We developed a system for optogenetic release of single molecules in cells. We confined soluble and transmembrane proteins to the Golgi apparatus via a photocleavable protein and released them by short pulses of light. Our method allows for a light dose-dependent delivery of functional proteins to the cytosol and plasma membrane in amounts compatible with single-molecule imaging, greatly simplifying access to single-molecule microscopy of any protein in live cells. We were able to reconstitute ion conductance by delivering BK and LRRC8/volume-regulated anion channels to the plasma membrane. Finally we were able to induce NF-kB signaling in T lymphoblasts stimulated by interleukin-1 by controlled release of a signaling protein that had been knocked out. We observed light-induced formation of functional inflammatory signaling complexes that triggered phosphorylation of the inhibitor of nuclear factor kappa-B kinase only in activated cells. We thus developed an optogenetic method for the reconstitution and investigation of cellular function at the single-molecule level.
Weniger anzeigenWeak serpentine minerals affect the mechanical behavior of serpentinized peridotites at depth, and may play a significant role in deformation localization within subduction zones, at local or regional scale. Mixtures of olivine with 5, 10, 20 and 50 vol. % fraction of antigorite, proxies for serpentinized peridotites, were deformed in axial shortening geometry under high pressures (ca. 2–5 GPa) and moderate temperatures (ca. 350°C), with in situ stress and strain measurements using synchrotron X-rays. We evaluate the average partitioning of stresses at the grains scale within each phase (mineral) of the aggregate and compare with pure olivine aggregates in the same conditions. The in situ stress balance is different between low antigorite contents up to 10 vol. %, and higher contents above 20 vol. %. Microstructure and stress levels suggest the deformation mechanisms under these experimental conditions are akin to (semi)brittle and frictional processes. Unlike when close to dehydration temperatures, hardening of the aggregate is observed at low serpentine fractions, due to an increase in local stress concentrations. Below and above the 10–20 vol. % threshold, the stress state in the aggregate corresponds to friction laws already measured for pure olivine aggregates and pure antigorite aggregates respectively. As expected, the behavior of the two-phase aggregate does not evolve as calculated from simple iso-stress or iso-strain bounds, and calls for more advanced physical models of two-phase mixtures.
Weniger anzeigenMagnetic skyrmions, topologically-stabilized spin textures that emerge in magnetic systems, have garnered considerable interest due to a variety of electromagnetic responses that are governed by the topology. The topology that creates a microscopic gyrotropic force also causes detrimental effects, such as the skyrmion Hall effect, which is a well-studied phenomenon highlighting the influence of topology on the deterministic dynamics and drift motion. Furthermore, the gyrotropic force is anticipated to have a substantial impact on stochastic diffusive motion; however, the predicted repercussions have yet to be demonstrated, even qualitatively. Here we demonstrate enhanced thermally-activated diffusive motion of skyrmions in a specifically designed synthetic antiferromagnet. Suppressing the effective gyrotropic force by tuning the angular momentum compensation leads to a more than 10 times enhanced diffusion coefficient compared to that of ferromagnetic skyrmions. Consequently, our findings not only demonstrate the gyro-force dependence of the diffusion coefficient but also enable ultimately energy-efficient unconventional stochastic computing.
Weniger anzeigenAims
The present study investigated the potential links between Internet Use Disorder tendencies, well-being and the impact of COVID-19 on Internet usage patterns.
Method
A sample of 2498 participants filled out the Compulsive Internet Use Scale (CIUS), the Satisfaction with Life Scale (SWLS; the cognitive facet of well-being) and the Sofalizing Scale which comprises the Online Displacement and Social Compensation dimensions. Participants were also asked to report the extent to which changes in Internet use occurred due to COVID-19 pandemic (i.e., reductions, no changes, increases). The present study comprised a survey study with cross-sectional character.
Results
The statistical analyses demonstrated that the aforementioned variables were robustly associated with each other. In a first mediation model, the association between higher levels of Internet Use Disorder and reduced well-being was partially mediated by the two dimensions of the Sofalizing scale called Online Displacement and Social Compensation. The results of the second mediation model showed that the relationship between changes in Internet use due to COVID-19 pandemic and well-being was fully mediated by CIUS scores, suggesting that increased Internet use due to the COVID-19 pandemic increased levels of Internet Use Disorder tendencies, which in turn decreased levels of well-being.
