Dendritic neurotransmitter release and its modulation in accessory olfactory bulb circuits

Dendrites are classically regarded as the brain's "listeners," while neuronal output is thought to be the exclusive privilege of the axon. Although we now appreciate the complexity of dendritic integration, the role of dendrites as output structures has received less attention. This is becoming an increasingly important topic, as the list of cell types with release competent dendrites continues to grow. One boon of coupling dendritic activity to dendritic release is that outputs from a single neuron - typically thought to occur from fixed sites with stereotyped dynamics - may occur for signals of varying spatial extent, timecourse, and release efficacy. In essence, dendritic output may "inherit" the same diversity characteristic of events in excitable dendrites. Here I studied dendritic transmitter output and its modulation in cells of the accessory olfactory bulb - a CNS structure critical for processing species-specific chemical signals called pheromones. Because of the stereotypy of its inputs, the prevalence of dendritic transmitter release from its cells, and its well-defined outputs, the AOB offers a superb model system for studying the integrative and output properties of dendrites. I first characterized basic excitable properties of the apical dendrites of mitral cells (the principal AOB neurons), and observed that they conduct non-decremental action potentials (APs). In addition to APs, these dendrites were also found to support compartmentalized, synaptically-evoked calcium spikes. Both APs and local spikes were triggers of dendritic glutamate release and feedback inhibition, suggesting that neuronal output can be flexibly routed to particular populations of postysynaptic cells. I next asked whether the relative efficacy of particular dendritic events as triggers of transmitter release can be altered, as this could provide an additional level of control over single neuron output. I found that metabotropic glutamate receptors (mGluRs) play a key role in controlling dendritic output from AOB mitral cells and an obligatory role in concomitant feedback inhibition. This work culminates with the demonstration of a new principle of neuronal signaling: the ability of mGluRs to gate a transition between phasic and tonic dendritic transmitter release. Taken in total, these results extend our understanding of how the outputs from single neurons are controlled

Comparing anaphora resolution in early and late Brazilian Portuguese-European Portuguese bidialectal bilinguals

The present study examines anaphora resolution in two groups of speakers exposed to Brazilian and European Portuguese (BP and EP, respectively), considering the different null subject distribution in these languages. Our research question is whether late BP-EP bilinguals (age of EP onset: 29.1) and heritage BP speakers raised in Portugal (age of EP onset 5.6), tested in both dialects, will pattern like the native controls or display some effects of EP in their native BP or vice-versa. This is an interesting question in light of the Interface Hypothesis, which claims that external interfaces should be subject to general bilingualism effects irrespective of language pairing and age (Sorace, 2011). The results show that age has an effect, as the heritage speakers do not perform like the late learners, and that the high degree of typological proximity between the two languages rules out the possibility of late bidialectal acquisition

New Damped Lyα Metallicities from Echellette Spectrograph and Imager Spectroscopy of Five Palomar Sky Survey Quasars

This paper presents chemical abundance measurements for 12 new z > 3 damped Lyα systems discovered toward five quasars from the Palomar Sky Survey. We determine H I column densities from profile fits to the observed damped Lyα profiles and measure ionic column densities and limits for all observed metal line transitions. This data set, acquired with the Echellette Spectrograph and Imager on the Keck II telescope, adds to the rapidly growing database of damped Lyα abundances. It will impact studies of chemical evolution in the early universe and help identify candidates for detailed follow-up observations with echelle spectrographs. We report the discovery of the first quasar sight line with four cosmologically distinct damped Lyα systems

New Damped Lya Metallicities from ESI Spectroscopy of Five Palomar Sky Survey Quasars

This paper presents chemical abundance measurements for 12 new z>3 damped Lya systems discovered toward five quasars from the Palomar Sky Survey. We determine HI column densities from profile fits to the observed damped Lya profiles and measure ionic column densities and limits for all observed metal-line transitions. This dataset, acquired with the Echellette Spectrograph and Imager on the KeckII telescope, adds to the rapidly growing database of damped Lya abundances. It will impact studies of chemical evolution in the early universe and help identify candidates for detailed follow-up observations with echelle spectrographs. We report the discovery of the first quasar sightline with four cosmologically distinct damped Lya systems.Comment: 14 pages, 20 figures. Accepted to ApJS, May 9, 200

The critical image: ethics and the art of Vernon Ah Kee

For Lithuanian philosopher, Emmanuel Levinas, the idea of totality and infinity is made possible due to the notion that the Other is irreducible to comprehension Levinas1996, p.6). The Other overflows any meaning that can be attributed and any attempt to reduce the subject to a concept is a form of ‘totalisation’. Levinas’s Other is ‘infinite’, in that the subject exceeds any concept that one can possibly designate (Levinas 1969, p.22). The Other is beyond my full understanding; I cannot comprehend the maximum extent of their complexities, subtleties, choices and freedom. I can only come ‘face to face’ with them, in dialogue. This thesis applies the concept of Levinas’s ‘face to face’ theory to the contemporary artwork of Australian Indigenous artist Vernon Ah Kee. I introduce the term ‘critical image’ to describe works of art that have criticality at their core and enter into dialogues that challenge contemporary thought. I ask, if Vernon Ah Kee’s images are ‘critical images’ what are they critical of? In response to this question, I examine the colonial context of Ah Kee’s work, including the role of anthropology in creating colonial identities for Indigenous Australians. Ah Kee’s artwork is discussed in relationship to Levinas’s key concepts of ‘responsibility’, ‘proximity’, ‘infinity’ and ‘totality’. Levinas’s theories, it is argued, are useful tools in examining Ah Kee’s work in that they provide an ethical framework for interactions with the Other, preserving their alterity, and confronting us in the way we see Other people. This thesis utilises a post colonial methodology that incorporates art criticism and philosophical questioning. This study recontextualises colonial critique within the ethical framework of Levinas’s thought, not only reconsidering the usage of Levinas but repositioning Ah Kee’s work in this new context

¿El declive del significado social de la música?

