cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Evaluation of a multi-scale enhancement protocol for digital mammography
Creators: name: Mekle, Ralf
name: Laine, Andrew F.
name: Smith, Suzanne
name: Singer, Cory
name: Koenigsberg, Tova
name: Brown, Marc
Publisher: name: Columbia University
Year: 2000
Subjects: Medicine
Biomedical engineering

description: We have carried out a receiver operating characteristics (ROC) study for the enhancement of mammographic features in digitized mammograms. The study evaluated the benefits of multi-scale enhancement methods in terms of diagnostic performance of radiologists. The enhancement protocol relied on multi-scale expansions and non-linear enhancement functions. Dyadic spline wavelet functions were used together with a sigmoidal non-linear enhancement function. We designed a computer interface ona softcopy display and performed an ROC study with three radiologists, who specialized in mammography. Clinical cases were obtained from a national mammography database of digitized radiographs prepared by the University of South Florida and Harvard Medical School. Our study focused on dense mammograms, i.e. mammograms of density 3 and 4 on the American College of Radiology breast density rating, which are the most difficult cases in screening, were selected. To compare the performance of radiologists with an without using multi-scale enhancement, two groups of 30 cases each were diagnosed. Each group contained 15 cases of cancerous and 15 cases of normal mammograms. Conventional ROC analysis was applied, and the resulting ROC curves indicated improved diagnostic performance when radiologists used multi-scale non-linear enhancement.
Keynote: Advances and Challenges of Industrial IoT
Creators: name: Artemenko, Alexander
Publisher: name: Zenodo
Year: 2021

description: The main challenges of the first Internet of Things generation were related to communication latency due to high physical and logical distance between end devices and server resources, vulnerability for network problems along the long routes as well as power consumption management. Thanks to the unveiling of the latest wireless technologies like 4G and 5G, WiFi 5 and 6 as well as BLE, the last-mile connection performance - communication latency in particular - is taking a huge leap, and therefore introducing new possibilities for industrial applications. However, many open challenges remain. These include smart and efficient analysis of massive data, automated management of the full life cycle of IoT devices, etc. The newest developments in Artificial Intelligence, massive softwarization and virtualization, technologies beyond 5G and WiFi 6 give hope for the unveiling of new potentials. This talk uncovers the above dynamics.
Fe-spin reorientation in PrFeAsO : Evidences from resistivity and specific heat studies
Creators: name: Bhoi, D.
name: Mandal, P.
name: Choudhury, P.
name: Pandya, S.
name: Ganesan, V.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We report the magnetic field dependence of resistivity ($ρ$) and specific heat ($C$) for the non-superconducting PrFeAsO compound. Our study shows a hitherto unobserved anomaly at $T_{SR}$ in the resistivity and specific heat data which arises as a result of the interplay of antiferromagnetic (AFM) Pr and Fe sublattices. Below the AFM transition temperature ($T_N^{\rm{Pr}}$), Pr moment orders along the crystallographic c axis and its effect on the iron subsystem causes a reorientation of the ordered inplane Fe moments in a direction out of the $ab$ plane. Application of magnetic field introduces disorder in the AFM Pr sublattice, which, in turn, reduces the out-of-plane Pr-Fe exchange interaction responsible for Fe spin reorientation. Both in $ρ$($T$) and $d(C/T)/dT$ curves, the peak at $T_{SR}$ broadens with the increase of $H$ due to the introduction of the disorder in the AFM Pr sublattice by magnetic field. In $ρ$($T$) curve, the peak shifts towards lower temperature with $H$ and disappears above 6 T while in $d(C/T)/dT$ curve the peak remains visible up to 14 T. The broadening of the anomaly at $T_N^{\rm{Pr}}$ in $C(T)$ with increasing $H$ further confirms that magnetic field induces disorder in the AFM Pr sublattice.
description: 8 pages, 10 Figures
Variational segmentation framework in prolate spheroidal coordinates for 3D real-time echocardiography
Creators: name: Vallet, Bruno
name: Angelini, Elsa D.
name: Laine, Andrew F.
Publisher: name: Columbia University
Year: 2006
Subjects: Medicine
Biomedical engineering

