The role of scaffold architecture and composition on the bone formation by adipose-derived stem cells

Scaffold architecture and composition are crucial parameters determining the initial cell spatial distribution and consequently bone tissue formation. Three-dimensional poly-ε-caprolactone (PCL) scaffolds with a 0/90° lay-down pattern were plotted and subjected to 1) an oxygen plasma (PCL O) or 2) a post-argon plasma modification with gelatine and fibronectin (PCL Fn). These scaffolds with an open pore structure were compared with more compact scaffolds fabricated by conventional processing techniques: oxidized polylactic acid (LA O) and collagen (COL) scaffolds. Human adipose tissue derived stem cell/scaffold interaction was studied. The study revealed that the biomimetic surface modification of plotted scaffolds did not increase the seeding efficiency. The proliferation and colonization was superior for PCL Fn in comparison with PCL O. The plotted PCL Fn was completely colonized throughout the scaffold whereas conventional scaffolds only at the edge. Protein-based scaffolds (PCL Fn and COL) enhanced the differentiation, although plotted scaffolds showed a delay in their differentiation compared with compact scaffolds. In conclusion, protein modification of plotted PCL scaffolds enhances uniform tissue formation but shows a delayed differentiation in comparison with compact scaffolds. The present study demonstrates that biomimetic PCL scaffolds could serve as a guiding template to obtain a uniform bone tissue formation in vivo

Communication strategies for moral rebels:How to talk about change in order to inspire self-efficacy in others

Current carbon-intensive lifestyles are unsustainable and drastic social changes are required to combat climate change. To achieve such change, moral rebels (i.e., individuals who deviate from current behavioral norms based on ethical considerations) may be crucial catalyzers. However, the current literature holds that moral rebels may do more harm than good. By deviating from what most people do, based on a moral concern, moral rebels pose a threat to the moral self-view of their observers who share but fail to uphold that concern. Those observers may realize that their behavior does not live up to their moral values, and feel morally inadequate as a result. Work on “do-gooder derogation” demonstrates that rebel-induced threat can elicit defensive reactance among observers, resulting in the rejection of moral rebels and their behavioral choices. Such findings suggest that advocates for social change should avoid triggering moral threat by, for example, presenting nonmoral justifications for their choices. We challenge this view by arguing that moral threat may be a necessary ingredient to achieve social change precisely because it triggers ethical dissonance. Thus, instead of avoiding moral justifications, it may be more effective to harness that threat. Ethical dissonance may offer the fuel needed for observers to engage in self-improvement after being exposed to moral rebels, provided that observers feel capable of changing. Whether or not observers feel capable of changing, however, depends on how rebels communicate their moral choices to others—how they talk about change. This article is categorized under: Perceptions, Behaviour and Communication of Climate Change > Behaviour Change and Responses

Searching with and against each other: Spatiotemporal coordination of visual search behavior in collaborative and competitive settings

Although in real life people frequently perform visual search together, in lab experiments this social dimension is typically left out. Here, we investigate individual, collaborative and competitive visual search with visualization of search partners' gaze. Participants were instructed to search a grid of Gabor patches while being eye tracked. For collaboration and competition, searchers were shown in real time at which element the paired searcher was looking. To promote collaboration or competition, points were rewarded or deducted for correct or incorrect answers. Early in collaboration trials, searchers rarely fixated the same elements. Reaction times of couples were roughly halved compared with individual search, although error rates did not increase. This indicates searchers formed an efficient collaboration strategy. Overlap, the proportion of dwells that landed on hexagons that the other searcher had already looked at, was lower than expected from simulated overlap of two searchers who are blind to the behavior of their partner. The proportion of overlapping dwells correlated positively with ratings of the quality of collaboration. During competition, overlap increased earlier in time, indicating that competitors divided space less efficiently. Analysis of the entropy of the dwell locations and scan paths revealed that in the competition condition, a less fixed looking pattern was exhibited than in the collaborate and individual search conditions. We conclude that participants can efficiently search together when provided only with information about their partner's gaze position by dividing up the search space. Competing search exhibited more random gaze patterns, potentially reflecting increased interaction between searchers in this condition

Auditory and Visual Integration for Emotion Recognition and Compensation for Degraded Signals are Preserved With Age

Since emotion recognition involves integration of the visual and auditory signals, it is likely that sensory impairments worsen emotion recognition. In emotion recognition, young adults can compensate for unimodal sensory degradations if the other modality is intact. However, most sensory impairments occur in the elderly population and it is unknown whether older adults are similarly capable of compensating for signal degradations. As a step towards studying potential effects of real sensory impairments, this study examined how degraded signals affect emotion recognition in older adults with normal hearing and vision. The degradations were designed to approximate some aspects of sensory impairments. Besides emotion recognition accuracy, we recorded eye movements to capture perceptual strategies for emotion recognition. Overall, older adults were as good as younger adults at integrating auditory and visual information and at compensating for degraded signals. However, accuracy was lower overall for older adults, indicating that aging leads to a general decrease in emotion recognition. In addition to decreased accuracy, older adults showed smaller adaptations of perceptual strategies in response to video degradations. Concluding, this study showed that emotion recognition declines with age, but that integration and compensation abilities are retained. In addition, we speculate that the reduced ability of older adults to adapt their perceptual strategies may be related to the increased time it takes them to direct their attention to scene aspects that are relatively far away from fixation

Degraded visual and auditory input individually impair audiovisual emotion recognition from speech-like stimuli, but no evidence for an exacerbated effect from combined degradation

