Inertially arbitrary sign patterns with no nilpotent realization

AbstractAn n by n sign pattern S is inertially arbitrary if each ordered triple (n1,n2,n3) of nonnegative integers with n1+n2+n3=n is the inertia of some real matrix in Q(S), the sign pattern class of S. If every real, monic polynomial of degree n having a positive coefficient of xn−2 is the characteristic polynomial of some matrix in Q(S), then it is shown that S is inertially arbitrary. A new family of irreducible sign patterns G2k+1(k⩾2) is presented and proved to be inertially arbitrary, but not potentially nilpotent (and thus not spectrally arbitrary). The well-known Nilpotent-Jacobian method cannot be used to prove that G2k+1 is inertially arbitrary, since G2k+1 has no nilpotent realization. In order to prove that Q(G2k+1) allows each inertia with n3⩾1, a realization of G2k+1 with only zero eigenvalues except for a conjugate pair of pure imaginary eigenvalues is identified and used with the Implicit Function Theorem. Matrices in Q(G2k+1) with inertias having n3=0 are constructed by a recursive procedure from those of lower order. Some properties of the coefficients of the characteristic polynomial of an arbitrary matrix having certain fixed inertias are derived, and are used to show that G5 and G7 are minimal inertially arbitrary sign patterns

Semi-supervised prediction of protein interaction sentences exploiting semantically encoded metrics

Protein-protein interaction (PPI) identification is an integral component of many biomedical research and database curation tools. Automation of this task through classification is one of the key goals of text mining (TM). However, labelled PPI corpora required to train classifiers are generally small. In order to overcome this sparsity in the training data, we propose a novel method of integrating corpora that do not contain relevance judgements. Our approach uses a semantic language model to gather word similarity from a large unlabelled corpus. This additional information is integrated into the sentence classification process using kernel transformations and has a re-weighting effect on the training features that leads to an 8% improvement in F-score over the baseline results. Furthermore, we discover that some words which are generally considered indicative of interactions are actually neutralised by this process

Feasibility study and design concept for an orbiting ice-penetrating radar sounder to characterize in three-dimensions the Europan ice mantle down to (and including) any ice/ocean interface

This report presents a radar sounding model based on the range of current working hypotheses for the nature of Europa's icy shell.Institute for Geophysic

Neuroinflammation in post-acute sequelae of COVID-19 (PASC) as assessed by [11C]PBR28 PET correlates with vascular disease measures

The COVID-19 pandemic caused by SARS-CoV-2 has triggered a consequential public health crisis of post-acute sequelae of COVID-19 (PASC), sometimes referred to as long COVID. The mechanisms of the heterogeneous persistent symptoms and signs that comprise PASC are under investigation, and several studies have pointed to the central nervous and vascular systems as being potential sites of dysfunction. In the current study, we recruited individuals with PASC with diverse symptoms, and examined the relationship between neuroinflammation and circulating markers of vascular dysfunction. We used [ 11C]PBR28 PET neuroimaging, a marker of neuroinflammation, to compare 12 PASC individuals versus 43 normative healthy controls. We found significantly increased neuroinflammation in PASC versus controls across a wide swath of brain regions including midcingulate and anterior cingulate cortex, corpus callosum, thalamus, basal ganglia, and at the boundaries of ventricles. We also collected and analyzed peripheral blood plasma from the PASC individuals and found significant positive correlations between neuroinflammation and several circulating analytes related to vascular dysfunction. These results suggest that an interaction between neuroinflammation and vascular health may contribute to common symptoms of PASC

Axion-photon Couplings in Invisible Axion Models

We reexamine the axion-photon couplings in various invisible axion models motivated by the recent proposal of using optical interferometry at the ASST facility in the SSCL to search for axion. We illustrate that the assignment of $U(1)_{PQ}$ charges for the fermion fields plays an important role in determining the couplings. Several simple non-minimal invisible axion models with suppressed and enhanced axion-photon couplings are constructed, respectively. We also discuss the implications of possible new experiments to detect solar axions by conversion to $X$-rays in a static magnetic apparatus tracking the sun.Comment: 14 pages, LaTeX fil

