model allowing for seasonal variations only. Some evidence can be found that the impact of climate change on extreme precipitation in Germany can be detected, whereas changes are regionally very different. In general, an increase in return levels is more prevalent than a decrease. The median of the extreme precipitation distribution (2-year return level) generally increases during spring and autumn and is shifted to later times in the year; heavy precipitation (100-year return level) rises mainly in summer and occurs earlier in the year.
Weniger anzeigenSalt structures and their surroundings can play an important role in the energy transition related to a number of storage and energy applications. Thus, it is important to assess the current and future stability of salt bodies in their specific geological settings. We investigate the influence of ice sheet loading and unloading on subsurface salt structures using physical models based on the geological setting of northern Germany, which was repeatedly glaciated by the Scandinavian Ice Sheet during the Pleistocene. Apparent spatial correlations between subsurface salt structures in northern Germany and Weichselian ice marginal positions have been observed before, and the topic is a matter of ongoing debate. Recently described geomorphological features – termed surface cracks – have been interpreted as a direct result of ice-sheet-induced salt movement resulting in surface expansion. The spatial clustering and orientation of these surface cracks has not been well understood so far, owing to only a limited number of available studies dealing with the related salt tectonic processes. Thus, we use four increasingly complex physical models to test the basic loading and unloading principle, to analyze flow patterns within the salt source layer and within salt structures, and to examine the influence of the shape and orientation of the salt structures with respect to a lobate ice margin in a three-dimensional laboratory environment. Three salt structures of the northern German basin were selected as examples that were replicated in the laboratory. Salt structures were initially grown by differential loading and buried before loading. The ice load was simulated by a weight that was temporarily placed on a portion of the surface of the models. The replicated salt structures were either completely covered by the load, partly covered by the load, or situated outside the load extent. In all scenarios, a dynamic response of the system to the load could be observed; while the load was applied, the structures outside the load margin started to rise, with a decreasing tendency with distance from the load margin, and, at the same time, the structures under the load subsided. After the load was removed, a flow reversal set in, and previously loaded structures started to rise, whereas the structures outside the former load margin began to subside. The vertical displacements during the unloading stage were not as strong as during the load stage, and thus the system did not return to its pre-glaciation status. Modeled salt domes that were located at distance from the load margin showed a comparably weak reaction. A more extreme response was shown by modeled salt pillows whose margins varied from sub-parallel to sub-perpendicular to the load margin and were partly covered by the load. Under these conditions, the structures showed a strong reaction in terms of strain and vertical displacement. The observed strain patterns at the surface were influenced by the shape of the load margin and the shape of the salt structure at depth, resulting in complex deformation patterns. These physical modeling results provide more evidence for a possible interplay between ice sheets and subsurface salt structures, highlighting the significance of three-dimensional effects in dynamic geological settings. Our results lead to a better understanding of spatial patterns of the surface cracks that were mapped at the surface above salt structures and offer further room for interpretation of the influence of salt movements on the present-day landscape.
Weniger anzeigenHigh-impact river floods are often caused by very extreme precipitation events with return periods of several decades or centuries, and the design of flood protection measures thus relies on reliable estimates of the corresponding return values. However, calculating such return values from observations is associated with large statistical uncertainties due to the limited length of observational time series, uneven spatial distributions of rain gauges and trends associated with anthropogenic climate change. Here, 100-year return values of daily precipitation are estimated on a global grid based on a large data set of model-generated precipitation events from ensemble weather prediction. In this way, the statistical uncertainties in the return values can be substantially reduced compared to observational estimates due to the substantially longer time series. In spite of a general agreement in spatial patterns, the model-generated data set leads to systematically higher return values than the observations in many regions, with statistically significant differences, for instance, over the Amazon, western Africa, the Arabian Peninsula and India. This might be linked to an overestimation of tropical extreme precipitation in the model or an underestimation of extreme precipitation events in observations, which, if true, would have important consequences for practical water management.
