Schrijver graphs and projective quadrangulations

In a recent paper [J. Combin. Theory Ser. B}, 113 (2015), pp. 1-17], the authors have extended the concept of quadrangulation of a surface to higher dimension, and showed that every quadrangulation of the $n$-dimensional projective space $P^n$ is at least $(n+2)$-chromatic, unless it is bipartite. They conjectured that for any integers $k\geq 1$ and $n\geq 2k+1$, the Schrijver graph $SG(n,k)$ contains a spanning subgraph which is a quadrangulation of $P^{n-2k}$. The purpose of this paper is to prove the conjecture

Transient topographies: a photographic languaje for impermanence

The Glass/Wood photographic project started as a research initiative by architectural photographer Erieta Attali under the auspices of Melbourne RMIT’s Doctorate program. This paper examines the discussion that led to the project’s conception, the process behind it and finally the outcome: a case-study monograph by the same name. The aim is to demonstrate how a photographic narrative can articulate an architectural argument and feed back into the design discourse, transgressing the limits between documentation and interpretation of architecture. Attali photographed Glass/Wood in New Canaan, Connecticut, a guesthouse extension by Kengo Kuma in 2010 to an existing modernist pavilion buried deep within a deciduous forest, in the course of two years. As the passage of eight seasons narrates the continuity between landscape and architecture, both architect’s and photographer’s ambitions become apparent: architecture that dissolves into the landscape and photography as a medium that communicates shifting relations instead of static, iconic images. The challenge we faced was how to communicate this synergy and the reciprocal processes that feed it. The paper has a tripartite structure. The first section examines Attali’s photographic language formulated in landscapes and archaeological sites, its translation into architecture and the narrative that it builds around Glass/Wood. The second section approaches the architectural subject of the series by dissecting some of the theoretical foundations of Kuma’s practice, especially its ambiguous relation to image representation in general and photography in particular. The third and final section recounts the creation of the Glass/Wood book through a multidisciplinary effort towards the articulation of a consistent visual argument in the form of a hybrid architectural/photographic monograph

Sound archaeology: terminology, Palaeolithic cave art and the soundscape

This article is focused on the ways that terminology describing the study of music and sound within archaeology has changed over time, and how this reflects developing methodologies, exploring the expectations and issues raised by the use of differing kinds of language to define and describe such work. It begins with a discussion of music archaeology, addressing the problems of using the term ‘music’ in an archaeological context. It continues with an examination of archaeoacoustics and acoustics, and an emphasis on sound rather than music. This leads on to a study of sound archaeology and soundscapes, pointing out that it is important to consider the complete acoustic ecology of an archaeological site, in order to identify its affordances, those possibilities offered by invariant acoustic properties. Using a case study from northern Spain, the paper suggests that all of these methodological approaches have merit, and that a project benefits from their integration

wallace 2: a shiny app for modeling species niches and distributions redesigned to facilitate expansion via module contributions

Released 4 years ago, the Wallace EcoMod application (R package wallace) provided an open-source and interactive platform for modeling species niches and distributions that served as a reproducible toolbox and educational resource. wallace harnesses R package tools documented in the literature and makes them available via a graphical user interface that runs analyses and returns code to document and reproduce them. Since its release, feedback from users and partners helped identify key areas for advancement, leading to the development of wallace 2. Following the vision of growth by community expansion, the core development team engaged with collaborators and undertook a major restructuring of the application to enable: simplified addition of custom modules to expand methodological options, analyses for multiple species in the same session, improved metadata features, new database connections, and saving/loading sessions. wallace 2 features nine new modules and added functionalities that facilitate data acquisition from climate-simulation, botanical and paleontological databases; custom data inputs; model metadata tracking; and citations for R packages used (to promote documentation and give credit to developers). Three of these modules compose a new component for environmental space analyses (e.g., niche overlap). This expansion was paired with outreach to the biogeography and biodiversity communities, including international presentations and workshops that take advantage of the software's extensive guidance text. Additionally, the advances extend accessibility with a cloud-computing implementation and include a suite of comprehensive unit tests. The features in wallace 2 greatly improve its expandability, breadth of analyses, and reproducibility options, including the use of emerging metadata standards. The new architecture serves as an example for other modular software, especially those developed using the rapidly proliferating R package shiny, by showcasing straightforward module ingestion and unit testing. Importantly, wallace 2 sets the stage for future expansions, including those enabling biodiversity estimation and threat assessments for conservation.journal articl

Stretching and Bending the Frame – Green Possibilities in Popular Romantic Narratives

This article examines frame theory, popular culture, and environmental values. Reviewing frame theory across journalism, communication studies, linguistics, and fine art, it will examine in particular ‘cultural framing’. Radical thought is invariably associated with the avant-garde, yet narrative or genre innovations in popular culture can also trigger ‘deeper’ cognitive shifts, potentially transforming ‘common culture’. Citing comics, films, and animation, the main example is popular music and how Björk and British Sea Power have subverted generic and acoustic conventions (e.g. melody), and music’s habitual romantic narratives, to re-frame human–nonhuman relationships ecologically. By stretching and manipulating frames, popular culture can adapt and engender environmental narratives for mass consumption

Three-layer model with absorption for conservative estimation of the maximum acoustic transmission coefficient through the human skull for transcranial ultrasound stimulation.

