On a method to resolve the nuclear activity in galaxies as applied to the Seyfert 2 galaxy NGC1358

Nuclear regions of galaxies generally host a mixture of components with different exitation, composition, and kinematics. Derivation of emission line ratios and kinematics could then be misleading, if due correction is not made for the limited spatial and spectral resolutions of the observations.The aim of this paper is to demonstrate, with application to a long slit spectrum of the Seyfert 2 galaxy NGC 1358, how line intensities and velocities, together with modelling and knowledge of the point spread function, may be used to resolve the differing structures. In the situation outlined above, the observed kinematics differs for different spectral lines. From the observed intensity and velocity distributions of a number of spectral lines and with some reasonable assumptions to diminish the number of free parameters, the true line ratios and velocity structures may be deduced. A preliminary solution for the nuclear structure of NGC 1358 is obtained, involving a nuclear point source and an emerging outflow of high exitation, as well as a nuclear emission line disk rotating in the potential of a stellar bulge and expressing a radial excitation gradient. The method results in a likely scenario for the nuclear structure of the Seyfert 2 galaxy NGC 1358. For definitive results an extrapolation of the method to two dimensions combined with the use of integral field spectroscopy will generally be necessary.Comment: Accepted for Publication in The Astrophysical Journa

Whole MILC: generalizing learned dynamics across tasks, datasets, and populations

Behavioral changes are the earliest signs of a mental disorder, but arguably, the dynamics of brain function gets affected even earlier. Subsequently, spatio-temporal structure of disorder-specific dynamics is crucial for early diagnosis and understanding the disorder mechanism. A common way of learning discriminatory features relies on training a classifier and evaluating feature importance. Classical classifiers, based on handcrafted features are quite powerful, but suffer the curse of dimensionality when applied to large input dimensions of spatio-temporal data. Deep learning algorithms could handle the problem and a model introspection could highlight discriminatory spatio-temporal regions but need way more samples to train. In this paper we present a novel self supervised training schema which reinforces whole sequence mutual information local to context (whole MILC). We pre-train the whole MILC model on unlabeled and unrelated healthy control data. We test our model on three different disorders (i) Schizophrenia (ii) Autism and (iii) Alzheimers and four different studies. Our algorithm outperforms existing self-supervised pre-training methods and provides competitive classification results to classical machine learning algorithms. Importantly, whole MILC enables attribution of subject diagnosis to specific spatio-temporal regions in the fMRI signal.Comment: Accepted at MICCAI 2020. arXiv admin note: substantial text overlap with arXiv:1912.0313

Law Libraries and Laboratories: The Legacies of Langdell and His Metaphor

Law Librarians and others have often referred to Harvard Law School Dean C.C. Langdell’s statements that the law library is the lawyer’s laboratory. Professor Danner examines the context of what Langdell through his other writings, the educational environment at Harvard in the late nineteenth century, and the changing perceptions of university libraries generally. He then considers how the “laboratory metaphor” has been applied by librarians and legal scholars during the twentieth century and into the twenty-first. The article closes with thoughts on Langdell’s legacy for law librarians and the usefulness of the laboratory metaphor

Quantifying cancer progression with conjunctive Bayesian networks

Motivation: Cancer is an evolutionary process characterized by accumulating mutations. However, the precise timing and the order of genetic alterations that drive tumor progression remain enigmatic

HST FOC spectroscopy of the NLR of NGC 4151. I. Gas kinematics

We present the results from a detailed kinematic analysis of both ground-based, and Hubble Space Telescope/Faint Object Camera long-slit spectroscopy at sub-arcsec spatial resolution, of the narrow-line region of NGC 4151. In agreement with previous work, the extended emission gas (R > 4") is found to be in normal rotation in the galactic plane, a behaviour that we were able to trace even across the nuclear region, where the gas is strongly disturbed by the interaction with the radio jet, and connects smoothly with the large scale rotation defined by the neutral gas emission. The HST data, at 0.029" spatial resolution, allow us for the first time to truly isolate the kinematic behaviour of the individual clouds in the inner narrow-line region. We find that, underlying the perturbations introduced by the radio ejecta, the general velocity field can still be well represented by planar rotation down to a radius of ~ 0.5" (30 pc), distance at which the rotation curve has its turnover. The most striking result that emerges from our analysis is that the galaxy potential derived fitting the rotation curve changes from a "dark halo" at the ENLR distances to dominated by the central mass concentration in the NLR, with an almost Keplerian fall-off in the 1"< R < 4" interval. The observed velocity of the gas at 0.5" implies a mass of M ~ 10E9 M(sol) within the inner 60 pc. The presence of a turnover in the rotation curve indicates that this central mass concentration is extended. The first measured velocity point (outside the region saturated by the nucleus) would imply an enclosed mass of ~ 5E7 M(sol) within R ~ 0.15" (10 pc) which represents an upper limit to any nuclear point mass.Comment: 30 pages (aaspp4.sty), 14 figures. Fig. 1, 2 and 4 available by anonymous FTP at 143.54.2.51 (cd /pub/winge) as GIF files; or upon request to [email protected]. Accepted for publication in the Astrophysical Journal (part 1

