The Non-lte Spectroscopy Of Molecular Reactions Using The Exomol Database

This talk describes our recent development of two robust methods for calculating non-local thermal equilibrium (non-{LTE}) spectra of polyatomic molecules. Specifically, we look at molecules produced in reactive or dissociative environments, with vibrational populations outside local thermal equilibrium ({LTE}). The methodology is based on {E}xo{M}ol's accurate and extensive ro-vibrational line lists containing transitions with high vibrational excitations and relies on the detailed ro-vibrational assignments. Two approaches for non-LTE vibrational populations of the product are introduced: a simplistic 1D approach based on the Harmonic approximation, and full 3D model incorporating accurate vibrational wavefunctions computed variationally with the {TROVE} ({T}heoretical {ROV}ibrational {E}nergy) program. The developed methodology is applied to two molecules, silylene (SiH$_2$) produced in a decomposition of disilane (Si$_2$H$_6$), and carbon monoxide (CO) produced by formamide (CH$_{3}$NO) glow discharge. We show how the two approaches compare well to each other and to experimentally obtained spectra, and how their non-{LTE} spectral signatures can be used to trace different reaction channels of molecular dissociations

Testis-Ova in Spawning Blue Tilapia, Oreochromis aureus

Hermaphroditism characterized by the presence of oocytes in the testes is described in the blue tilapia, Oreochromis aureus, for the first time. Testis-ova were observed in three of 24 spawning males exhibiting otherwise normal male morphology. The testis-ova appeared non-vitellogenic and lacked a follicle cell layer. It is speculated that the testis-ova did not become vitellogenic due to their association with Sertoli cells and the hormonal environment of the male

Testis-Ova in Spawning Blue Tilapia, Oreochromis aureus

Hermaphroditism characterized by the presence of oocytes in the testes is described in the blue tilapia, Oreochromis aureus, for the first time. Testis-ova were observed in three of 24 spawning males exhibiting otherwise normal male morphology. The testis-ova appeared non-vitellogenic and lacked a follicle cell layer. It is speculated that the testis-ova did not become vitellogenic due to their association with Sertoli cells and the hormonal environment of the male

The vibrational properties of benzene on an ordered water ice surface

We present a hybrid CCSD(T) + PBE-D3 approach to calculating the vibrational signatures for gas-phase benzene and benzene adsorbed on an ordered water ice surface. We compare the results of our method against experimentally recorded spectra and calculations performed using PBE-D3-only approaches (harmonic and anharmonic). Calculations use a proton ordered XIh water ice surface consisting of 288 water molecules, and results are compared against experimental spectra recorded for an ASW ice surface. We show the importance of including a water ice surface into spectroscopic calculations, owing to the resulting differences in vibrational modes, frequencies, and intensities of transitions seen in the IR spectrum. The overall intensity pattern shifts from a dominating ?11 band in the gas-phase to several high-intensity carriers for an IR spectrum of adsorbed benzene. When used for adsorbed benzene, the hybrid approach presented here achieves an RMSD for IR active modes of 21 cm-1, compared to 72 cm-1 and 49 cm-1 for the anharmonic and harmonic PBE-D3 approaches, respectively. Our hybrid model for gaseous benzene also achieves the best results when compared to experiment, with an RMSD for IR active modes of 24 cm-1, compared to 55 cm-1 and 31 cm-1 for the anharmonic and harmonic PBE-D3 approaches, respectively. To facilitate assignment, we generate and provide a correspondence graph between the normal modes of the gaseous and adsorbed benzene molecules. Finally, we calculate the frequency shifts, ??, of adsorbed benzene relative to its gas-phase to highlight the effects of surface interactions on vibrational bands and evaluate the suitability of our chosen dispersion-corrected density functional theory

Exploiting orbital constraints from optical data to detect binary gamma-Ray pulsars

It is difficult to discover pulsars via their gamma-ray emission because current instruments typically detect fewer than one photon per million rotations. This creates a significant computing challenge for isolated pulsars, where the typical parameter search space spans wide ranges in four dimensions. It is even more demanding when the pulsar is in a binary system, where the orbital motion introduces several additional unknown parameters. Building on earlier work by Pletsch & Clark, we present optimal methods for such searches. These can also incorporate external constraints on the parameter space to be searched, for example, from optical observations of a presumed binary companion. The solution has two parts. The first is the construction of optimal search grids in parameter space via a parameter space metric, for initial semicoherent searches and subsequent fully coherent follow-ups. The second is a method to demodulate and detect the periodic pulsations. These methods have different sensitivity properties than traditional radio searches for binary pulsars and might unveil new populations of pulsars. © 2020. The Author(s). Published by the American Astronomical Society

