We compare linear spectral modeling solutions yielding surface abundance estimates and water ice grain size information from low‐noise Galileo Near‐Infrared Mapping Spectrometer (NIMS) observations ...for three widely spaced locations on Europa. Bright equatorial plains on the orbital leading side are dominated by fine‐grained (∼50–75 μm) water ice (>80 wt%). This area shows a low abundance of hydrated salts and statistically insignificant amounts of hydrated sulfuric acid. A midlatitude northern hemisphere location on the trailing side exhibits strikingly different surface composition and properties for similar terrain. The modeled abundance of hydrated sulfuric acid exceeds 40% here; large‐grained water ice (∼250 μm diameter) dominates the ice grain size distribution. A third location at high southern latitudes on the leading side exhibits high abundances of water ice (>67%) and no detectable sulfuric acid hydrate. Water ice grain sizes here are intermediate between those of the other locations, at 75–100 μm. We resolve compositional differences between the darkest materials (at visible wavelengths) and the most hydrated materials (as evidenced by the distortion of water ice absorption bands) on Europa's leading side. Distinctive water ice grain size distributions are associated with visibly dark materials in all three locations. Our results help distinguish between exogenic and endogenic influences on Europa's present‐day surface composition. The results are consistent with migration and redeposition of sputtered water ice molecules from trailing to leading side locations.
Key Points
Europa's surface contains varying proportions of ice and hydrates
Surface abundances are influenced by both endogenic and exogenic processes
Ice grain sizes suggest sputtering and preferential redeposition
We derive optical constants (n(λ) and k(λ)) from laboratory reflectance spectra acquired at visible to near‐infrared wavelengths for epsomite (MgSO4⋅7H2O), bloedite (Na2Mg(SO4)2⋅4H2O), and ...hexahydrite (MgSO4⋅6H2O) at both room temperature and 120 K. These hydrated sulfates are candidate surface compounds for outer solar system icy satellites such as Europa, Ganymede, and Callisto, as well as Mars. Our results permit quantitative abundance modeling of Galileo, Cassini‐Huygens, New Horizons, Mars Reconnaissance Orbiter, Mars Express, and future mission spacecraft observations leading to better interpretation of these objects' surface and interior geological processes and histories.
Key Points
We derived complex indices of refraction for epsomite, hexahydrite and bloedite
These refractive indices have been derived at room temperature and at 120K
These indices enable intimate mixture models of Mars, Europa and Ganymede
In this paper, we describe the first data release of the Visible and Infrared Survey Telescope for Astronomy (VISTA) Deep Extragalactic Observations (VIDEO) survey. VIDEO is a ∼12 deg2 survey in the ...near-infrared Z, Y, J, H and K
s bands, specifically designed to enable the evolution of galaxies and large structures to be traced as a function of both epoch and environment from the present day out to z = 4, and active galactic nuclei (AGNs) and the most massive galaxies up to and into the epoch of reionization. With its depth and area, VIDEO will be able to fully explore the period in the Universe where AGN and starburst activity were at their peak and the first galaxy clusters were beginning to virialize. VIDEO therefore offers a unique data set with which to investigate the interplay between AGN, starbursts and environment, and the role of feedback at a time when it was potentially most crucial.
We provide data over the VIDEO-XMM3 tile, which also covers the Canada-France-Hawaii Telescope Legacy Survey Deep-1 field (CFHTLS-D1). The released VIDEO data reach a 5σ AB-magnitude depth of Z = 25.7, Y = 24.5, J = 24.4, H = 24.1 and K
s = 23.8 in 2 arcsec diameter apertures (the full depth of Y = 24.6 will be reached within the full integration time in future releases). The data are compared to previous surveys over this field and we find good astrometric agreement with the Two Micron All Sky Survey, and source counts in agreement with the recently released UltraVISTA survey data. The addition of the VIDEO data to the CFHTLS-D1 optical data increases the accuracy of photometric redshifts and significantly reduces the fraction of catastrophic outliers over the redshift range 0 < z < 1 from 5.8 to 3.1 per cent in the absence of an i-band luminosity prior. However, we expect that the main improvement in photometric redshifts will come in the redshift range 1 < z < 4 due to the sensitivity to the Balmer and 4000 Å breaks provided by the near-infrared VISTA filters. All images and catalogues presented in this paper are publicly available through ESO's phase 3 archive and the VISTA Science Archive.
The CGLMP Bell inequalities Dalton, B. J.