Review of the research knowledge and gaps on fish populations, fisheries and linked ecosystems in the Central Arctic Ocean (CAO)

This report presents a review of the research knowledge and gaps on fish populations, fisheries and linked ecosystems in the Central Arctic Ocean (CAO). The CAO comprises the deep basins of the Arctic Ocean beyond the shelf break, which largely overlap with the High Seas of the Arctic Ocean, i.e. the marine areas outside the Exclusive Economic Zones (EEZs) of the Arctic coastal nations. The authors of the report are members of the European Fisheries Inventory in the Central Arctic Ocean (EFICA) Consortium. This study was funded by the European Commission as an EU contribution to the international cooperation within the Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean. The report contains desk-based research, using scientific research data bases as well as any available research performed by the EFICA Consortium partners and EU institutions or others. In Chapters 2-8 the authors review the literature and identify specific knowledge gaps. The gap analyses involve comparisons of actual knowledge with desired knowledge on the fish stocks of the CAO to be able to evaluate possibilities for future sustainable fisheries in the area. Chapter 1 is an introductory chapter, and Chapter 9 presents a holistic gap analysis based on Chapters 2-8 and recommendations for research priorities and the next steps. The critical gap analysis highlights that the knowledge gaps for the CAO are enormous and obstruct any quantitative analyses of its fish stocks. This agrees with the conclusions from the Fifth FiSCAO Report (FiSCAO 2018). While data for the physical environment in the CAO (oceanography, bottom topography and ice-cover dynamics) would be sufficient for fish stock modelling and assessment, there is a massive lack of biological and ecological data. The CAO is not a closed system and some aspects of the shelf seas are of high relevance for the CAO, notably connectivity of fish stocks and fish species moving north with climate warming. Scientific research and monitoring programs are established in the shelf seas, and new data are constantly being produced. Fish stock data are available from scientific projects and monitoring programs for some of the shelf seas (Barents Sea, Bering Sea, and to a lesser extent for the Beaufort Sea and the Chukchi Sea). Data exist also for the Russian shelf seas (Kara Sea, Laptev Sea, East Siberian Sea), but these data are not internationally available, while for the areas north of Canada/Greenland data are missing; they do not exist because of the severe ice conditions there. More data from all shelf seas may be hidden in reports that are not publicly accessible. We recommend to make current knowledge generally available by translating key publications and identification of valuable data reports. Research priorities comprise the collection and analysis of primary data in the CAO, and – to a limited extent – from adjacent waters through collaborations with other Signatories of the Agreement (e.g. on population genetics). Further research priorities include an evaluation of ecosystem vulnerability, social-ecological analyses, i.e. recognizing the close and often complex interactions between humans and nature, and recommendations for governance of the CAO. Fulfilling the 14 specific research priorities mentioned in Chapter 9 to “sufficient knowledge available” could enable the potential, future application of an Ecosystem Approach to Management for the CAO

High field x-ray diffraction study on a magnetic-field-induced valence transition in YbInCu4

We report the first high-field x-ray diffraction experiment using synchrotron x-rays and pulsed magnetic fields exceeding 30 T. Lattice deformation due to a magnetic-field-induced valence transition in YbInCu4 is studied. It has been found that the Bragg reflection profile at 32 K changes significantly at around 27 T due to the structural transition. In the vicinity of the transition field the low-field and the high-field phases are observed simultaneously as the two distinct Bragg reflection peaks: This is a direct evidence of the fact that the field-induced valence state transition is the first order phase transition. The field-dependence of the low-field-phase Bragg peak intensity is found to be scaled with the magnetization.Comment: 5 pages, 6 figures, submitted to J. Phys. Soc. Jp

Concentration Dependence of Superconductivity and Order-Disorder Transition in the Hexagonal Rubidium Tungsten Bronze RbxWO3. Interfacial and bulk properties

We revisited the problem of the stability of the superconducting state in RbxWO3 and identified the main causes of the contradictory data previously published. We have shown that the ordering of the Rb vacancies in the nonstoichiometric compounds have a major detrimental effect on the superconducting temperature Tc.The order-disorder transition is first order only near x = 0.25, where it cannot be quenched effectively and Tc is reduced below 1K. We found that the high Tc's which were sometimes deduced from resistivity measurements, and attributed to compounds with .25 < x < .30, are to be ascribed to interfacial superconductivity which generates spectacular non-linear effects. We also clarified the effect of acid etching and set more precisely the low-rubidium-content boundary of the hexagonal phase.This work makes clear that Tc would increase continuously (from 2 K to 5.5 K) as we approach this boundary (x = 0.20), if no ordering would take place - as its is approximately the case in CsxWO3. This behaviour is reminiscent of the tetragonal tungsten bronze NaxWO3 and asks the same question : what mechanism is responsible for this large increase of Tc despite the considerable associated reduction of the electron density of state ? By reviewing the other available data on these bronzes we conclude that the theoretical models which are able to answer this question are probably those where the instability of the lattice plays a major role and, particularly, the model which call upon local structural excitations (LSE), associated with the missing alkali atoms.Comment: To be published in Physical Review