Discussion
The findings are discussed in the context of human social needs in a time of crisis, where meeting people in-person was restricted.
Weniger anzeigenIn the spirit of multiscale modeling, we develop a theoretical framework for spin-lattice coupling that connects, on the one hand, to ab initio calculations of spin-lattice coupling parameters and, on the other hand, to the magnetoelastic continuum theory. The derived Hamiltonian describes a closed system of spin and lattice degrees of freedom and explicitly conserves the total momentum, angular momentum, and energy. Using a numerical implementation that corrects earlier Suzuki-Trotter decompositions we perform simulations on the basis of the resulting equations of motion to investigate the combined magnetic and mechanical motion of a ferromagnetic nanoparticle, thereby validating our developed method. In addition to the ferromagnetic resonance mode of the spin system, we find another low-frequency mechanical response and a rotation of the particle according to the Einstein–de Haas effect. The framework developed herein will enable the use of multiscale modeling for investigating and understanding a broad range of magnetomechanical phenomena from slow to ultrafast timescales.
Weniger anzeigenMalaria parasites are known to infect a variety of vertebrate hosts, including ungulates. However, ungulates of Amazonia have not been investigated. We report for the first time, the presence of parasite lineages closely related to Plasmodium odocoilei clade 1 and clade 2 in free-ranging South American red-brocket deer (Mazama americana; 44.4%, 4/9) and gray-brocket deer (Mazama nemorivaga; 50.0%, 1/2). We performed PCR-based analysis of blood samples from 47 ungulates of five different species collected during subsistence hunting by an indigenous community in the Peruvian Amazon. We detected Plasmodium malariae/brasilianum lineage in a sample from red-brocket deer. However, no parasite DNA was detected in collared peccary (Pecari tajacu; 0.0%, 0/10), white-lipped peccary (Tayassu pecari; 0.0%, 0/15), and tapir (Tapirus terrestris; 0.0%, 0/11). Concordant phylogenetic analyses suggested a possible co-evolutionary relationship between the Plasmodium lineages found in American deer and their hosts.
Weniger anzeigenWe discuss data of three laboratory stick-slip experiments on Westerly Granite samples performed at elevated confining pressure and constant displacement rate on rough fracture surfaces. The experiments produced complex slip patterns including fast and slow ruptures with large and small fault slips, as well as failure events on the fault surface producing acoustic emission bursts without externally-detectable stress drop. Preparatory processes leading to large slips were tracked with an ensemble of ten seismo-mechanical and statistical parameters characterizing local and global damage and stress evolution, localization and clustering processes, as well as event interactions. We decompose complex spatio-temporal trends in the lab-quake characteristics and identify persistent effects of evolving fault roughness and damage at different length scales, and local stress evolution approaching large events. The observed trends highlight labquake localization processes on different spatial and temporal scales. The preparatory process of large slip events includes smaller events marked by confined bursts of acoustic emission activity that collectively prepare the fault surface for a system-wide failure by conditioning the large-scale stress field. Our results are consistent overall with an evolving process of intermittent criticality leading to large failure events, and may contribute to improved forecasting of large natural earthquakes.
Weniger anzeigenRecently, the interplay between spin and lattice degrees of freedom has gained a lot of attention due to its importance for various fundamental phenomena as well as for spintronic and magnonic applications. Examples are ultrafast angular momentum transfer between the spin and lattice subsystems during ultrafast demagnetization, frustration driven by structural distortions in transition-metal oxides, or in acoustically driven spin-wave resonances. In this work, we provide a systematic analysis of spin-lattice interactions for ferro- and antiferromagnetic materials and focus on the role of lattice symmetries and dimensions, magnetic order, and the relevance of spin-lattice interactions for angular momentum transfer as well as magnetic frustration. For this purpose, we use a recently developed scheme, which allows an efficient calculation of spin-lattice interaction tensors from first principles. In addition to that, we provide a more accurate and self-consistent scheme to calculate ab initio spin-lattice interactions by using embedded clusters, which allows us to benchmark the performance of the scheme introduced previously.