The European physical journal. ST, Special topics,
2021/6, Letnik:
230, Številka:
4
Journal Article
Recenzirano
Quantum non-locality tests have been of interest since the 1960s paper by Bell on the original EPR paradox. The present paper discusses whether the CGLMP (Bell) inequalities obtained by Collins et ...al. are possible tests for showing that quantum theory is not underpinned by local hidden variable theory (LHVT). It is found by applying Fine’s theorem that the CGLMP approach involves a LHVT for the joint probabilities associated with the measurement of one observable from each of the two sub-systems, even though the underlying probabilities for joint measurements of all four observables involve a hidden variable theory which is not required to be local. The latter HVT probabilities involve outcomes of simultaneous measurements of pairs of observables corresponding to non-commuting quantum operators, which is allowed in classical theory. Although the CGLMP inequalities involve probabilities for measurements of one observable per sub-system and are compatible with the Heisenberg uncertainty principle, there is no unambiguous quantum measurement process linked to the probabilities in the CGLMP inequalities. Quantum measurements corresponding to the different classical measurements that give the same CGLMP probability are found to yield different CGLMP probabilities. However, violation of a CGLMP inequality based on any one of the possible quantum measurement sequences is sufficient to show that the Collins et al. LHVT does not predict the same results as quantum theory. This is found to occur for a state considered in their paper—though for observables whose physical interpretation is unclear. In spite of the problems of comparing the HVT inequalities with quantum expressions, it is concluded that in spite of the contextuality loophole, the CGLMP inequalities are indeed suitable for ruling out local hidden variable theories and also non-local ones as well. The state involved could apply to a macroscopic system, so the CGLMP Bell inequalities are important for finding cases of macroscopic violations of Bell locality. Possible experiments in double-well Bose condensates involving atoms with two hyperfine components are discussed.
Revisiting the Soybean GmNAC Superfamily Melo, Bruno P; Fraga, Otto T; Silva, José Cleydson F ...
Frontiers in plant science,
12/2018, Letnik:
9
Journal Article
Recenzirano
Odprti dostop
The
(NAM, ATAF, and CUC) genes encode transcription factors involved with the control of plant morph-physiology and stress responses. The release of the last soybean
genome assembly (Wm82.a2.v1) ...raised the possibility that new NAC genes would be present in the soybean genome. Here, we interrogated the last version of the soybean genome against a conserved NAC domain structure. Our analysis identified 32 putative novel NAC genes, updating the superfamily to 180 gene members. We also organized the genes in 15 phylogenetic subfamilies, which showed a perfect correlation among sequence conservation, expression profile, and function of orthologous
genes and NAC soybean genes. To validate our
analyses, we monitored the stress-mediated gene expression profiles of eight new NAC-genes by qRT-PCR and monitored the GmNAC senescence-associated genes by RNA-seq. Among ER stress, osmotic stress and salicylic acid treatment, all the novel tested GmNAC genes responded to at least one type of stress, displaying a complex expression profile under different kinetics and extension of the response. Furthermore, we showed that 40% of the GmNACs were differentially regulated by natural leaf senescence, including eight (8) newly identified GmNACs. The developmental and stress-responsive expression profiles of the novel NAC genes fitted perfectly with their phylogenetic subfamily. Finally, we examined two uncharacterized senescence-associated proteins, GmNAC065 and GmNAC085, and a novel, previously unidentified, NAC protein, GmNAC177, and showed that they are nuclear localized, and except for GmNAC065, they display transactivation activity in yeast. Consistent with a role in leaf senescence, transient expression of GmNAC065 and GmNAC085 induces the appearance of hallmarks of leaf senescence, including chlorophyll loss, leaf yellowing, lipid peroxidation and accumulation of H
O
. GmNAC177 was clustered to an uncharacterized subfamily but in close proximity to the TIP subfamily. Accordingly, it was rapidly induced by ER stress and by salicylic acid under late kinetic response and promoted cell death
. Collectively, our data further substantiated the notion that the GmNAC genes display functional and expression profiles consistent with their phylogenetic relatedness and established a complete framework of the soybean NAC superfamily as a foundation for future analyses.