description: This paper presents a new formulation of a deformable model segmentation in prolate spheroidal coordinates for segmentation of 3D cardiac echocardiography data. The prolate spheroidal coordinate system enables a representation of the segmented surface with descriptors specifically adapted to the "ellipsoidal" shape of the ventricle. A simple data energy term, based on gray-level information, guides the segmentation. The segmentation framework provides a very fast and simple algorithm to evolve an initial ellipsoidal object towards the endocardial surface of the myocardium with near real-time deformations. With near real-time performance, additional constraints on landmark points, can be used interactively to prevent leakage of the surface.
Heat Transfer Model of Hyporthermic Intracarotid Infusion of Cold Saline for Stroke Therapy
Creators: name: Neimark, Matthew A.
name: Konstas, Angelos-Aristeidis
name: Laine, Andrew F.
name: Pile-Spellman, John
Publisher: name: Columbia University
Year: 2006
Subjects: Medicine
Biomedical engineering

description: A 3-dimensional hemispheric computational brain model is developed to simulate infusion of cold saline in the carotid arteries in terms of brain cooling for stroke therapy. The model is based on the Pennes bioheat equation, with four tissue layers: white matter, gray matter, skull, and scalp. The stroke lesion is simulated by reducing blood flow to a selected volume of the brain by a factor of one-third, and brain metabolism by 50%. A stroke penumbra was also generated surrounding the core lesion (blood volume reduction 25%, metabolism reduction 20%). The finite difference method was employed to solve the system of partial differential equations. This model demonstrated a reduction in brain temperature, at the stroke lesion, to 32°C in less than 10 minutes.
Overcomplete Lifted Wavelet Representations for Multiscale Feature Analysis
Creators: name: Shim, Minbo
name: Laine, Andrew F.
Publisher: name: Columbia University
Year: 1998
Subjects: Medicine
Biomedical engineering

description: The lifting scheme was introduced as a flexible tool to construct compactly supported second generation wavelets and the wavelet transform. However because it is not translation invariant, the traditional lifting framework may not be good for multiscale feature analysis where translation-invariant characteristics are highly desirable. In this paper we address the following question: can the lifting scheme be used as a framework for overcomplete wavelet representations with multiscale feature analysis in mind? We address this question by investigating each stage of the multiscale analysis: split, dual lifting and primal lifting. We introduce a smoothing lazy wavelet in the split stage. We then show that only the dual lifting is necessary since the primal lifting required to compensate for  the aliasing needs no longer exist. We also demonstrate that the proposed scheme achieves better performance without introducing boundary artifacts that exist in the traditional methods.
How instruction supportive of self-regulated learning might foster self-efficacy for students with and without learning disabilities during literacy tasks
Creators: name: Scott, Jennifer
Publisher: name: University of British Columbia
Year: 2011

description: While self-efficacy (SE) and self-regulated learning (SRL) are key processes that are related to successful literacy performance, these are two areas where students often struggle, particularly students with learning disabilities (LD). Fortunately, research has identified instructional features that can be embedded in classrooms to support SRL. This study built from that research to investigate whether those SRL-supportive instructional features might also support students’ SE while working on literacy tasks in different kinds of classroom placements (inclusive, support, or pull-out). An instrumental qualitative case study design was used to examine the SE of seven intermediate students at different achievement levels, including three students with learning disabilities. Results revealed: (a) similarities across teachers working in different kinds of placements in their use of SRL-supportive instructional features, with some features being implemented with greater frequency and consistency, (b) relationships between environmental conditions and SE, such as the provision of choices, but also (c) the ways in which SE perceptions were mediated by students' perceptions of environmental conditions. Overall, cross-case analyses highlighted the complex, dynamic, and situated nature of SE, and identified ways in which environmental and personal factors interacted in students’ SE attributions. In closing the thesis, these results are considered in the context of previous research, and theoretical, methodological, and practical limitations, contributions and implications are outlined.
True-false lumen segmentation of aortic dissection using multi-scale wavelet analysis and generative-discriminative model matching
Creators: name: Lee, Noah
name: Tek, Huseyin
name: Laine, Andrew F.
Publisher: name: Columbia University
Year: 2008
Subjects: Medicine
Biomedical engineering

description: Computer aided diagnosis in the medical image domain requires sophisticated probabilistic models to formulate quantitative behavior in image space. In the diagnostic process detailed knowledge of model performance with respect to accuracy, variability, and uncertainty is crucial. This challenge has lead to the fusion of two successful learning schools namely generative and discriminative learning. In this paper, we propose a generative-discriminative learning approach to predict object boundaries in medical image datasets. In our approach, we perform probabilistic model matching of both modeling domains to fuse into the prediction step appearance and structural information of the object of interest while exploiting the strength of both learning paradigms. In particular, we apply our method to the task of true-false lumen segmentation of aortic dissections an acute disease that requires automated quantification for assisted medical diagnosis. We report empirical results for true-false lumen discrimination of aortic dissection segmentation showing superior behavior of the hybrid generative-discriminative approach over their non hybrid generative counterpart.
Multiscale wavelet representations for mammographic feature analysis
Creators: name: Laine, Andrew F.
name: Song, Shuwu
Publisher: name: Columbia University
Year: 1992
Subjects: Medicine
Biomedical engineering