Weniger anzeigenOrganizations, as central actors in societal structure, undergo significant transformations due to the impact of digitalization, often resulting in disruptive changes. Consequently, organizations increasingly view digitalization as an ongoing process of negotiation, which has led to the emergence of new operational modes and organizational norms. In this context, the interaction between organizations and digital technologies is characterized by recursive dynamics, which blur conventional boundaries. This presents a challenge in defining the distinct domains of the digital and the organizational within the framework of recursivity. This article draws upon new materialism and agential realism to propose an ontological-relational approach to understanding organizational digitality. This approach suggests a reconceptualization of organizational digitality as a mechanism that generates relational entities, thereby reshaping their inherent meanings. By transcending traditional boundaries between organizations and digital, this perspective provides a nuanced understanding of digital phenomena within organizational contexts.
Weniger anzeigenWe analyze connections between two low rank modeling approaches from the last decade for treating dynamical data. The first one is the coherence problem (or coherent set approach), where groups of states are sought that evolve under the action of a stochastic transition matrix in a way maximally distinguishable from other groups. The second one is a low rank factorization approach for stochastic matrices, called direct Bayesian model reduction (DBMR), which estimates the low rank factors directly from observed data. We show that DBMR results in a low rank model that is a projection of the full model, and exploit this insight to infer bounds on a quantitative measure of coherence within the reduced model. Both approaches can be formulated as optimization problems, and we also prove a bound between their respective objectives. On a broader scope, this work relates the two classical loss functions of nonnegative matrix factorization, namely the Frobenius norm and the generalized Kullback–Leibler divergence, and suggests new links between likelihood-based and projection-based estimation of probabilistic models.
Weniger anzeigenThe present article examines the particular role that cities have played, and should play, in global social history. It notes that many of the historiographical discussions that in the past years have addressed the reach and limits of the bourgeoisie and the middle class as a globalized social formation have implicitly focused on cities. It also notes that these discussions have often not been very forthcoming in explicitly acknowledging this urban focus. From this starting point, the present article ponders the implications and ramifications of making this focus more explicit. What do we conclude from the observation that the ‘global bourgeoisie’ or the ‘global middle class’, inasmuch as they existed at all, were quintessentially urban formations? And what do these conclusions, conversely, entail for the field of urban history? Highlighting density and differentiation as key traits of the urban form, the article ultimately argues for greater attention to the spatiality and to the built environment of class formation in global history.
Weniger anzeigenProteomic investigations result in high dimensional datasets, but integration or comparison of different studies is hampered by high variances due to different experimental setups. In addition, cell culture conditions can have a huge impact on the outcome. This study systematically investigates the impact of experimental parameters on the proteomic profiles of commonly used cell lines—A549, differentiated THP-1 macrophage-like cells, and NR8383—for toxicity studies. The work focuses on analyzing the influence at the proteome level of cell culture setup involving different vessels, cell passage numbers, and post-differentiation harvesting time, aiming to improve the reliability of proteomic analyses for hazard assessment. Mass-spectrometry-based proteomics was utilized for accurate protein quantification by means of a label-free approach. Our results showed that significant proteome variations occur when cells are cultivated under different setups. Further analysis of these variations revealed their association to specific cellular pathways related to protein misfolding, oxidative stress, and proteasome activity. Conversely, the influence of cell passage numbers on the proteome is minor, suggesting a reliable range for conducting reproducible biological replicates. Notable, substantial proteome alterations occur over-time post-differentiation of dTHP-1 cells, particularly impacting pathways crucial for macrophage function. This finding is key for the interpretation of experimental results. These results highlight the need for standardized culture conditions in proteomic-based evaluations of treatment effects to ensure reliable results, a prerequisite for achieving regulatory acceptance of proteomics data.
Weniger anzeigenHoneybees encode in their waggle dances the vector (distance and direction) of an outbound flight to a food source or a new nest site. Optic flow has been identified as the major source of information in the distance estimation. Additional components of distance estimation were also identified, e.g. the sequence of experienced landmarks. Here we address the question of whether bees also use the landscape memory developed during exploratory orientation flights to estimate distance. We took advantage of the fact that flights in a narrow tunnel lead to further distance measures due to higher optic flow. We find that this effect is lost when bees had explored the area in which the tunnel is located and when they have somewhat restricted visual access to the surrounding environment through the mesh on top of the tunnel. These data are interpreted in the context of other findings about the structure of navigational memory in bees that develops during exploratory orientation flights. In particular, the data suggest that bees embed distance measures into a representation of navigational space that stores previously experienced landscape features.