We present new results on the cosmic star formation history in the Subaru/XMM-Newton Deep Survey (SXDS)-Ultra Deep Survey (UDS) field out to z = 1.6. We compile narrow-band data from the Subaru ...Telescope and the Visible and Infrared Survey Telescope for Astronomy (VISTA) in conjunction with broad-band data from the SXDS and UDS, to make a selection of 5725 emission-line galaxies in 12 redshift slices, spanning 10 Gyr of cosmic time. We determine photometric redshifts for the sample using 11-band photometry, and use a spectroscopically confirmed subset to fine tune the resultant redshift distribution. We use the maximum-likelihood technique to determine luminosity functions in each redshift slice and model the selection effects inherent in any narrow-band selection statistically, to obviate the retrospective corrections ordinarily required. The deep narrow-band data are sensitive to very low star formation rates (SFRs), and allow an accurate evaluation of the faint end slope of the Schechter function, α. We find that α is particularly sensitive to the assumed faintest broad-band magnitude of a galaxy capable of hosting an emission line, and propose that this limit should be empirically motivated. For this analysis, we base our threshold on the limiting observed equivalent widths of emission lines in the local Universe. We compute the characteristic SFR of galaxies in each redshift slice, and the integrated SFR density, ρSFR. We find our results to be in good agreement with the literature and parametrize the evolution of the SFR density as ρSFR ∝ (1 + z)4.58 confirming a steep decline in star formation activity since z ∼ 1.6.
The categorization of quantum states for composite systems as either separable or entangled, or alternatively as Bell local or Bell non-local states based on local hidden variable theory is outlined, ...focusing on simple bipartite systems. The significance of states demonstrating Bell non-locality for settling the long standing controversy between the Copenhagen interpretation of the quantum measurement process involving “collapse of the wave-function” and the alternative interpretation based on pre-existing hidden variables is emphasized. Although experiments demonstrating violations of Bell locality in microscopic systems have now been carried out, there is current interest in finding Bell non-locality in quantum systems on a macroscopic scale, since this is a regime where a classical hidden variable theory might still apply. Progress towards finding macroscopic quantum states that violate Bell inequalities is reviewed. A new test for Bell non-locality that applies when the sub-system measured quantities are spin components with large outcomes is described, and applied to four mode systems of identical massive bosons in Bose-Einstein condensates.
The association between preoperative blood glucose (BG) concentration and outcomes after non-cardiac surgery and the impact of the diabetes diagnosis status remain unclear. We tested two hypotheses: ...that preoperative BG is related to surgical outcomes; and that this relationship depends on the diabetes diagnosis status of the patient.
We retrospectively analysed data on 61 536 consecutive elective non-cardiac surgery patients treated at our tertiary care facility. Logistic regression models were used to test the hypotheses before and after adjustment for baseline patient characteristics. Our primary outcome was a composite of in-hospital serious complications and mortality. A second primary outcome was 1 yr mortality.
The crude incidence of the composite in-hospital outcome was significantly related to preoperative BG (P<0.001), but not after covariable adjustment (P=0.40). This relationship did not significantly differ between patients with and without diagnosed diabetes (P=0.09). One year mortality was significantly related to preoperative BG, both univariably (P<0.001) and after covariable-adjustment (P<0.001). Patients with diagnosed diabetes and preoperative euglycaemia generally had worse 1 yr mortality than those without diabetes at the same BG {e.g. odds ratio (OR) 95% confidence interval (CI) of 1.27 (1.06, 1.53) at 6 mmol litre(-1) (108 mg dl(-1)), P=0.003}. Conversely, hyperglycaemic patients with diagnosed diabetes displayed a significantly lower 1 yr mortality than hyperglycaemic patients without diabetes OR (95% CI) of 0.58 (0.44, 0.77) at 12 mmol litre(-1) (216 mg dl(-1)), P<0.001.
For elective non-cardiac surgery, preoperative hyperglycaemia should be given greater consideration in patients without diabetes than in those with diagnosed diabetes.
In many situations, the energy levels for a quantum system, whose Hamiltonian is invariant under a specific symmetry group, are split when the Hamiltonian is replaced by a new one with lower ...symmetry. In non-rigid molecules (NRM), fast quantum tunnelling processes allow the molecule to change between different geometrical configurations related by permutations of identical nuclei (or with inversion as well), resulting in the splitting of the energy levels for the rigid molecule (RM) case where tunnelling is absent. However, for NRM, there is apparently a paradoxical situation where although the original RM energy levels are associated with a symmetry group isomorphic to the point group for the geometrical configuration, the split NRM energy levels are associated with a symmetry group consisting of all permutations and inversions related to the fast quantum tunnelling processes between configurations, and for which the point group is a subgroup. The resolution of this paradox, where energy level splitting is evidently accompanied by an enlargement of the symmetry group, is the subject of this article.
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