An HST/WFC3-UVIS View of the Starburst in the Cool Core of the Phoenix Cluster

We present Hubble Space Telescope Wide Field Camera 3 observations of the core of the Phoenix Cluster SPT-CLJ2344-4243 in five broadband filters spanning rest-frame 1000--5500A. These observations reveal complex, filamentary blue emission, extending for >40kpc from the brightest cluster galaxy. We observe an underlying, diffuse population of old stars, following an r^1/4 distribution, confirming that this system is somewhat relaxed. The spectral energy distribution in the inner part of the galaxy, as well as along the extended filaments, is a smooth continuum and is consistent with that of a star-forming galaxy, suggesting that the extended, filamentary emission is not due to the central AGN, either from a large-scale ionized outflow or scattered polarized UV emission, but rather a massive population of young stars. We estimate an extinction-corrected star formation rate of 798 +/- 42 Msun/yr, consistent with our earlier work based on low spatial resolution ultraviolet, optical, and infrared imaging. The lack of tidal features and multiple bulges, combine with the need for an exceptionally massive (>10^11 Msun) cold gas reservoir, suggest that this star formation is not the result of a merger of gas-rich galaxies. Instead, we propose that the high X-ray cooling rate of ~2700 Msun/yr is the origin of the cold gas reservoir. The combination of such a high cooling rate and the relatively weak radio source in the cluster core suggests that feedback has been unable to halt cooling in this system, leading to this tremendous burst of star formation.Comment: 7 pages, 5 figures, accepted for publication in ApJ Letter

Beamline design and performance

The Energy Materials In-Situ Laboratory Berlin (EMIL) at BESSY-II is currently under construction. Two canted undulators for soft- and hard X-rays will be installed into the BESSY II storage ring in one straight section, complex beamlines with more than twenty optical elements will be set up and a new laboratory building attached to BESSY II will host three endstations and a large UHV-transfer system connecting various HV- and UHV-deposition systems. The undulators, UE48 and U17, provide a broad energy spectrum of 80 - 10000 eV, of which the harder radiation (>700 eV) is provided by a cryogenic in- vacuum device. Three monochromators (two plane grating monochromators (PGM) and one LN2-cooled double crystal monochromator (DCM)) disperse the radiation into separate pathways of 65 m length, while downstream of the monochromators split-mirror chambers distribute the photon beam to one (or simultaneously to two) of five upcoming endstations. Three of these endstations are designed for the full energy range with spatial overlap of the soft and hard foci, whereas one endstation (PEEM) uses only the soft and another one (PINK) only the hard branch, respectively

Raman spectroscopy as probe of nanometer-scale strain variations in graphene

Confocal Raman spectroscopy is a versatile, non-invasive investigation tool and a major workhorse for graphene characterization. Here we show that the experimentally observed Raman 2D line width is a measure of nanometer-scale strain variations in graphene. By investigating the relation between the G and 2D line at high magnetic fields we find that the 2D line width contains valuable information on nanometer-scale flatness and lattice deformations of graphene, making it a good quantity for classifying the structural quality of graphene even at zero magnetic field.Comment: 7 pages, 4 figure

Single-qubit unitary gates by graph scattering

We consider the effects of plane-wave states scattering off finite graphs, as an approach to implementing single-qubit unitary operations within the continuous-time quantum walk framework of universal quantum computation. Four semi-infinite tails are attached at arbitrary points of a given graph, representing the input and output registers of a single qubit. For a range of momentum eigenstates, we enumerate all of the graphs with up to $n=9$ vertices for which the scattering implements a single-qubit gate. As $n$ increases, the number of new unitary operations increases exponentially, and for $n>6$ the majority correspond to rotations about axes distributed roughly uniformly across the Bloch sphere. Rotations by both rational and irrational multiples of $\pi$ are found.Comment: 8 pages, 7 figure

Image of the Energy Gap Anisotropy in the Vibrational Spectum of a High Temperature Superconductor

