145 research outputs found
Subcellular sequencing of single neurons reveals the dendritic transcriptome of GABAergic interneurons
Although mRNAs are localized in the processes of excitatory neurons, it is still unclear whether interneurons also localize a large population of mRNAs. In addition, the variability in the localized mRNA population within and between cell-types is unknown. Here we describe the unbiased transcriptomic characterization of the subcellular compartments of hundreds of single neurons. We separately profiled the dendritic and somatic transcriptomes of individual rat hippocampal neurons and investigated mRNA abundances in the soma and dendrites of single glutamatergic and GABAergic neurons. We found that, like their excitatory counterparts, interneurons contain a rich repertoire of ~4000 mRNAs. We observed more cell type-specific features among somatic transcriptomes than their associated dendritic transcriptomes. Finally, using cell-type specific metabolic labelling of isolated neurites, we demonstrated that the processes of Glutamatergic and, notably, GABAergic neurons were capable of local translation, suggesting mRNA localization and local translation is a general property of neurons
Virtual Reality, Presence, and Attitude Change: Empirical Evidence from Tourism
The rapid development of virtual reality (VR) technology offers opportunities for a widespread consumption of VR tourism content. It also presents challenges to better understand the effectiveness of VR experience in inducing more favorable attitude toward tourism destinations and shaping visitation intention. Based on two studies, one conducted in Hong Kong with 202 participants and another in the United Kingdom with 724 participants, this research identified several positive consequences of the sense of presence in VR experiences. First, the feeling of being in the virtual environment increases enjoyment of VR experiences. Second, the heightened feeling of being there results in stronger liking and preference in the destination. Third, positive attitude change leads to a higher level of visitation intention. Therefore, this study provides empirical evidence to confirm the effectiveness of VR in shaping consumers’ attitude and behavior
Google Glass Augmented Reality: Generic Learning Outcomes for Art Galleries
Art galleries are increasingly asked to provide evidence of their efforts towards facilitating visitors’ learning experience. Augmented reality (AR) and wearable computing has the potential to create a realistic learning environment. Using Google Glass allows art gallery visitors to receive augmented information while looking at paintings. The Generic Learning Outcomes (GLO) framework was specifically designed to investigate visitors’ learning experience in museums and art galleries however, research on art galleries visitors’ learning experience through wearable computing and AR applications is scarce. This study aims to assess how Google Glass enhances visitors’ learning outcomes within the art gallery environment. Twenty-two visitors participated in a test of the Google Glass Museum Zoom application. Visitors were interviewed and the data were analysed using thematic analysis and revealed that Google Glass helps visitors to see connections and enhance the knowledge and understanding of paintings
The translatome of neuronal cell bodies, dendrites,and axons
To form synaptic connections and store information, neurons continuously remodel their proteomes. The impressive length of dendrites and axons imposes logistical challenges to maintain synaptic proteins at locations remote from the transcription source (the nucleus). The discovery of thousands of messenger RNAs (mRNAs) near synapses suggested that neurons overcome distance and gain autonomy by producing proteins locally. It is not generally known, however, if, how, and when localized mRNAs are translated into protein. To investigate the translational landscape in neuronal subregions, we performed simultaneous RNA sequencing (RNA-seq) and ribosome sequencing (Ribo-seq) from microdissected rodent brain slices to identify and quantify the transcriptome and translatome in cell bodies (somata) as well as dendrites and axons (neuropil). Thousands of transcripts were differentially translated between somatic and synaptic regions, with many scaffold and signaling molecules displaying increased translation levels in the neuropil. Most translational changes between compartments could be accounted for by differences in RNA abundance. Pervasive translational regulation was observed in both somata and neuropil influenced by specific mRNA features (e.g., untranslated region [UTR] length, RNA-binding protein [RBP] motifs, and upstream open reading frames [uORFs]). For over 800 mRNAs, the dominant source of translation was the neuropil. We constructed a searchable and interactive database for exploring mRNA transcripts and their translation levels in the somata and neuropil [MPI Brain Research, The mRNA translation landscape in the synaptic neuropil. https://public.brain.mpg.de/dashapps/localseq/ Accessed 5 October 2021]. Overall, our findings emphasize the substantial contribution of local translation to maintaining synaptic protein levels and indicate that on-site translational control is an important mechanism to control synaptic strength
Tourists’ Virtual Reality Adoption: An Exploratory Study from Lake District National Park
