Impact of Saturn's rings on mission analysis for MJS 77

Mariner Jupiter-Saturn '77 mission objectives for Saturn are considered which affect the trajectory design and in particular the aim point at Saturn. These objectives include the following: (1) earth, sun occulation of Saturn, rings, and satellites; (2) close as possible to surface; (3) close as possible to rings; (4) close encounter with Titan (approximately 20,000 km); (5) close encounter with lapetus; (6) multiple satellite encounters; (7) post-Saturn trajectory to Uranus; and (8) post-Saturn trajectory toward solar apex

Quantum spin Hall effect in bound states in continuum

Moving the polarization of the incident wave along a meridian of the Poincaré sphere, experimentally we show that the coupling with the fundamental Bloch's surface waves of the mode, provide a spatially coherent, macroscopic spinmomentum locked propagation along the symmetry axes of the PhCM. This novel mechanism of light-spin manipulation enables a versatile implementation of spin-optical structures that may pave the way to novel strategies for light spin technology and photonic multiplatform implementations

Fear Conditioning Potentiates Synaptic Transmission onto Long-Range Projection Neurons in the Lateral Subdivision of Central Amygdala

Recent studies indicate that the lateral subdivision of the central amygdala (CeL) is essential for fear learning. Specifically, fear conditioning induces cell-type-specific synaptic plasticity in CeL neurons that is required for the storage of fear memories. The CeL also controls fear expression by gating the activity of the medial subdivision of the central amygdala (CeM), the canonical amygdala output to areas that mediate defensive responses. In addition to the connection with CeM, the CeL sends long-range projections to innervate extra-amygdala areas. However, the long-range projection CeL neurons have not been well characterized, and their role in fear regulation is unknown. Here we show in mice that a subset of CeL neurons directly project to the midbrain periaqueductal gray (PAG) and the paraventricular nucleus of the thalamus, two brain areas implicated in defensive behavior. These long-range projection CeL neurons are predominantly somatostatin-positive (SOM(+)) neurons, which can directly inhibit PAG neurons, and some of which innervate both the PAG and paraventricular nucleus of the thalamus. Notably, fear conditioning potentiates excitatory synaptic transmission onto these long-range projection CeL neurons. Thus, our study identifies a subpopulation of SOM(+) CeL neurons that may contribute to fear learning and regulate fear expression independent of CeM

Dark MaGICC: the effect of Dark Energy on galaxy formation. Cosmology does matter

We present the Dark MaGICC project, which aims to investigate the effect of Dark Energy (DE) modeling on galaxy formation via hydrodynamical cosmological simulations. Dark MaGICC includes four dynamical Dark Energy scenarios with time varying equations of state, one with a self-interacting Ratra-Peebles model. In each scenario we simulate three galaxies with high resolution using smoothed particle hydrodynamics (SPH). The baryonic physics model is the same used in the Making Galaxies in a Cosmological Context (MaGICC) project, and we varied only the background cosmology. We find that the Dark Energy parameterization has a surprisingly important impact on galaxy evolution and on structural properties of galaxies at z=0, in striking contrast with predictions from pure Nbody simulations. The different background evolutions can (depending on the behavior of the DE equation of state) either enhance or quench star formation with respect to a LCDM model, at a level similar to the variation of the stellar feedback parameterization, with strong effects on the final galaxy rotation curves. While overall stellar feedback is still the driving force in shaping galaxies, we show that the effect of the Dark Energy parameterization plays a larger role than previously thought, especially at lower redshifts. For this reason, the influence of Dark Energy parametrization on galaxy formation must be taken into account, especially in the era of precision cosmology.Comment: 11 pages, 13 figure

Tuning the exponential sensitivity of a bound-state-in-continuum optical sensor.

In this work, we investigate the evanescent field sensing mechanism provided by an all-dielectric metasurface supporting bound states in the continuum (BICs). The metasurface is based on a transparent photonic crystal with subwavelength thickness. The BIC electromagnetic field is localized along the direction normal to the photonic crystal nanoscale-thin slab (PhCS) because of a topology-induced confinement, exponentially decaying in the material to detect. On the other hand, it is totally delocalized in the PhCS plane, which favors versatile and multiplexing sensing schemes. Liquids with different refractive indices, ranging from 1.33 to 1.45, are infiltrated in a microfluidic chamber bonded to the sensing dielectric metasurface. We observe an experimental exponential sensitivity leading to differential values as large as 226 nm/RIU with excellent FOM. This behavior is explained in terms of the physical superposition of the field with the material under investigation and supported by a thorough numerical analysis. The mechanism is then translated to the case of molecular adsorption where a suitable theoretical engineering of the optical structure points out potential sensitivities as large as 4000 nm/RIU

NIHAO IV: Core creation and destruction in dark matter density profiles across cosmic time

We use the NIHAO simulations to investigate the effects of baryonic physics on the time evolution of Dark Matter central density profiles. The sample is made of $\approx 70$ independent high resolution hydrodynamical simulations of galaxy formation and covers a wide mass range: 1e10< Mhalo <1e12, i.e., from dwarfs to L* . We confirm previous results on the dependence of the inner dark matter density slope, $\alpha$, on the ratio between stellar-to-halo mass. We show that this relation holds approximately at all redshifts (with an intrinsic scatter of ~0.18 in $\alpha$). This implies that in practically all haloes the shape of their inner density profile changes quite substantially over cosmic time, as they grow in stellar and total mass. Thus, depending on their final stellar-to-halo mass ratio, haloes can either form and keep a substantial density core (size~1 kpc), or form and then destroy the core and re-contract the halo, going back to a cuspy profile, which is even steeper than CDM predictions for massive galaxies (~1e12 Msun). We show that results from the NIHAO suite are in good agreement with recent observational measurements of $\alpha$ in dwarf galaxies. Overall our results suggest that the notion of a universal density profile for dark matter haloes is no longer valid in the presence of galaxy formation.Comment: 11 pages, 13 figures. Corrected typo in table 2 (middle row) with respect to the version published in MNRA