Weniger anzeigenIntroduction: This study investigated the occurrence of various animal welfare violations at German abattoirs by analyzing the results of an anonymous online survey and relevant German court decisions.
Methods: The survey targeted official veterinarians (OVs) and other individuals responsible for enforcing animal welfare laws and regulations at German abattoirs. Participants were asked to report the five most common animal welfare violations in their workplaces during the past 3 years (2019–2021), and whether 22 specific given violations had occurred or not (in the same timeframe). The court decisions were examined to determine how many abattoirs were penalized for a specific animal welfare violation and the details about the number and species of affected animals.
Results: Overall, the violations examined throughout this study fell into one of the following categories: (1) use of prohibited driving aids (e.g., illicit use of electric prods, or hitting/beating animals); (2) inadequate husbandry in lairage; (3) inappropriate handling of animals with special care needs; (4) improper restraint, stunning, and bleeding of animals; and (5) unqualified task execution/inadequate administrative work (e.g., documentation of a violation). The violations analyzed in the scope of this study most frequently fell into categories 1, 2, and 4. Regarding the five violations that survey participants reported to be the most common in the years 2019–2021, 42.6% of responses (N = 277 reported violations) fell into category 4, followed closely by category 1 with 37.9%. Of the 22 violations surveyed in the second part of the survey, those reported by 50.0% or more participants were concentrated in categories 1, 2, and 4. Regarding the 16 relevant court rulings spanning from 2015 to 2022, the most frequently documented instances of misconduct primarily fell into category 1.
Discussion: The collected data suggest that there may be need for improvements regarding compliance with animal welfare legislation, especially concerning categories 1, 2, and 4. The authors suggest OVs to consider these findings when conducting monitoring activities at abattoirs and in the training and education of abattoir personnel.
Weniger anzeigenSheep ectoparasites such as chewing lice, fleas and ticks are serious constraints to sheep productivity and are the cause of skin lesions in animals that decrease their market value. This study aims at investigating the ectoparasite fauna infesting small ruminants in the district of Sidi Bouzid (central Tunisia). A total of 1243 Barbarine and Queue Fine de l’Ouest (QFO) sheep were examined every two months for one year. Of the total animals examined, 74 were infested by at least 1 parasite group (5.95%). Three ectoparasite groups were identified as Psoroptes ovis (0.48%; 6/1243), ticks (5.3%; n = 66/1243) and one specimen of Ctenocephalides canis (0.08%; n = 1/1243). The most abundant tick among the 358 specimens was Rhipicephalus sanguineus sensu lato (n = 337; 94.1%), followed by Hyalomma impeltatum (n = 7/358; 1.9%), H. dromedarii (n = 7/358; 1.9%), H. excavatum (n = 5/358; 1.4%) and only two specimens of H. scupense (n = 2/358; 0.55%). The sheep herds showed low infestation prevalence by ectoparasite over the year, with a significant difference according to the seasons (p < 0.05). A higher infestation prevalence was recorded in March (14.36%). Barbarine sheep breed showed significantly higher infestation prevalence (16.8%) compared to QFO (0.8%) (p < 0.01). There were no differences in infestation prevalence according to sex of the animal or age groups. Knowledge of the ectoparasite population harboured by sheep, its activity dynamics and risk factors is required to develop effective ectoparasite control options. The low prevalence of ectoparasite infestation in sheep reported here may be due to possible genetic resistance or simply to successful hygiene measures implemented by farmers.
Weniger anzeigenEmotional disturbances are an inherent aspect of most mental disorders and possibly driven by impaired emotion regulation. In the present study, we examined how exactly affected individuals differ from healthy individuals in regulating their emotions and whether individuals suffering from different mental disorders face similar or distinct difficulty in emotion regulation. We overcome earlier methodological constraints by using a 7-day experience sampling assessing the employment and effectiveness of six regulation strategies real time in 55 individuals with current major depressive disorder, 52 individuals with borderline personality disorder (BPD), and 55 healthy individuals. All participants were female. Both clinical groups employed rumination and suppression more often and acceptance less often than healthy individuals. Depressed individuals ruminated even more often than individuals with BPD. Expressive suppression and rumination showed negative effects on subsequent emotions in all groups. Remarkably, both clinical groups were able to benefit from adaptive regulation strategies if they did select them.