Weniger anzeigenRNA and protein-based therapeutics constitute almost half of recent drug approvals and receive considerable attention within biotechnology industries. Ensuring their stability and longevity in the context of heat, freezing, and lyophilization processes are paramount to a successful deployment. However, the advancement of formulations designed to achieve this goal is still in its nascent phase. To address these challenges, a new class of semi-dendritic hydrophilic polymer with extended linear units is reported, which showcase very high hydration. These novel polymers demonstrated exceptional efficacy in preserving messenger RNA- (mRNA-) and self-amplifying RNA- (saRNA-) lipid nanoparticles during freezing and lyophilization. Additionally, they have been found to protect therapeutic proteins against external stressors such as freezing, heat, and lyophilization. These polymers are non-toxic, which enables their utilization at high concentrations and eliminates the requirement for removal prior to administration. It is found that their unique topology contributes to the high hydration. These excipients are anticipated to create new prospects in biotechnology, food science, and cryopreservation.
Weniger anzeigenThe Pharmpy Automatic Model Development (AMD) tool automates the building of population pharmacokinetic (popPK) models by utilizing a systematic stepwise process. In this study, the performance of the AMD tool was assessed using simulated datasets. Ten true models mimicking classical popPK models were created. From each true model, dataset replicates were simulated assuming a typical phase I study design—single and multiple ascending doses with/without dichotomous food effect, with rich PK sampling. For every dataset replicate, the AMD tool automatically built an AMD model utilizing NONMEM for parameter estimation. The AMD models were compared to the true and reference models (true model fitted to simulated datasets) based on their model components, predicted population and individual secondary PK parameters (SP) (AUC0-24, cmax, ctrough), and model quality metrics (e.g., model convergence, parameter relative standard errors (RSEs), Bayesian Information Criterion (BIC)). The models selected by the AMD tool closely resembled the true models, particularly in terms of distribution and elimination, although differences were observed in absorption and inter-individual variability components. Bias associated with the derived SP was low. In general, discrepancies between AMD and true SP were also observed for reference models and therefore were attributed to the inherent stochasticity in simulations. In summary, the AMD tool was found to be a valuable asset in automating repetitive modeling tasks, yielding reliable PK models in the scenarios assessed. This tool has the potential to save time during early clinical drug development that can be invested in more complex modeling activities within model-informed drug development.
Weniger anzeigenThiol-mediated uptake (TMU) is thought to occur through dynamic covalent cascade exchange networks. Here we show that the cascade accounting for TMU of asparagusic acid derivatives (AspA) ends in the Golgi apparatus (G) and shifts from disulfide to thioester exchange with palmitoyl transferases as the final exchange partner. As a result, AspA combined with pH-sensitive fluoresceins, red-shifted silicon-rhodamines, or mechanosensitive flipper probes selectively labels the Golgi apparatus in fluorescence microscopy images in living and fixed cells. AspA Golgi trackers work without cellular engineering and excel with speed, simplicity, generality, and compatibility with G/ER and cis/trans discrimination, morphological changes, anterograde vesicular trafficking, and superresolution imaging by stimulated emission depletion microscopy. Golgi flippers in particular can image membrane order and tension in the Golgi and, if desired, at the plasma membrane during TMU.
Weniger anzeigenThis paper investigates contemporary transformations of citizenship in India, Sri Lanka, and Myanmar in their historical trajectories. More specifically, we focus on the contestation of liberal aspects of the respective citizenship regimes, in particular principles of non-discrimination on the basis of caste, race, gender, religion, or ethnic belonging as well as a high degree of legal certainty about one’s citizenship status. We advance two central arguments. Firstly, we argue that while often studied in isolation, the processes by which liberal citizenship is contested across the three countries bear remarkable similarities. We therefore develop a transnational comparative perspective to highlight the legal mechanisms and social logics by which citizenship regimes across the region are being transformed. Secondly, we argue that to capture these transformations, we need to complement the analyses of legislative changes with an investigation of socio-legal practices. This dual focus reveals how the interplay between seemingly innocent legislative changes and particular bureaucratic practices across all three countries produces zones of liminality, in which entire population groups experience increasingly precarious citizenship status. We theorise this production of liminal citizenship by focusing on the social lives of official documents and the proliferation of rules and regulations governing the respective citizenship regimes.
