Retaining memory after hibernation: performance varies independently of activity levels in wild grey mouse (advance online)

Abstract Hibernation, a hypometabolic state associated with low body temperature and reduced metabolic and activity rates, represents one adaptation to harsh seasonal environmental conditions. As a consequence of hypometabolism, energetically costly neuronal processes also ought to be reduced. Since active neuronal pathways are prerequisites for learning and memory, and because previous studies revealed variable patterns, it remains unclear whether and how hibernating animals retain memories, however. Here, we investigated the effect of seasonally reduced activity on memory retention in 36 wild grey mouse lemurs (Microcebus murinus). Data from activity loggers confirmed that female grey mouse lemurs entered hibernation during the cool dry season, whereas males exhibited episodic bursts of activity throughout the austral winter. Thus, compared to males, we predicted females to show lower memory retention of visual and spatial stimulus?reward associations learned before hibernation. In contrast to our prediction, all individuals performed worse in the post-hibernation testing session in both types of tests, compared to the pre-hibernation learning session, and males (N =?11) performed even worse than females (N =?14) in the post-hibernation testing session. Although females (N =?9) equipped with activity loggers tended to be less active than males (N =?4), sex-specific activity levels were unrelated to interindividual differences in memory retention. Hence, the post-hibernation decrease in performance of grey mouse lemurs may reflect a more general disability to retain stimulus?reward associations than a lack of memory retention due to seasonal hypometabolism, as suggested for some species of bats or squirrels

Vanishing Fe 3d orbital moments in single-crystalline magnetite

We show detailed magnetic absorption spectroscopy results of an in situ cleaved high quality single crystal of magnetite. In addition the experimental setup was carefully optimized to reduce drift, self absorption, and offset phenomena as far as possible. In strong contradiction to recently published data, our observed orbital moments are nearly vanishing and the spin moments are quite close to the integer values proposed by theory. This very important issue supports the half metallic full spin polarized picture of magnetite.Comment: 7 pages, 4 figure

The interstellar oxygen-K absorption edge as observed by XMM-Newton

High resolution X-ray spectra of the Reflection Grating Spectrometer (RGS) on board the XMM satellite are used to resolve the oxygen K absorption edge. By combining spectra of low and high extinction sources, the observed absorption edge can be split in the true interstellar (ISM) extinction and the instrumental absorption. The detailed ISM edge structure closely follows the edge structure of neutral oxygen as derived by theoretical R-matrix calculations. However, the position of the theoretical edge requires a wavelength shift. In addition the detailed instrumental RGS absorption edge structure is presented. All results are verified by comparing to a subset of Chandra LETG-HRC observations.Comment: LaTeX2e A&A style, 10 pages, 12 postscript figures, accepted for publication in Astronomy and Astrophysic

Hot dense capsule implosion cores produced by z-pinch dynamic hohlraum radiation

Hot dense capsule implosions driven by z-pinch x-rays have been measured for the first time. A ~220 eV dynamic hohlraum imploded 1.7-2.1 mm diameter gas-filled CH capsules which absorbed up to ~20 kJ of x-rays. Argon tracer atom spectra were used to measure the Te~ 1keV electron temperature and the ne ~ 1-4 x10^23 cm-3 electron density. Spectra from multiple directions provide core symmetry estimates. Computer simulations agree well with the peak compression values of Te, ne, and symmetry, indicating reasonable understanding of the hohlraum and implosion physics.Comment: submitted to Phys. Rev. Let

Signatures of the charge density wave collective mode in the infrared optical response of VSe₂

We present a detailed study of the bulk electronic structure of high quality VSe$_{2}$ single crystals using optical spectroscopy. Upon entering the charge density wave phase below the critical temperature of 112 K, the optical conductivity of VSe$_2$ undergoes a significant rearrangement. A Drude response present above the critical temperature is suppressed while a new interband transition appears around 0.07\,eV. From our analysis, we estimate that part of the spectral weight of the Drude response is transferred to a collective mode of the CDW phase. The remaining normal state charge dynamics appears to become strongly damped by interactions with the lattice as evidenced by a mass enhancement factor m$^{*}$/m$\approx$3. In addition to the changes taking place in the electronic structure, we observe the emergence of infrared active phonons below the critical temperature associated with the 4a x 4a lattice reconstruction