Transcranial ultrasound stimulation (TUS) has been shown to be a safe and effective technique for non-invasive superficial and deep brain stimulation. Safe and efficient translation to humans requires estimating the acoustic attenuation of the human skull. Nevertheless, there are no international guidelines for estimating the impact of the skull bone. A tissue independent, arbitrary derating was developed by the U.S. Food and Drug Administration to take into account tissue absorption (0.3 dB/cm-MHz) for diagnostic ultrasound. However, for the case of transcranial ultrasound imaging, the FDA model does not take into account the insertion loss induced by the skull bone, nor the absorption by brain tissue. Therefore, the estimated absorption is overly conservative which could potentially limit TUS applications if the same guidelines were to be adopted. Here we propose a three-layer model including bone absorption to calculate the maximum pressure transmission through the human skull for frequencies ranging between 100 kHz and 1.5 MHz. The calculated pressure transmission decreases with the frequency and the thickness of the bone, with peaks for each thickness corresponding to a multiple of half the wavelength. The 95th percentile maximum transmission was calculated over the accessible surface of 20 human skulls for 12 typical diameters of the ultrasound beam on the skull surface, and varies between 40% and 78%. To facilitate the safe adjustment of the acoustic pressure for short ultrasound pulses, such as transcranial imaging or transcranial ultrasound stimulation, a table summarizes the maximum pressure transmission for each ultrasound beam diameter and each frequency

Flows and cohesion: balancing capabilities across an expanded union

The dynamics of physical relocation of intellectual capital is seen in the flow of skilled workers across international boundaries and the internal movements within the increasingly integrated economy of the European Union. This article describes a research framework developed within the context of a globalised economy and its potential application to issues within the boundaries of the European Unio

Ultrasound modulation of macaque prefrontal cortex selectively alters credit assignment–related activity and behavior

Contains fulltext : 242467.pdf (Publisher’s version ) (Open Access)Credit assignment is the association of specific instances of reward to the specific events, such as a particular choice, that caused them. Without credit assignment, choice values reflect an approximate estimate of how good the environment was when the choice was made - the global reward state - rather than exactly which outcome the choice caused. Combined transcranial ultrasound stimulation (TUS) and functional magnetic resonance imaging in macaques demonstrate credit assignment–related activity in prefrontal area 47/12o, and when this signal was disrupted with TUS, choice value representations across the brain were impaired. As a consequence, behavior was no longer guided by choice value, and decision-making was poorer. By contrast, global reward state-related activity in the adjacent anterior insula remained intact and determined decision-making after prefrontal disruption.14 p

Orally Administrated Cinnamon Extract Reduces β-Amyloid Oligomerization and Corrects Cognitive Impairment in Alzheimer's Disease Animal Models

An increasing body of evidence indicates that accumulation of soluble oligomeric assemblies of β-amyloid polypeptide (Aβ) play a key role in Alzheimer's disease (AD) pathology. Specifically, 56 kDa oligomeric species were shown to be correlated with impaired cognitive function in AD model mice. Several reports have documented the inhibition of Aβ plaque formation by compounds from natural sources. Yet, evidence for the ability of common edible elements to modulate Aβ oligomerization remains an unmet challenge. Here we identify a natural substance, based on cinnamon extract (CEppt), which markedly inhibits the formation of toxic Aβ oligomers and prevents the toxicity of Aβ on neuronal PC12 cells. When administered to an AD fly model, CEppt rectified their reduced longevity, fully recovered their locomotion defects and totally abolished tetrameric species of Aβ in their brain. Furthermore, oral administration of CEppt to an aggressive AD transgenic mice model led to marked decrease in 56 kDa Aβ oligomers, reduction of plaques and improvement in cognitive behavior. Our results present a novel prophylactic approach for inhibition of toxic oligomeric Aβ species formation in AD through the utilization of a compound that is currently in use in human diet

Auditory Space, Ethics and Hospitality: ‘Noise’, Alterity and Care at the End of Life

This paper examines the limits and potential of hospitality through struggles over auditory space in care at the end of life. Using an account of noisy mourning in a multicultural hospice ward, the paper argues that the insurgent force of noise as corporeal generosity can produce impossible dilemmas for care, whilst also provoking surprising ethical relations and potentialities. Derrida’s ideas about the aporias of the gift and absolute responsibility are drawn upon to make sense of the pushy generosity of alterity as it is made to matter through sound