We present a new method of determining the anisotropy of the gap function in layered high-Tc superconductors. Careful inelastic neutron scattering measurements at low temperature of the phonon dispersion curves in the (100) direction in La_(1.85)Sr_(.15)CuO_4 would determine whether the gap is predominately s-wave or d-wave. We also propose an experiment to determine the gap at each point on a quasi-two-dimensional Fermi surface.Comment: 12 pages + 2 figures (included

Relocating obesity with multiauthor ethnography

Reflecting on the World Health Organization’s (WHO) account of obesity and recent developments in ethnography, I advocate for a collaborative, multiauthor approach to studying obesity and, more broadly, chronic disease. To illustrate this, I show how recent ethnographies of obesity and metabolism have convincingly challenged and reframed the WHO’s account of obesity. I further suggest that future ethnographic studies of obesity (and chronic disease) could expand their analytical scope – without sacrificing a critical and people-centred approach – through coordination and collaboration. A multiauthor approach to obesity research would increase the capacity of ethnography to demonstrate the many conditions that must be fulfilled for a person to become ‘obese’, productively foregrounding how ‘obesity’ emerges out of a web of social, economic, political, chemical, and historical connections. This would enable a more comprehensive understanding of the uneven emergence of obesity (and other chronic diseases) worldwide

Characterising Pulmonary Plasmacytoid Dendritic Cells

INTRODUCTION The lung’s exceptionally large surface area, and minimal distance between the blood and external environment leave it vulnerable to infection. Most importantly is-that pulmonary infections can often lead to severe complications such as sepsis or septic shock. We are interested in pulmonary Plasmacytoid Dendritic Cells (pDC) which in other organs of the body have been shown to be critical in fighting severe infection through the initiation of inflammation and the modulation of T cell responses [1, 2]. We hypothesize that pDC, are prepositioned in the lung and are capable of rapidly responding to pathogenic insults. METHODS Lungs from the mouse were exsanguinated and excised from the mouse and prepared as a whole lung homogenate. The cells were then Fc blocked and then stained with the antibody cocktail. Following the staining, the cells were analysed using flow cytometry. RESULTS Using flow-cytometry, we have identified pDC using the cell surface markers PDCA-1+ and Siglec-H+ within exsanguinated unstimulated whole lung homogenates.  Analysing the anatomical locations of lung pDC revealed at baseline, pDC are almost exclusively located in the pulmonary vasculature with a small population in the lung parenchyma and none within the alveolus. pDC make up 0.5 % of total CD45+ pulmonary leukocytes.  Stimulating the lung with pathogen associated molecular patterns that either directly or indirectly activate pDC demonstrated that early on during inflammation the absolute number of pDC does not change, suggesting they are not recruitable. Following either stimulation, the population of PDCA-1+ cells increased; however, using our more rigorous definition of pDC by employing multiple cell surface markers we discovered that the true pDC population (PDCA-1+/Siglec-H+) did not change in number. Under unstimulated conditions, PDCA-1+ pDC were visualized within the vasculature. These cells crawled along the endothelium and were not part of the blood cellular blood flow. Following 24 hours after stimulation with a TLR 9 agonist, an increase in the total number of the PDCA-1+ was observed. The PDCA-1+ cells displayed a mix of a crawling and stationary phenotype. DISCUSSION AND CONCLUSIONS We have examined in detail our current definitions of pDC, the phenotypic markers used in the identification of them, their anatomical location within the lung, and finally the effects of two TLR agonists on pDC. We created an assay to identify the anatomical locations of pulmonary leukocytes, and developed methods to identify the roles that these cells play in pulmonary host defence. We now know that PDCA-1 is not an effective marker for pDC during inflammatory conditions and that a rigorous definition of pDC is needed to identify them during inflammatory conditions. We made the novel observation that pDC, upon stimulation will react differently depending on the stimuli, which means they display plasticity in their roles within the hierarchy of host defence. The findings in this paper provides the basis for further insight into the nature of pulmonary pDC and their roles in pulmonary inflammation. We will explore these exciting new avenues by asking questions regarding the roles and interactions which pDC have in the initiation of severe pneumonia, and its functions during. This work will allow us to continue to investigate the unknown roles and functions that pDC play during pulmonary inflammation, which will reveal exciting new pathways to treat severe pneumonia, or pulmonary inflammation