Seeing and Perceptual Content

There are two widely held assumptions about perception: ascriber-independence (the view that the facts regarding what a subject perceives, as well as what her perceptual states represent, are independent of the interests of those attributing the relevant states to her), and determinacy (the view that perceptual content is relatively determinate). I challenge both of these assumptions, and develop a new approach to perceptual content, with implications for theories of mental content more broadly. In chapter one, I address the question of whether, in addition to low-level features, vision represents ordinary objects. I argue that there is just no fact of the matter. In chapter two, I defend a contextualist account of object-seeing: one that illuminates the inscrutability thesis defended in chapter 1. Finally, in chapter three, I address the question of whether the contents of vision are object-dependent. I argue that it is simply indeterminate whether the particulars we perceive enter into the contents of our perceptual states. I then address various worries about the indeterminacy thesis, arguing that we should embrace the view that there are multiple, equally acceptable, ways to assign contents to our perceptual experiences

Thresholdless Coherent Light Scattering from Subband-polaritons in a Strongly-Coupled Microcavity

We study a "strongly-coupled" (SC) polariton system formed between the atom-like intersubband transitions in a semiconductor nanostructure and the THz optical modes that are localised at the edges of a gold aperture. The polaritons can be excited optically, by incoherent excitation with bandgap radiation, and we find that they also coherently scatter the same input laser, to give strikingly sharp "sideband" (SB) spectral peaks in the backscattered spectrum. The SB intensity is a sensitive track of the polariton density and they can be detected down to a quantum noise floor that is more than 2500 times lower than the excitation thresholds of comparable quantum cascade laser diodes. Compared with other coherent scattering mechanisms, higher order SB scattering events are readily observable, and we speculate that the effect may find utility as a passive all-optical wavelength shifting mechanism in telecommunications systems.Comment: 4 page

The architecture of EMC reveals a path for membrane protein insertion.

Funder: Boehringer Ingelheim Fonds; FundRef: http://dx.doi.org/10.13039/501100001645Funder: Naito Foundation; FundRef: http://dx.doi.org/10.13039/100007428Funder: Japanese Biochemical SocietyApproximately 25% of eukaryotic genes code for integral membrane proteins that are assembled at the endoplasmic reticulum. An abundant and widely conserved multi-protein complex termed EMC has been implicated in membrane protein biogenesis, but its mechanism of action is poorly understood. Here, we define the composition and architecture of human EMC using biochemical assays, crystallography of individual subunits, site-specific photocrosslinking, and cryo-EM reconstruction. Our results suggest that EMC's cytosolic domain contains a large, moderately hydrophobic vestibule that can bind a substrate's transmembrane domain (TMD). The cytosolic vestibule leads into a lumenally-sealed, lipid-exposed intramembrane groove large enough to accommodate a single substrate TMD. A gap between the cytosolic vestibule and intramembrane groove provides a potential path for substrate egress from EMC. These findings suggest how EMC facilitates energy-independent membrane insertion of TMDs, explain why only short lumenal domains are translocated by EMC, and constrain models of EMC's proposed chaperone function

The architecture of EMC reveals a path for membrane protein insertion

Approximately 25% of eukaryotic genes code for integral membrane proteins that are assembled at the endoplasmic reticulum. An abundant and widely conserved multi-protein complex termed EMC has been implicated in membrane protein biogenesis, but its mechanism of action is poorly understood. Here, we define the composition and architecture of human EMC using biochemical assays, crystallography of individual subunits, site-specific photocrosslinking, and cryo-EM reconstruction. Our results suggest that EMC’s cytosolic domain contains a large, moderately hydrophobic vestibule that can bind a substrate’s transmembrane domain (TMD). The cytosolic vestibule leads into a lumenally-sealed, lipid-exposed intramembrane groove large enough to accommodate a single substrate TMD. A gap between the cytosolic vestibule and intramembrane groove provides a potential path for substrate egress from EMC. These findings suggest how EMC facilitates energy-independent membrane insertion of TMDs, explain why only short lumenal domains are translocated by EMC, and constrain models of EMC’s proposed chaperone function

The architecture of EMC reveals a path for membrane protein insertion

Approximately 25% of eukaryotic genes code for integral membrane proteins that are assembled at the endoplasmic reticulum. An abundant and widely conserved multi-protein complex termed EMC has been implicated in membrane protein biogenesis, but its mechanism of action is poorly understood. Here, we define the composition and architecture of human EMC using biochemical assays, crystallography of individual subunits, site-specific photocrosslinking, and cryo-EM reconstruction. Our results suggest that EMC’s cytosolic domain contains a large, moderately hydrophobic vestibule that can bind a substrate’s transmembrane domain (TMD). The cytosolic vestibule leads into a lumenally-sealed, lipid-exposed intramembrane groove large enough to accommodate a single substrate TMD. A gap between the cytosolic vestibule and intramembrane groove provides a potential path for substrate egress from EMC. These findings suggest how EMC facilitates energy-independent membrane insertion of TMDs, explain why only short lumenal domains are translocated by EMC, and constrain models of EMC’s proposed chaperone function

Screening current effects in Josephson junction arrays

The purpose of this work is to compare the dynamics of arrays of Josephson junctions in presence of magnetic field in two different frameworks: the so called XY frustrated model with no self inductance and an approach that takes into account the screening currents (considering self inductances only). We show that while for a range of parameters the simpler model is sufficiently accurate, in a region of the parameter space solutions arise that are not contained in the XY model equations.Comment: Figures available from the author