¿Nos encontramos ante un declive del significado social de la música? Por un lado las innovaciones tecnológicas, especialmente la digitalización, modifican las formas sociales de acceso a la música, con un progresivo aumento de disposiciones más individuales que no requieren redes personales cara a cara -las cuales potenciaban la construcción identitaria alrededor de la música. Por otra parte, la lógica del mercado cultural global, del usar y tirar, impacta en la música, disminuyendo su capacidad de proveer significado social e identidad. Como resultado, planteamos que el “declive” se refiere a un cambio en el significado social de la música, pasando de ser un elemento de construcción identitaria hacia uno de socialidad comunicativa. Hoy en día su principal función es la de compartir, proveyendo un lenguaje común para la socialidad, donde las neotribus se disuelven.Sommes nous confrontés à un déclin de la signification sociale de la musique? D'une part les innovations technologiques, en particulier la digitalisation, ont modifié les habitudes sociales d'accès à la musique, par le truchement d'une croissance progressive d'attitudes plus individualistes qui ne requièrent pas de réseaux person nels “face à face” - qui potentialisaient la construction identitaire autour de la musique. D'autre part, la logique du marché culturel mondial, d'utiliser et de jeter, a un impact sur la musique en diminuant sa capacité de générer une signification sociale et identitaire. En conclusion, nous avançons que le “déclin” est dû à un changement de la signification sociale de la musique, qui cesse d'être un élément de construction identitaire pour devenir un élément de socialité communicative. De nos jours, sa principale fonction est celle de partager, en fournissant un langage commun à la société, dans laquelle les néo tribus se dissolvent.Are we witnessing a decline in the social significance of music? On one hand, technological innovations, especially digitalization, have changed social forms of accessing music, with the increasing importance of individual modes that do not require the face to face personal networks that had previously enabled social groups to construct their identities around music. On the other hand, the global cultural market logic of pick and mix and use and discard has had an impact on music, making it difficult to provide social meaning and identity. Based on these observations, this article proposes that the ‘decline' is, in fact, a change in the social meaning of music, from an element involved in the construction of identity to an element of communicative sociality. Its main function today is that of sharing, providing a common language for sociality where neo tribes are dissolving

Using the Behavior Change Wheel to Understand University Students’ Prolonged Sitting Time and Identify Potential Intervention Strategies

Background Several national public health guidelines recommend individuals minimize time spent in prolonged, continuous periods of sitting. Developing effective interventions to break up sitting, however, requires in-depth understanding of the behavior as well as identification of the key elements that need to be targeted to achieve change. This qualitative study focused on university students – a highly sedentary group – with the aim of: (i) exploring the factors influencing prolonged sitting time in this population; and (ii) identifying potential avenues for future intervention, based on the Behavior Change Wheel framework. Method Eighteen ambulatory undergraduate students participated in semi-structured one-on-one interviews, using the Capability, Opportunity, Motivation, Behavior (COM-B) model and the complementary Theoretical Domains Framework (TDF) as the theoretical framework. Data were analyzed using a directed content analysis approach, followed by inductive thematic analysis. Results All COM-B components and eight TDF domains were identified as relevant for influencing the target behavior. Conclusion Findings suggest that interventions and policies aimed at reducing prolonged sitting time in university students should: (i) raise awareness about negative health implications; (ii) address productivity concerns; (iii) provide training in behavioral self-regulation; (iv) use external reminders; (v) implement habit formation techniques; and (vi) promote social acceptability for breaking up sitting

A review of 28 free animal tracking software: current features and limitations

This version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1038/s41684-021-00811-1[Abstract]: Well-quantified laboratory studies can provide a fundamental understanding of animal behavior in ecology, ethology and ecotoxicology research. These types of studies require observation and tracking of each animal in well-controlled and defined arenas, often for long timescales. Thus, these experiments produce long time series and a vast amount of data that require the use of software applications to automate the analysis and reduce manual annotation. In this review, we examine 28 free software applications for animal tracking to guide researchers in selecting the software that might best suit a particular experiment. We also review the algorithms in the tracking pipeline of the applications, explain how specific techniques can fit different experiments, and finally, expose each approach’s weaknesses and strengths. Our in-depth review includes last update, type of platform, user-friendliness, off- or online video acquisition, calibration method, background subtraction and segmentation method, species, multiple arenas, multiple animals, identity preservation, manual identity correction, data analysis and extra features. We found, for example, that out of 28 programs, only 3 include a calibration algorithm to reduce image distortion and perspective problems that affect accuracy and can result in substantial errors when analyzing trajectories and extracting mobility or explored distance. In addition, only 4 programs can directly export in-depth tracking and analysis metrics, only 5 are suited for tracking multiple unmarked animals for more than a few seconds and only 11 have been updated in the period 2019–2021