53 research outputs found
SPRINT, STAR: Két Hatékony Kezelési Protokoll Az Intenzív Osztályon Kezelt Betegek Vércukorszintjének Normoglikémiás Tartományban Tartásához
(In Hungarian) Paper P0
Different output properties of perisomatic region-targeting interneurons in the basal amygdala
Perisomatic region of principal neurons in
the
cortical regions is
innervated
by three types of
GABAergic interneurons, including parvalbumi
n
-
containing basket cells (PVBCs) and axo
-
axonic cells (AACs), as well as cholecystokinin and type 1 cannabinoid receptor
-
expressing
basket cells (CCK/CB1BCs). These perisomatic inhibitory cell types can also be found in the
basal
nucleus
of the amygdala,
however, their output properties are largely unknown. Here,
we performed whole
-
cell recordings in
morphologically
identified interneurons in slices
prepared from transgenic mice, in which the GABAergic cells could be
selectively
targeted.
By investigating
the passive and active membrane properties of interneurons
located within
the bas
al amygdala
,
w
e observed that the three interneuron types had distinct single
-
cell
properties
.
For instance,
the
input resistance, spike rate, accommodation
in discharge rate
,
or
after
-
hyperpolarization width at the half maximal amplitude separated the three interneuron
types
.
Furthermore
, we performed paired recordings from interneurons and principal
neurons
to uncover the basic features of unitary inhibitory postsynaptic curr
ents (uIPSCs). We found
that, although there was no difference in the magnitude of responses measured in the principal
neurons
, the uIPSCs originated from the distinct interneuron types differed in the rise time,
failure rate, latency and short
-
term dynami
cs. Moreover, the asynchronous transmitter release
induced by a train of action potentials was typical for the output synapses of CCK/CB1BCs.
Our results suggest that
, although the
three perisomatic inhibitory cell types
give rise to
uIPSCs with similar ma
gnitude, their distinct
spiking
characteristics may help to accomplish
specific function in amygdala operation
Optical Properties of Layered Superconductors near the Josephson Plasma Resonance
We study the optical properties of crystals with spatial dispersion and show
that the usual Fresnel approach becomes invalid near frequencies where the
group velocity of the wave packets inside the crystal vanishes. Near these
special frequencies the reflectivity depends on the atomic structure of the
crystal provided that disorder and dissipation are very low. This is
demonstrated explicitly by a detailed study of layered superconductors with
identical or two different alternating junctions in the frequency range near
the Josephson plasma resonance. Accounting for both inductive and charge
coupling of the intrinsic junctions, we show that multiple modes are excited
inside the crystal by the incident light, determine their relative amplitude by
the microscopic calculation of the additional boundary conditions and finally
obtain the reflectivity.
Spatial dispersion also provides a novel method to stop light pulses, which
has possible applications for quantum information processing and the artificial
creation of event horizons in a solid.Comment: 25 pages, 20 figures, submitted to Phys. Rev.
Spi-OPS : Spitzer and CHEOPS confirm the near-polar orbit of MASCARA-1 b and reveal a hint of dayside reflection
A.C.C. and T.G.W. acknowledge support from STFC consolidated grant number ST/M001296/1.Context. The light curves of tidally locked hot Jupiters transiting fast-rotating, early-type stars are a rich source of information about both the planet and star, with full-phase coverage enabling a detailed atmospheric characterisation of the planet. Although it is possible to determine the true spin–orbit angle Ψ – a notoriously difficult parameter to measure – from any transit asymmetry resulting from gravity darkening induced by the stellar rotation, the correlations that exist between the transit parameters have led to large disagreements in published values of Ψ for some systems. Aims. We aimed to study these phenomena in the light curves of the ultra-hot Jupiter MASCARA-1 b, which is characteristically similar to well-studied contemporaries such as KELT-9 b and WASP-33 b. Methods. We obtained optical CHaracterising ExOPlanet Satellite (CHEOPS) transit and occultation light curves of MASCARA-1 b, and analysed them jointly with a Spitzer/IRAC 4.5 μm full-phase curve to model the asymmetric transits, occultations, and phase-dependent flux modulation. For the latter, we employed a novel physics-driven approach to jointly fit the phase modulation by generating a single 2D temperature map and integrating it over the two bandpasses as a function of phase to account for the differing planet–star flux contrasts. The reflected light component was modelled using the general ab initio solution for a semi-infinite atmosphere. Results. When fitting the CHEOPS and Spitzer transits together, the degeneracies are greatly diminished and return results consistent with previously published Doppler tomography. Placing priors informed by the tomography achieves even better precision, allowing a determination of Ψ = 72.1−2.4+2.5 deg. From the occultations and phase variations, we derived dayside and nightside temperatures of 3062−68+66 K and 1720 ± 330 K, respectively.Our retrieval suggests that the dayside emission spectrum closely follows that of a blackbody. As the CHEOPS occultation is too deep to be attributed to blackbody flux alone, we could separately derive geometric albedo Ag = 0.171−0.068+0.066 and spherical albedo As = 0.266−0.100+0.097 from the CHEOPS data, and Bond albedoAB = 0.057−0.101+0.083 from the Spitzer phase curve.Although small, the Ag and As indicate that MASCARA-1 b is more reflective than most other ultra-hot Jupiters, where H− absorption is expected to dominate. Conclusions. Where possible, priors informed by Doppler tomography should be used when fitting transits of fast-rotating stars, though multi-colour photometry may also unlock an accurate measurement of Ψ. Our approach to modelling the phase variations at different wavelengths provides a template for how to separate thermal emission from reflected light in spectrally resolved James Webb Space Telescope phase curve data.Publisher PDFPeer reviewe
A CHEOPS-enhanced view of the HD 3167 system
A. C. C. and T. G. W. acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1.Much remains to be understood about the nature of exoplanets smaller than Neptune, most of which have been discovered in compact multi-planet systems. With its inner ultra-short period planet b aligned with the star and two larger outer planets d-c on polar orbits, the multi-planet system HD 3167 features a peculiar architecture and offers the possibility to investigate both dynamical and atmospheric evolution processes. To this purpose we combined multiple datasets of transit photometry and radial velocimetry (RV) to revise the properties of the system and inform models of its planets. This effort was spearheaded by CHEOPS observations of HD 3167b, which appear inconsistent with a purely rocky composition despite its extreme irradiation. Overall the precision on the planetary orbital periods are improved by an order of magnitude, and the uncertainties on the densities of the transiting planets b and c are decreased by a factor of 3. Internal structure and atmospheric simulations draw a contrasting picture between HD 3167d, likely a rocky super-Earth that lost its atmosphere through photo-evaporation, and HD 3167c, a mini-Neptune that kept a substantial primordial gaseous envelope. We detect a fourth, more massive planet on a larger orbit, likely coplanar with HD 3167d-c. Dynamical simulations indeed show that the outer planetary system d-c-e was tilted, as a whole, early in the system history, when HD 3167b was still dominated by the star influence and maintained its aligned orbit. RV data and direct imaging rule out that the companion that could be responsible for the present-day architecture is still bound to the HD 3167 system. Similar global studies of multi-planet systems will tell how many share the peculiar properties of the HD 3167 system, which remains a target of choice for follow-up observations and simulations. © 2022 EDP Sciences. All rights reserved.Publisher PDFPeer reviewe
Transit detection of the long-period volatile-rich super-Earth ν^2 Lupi d with CHEOPS
Stars and planetary system
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