The architecture of EMC reveals a path for membrane protein insertion

Approximately 25% of eukaryotic genes code for integral membrane proteins that are assembled at the endoplasmic reticulum. An abundant and widely conserved multi-protein complex termed EMC has been implicated in membrane protein biogenesis, but its mechanism of action is poorly understood. Here, we define the composition and architecture of human EMC using biochemical assays, crystallography of individual subunits, site-specific photocrosslinking, and cryo-EM reconstruction. Our results suggest that EMC’s cytosolic domain contains a large, moderately hydrophobic vestibule that can bind a substrate’s transmembrane domain (TMD). The cytosolic vestibule leads into a lumenally-sealed, lipid-exposed intramembrane groove large enough to accommodate a single substrate TMD. A gap between the cytosolic vestibule and intramembrane groove provides a potential path for substrate egress from EMC. These findings suggest how EMC facilitates energy-independent membrane insertion of TMDs, explain why only short lumenal domains are translocated by EMC, and constrain models of EMC’s proposed chaperone function

Embodiment and social distancing: Practices

A collection of five video essays on embodiment and social distancing, with a focus on practices. RAFFAELE RUFO, “Dancing Together Alone: What Can Be Learnt About Connection When Touch is Forbidden?” (00:10): This video essay reengages the experience of leading a dance improvisation practice on Zoom during the Coronavirus lockdown. As a tango and contact improvisation dancer confined at home, I felt urged to ask: what can be learnt about embodied connection when we are not allowed to physically touch each other? ANAT BEN-DAVID AND CATHARINE ANNE CARY, “What’s the Matter?” (05:54): Performers, scenographers, musicians and wordsmiths Anat Ben-David and Catharine Cary improvised via ZOOM every Tuesday from March to May 2020. Embracing latency, zoom’s affordances, limitations and distortions, they show here excerpts of a transformed body of work. Separated by 5218 km, given the Covid-19 situation, it could have been 200 meters. DEANNA BORLAND-SENTINELLA, LOUISE GWENNETH PHILLIPS, AND ALICE OWEN, “Virtually Embodied: Remembering the Sensations of Connection” (12:04): This film is an exploration of the body: Being present to place and time; being aware of connection with others, whether that be in reality or through virtual connection and sensorial memory. NATHALIE S. FARI, “Notes from a zoom 5Rhythms® session” (17:10): By using a three-hour 5Rhythms® online workshop as basis, this video sheds light into the ways in which the practitioner interacts and engages with both one’s own bodily awareness and the new technology of zoom. AMBERBECKYCREATIVE, “Sheltering in Spacetimematterings: Audiovisual Considerations of Social Distancing” (22:42): Two socially distant authors glitch audiovisual intra-actions through embodied (dis)orientations of space, time, and matter in past/present/future collapsed to (re)present what it’s like to shelter in place during the COVID-19 pandemic

Late outcome of repair of congenital coronary artery fistulas—a word of caution

ObjectivesWe reviewed our experience with repair of congenital coronary artery fistulas.MethodsFrom June 1983 to December 2009, 46 patients (median age, 59 years; range, 1-84 years) underwent surgical repair. The presenting symptoms included angina in 16 patients (35%), congestive heart failure in 11 (24%), and bacterial endocarditis in 5 (11%). Preoperatively, 9 patients (20%) had at least moderate tricuspid regurgitation. Coronary artery dominance was right in 38 patients (83%). Coronary artery aneurysms were found in 8 patients (17%). The most common pattern was right coronary artery-to-coronary sinus fistula (18 patients, 39%); 11 patients had (23%) more than 1 fistula. One patient had undergone previous coil embolization.ResultsCardiopulmonary bypass was used in 39 patients (85%), with extracardiac and intracardiac repair performed in 30 (65%) and 16 (35%), respectively. The most common associated procedures were coronary artery bypass in 13 patients (28%). Early mortality occurred in 1 patient (2%). Postoperative myocardial infarction occurred in 5 patients (11%); 4 of these patients underwent simple ligation or division of their fistulas. The mean follow-up was 6 ± 5.8 years (maximum, 22 years). Late mortality occurred in 11 patients (24%). Two patients underwent reoperation for severe tricuspid regurgitation. Survival was significantly reduced compared with the age- and gender-matched population (P = .03). Residual fistulas were detected in 3 patients (6%), with no reintervention needed.ConclusionsPerioperative myocardial infarction is an important complication of ligation of coronary artery fistulas and can contribute to reduced late survival. The tricuspid valve should be evaluated carefully at repair because of the relatively high rate of residual regurgitation in survivors

Making predictions in the multiverse

I describe reasons to think we are living in an eternally inflating multiverse where the observable "constants" of nature vary from place to place. The major obstacle to making predictions in this context is that we must regulate the infinities of eternal inflation. I review a number of proposed regulators, or measures. Recent work has ruled out a number of measures by showing that they conflict with observation, and focused attention on a few proposals. Further, several different measures have been shown to be equivalent. I describe some of the many nontrivial tests these measures will face as we learn more from theory, experiment, and observation.Comment: 20 pages, 3 figures; invited review for Classical and Quantum Gravity; v2: references improve