On circuits and pancyclic line graphs

Clark proved that L(G) is hamiltonian if G is a connected graph of order n ≥ 6 such that deg u + deg v ≥ n - 1 - p(n) for every edge uv of G, where p(n) = 0 if n is even and p(n) = 1 if n is odd. Here it is shown that the bound n - 1 - p(n) can be decreased to (2n + 1)/3 if every bridge of G is incident with a vertex of degree 1, which is a necessary condition for hamiltonicity of L(G). Moreover, the conclusion that L(G) is hamiltonian can be strengthened to the conclusion that L(G) is pancyclic. Lesniak-Foster and Williamson proved that G contains a spanning closed trail if |V(G)| = n ≥ 6, δ(G) 2 and deg u + deg v ≥ n - 1 for every pair of nonadjacent vertices u and v. The bound n - 1 can be decreased to (2n + 3)/3 if G is connected and bridgeless, which is necessary for G to have a spanning closed trail

First principles calculation of uniaxial magnetic anisotropy and magnetostriction in strained CMR films

We performed first - principles relativistic full-potential linearized augmented plane wave calculations for strained tetragonal ferromagnetic La(Ba)MnO$_3$ with an assumed experimental structure of thin strained tetragonal La$_{0.67}$Ca$_{0.33}$MnO$_3$ (LCMO) films grown on SrTiO$_3$[001] and LaAlO$_3$[001] substrates. The calculated uniaxial magnetic anisotropy energy (MAE) values, are in good quantitative agreement with experiment for LCMO films on SrTiO$_3$ substrate. We also analyze the applicability of linear magnetoelastic theory for describing the stain dependence of MAE, and estimate magnetostriction coefficient $\lambda_{001}$.Comment: Talk given at APS99 Meeting, Atlanta, 199

A novel substitution 1381V in the sterol 14alpha-demethylase (CYP51) of Mycosphaerella graminicola is differentially selected by azole fungicides

The recent reduction in the efficacy of azole fungicides in controlling Septoria leaf blotch of wheat, caused by Mycosphaerella graminicola, has prompted concerns over possible development of resistance, particularly in light of the recent emergence of widespread resistance to quinone outside inhibitors (QoIs). We have recently implicated alterations in the target-encoding sterol 14 alpha-demethylase protein (CYP51), and over-expression of genes encoding efflux pumps, in reducing sensitivity to the azole class of sterol demethylation inhibitors (DMIs) in M. graminicola. Here we report on the prevalence and selection of two CYP51 alterations, substitution I381V and deletion of codons 459 and 460 (Delta Y459/G460), in populations of M. graminicola. Neither alteration has previously been identified in human or plant pathogenic fungi resistant to azoles. The presence of Delta Y459/G460 showed a continuous distribution of EC50 values across isolates with either I381 or V381, and had no measurable effect on azole sensitivity. Data linking fungicide sensitivity with the presence of I381V in M. graminicola show for the first time that a particular CYP51 alteration is differentially selected by different azoles in field populations of a plant pathogen. Substitution I381V although not an absolute requirement for reduced azole sensitivity, is selected by tebuconazole and difenoconazole treatment, suggesting an adaptive advantage in the presence of these two compounds. Prochloraz treatments appeared to select negatively for I381V, whereas other azole treatments did not or only weakly impacted on the prevalence of this substitution. These findings suggest treatments with different members of the azole class of fungicides could offer a resistance management strategy

Probing Heavy Higgs Boson Models with a TeV Linear Collider

The last years have seen a great development in our understanding of particle physics at the weak scale. Precision electroweak observables have played a key role in this process and their values are consistent, within the Standard Model interpretation, with a light Higgs boson with mass lower than about 200 GeV. If new physics were responsible for the mechanism of electroweak symmetry breaking, there would, quite generally, be modifications to this prediction induced by the non-standard contributions to the precision electroweak observables. In this article, we analyze the experimental signatures of a heavy Higgs boson at linear colliders. We show that a linear collider, with center of mass energy \sqrt{s} <= 1 TeV, would be very useful to probe the basic ingredients of well motivated heavy Higgs boson models: a relatively heavy SM-like Higgs, together with either extra scalar or fermionic degrees of freedom, or with the mixing of the third generation quarks with non-standard heavy quark modes.Comment: 21 page

Seizure characterisation using frequency-dependent multivariate dynamics

The characterisation of epileptic seizures assists in the design of targeted pharmaceutical seizure prevention techniques and pre-surgical evaluations. In this paper, we expand on recent use of multivariate techniques to study the crosscorrelation dynamics between electroencephalographic (EEG) channels. The Maximum Overlap Discrete Wavelet Transform (MODWT) is applied in order to separate the EEG channels into their underlying frequencies. The dynamics of the cross-correlation matrix between channels, at each frequency, are then analysed in terms of the eigenspectrum. By examination of the eigenspectrum, we show that it is possible to identify frequency dependent changes in the correlation structure between channels which may be indicative of seizure activity. The technique is applied to EEG epileptiform data and the results indicate that the correlation dynamics vary over time and frequency, with larger correlations between channels at high frequencies. Additionally, a redistribution of wavelet energy is found, with increased fractional energy demonstrating the relative importance of high frequencies during seizures. Dynamical changes also occur in both correlation and energy at lower frequencies during seizures, suggesting that monitoring frequency dependent correlation structure can characterise changes in EEG signals during these. Future work will involve the study of other large eigenvalues and inter-frequency correlations to determine additional seizure characteristics