description: This paper introduces a novel approach for accomplishing mammographic feature analysis through multiresolution representations. We show that efficient (nonredundant) representations may be identified from digital mammography and used to enhance specific mammographic features within a continuum of scale space. The multiresolution decomposition of wavelet transforms provides a natural hierarchy in which to embed an interactive paradigm for accomplishing scale space feature analysis. Choosing wavelets (or analyzing functions) that are simultaneously localized in both space and frequency, results in a powerful methodology for image analysis. Multiresolution and orientation selectivity, known biological mechanisms in primate vision, are ingrained in wavelet representations and inspire the techniques presented in this paper. Our approach includes local analysis of complete multiscale representations. Mammograms are reconstructed from wavelet coefficients, enhanced by linear, exponential and constant weight functions localized in scale space. By improving the visualization of breast pathology we can improve the changes of early detection of breast cancers (improve quality) while requiring less time to evaluate mammograms for most patients (lower costs).
Thawing Versus. Tracker Behaviour: Observational Evidence
Creators: name: Thakur, Shruti
name: Nautiyal, Akhilesh
name: Sen, Anjan A
name: Seshadri, T R
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Currently there is a variety of scalar field models to explain the late time acceleration of the Universe. This includes the standard canonical and non-canonical scalar field models together with recently proposed Galileon scalar field models. One can divide all these scalar field models into two broad categories, namely the thawing and the tracker class. In this work we investigate the evidence for these models with the presently available observational data using the Bayesian approach. We use the Generalized Chaplygin Gas (GCG) parametrization for dark energy equation of state (EoS) as it gives rise to both the thawing and tracking behaviours for different values of the parameters. Analysis of the observational data does not give any clear evidence for either thawing or tracking behaviour within the context of background cosmology, However, if we consider the evolution of inhomogenities and analyze the data in this context then there is a significant evidence in favour of thawing behaviour.
description: 6 Pages, three eps figures, new material added, new references added. Conclusion changed. Accepted for publication MNRAS
Análisis comparado de gobernanza en Chile: cambio climático, GRD, ordenamiento territorial
Creators: name: Danae Nuñez
name: Billi, Marco
Publisher: name: Open Science Framework
Year: 2023
Subjects: subject: gobernanza
subject: gestión de riesgo de desastres
subject: ordenamiento territorial
subject: Chile
subject: ley marco de cambio climático
subject: cambio climático

description: Análisis comparado de los marcos normativos del cambio climático, la gestión del riesgo de desastres y el ordenamiento territorial en Chile, en base a las nuevas normativas vigentes
Multiscale sub-octave wavelet transform for de-noising and enhancement
Creators: name: Laine, Andrew F.
name: Zong, Xuli
Publisher: name: Columbia University
Year: 1996
Subjects: Medicine
Biomedical engineering

description: This paper describes an approach for accomplishing sub- octave wavelet analysis and its discrete implementation for noise reduction and feature enhancement. Sub-octave wavelet transforms allow us to more closely characterize features within distinct frequency bands. By dividing each octave into sub-octave components, we demonstrate a superior ability to capture transient activities in a signal or image more reliably. De-noising and enhancement are accomplished through techniques of minimizing noise energy and nonlinear processing of transform coefficient energy by gain.
Spin waves in a skyrmion crystal
Creators: name: Petrova, Olga
name: Tchernyshyov, Oleg
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We derive the spectrum of low-frequency spin waves in skyrmion crystals observed recently in noncentrosymmetric ferromagnets. We treat the skyrmion crystal as a superposition of three helices whose wavevectors form an equilateral triangle. The low-frequency spin waves are Goldstone modes associated with displacements of skyrmions. Their dispersion is determined by the elastic properties of the skyrmion crystal and by the kinetic terms of the effective Lagrangian, which include both kinetic energy and a Berry-phase term reflecting a nontrivial topology of magnetization. The Berry-phase term acts like an effective magnetic field, mixing longitudinal and transverse vibrations into a gapped cyclotron mode and a twist wave with a quadratic dispersion.
description: 9 pages, 3 figures; final version to appear in Phys. Rev. B
Gas Flaring and Low Carbon Development: A Comparative Analysis of Nigeria, UK and Alberta
Creators: name: Mene, Boritsefere Elizabeth
Publisher: name: Law
Year: 2019
Subjects: subject: Gas Flaring
subject: Low Carbon Development
subject: Common But Differentiated Responsibilities
subject: Intergenerational Equity
subject: Environmental Ethics
subject: Climate Change
subject: Paris Agreement
subject: UNFCCC Agreement
subject: Kyoto Protocol
subject: Carbon Emissions
subject: Literature--Canadian (English)