Weniger anzeigenThe mostly welcoming attitudes toward refugees from Ukraine stand in stark contrast to restrictive policies and often negative attitudes toward refugees from Syria in Europe. By emphasizing certain aspects of reality whilst leaving out others, media framing plays an important role in the public image of both refugee groups. To better understand how the different refugee groups were framed in European media, we applied Latent Dirichlet Allocation (LDA) topic modeling and a thorough manual analysis and validation process to identify frames from the topic modeling results. We identified eleven generic and issue-specific emphasis frames in a sample of 84,623 newspaper articles from Germany, Spain, the UK, and Switzerland from 2014–2022. The frames were grouped into four overarching frame categories: Fate, Threat, Value and Context Frames. Syrian refugees were mostly portrayed negatively through Threat Frames and Context Frames, whereas more positive humanitarian and victimization perspectives were pronounced in Fate Framing of Ukrainian refugees. The findings indicate more negative and delegitimizing framing patterns in news coverage about Syrian compared to Ukrainian refugees.
Weniger anzeigenHIV prevention with pre-exposure prophylaxis (PrEP) constitutes a major pillar in fighting the ongoing epidemic. While daily oral PrEP adherence may be challenging, long-acting (LA-)PrEP in oral or implant formulations could overcome frequent dosing with convenient administration. The novel drug islatravir (ISL) may be suitable for LA-PrEP, but dose-dependent reductions in CD4+ T cell and lymphocyte counts were observed at high doses. We developed a mathematical model to predict ISL pro-drug levels in plasma and active intracellular ISL-triphosphate concentrations after oral vs. subcutaneous implant dosing. Using phase II trial data, we simulated antiviral effects and estimated HIV risk reduction for multiple dosages and dosing frequencies. We then established exposure thresholds where no adverse effects on immune cells were observed. Our findings suggest that implants with 56–62 mg ISL offer effective HIV risk reduction without reducing lymphocyte counts. Oral 0.1 mg daily, 3–5 mg weekly, and 10 mg biweekly ISL provide comparable efficacy, but weekly and biweekly doses may affect lymphocyte counts, while daily dosing regimen offered no advantage over existing oral PrEP. Oral 0.5–1 mg on demand provided > 90 % protection, while not being suitable for post-exposure prophylaxis. These findings suggest ISL could be considered for further development as a promising and safe agent for implantable PrEP.
Weniger anzeigenAffect control theory (ACT) is a sociological theory of meaning processing in social interactions. Meaning, according to ACT, derives from cultural institutions and situational affordances, having denotative (declarative) as well as connotative (affective) properties. Mathematical formalizations of ACT allow predictions of affective incongruency (in the terminology of ACT, deflection), which arises from conflicting institutional and situational meanings in a given interaction context. Although ACT is theoretically consistent, its propositions regarding cognitive and affective processing have rarely been tested. The present study fills this gap by investigating the neural processing of affective incongruency in linguistic descriptions of social interactions. Following a neurosociological paradigm, the study draws on neurocognitive evidence on the effects of words’ affective content on word processing as well as on a previous electroencephalography study that investigated processing of affective incongruency using event-related brain potentials. We hypothesized that affective incongruency is associated with activation in the anterior cingulate cortex (ACC), a brain area known for conflict processing. To test this hypothesis, we replicated the electroencephalography study using functional magnetic resonance imaging: We visually presented sentences describing social interactions to 23 participants in a silent reading task while measuring differences in the hemodynamic response in two conditions of affective congruency. Results show expected increases in neural activity for affectively incongruent sentences in the left ACC, supporting the assumption that affective language content influences meaning-making at very early semantic processing stages. The results also add to the emerging neuroscientific evidence for ACT’s mathematical model of impression formation.
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