Virtual reality (VR) transforms the way destinations market their tourism offerings. To fully understand the opportunities of a technology, initial research is required assessing user adoption. However, empirical research and particularly exploratory qualitative research on VR adoption in tourism context is limited. Therefore, this study uses an exploratory interview approach with 35 participants near Lake District National Park, UK. Using thematic analysis, this study explores factors that influence VR adoption as well as the influencing factors on tourists’ behavioural intentions. This study adds to academia by qualitatively exploring the adoption of a scarcely researched technology within the tourism context
Enhancing Art Gallery Visitors’ Learning Experience using Wearable Augmented Reality: Generic Learning Outcomes Perspective
The potential of ICT-enhanced visitor learning experience is increasing with the advancement of new and emerging technologies in art gallery settings. However, studies on the visitor learning experience using wearable devices, and in particular those investigating the effects of wearable augmented reality on the learning experience within cultural heritage tourism attractions are limited. Using the Generic Learning Outcomes framework, this study aims to assess how the wearable augmented reality application enhances visitor’s learning experiences. Forty-four volunteers who were visiting an art gallery were divided into two groups, an experimental group and a control group. Following their visit to the gallery, the volunteers, who had and had not used wearable computing equipment, were interviewed, and the data were analysed using thematic analysis. Findings revealed that the wearable augmented reality application helps visitors to see connections between paintings and personalise their learning experience. However, there are some drawbacks such as lack of visitor-visitor engagement and the social acceptability
The Pure Virtual Braid Group Is Quadratic
If an augmented algebra K over Q is filtered by powers of its augmentation
ideal I, the associated graded algebra grK need not in general be quadratic:
although it is generated in degree 1, its relations may not be generated by
homogeneous relations of degree 2. In this paper we give a sufficient criterion
(called the PVH Criterion) for grK to be quadratic. When K is the group algebra
of a group G, quadraticity is known to be equivalent to the existence of a (not
necessarily homomorphic) universal finite type invariant for G. Thus the PVH
Criterion also implies the existence of such a universal finite type invariant
for the group G. We apply the PVH Criterion to the group algebra of the pure
virtual braid group (also known as the quasi-triangular group), and show that
the corresponding associated graded algebra is quadratic, and hence that these
groups have a (not necessarily homomorphic) universal finite type invariant.Comment: 53 pages, 15 figures. Some clarifications added and inaccuracies
corrected, reflecting suggestions made by the referee of the published
version of the pape
Active zone proteins are dynamically associated with synaptic ribbons in rat pinealocytes
Synaptic ribbons (SRs) are prominent organelles that are abundant in the ribbon synapses of sensory neurons where they represent a specialization of the cytomatrix at the active zone (CAZ). SRs occur not only in neurons, but also in neuroendocrine pinealocytes where their function is still obscure. In this study, we report that pinealocyte SRs are associated with CAZ proteins such as Bassoon, Piccolo, CtBP1, Munc13–1, and the motorprotein KIF3A and, therefore, consist of a protein complex that resembles the ribbon complex of retinal and other sensory ribbon synapses. The pinealocyte ribbon complex is biochemically dynamic. Its protein composition changes in favor of Bassoon, Piccolo, and Munc13–1 at night and in favor of KIF3A during the day, whereas CtBP1 is equally present during the night and day. The diurnal dynamics of the ribbon complex persist under constant darkness and decrease after stimulus deprivation of the pineal gland by constant light. Our findings indicate that neuroendocrine pinealocytes possess a protein complex that resembles the CAZ of ribbon synapses in sensory organs and whose dynamics are under circadian regulation
Ramond-Ramond Fields, Fractional Branes and Orbifold Differential K-Theory
We study D-branes and Ramond-Ramond fields on global orbifolds of Type II
string theory with vanishing H-flux using methods of equivariant K-theory and
K-homology. We illustrate how Bredon equivariant cohomology naturally realizes
stringy orbifold cohomology. We emphasize its role as the correct cohomological
tool which captures known features of the low-energy effective field theory,
and which provides new consistency conditions for fractional D-branes and
Ramond-Ramond fields on orbifolds. We use an equivariant Chern character from
equivariant K-theory to Bredon cohomology to define new Ramond-Ramond couplings
of D-branes which generalize previous examples. We propose a definition for
groups of differential characters associated to equivariant K-theory. We derive
a Dirac quantization rule for Ramond-Ramond fluxes, and study flat
Ramond-Ramond potentials on orbifolds.Comment: 46 pages; v2: typos correcte
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