description: I bet if the environment could talk, it would have many things to say. If the environment could challenge certain actions by humankind on its person, everyone would have an earful. Sadly, the environment has no voice; it relies on environmental activists to tell its story and save it, or at least what remains of it. In this research, I tell a tale of gas flaring stemming from upstream oil and gas production in Nigeria. This comparative study analyses gas flaring in Nigerian upstream oil and gas industry as a hindrance to low carbon development, and the reasons why the 43 years efforts to phase out gas flaring are unsuccessful. It argues that if there is no address of the five obstacles to phasing out gas flaring that it discusses, Nigeria would never meet its year 2030 commitment of phasing out gas flaring which it declares in its NDC in the Paris Agreement. It uses two jurisdictions, the UK and Alberta, as comparators in determining how two other oil-producing jurisdictions address the gas flaring problems Nigeria faces in its oil and gas industry. It uses the theory of environmental ethics as a basis for the need for environmental protection and accountability in the oil and gas industry.
Interactive Segmentation in Multimodal Medical Imagery Using a Bayesian Transductive Learning Approach
Creators: name: Lee, Noah
name: Caban, Jesus
name: Ebadollahi, Shahram
name: Laine, Andrew F.
Publisher: name: Columbia University
Year: 2009
Subjects: Medicine
Biomedical engineering

description: Labeled training data in the medical domain is rare and expensive to obtain. The lack of labeled multimodal medical image data is a major obstacle for devising learning-based interactive segmentation tools. Transductive learning (TL) or semi-supervised learning (SSL) offers a workaround by leveraging unlabeled and labeled data to infer labels for the test set given a small portion of label information. In this paper we propose a novel algorithm for interactive segmentation using transductive learning and inference in conditional mixture nave Bayes models (T-CMNB) with spatial regularization constraints. T-CMNB is an extension of the transductive nave Bayes algorithm [1, 20]. The multimodal Gaussian mixture assumption on the class-conditional likelihood and spatial regularization constraints allow us to explain more complex distributions required for spatial classification in multimodal imagery. To simplify the estimation we reduce the parameter space by assuming nave conditional independence between the feature space and the class label. The nave conditional independence assumption allows efficient inference of marginal and conditional distributions for large scale learning and inference [19]. We evaluate the proposed algorithm on multimodal MRI brain imagery using ROC statistics and provide preliminary results. The algorithm shows promising segmentation performance with a sensitivity and specificity of 90.37% and 99.74% respectively and compares competitively to alternative interactive segmentation schemes.
Fast X-ray transients in the Galactic bulge with the Rossi X-ray Timing Explorer
Creators: name: Smith, David M.
name: Markwardt, Craig B.
name: Swank, Jean H.
name: Negueruela, Ignacio
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In X-ray binaries, rapid variability in X-ray flux of greater than an order of magnitude on time-scales of a day or less appears to be a signature of wind accretion from a supergiant companion. When the variability takes the form of rare, brief, bright outbursts with only faint emission between them, the systems are called Supergiant Fast X-ray Transients (SFXTs). We present data from twice-weekly scans of the Galactic bulge by the Rossi X-ray Timing Explorer (RXTE) that allow us to compare the behaviour of known SFXTs and possible SFXT candidates with the persistently bright supergiant X-ray binary 4U 1700-377. We independently confirm the orbital periods reported by other groups for SFXTs SAX J1818.6-1703 and IGR J17544-2619. The new data do not independently reproduce the orbital period reported for XTE J1739-302, but slightly improve the significance of the original result when the data are combined. The bulge source XTE J1743-363 shows a combination of fast variability and a long-term decline in activity, the latter behaviour not being characteristic of supergiant X-ray binaries. A far-red spectrum of the companion suggests that it is a symbiotic neutron star binary rather than a high-mass binary, and the reddest known of this class: the spectral type is approximately M8 III.
description: 15 pages, 16 figures, 5 tables, accepted for publication in Monthly Notices of the Royal Astronomical Society
Wavelet processing techniques for digital mammography
Creators: name: Laine, Andrew F.
name: Song, Shuwu
Publisher: name: Columbia University
Year: 1992
Subjects: Medicine
Biomedical engineering