Corporal diagnostic work and diagnostic spaces: Clinicians' use of space and bodies during diagnosis

© 2015 The Authors. Sociology of Health & Illness © 2015 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.An emerging body of literature in sociology has demonstrated that diagnosis is a useful focal point for understanding the social dimensions of health and illness. This article contributes to this work by drawing attention to the relationship between diagnostic spaces and the way in which clinicians use their own bodies during the diagnostic process. As a case study, we draw upon fieldwork conducted with a multidisciplinary clinical team providing deep brain stimulation (DBS) to treat children with a movement disorder called dystonia. Interviews were conducted with team members and diagnostic examinations were observed. We illustrate that clinicians use communicative body work and verbal communication to transform a material terrain into diagnostic space, and we illustrate how this diagnostic space configures forms of embodied 'sensing-and-acting' within. We argue that a 'diagnosis' can be conceptualised as emerging from an interaction in which space, the clinician-body, and the patient-body (or body-part) mutually configure one another. By conceptualising diagnosis in this way, this article draws attention to the corporal bases of diagnostic power and counters Cartesian-like accounts of clinical work in which the patient-body is objectified by a disembodied medical discourse.The Wellcome Trust (Wellcome Trust Biomedical Strategic Award 086034

Optimizing cell viability in dropletbased cell deposition

Biofabrication commonly involves the use of liquid droplets to transport cells to the printed structure. However, the viability of the cells after impact is poorly controlled and understood, hampering applications including cell spraying, inkjet bioprinting, and laser-assisted cell transfer. Here, we present an analytical model describing the cell viability after impact as a function of the cell-surrounding droplet characteristics. The model connects (1) the cell survival as a function of cell membrane elongation, (2) the membrane elongation as a function of the cell-containing droplet size and velocity, and (3) the substrate properties. The model is validated by cell viability measurements in cell spraying, which is a method for biofabrication and used for the treatment of burn wounds. The results allow for rational optimization of any droplet-based cell deposition technology, and we include practical suggestions to improve the cell viability in cell spraying

Ultrafast Spectroscopy of [Mn(CO)3] Complexes: Tuning the Kinetics of Light-Driven CO Release and Solvent Binding

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.inorgchem.9b02758.Manganese tricarbonyl complexes are promising catalysts for CO2 reduction, but complexes in this family are often photo-sensitive and decompose rapidly upon exposure to visible light. In this report, synthetic and photochemical studies probe the initial steps of light-driven speciation for Mn(CO)3(Rbpy)Br complexes bearing a range of 4,4′-disubstituted-2,2′-bipyridyl ligands (Rbpy, R = tBu, H, CF3, NO2). Transient absorption spectroscopy measurements for the Mn(CO)3(Rbpy)Br coordination compounds with R = tBu, H, and CF3 in acetonitrile reveal ultrafast loss of a CO ligand on the femtosecond timescale, followed by solvent coordination on the picosecond timescale. The Mn(CO)3(NO2bpy)Br complex is unique among the four compounds in having a longer-lived excited state that does not undergo CO release or the subsequent solvent coordination. The kinetics of photolysis and solvent coordination for the light-sensitive complexes depend on the electronic properties of the di-substituted bipyridyl ligand. The results implicate roles for both metal-to-ligand charge transfer (MLCT) and dissociative ligand field (dd) excited states in the ultrafast photochemistry. Taken together, the findings suggest that more robust catalysts could be prepared with appropriately designed complexes that avoid crossing between the excited states that drive photochemical CO loss.Hall Chemical Research Fund at the University of KansasU.S. National Science Foundation (CHE-1151555)NIH T32 GM008545-2