Emotion recognition requires optimal integration of the multisensory signals from vision and hearing. A sensory loss in either or both modalities can lead to changes in integration and related perceptual strategies. To investigate potential acute effects of combined impairments due to sensory information loss only, we degraded the visual and auditory information in audiovisual video-recordings, and presented these to a group of healthy young volunteers. These degradations intended to approximate some aspects of vision and hearing impairment in simulation. Other aspects, related to advanced age, potential health issues, but also long-term adaptation and cognitive compensation strategies, were not included in the simulations. Besides accuracy of emotion recognition, eye movements were recorded to capture perceptual strategies. Our data show that emotion recognition performance decreases when degraded visual and auditory information are presented in isolation, but simultaneously degrading both modalities does not exacerbate these isolated effects. Moreover, degrading the visual information strongly impacts recognition performance and on viewing behavior. In contrast, degrading auditory information alongside normal or degraded video had little (additional) effect on performance or gaze. Nevertheless, our results hold promise for visually impaired individuals, because the addition of any audio to any video greatly facilitates performance, even though adding audio does not completely compensate for the negative effects of video degradation. Additionally, observers modified their viewing behavior to degraded video in order to maximize their performance. Therefore, optimizing the hearing of visually impaired individuals and teaching them such optimized viewing behavior could be worthwhile endeavors for improving emotion recognition

Окказионализмы vs неологизмы: критерии перехода

Статья посвящена проблеме новообразований современного английского языка: уточнению понятий "новообразование", "окказионализм" и "неологизм", проблеме их идентификации и стратификации. В работе предпринята попытка унификации существующего терминологического аппарата, используемого для разграничения разных типов новообразований в разговорной речи и литературных произведениях. Кроме того, в статье предложена система критериев идентификации новообразований, и рассмотрены условия перехода окказионализмов в неологизмы.Стаття присвячена проблемі новоутворень сучасної англійської мови: уточненню понять "новоутворення", "оказіоналізм" та "неологізм", проблемі їх ідентифікації та стратифікації. У роботі здійснюється спроба уніфікувати існуючий термінологічний апарат, що використовується для розмежування різних типів новоутворень у розмовній мові та літературних творах. Крім того, в статті запропонована система критеріїв ідентифікації новоутворень, а також розглянуті умови переходу оказіоналізмів у неологізми.The article is devoted to the problem of new-formations in Modern English, namely to specifying of such notions as "new-formations", "nonce-words" and "neologisms", to the problem of their identification and stratification. There was made an attempt in the research under consideration to unify the system of already existing terminology that is used to differentiate different types of new-formations in speech and in literary works. Besides an original system of criteria was suggested in the article to identify different types of new-formations and the conditions giving the opportunity to nonce-words to get the status of neologisms

Sialic acid-modified antigens impose tolerance via inhibition of T-cell proliferation and de novo induction of regulatory T cells

Sialic acids are negatively charged nine-carbon carboxylated monosaccharides that often cap glycans on glycosylated proteins and lipids. Because of their strategic location at the cell surface, sialic acids contribute to interactions that are critical for immune homeostasis via interactions with sialic acid-binding Ig-type lectins (siglecs). In particular, these interactions may be of importance in cases where sialic acids may be overexpressed, such as on certain pathogens and tumors. We now demonstrate that modification of antigens with sialic acids (Sia-antigens) regulates the generation of antigen-specific regulatory T (Treg) cells via dendritic cells (DCs). Additionally, DCs that take up Sia-antigen prevent formation of effector CD4+ and CD8+ T cells. Importantly, the regulatory properties endowed on DCs upon Sia-antigen uptake are antigen-specific: only T cells responsive to the sialylated antigen become tolerized. In vivo, injection of Sia-antigen–loaded DCs increased de novo Treg-cell numbers and dampened effector T-cell expansion and IFN-γ production. The dual tolerogenic features that Sia-antigen imposed on DCs are Siglec-E–mediated and maintained under inflammatory conditions. Moreover, loading DCs with Sia-antigens not only inhibited the function of in vitro–established Th1 and Th17 effector T cells but also significantly dampened ex vivo myelin-reactive T cells, present in the circulation of mice with experimental autoimmune encephalomyelitis. These data indicate that sialic acid-modified antigens instruct DCs in an antigen-specific tolerogenic programming, enhancing Treg cells and reducing the generation and propagation of inflammatory T cells. Our data suggest that sialylation of antigens provides an attractive way to induce antigen-specific immune tolerance

The influence of spatial pattern on visual short-term memory for contrast

Several psychophysical studies of visual short-term memory (VSTM) have shown high-fidelity storage capacity for many properties of visual stimuli. On judgments of the spatial frequency of gratings, for example, discrimination performance does not decrease significantly, even for memory intervals of up to 30 s. For other properties, such as stimulus orientation and contrast, however, such “perfect storage” behavior is not found, although the reasons for this difference remain unresolved. Here, we report two experiments in which we investigated the nature of the representation of stimulus contrast in VSTM using spatially complex, two-dimensional random-noise stimuli. We addressed whether information about contrast per se is retained during the memory interval by using a test stimulus with the same spatial structure but either the same or the opposite local contrast polarity, with respect to the comparison (i.e., remembered) stimulus. We found that discrimination thresholds got steadily worse with increasing duration of the memory interval. Furthermore, performance was better when the test and comparison stimuli had the same local contrast polarity than when they were contrast-reversed. Finally, when a noise mask was introduced during the memory interval, its disruptive effect was maximal when the spatial configuration of its constituent elements was uncorrelated with those of the comparison and test stimuli. These results suggest that VSTMfor contrast is closely tied to the spatial configuration of stimuli and is not transformed into a more abstract representation