A Fully Differential Digital CMOS Pulse UWB Generator

A new fully-digital CMOS pulse generator for impulse-radio Ultra-Wide-Band (UWB) systems is presented. First, the shape of the pulse which best fits the FCC regulation in the 3.1-5 GHz sub-band of the entire 3.1-10.6 GHz UWB bandwidth is derived and approximated using rectangular digital pulses. In particular, the number and width of pulses that approximate an ideal template is found through an ad-hoc optimization methodology. Then a fully differential digital CMOS circuit that synthesizes the pulse sequence is conceived and its functionality demonstrated through post-layout simulations. The results show a very good agreement with the FCC requirements and a low power consumptio

Typology and Perception of Informal Green Space in Urban Interstices: A case study of Ichikawa City, Japan

Multitudinous studies about urban green space (UGS) reveal that designed and managed UGS may provide not only social, environmental, and economic benefits for cities, but also mental, physical, and physiological benefits for their residents. However, past studies have focused on widely recognized green spaces in urban areas such as parks, gardens, and forests. Wasteland, wilderness, and unplanned in-between margins, which have been called informal green space (IGS), could provide supplementary green space. This study explores IGS in Ichikawa City, a post-industrial satellite town of Tokyo with scarce UGS, by addressing the following questions: (a) What types of non-standardized and unsystematised green space exist in the target area? (b) How is IGS in the target area perceived? (c) Could IGS be considered supplementary green space for the city? Using a systematic land use survey, we identified nine types of IGS in Ichikawa City that accounted for 6.35% of total land use. A questionnaire survey showed that undergraduate students recognize the existence of IGS in their neighbourhood, perceive multiple benefits and see especially street verges, unimproved land and water verges as potential supplementary green space. We conclude that IGS can serve as a supplementary green space and discuss how IGS might be integrated into green space planning to improve residents’ well-being

Interaction between M2-branes and Bulk Form Fields

We construct the interaction terms between the world-volume fields of multiple M2-branes and the 3- and 6-form fields in the context of ABJM theory with U($N$)$\times$U($N$) gauge symmetry. A consistency check is made in the simplest case of a single M2-brane, i.e, our construction matches the known effective action of M2-brane coupled to antisymmetric 3-form field. We show that when dimensionally reduced, our couplings coincide with the effective action of D2-branes coupled to R-R 3- and 5-form fields in type IIA string theory. We also comment on the relation between a coupling with a specific 6-form field configuration and the supersymmetry preserving mass deformation in ABJM theory.Comment: 30 pages, version to appear in JHE

Cloud-based automated clinical decision support system for detection and diagnosis of lung cancer in chest CT

Lung cancer is a major cause for cancer-related deaths. The detection of pulmonary cancer in the early stages can highly increase survival rate. Manual delineation of lung nodules by radiologists is a tedious task. We developed a novel computer-aided decision support system for lung nodule detection based on a 3D Deep Convolutional Neural Network (3DDCNN) for assisting the radiologists. Our decision support system provides a second opinion to the radiologists in lung cancer diagnostic decision making. In order to leverage 3-dimensional information from Computed Tomography (CT) scans, we applied median intensity projection and multi-Region Proposal Network (mRPN) for automatic selection of potential regionof-interests. Our Computer Aided Diagnosis (CAD) system has been trained and validated using LUNA16, ANODE09, and LIDC-IDR datasets; the experiments demonstrate the superior performance of our system, attaining sensitivity, specificity, AUROC, accuracy, of 98.4%, 92%, 96% and 98.51% with 2.1 FPs per scan. We integrated cloud computing, trained and validated our Cloud-Based 3DDCNN on the datasets provided by Shanghai Sixth People’s Hospital, as well as LUNA16, ANODE09, and LIDC-IDR. Our system outperformed the state-of-the-art systems and obtained an impressive 98.7% sensitivity at 1.97 FPs per scan. This shows the potentials of deep learning, in combination with cloud computing, for accurate and efficient lung nodule detection via CT imaging, which could help doctors and radiologists in treating lung cancer patients

The large-scale modulation of the density distribution in standard axionic CDM and its cosmological and physical impact

It is shown, that the energy density of coherent axion field oscillations in the cosmology of standard invisible axion should be distributed in the Universe in the form of archioles, being nonlinear inhomogeneous structure, reflecting the large scale distribution of Brownian structure of axion strings in the very early Universe. Spectrum of inhomogeneities, generated by archioles, is obtained and their effects in the spectrum and quadrupole anisotropy of relic radiation are considered. The axionic-string-decay-model-independent restriction on the scale of axion interaction is obtained.Comment: 8 pages, Talk presented at Workshop on Fundamental Physics at the Birth of the Universe II, Roma, May 19-24, 199