Weniger anzeigenPeyer’s patches (PPs) are part of the gut-associated lymphatic tissue (GALT) and represent the first line of the intestinal immunological defense. They consist of follicles with lymphocytes and an overlying subepithelial dome with dendritic cells and macrophages, and they are covered by the follicle-associated epithelium (FAE). A sealed paracellular pathway in the FAE is crucial for the controlled uptake of luminal antigens. Quercetin is the most abundant plant flavonoid and has a barrier-strengthening effect on tight junctions (TJs), a protein complex that regulates the paracellular pathway. In this study, we aimed to analyze the effect of quercetin on porcine PPs and the surrounding villus epithelium (VE). We incubated both tissue types for 4 h in Ussing chambers, recorded the transepithelial electrical resistance (TEER), and measured the unidirectional tracer flux of [3H]-mannitol. Subsequently, we analyzed the expression, protein amount, and localization of three TJ proteins, claudin 1, claudin 2, and claudin 4. In the PPs, we could not detect an effect of quercetin after 4 h, neither on TEER nor on the [3H]-mannitol flux. In the VE, quercetin led to a higher TEER value, while the [3H]-mannitol flux was unchanged. The pore-forming claudin 2 was decreased while the barrier-forming claudin 4 was increased and the expression was upregulated. Claudin 1 was unchanged and all claudins could be located in the paracellular membrane by immunofluorescence microscopy. Our study shows the barrier-strengthening effect of quercetin in porcine VE by claudin 4 upregulation and a claudin 2 decrease. Moreover, it underlines the different barrier properties of PPs compared to the VE.
Weniger anzeigenDrawing inspiration from transportation theory, in this work, we introduce the notions of “well-structured” and “stable” Gibbs states and we investigate their implications for quantum thermodynamics and its resource theory approach via thermal operations. It is found that, in the quasi-classical realm, global cyclic state transfers are impossible if and only if the Gibbs state is stable. Moreover, using a geometric approach by studying the so-called thermomajorization polytope, we prove that any subspace in equilibrium can be brought out of equilibrium via thermal operations. Interestingly, the case of some subsystem being in equilibrium can be witnessed via the degenerate extreme points of the thermomajorization polytope, assuming that the Gibbs state of the system is well structured. These physical considerations are complemented by simple new constructions for the polytope’s extreme points, as well as for an important class of extremal Gibbs-stochastic matrices.
Weniger anzeigenT cell receptor (TCR) repertoire sequencing has emerged as a powerful tool for understanding the diversity and functionality of T cells within the host immune system. Yet, the chicken TCR repertoire remains poorly understood due to incomplete genome annotation of the TCR loci, despite the importance of chickens in agriculture and as an immunological model. Here, we addressed this critical issue by employing 5’ rapid amplification of complementary DNA ends (5’RACE) TCR repertoire sequencing with molecular barcoding of complementary DNA (cDNA) molecules. Simultaneously, we enhanced the genome annotation of TCR Variable (V), Diversity (D, only present in β and δ loci) and Joining (J) genes in the chicken genome. To enhance the efficiency of TCR annotations, we developed <italic>VJ-gene-finder</italic>, an algorithm designed to extract VJ gene candidates from deoxyribonucleic acid (DNA) sequences. Using this tool, we achieved a comprehensive annotation of all known chicken TCR loci, including the α/δ locus on chromosome 27. Evolutionary analysis revealed that each locus evolved separately by duplication of long homology units. To define the baseline TCR diversity in healthy chickens and to demonstrate the feasibility of the approach, we characterized the splenic α/β/γ/δ TCR repertoire. Analysis of the repertoires revealed preferential usage of specific V and J combinations in all chains, while the overall features were characteristic of unbiased repertoires. We observed moderate levels of shared complementarity-determining region 3 (CDR3) clonotypes among individual birds within the α and γ chain repertoires, including the most frequently occurring clonotypes. However, the β and δ repertoires were predominantly unique to each bird. Taken together, our TCR repertoire analysis allowed us to decipher the composition, diversity, and functionality of T cells in chickens. This work not only represents a significant step towards understanding avian T cell biology, but will also shed light on host-pathogen interactions, vaccine development, and the evolutionary history of avian immunology.
