Autoethnography and activism:Movement, intensity and potential

In this short article, we pay attention to what an autoethnography might do. In relationality, we understand autoethnographic practices as assembling and dissembling bodies that are active in always territorializing space and in world making. They have the capacity to affect and be affected and, therefore, as performing and performative practices, they act and are acted upon. With Madison, we see these acts as activist, and we, therefore, see autoethnographic practice as always shifting, always about movement, intensity, and potentiality; it never resides, it lives in the creation of the next moment, the next step into the not yet known

Not all that <i>post</i>, not all that <i>new</i>:The disruption of challenging coloniality

What happens when, as scholars who have habitually been working with posthumanism and the new materialisms, we find ourselves summoned by thinkers who critique the covert coloniality present in these approaches? This work is the result of a year-long project where we set up the task of feeling our way through these critiques, exploring how they change our work and ourselves; and attempting to find a way of relating to the challenge of decoloniality. We use collaborative writing as an approach to delve into our encounters with readings, our own histories, and our ways of relating to the academy and each other. In this work, we start from our differing histories and positionalities—a Chilean woman and a British man; now colleagues and with a history of being a PhD supervisee-supervisor. Then, we grapple with how posthumanism/new materialism has neglected to think about how coloniality is entangled in who the “humans” it speaks to are and how it is further reproducing colonial dynamics of ethnocentric erasure that effectively do not allow it to go beyond the “human.” After considering possibilities of integration, reparation, survival, and refusal, we conclude it is crucial to reflexively acknowledge and work with our concrete positionalities and interests, thereby making our conceptualizations necessarily provincial, limited, and in some ways problematic. Otherwise, we run the risk of engulfing decolonial, postcolonial, anticolonial, and indigenous theories without any fundamental change, thus furthering coloniality

Confirming the Primarily Smooth Structure of the Vega Debris Disk at Millimeter Wavelengths

Clumpy structure in the debris disk around Vega has been previously reported at millimeter wavelengths and attributed to concentrations of dust grains trapped in resonances with an unseen planet. However, recent imaging at similar wavelengths with higher sensitivity has disputed the observed structure. We present three new millimeter wavelength observations that help to resolve the puzzling and contradictory observations. We have observed the Vega system with the Submillimeter Array (SMA) at a wavelength of 880 μm and an angular resolution of 5"; with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) at a wavelength of 1.3 mm and an angular resolution of 5"; and with the Green Bank Telescope (GBT) at a wavelength of 3.3 mm and angular resolution of 10". Despite high sensitivity and short baselines, we do not detect the Vega debris disk in either of the interferometric data sets (SMA and CARMA), which should be sensitive at high significance to clumpy structure based on previously reported observations. We obtain a marginal (3σ) detection of disk emission in the GBT data; the spatial distribution of the emission is not well constrained.We analyze the observations in the context of several different models, demonstrating that the observations are consistent with a smooth, broad, axisymmetric disk with inner radius 20–100 AU and width ≾50 AU. The interferometric data require that at least half of the 860 μm emission detected by previous single-dish observations with the James Clerk Maxwell Telescope be distributed axisymmetrically, ruling out strong contributions from flux concentrations on spatial scales of ≾100 AU. These observations support recent results from the Plateau de Bure Interferometer indicating that previous detections of clumpy structure in the Vega debris disk were spurious

Darkness and Silence: The Dis/connection of Writing Intimacy

Having written as a group for four years, we continue with an emblematic methodology of writing into the dark, writing into a space that has become an intensive, maturing, messy, ethically caring, collaborative venture of changing composition. Our collective self writes into a tentative anticipating trust in our presence though we are shaded in uncertainty. We have written with desire and labor, intimacy and work, stuttering and stumbling our way through what has been a vibrant and aging transatlantic writing group. And now we have come to the perhaps inevitable question about whether we want to continue writing together. This installment traces the complexity of that question. </jats:p

Hot debris dust around HD 106797

Photometry of the A0 V main-sequence star HD 106797 with AKARI and Gemini/T-ReCS is used to detect excess emission over the expected stellar photospheric emission between 10 and 20 micron, which is best attributed to hot circumstellar debris dust surrounding the star. The temperature of the debris dust is derived as Td ~ 190 K by assuming that the excess emission is approximated by a single temperature blackbody. The derived temperature suggests that the inner radius of the debris disk is ~ 14 AU. The fractional luminosity of the debris disk is 1000 times brighter than that of our own zodiacal cloud. The existence of such a large amount of hot dust around HD 106797 cannot be accounted for by a simple model of the steady state evolution of a debris disk due to collisions, and it is likely that transient events play a significant role. Our data also show a narrow spectral feature between 11 and 12 micron attributable to crystalline silicates, suggesting that dust heating has occurred during the formation and evolution of the debris disk of HD 106797.Comment: Accepted to ApJ Letters, 8 pages, 2 figure

Direct Imaging of Hippocampal Epileptiform Calcium Motifs Following Kainic Acid Administration in Freely Behaving Mice

Prolonged exposure to abnormally high calcium concentrations is thought to be a core mechanism underlying hippocampal damage in epileptic patients; however, no prior study has characterized calcium activity during seizures in the live, intact hippocampus. We have directly investigated this possibility by combining whole-brain electroencephalographic (EEG) measurements with microendoscopic calcium imaging of pyramidal cells in the CA1 hippocampal region of freely behaving mice treated with the pro-convulsant kainic acid (KA). We observed that KA administration led to systematic patterns of epileptiform calcium activity: a series of large-scale, intensifying flashes of increased calcium fluorescence concurrent with a cluster of low-amplitude EEG waveforms. This was accompanied by a steady increase in cellular calcium levels (>5 fold increase relative to the baseline), followed by an intense spreading calcium wave characterized by a 218% increase in global mean intensity of calcium fluorescence (n = 8, range [114 - 349%], p<10-4; t-test). The wave had no consistent EEG phenotype and occurred before the onset of motor convulsions. Similar changes in calcium activity were also observed in animals treated with 2 different proconvulsant agents, N-methyl-D-aspartate (NMDA) and pentylenetetrazol (PTZ), suggesting the measured changes in calcium dynamics are a signature of seizure activity rather than a KA-specific pathology. Additionally, despite reducing the behavioral severity of KA-induced seizures, the anticonvulsant drug valproate (VA, 300 mg/kg) did not modify the observed abnormalities in calcium dynamics. These results confirm the presence of pathological calcium activity preceding convulsive motor seizures and support calcium as a candidate signaling molecule in a pathway connecting seizures to subsequent cellular damage. Integrating in vivo calcium imaging with traditional assessment of seizures could potentially increase translatability of pharmacological intervention, leading to novel drug screening paradigms and therapeutics designed to target and abolish abnormal patterns of both electrical and calcium excitation