Weniger anzeigenAntarctic algae are exposed to prolonged periods of extreme darkness due to polar night, and coverage by ice and snow can extend such dark conditions to up to 10 months. A major group of microalgae in benthic habitats of Antarctica are diatoms, which are key primary producers in these regions. However, the effects of extremely prolonged dark exposure on their photosynthesis, cellular ultrastructure, and cell integrity remain unknown. Here we show that five strains of Antarctic benthic diatoms exhibit an active photosynthetic apparatus despite 10 months of dark-exposure. This was shown by a steady effective quantum yield of photosystem II (Y[II]) upon light exposure for up to 2.5 months, suggesting that Antarctic diatoms do not rely on metabolically inactive resting cells to survive prolonged darkness. While limnic strains performed better than their marine counterparts, Y(II) recovery to values commonly observed in diatoms occurred after 4-5 months of light exposure in all strains, suggesting long recovering times. Dark exposure for 10 months dramatically reduced the chloroplast ultrastructure, thylakoid stacking, and led to a higher proportion of cells with compromised membranes than in light-adapted cells. However, photosynthetic oxygen production was readily measurable after darkness and strong photoinhibition only occurred at high light levels (>800 µmol photons m<sup>-2</sup> s<sup>-1</sup>). Our data suggest that Antarctic benthic diatoms are well adapted to long dark periods. However, prolonged darkness for several months followed by only few months of light and another dark period may prevent them to regain their full photosynthetic potential due to long recovery times, which might compromise long-term population survival.
Weniger anzeigenBased on six newsroom surveys, this article analyzes the history of digital German journalism. The surveys cover a period of 17 years (1997–2014). Periodizing the history of digital journalism into three phases, this article considers the interplay between journalism and journalism research. The results show how journalistic digital media define their role in the relationships between old media and the Internet, digital media and other outlets, and digital media and their audiences. Furthermore, the results substantiate how digital editorial staff define their journalistic identities regarding tasks, rules, and skills. During the first period (surveys conducted in 1997 and 2000), the view from old mass media to the Internet dominated, also in scholarship where the mass media paradigm was extended to the Internet. The second period (surveys conducted in 2006 and 2007) was characterized by clarifying the relationships between journalism and newly emerged outlets. These studies focused on how participative formats (such as Wikipedia and blogs) and search engines could be used for journalistic purposes without compromising quality. These new outlets were not regarded then as much of a threat. This attitude did not change during the third period (surveys conducted in 2010 and 2014). In this phase, too, the studies focused on how editorial staff utilized the ever-increasing number of social media. The six surveys’ different research interests reveal that the reviewed journalism research primarily addressed changing demands in journalistic practice. Therefore, exogenous factors (“the sector”) had a greater impact than endogenous factors (the “scholarship”) on research interests.
Weniger anzeigenThis randomized, prospective clinical trial investigates the impact of a novel undenatured collagen type 2 (T2NDC)-based nutraceutical, ARTHROSHINE® HA² (AS), on postoperative rehabilitation following Tibial Plateau Leveling Osteotomy (TPLO) in 50 dogs with unilateral cranial cruciate ligament rupture (CCLR). The patients were randomly allocated to either group A, receiving AS once daily for 24 weeks post-TPLO surgery, or group B, without any supplementation. Frequency matching was applied to enhance group comparability. Assessment of outcomes included computerized gait analysis and a validated owner questionnaire. AS supplementation was well received, without any reported side effect. Consistently, patients in group A exhibited significantly higher peak vertical force values during all follow-up assessments. By the 12-week mark, gait analysis indicated a return to a physiological gait pattern in group A, while group B achieved this normalization only by the 24-week point. The administration of AS post-TPLO surgery demonstrates promise in enhancing limb function, leading to faster restoration of a physiological gait pattern. The inclusion of AS, a T2NDC-based nutraceutical, in the post-TPLO rehabilitation protocol may contribute to improved limb function and an expedited recovery, potentially facilitating a quicker return to normalcy. It is noteworthy that subjective owner perceptions did not differ between the two groups.
Weniger anzeigenThe article contributes to literature that critically scrutinizes knowledge production and transfer in conflict and intervention contexts. Drawing on original research on the Tunisian transitional justice process, it contributes an empirically grounded picture to the study of co-production of governance orders and security knowledges through transnational assemblages. These transnational assemblages are formed by complex coalitions of actors from the Global North and South, and the socio-material context they operate in. The article shows how security knowledge is produced, channelled, and steered into confined knowledge flows as transitional justice processes unfold. It then shows the ambivalent nature and different qualities of confined knowledge flows as they may be enabling and limiting, exclusionary and protective, and implicated with power relations. By doing so, it contributes to the understanding of how the (neo-)liberal politics of transitional justice are reproduced.
Weniger anzeigenIn response to pressing global challenges, sustainability transitions research has emerged as an interdisciplinary field focused on fundamental changes, necessitating novel approaches for strategy-making from research and innovation. Foresight practitioners need to extend their well-established methodological toolkit, which can inform subsequent planning processes about managing conflicts and shaping futures, to include the articulation of response options for contributing to the creation of more sustainable future systems. This research aims to contribute to this need by exploring future options characterized by discrepancies. Drawing from the Responsible Research and Innovation (RRI) literature to understand discrepancies between “desirability” and “probability” of future options as missed opportunities to secure social desirability in the future or as threats to it, this research argues for the collective identification and anticipation of discrepancies to reflect on options for making more responsive strategies. Thus, informed by RRI, a Delphi exercise was modified to engage experts from the German agri-food sector (n = 21) to assess divergent innovation-driven changes in the German agri-food sector that had been collectively anticipated and reflected upon beforehand. The results speak for a reduction of complexity by revealing specific actions necessary to redirect research and innovation processes away from unsustainable paths, as well as identifying determinants of discrepancies to do good or avoid harm.
Weniger anzeigen- Refined conversion factors for soil fungal biomarkers are proposed.
- High interspecific variability is present in all fungal biomarkers.
- A modeling approach supports the validity of biomarker estimates in diverse soils.
- ITS1 copies vary strongly, but are fungal-specific with least phylogenetic bias.
- A combination of fungal biomarkers will reveal soil fungal physiology and activity.
The abundances of fungi and bacteria in soil are used as simple predictors for carbon dynamics, and represent widely available microbial traits. Soil biomarkers serve as quantitative estimates of these microbial groups, though not quantifying microbial biomass per se. The accurate conversion to microbial carbon pools, and an understanding of its comparability among soils is therefore needed. We refined conversion factors for classical fungal biomarkers, and evaluated the application of quantitative PCR (qPCR, rDNA copies) as a biomarker for soil fungi. Based on biomarker contents in pure fungal cultures of 30 isolates tested here, combined with comparable published datasets, we propose average conversion factors of 95.3 g fungal C g−1 ergosterol, 32.0 mg fungal C µmol−1 PLFA 18:2ω6,9 and 0.264 pg fungal C ITS1 DNA copy−1. As expected, interspecific variability was most pronounced in rDNA copies, though qPCR results showed the least phylogenetic bias. A modeling approach based on exemplary agricultural soils further supported the hypothesis that high diversity in soil buffers against biomarker variability, whereas also phylogenetic biases impact the accuracy of comparisons in biomarker estimates. Our analyses suggest that qPCR results cover the fungal community in soil best, though with a variability only partly offset in highly diverse soils. PLFA 18:2ω6,9 and ergosterol represent accurate biomarkers to quantify Ascomycota and Basidiomycota. To conclude, the ecological interpretation and coverage of biomarker data prior to their application in global models is important, where the combination of different biomarkers may be most insightful.
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