description: This paper introduces a novel approach for accomplishing mammographic feature analysis through multiresolution representations. We show that efficient (nonredundant) representations may be identified from digital mammography and used to enhance specific mammographic features within a continuum of scale space. The multiresolution decomposition of wavelet transforms provides a natural hierarchy in which to embed an interactive paradigm for accomplishing scale space feature analysis. Similar to traditional coarse to fine matching strategies, the radiologist may first choose to look for coarse features (e.g., dominant mass) within low frequency levels of a wavelet transform and later examine finer features (e.g., microcalcifications) at higher frequency levels. In addition, features may be extracted by applying geometric constraints within each level of the transform. Choosing wavelets (or analyzing functions) that are simultaneously localized in both space and frequency, results in a powerful methodology for image analysis. Multiresolution and orientation selectivity, known biological mechanisms in primate vision, are ingrained in wavelet representations and inspire the techniques presented in this paper. Our approach includes local analysis of complete multiscale representations. Mammograms are reconstructed from wavelet representations, enhanced by linear, exponential and constant weight functions through scale space. By improving the visualization of breast pathology we can improve the chances of early detection of breast cancers (improve quality) while requiring less time to evaluate mammograms for most patients (lower costs).
Neutrinoproduction of Photons and Pions From Nucleons in a Chiral Effective Field Theory for Nuclei
Creators: name: Serot, Brian D.
name: Zhang, Xilin
Publisher: name: arXiv
Year: 2012
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Neutrino-induced productions (neutrinoproduction) of photons and pions from nucleons and nuclei are important for the interpretation of neutrino-oscillation experiments, as they are potential backgrounds in the MiniBooNE experiment [A. A. Aquilar-Arevalo et al. (MiniBooNE Collaboration), Phys. Rev. Lett. {\bf 100}, 032301 (2008)]. These processes are studied at intermediate energies, where the Δ(1232) resonance becomes important. The Lorentz-covariant effective field theory, which is the framework used in this series of study, contains nucleons, pions, Δs, isoscalar scalar (σ) and vector (ω) fields, and isovector vector (ρ) fields. The lagrangian exhibits a nonlinear realization of (approximate) $SU(2)_L \otimes SU(2)_R$ chiral symmetry and incorporates vector meson dominance. In this paper, we focus on setting up the framework. Power counting for vertices and Feynman diagrams is explained. Because of the built-in symmetries, the vector current is automatically conserved (CVC), and the axial-vector current is partially conserved (PCAC). To calibrate the axial-vector transition current (N $\leftrightarrow$ Δ), pion production from the nucleon is used as a benchmark and compared to bubble-chamber data from Argonne and Brookhaven National Laboratories. At low energies, the convergence of our power-counting scheme is investigated, and next-to-leading-order tree-level corrections are found to be small.
description: 21 pages, 7 figures, typos corrected. arXiv admin note: substantial text overlap with arXiv:1011.5913
{\it Ab initio} Studies on the Interplay between Spin-Orbit Interaction and Coulomb Correlation in Sr$_2$IrO$_4$ and Ba$_2$IrO$_4$
Creators: name: Arita, R.
name: Kuneš, J.
name: Kozhevnikov, A. V.
name: Eguiluz, A. G.
name: Imada, M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: {\it Ab initio} analyses of A$_2$IrO$_4$ (A=Sr, Ba) are presented. Effective Hubbard-type models for Ir 5$d$ $t_{2g}$ manifolds downfolded from the global band structure are solved based on the dynamical mean-field theory. The results for A=Sr and Ba correctly reproduce paramagnetic metals undergoing continuous transitions to insulators below the Néel temperature $T_N$. These compounds are classified not into Mott insulators but into Slater insulators. However, the insulating gap opens by a synergy of the Neel order and significant band renormalization, which is also manifested by a 2D bad metallic behavior in the paramagnetic phase near the quantum criticality.
description: 5 pages, 3 figures
Activation detection in fMRI data via multi-scale singularity detection
Creators: name: Mekle, Ralf
name: Laine, Andrew F.
name: Perera, Gerard M.
name: Delapaz, Robert L.
Publisher: name: Columbia University
Year: 2000
Subjects: Medicine
Biomedical engineering

description: Detection of active areas in the brain by functional magnetic resonance imaging (fMRI) is a challenging problem in medical imaging. Moreover, determining the onset and end of activation signal at specific locations in 3-space can determined networks of temporal relationships required for brain mapping. We introduce a method for activation detection in fMRI data via wavelet analysis of singular features. We pose the problem of determining activated areas as singularity detection in the temporal domain. Overcomplete wavelet expansion at integer scales are used to trace wavelet modulus maxima across scales to construct maxima lines. Form these maxima lines, singularities in the signal are located corresponding to the onset and end of an activation signal. We present result for simulated phantom waveforms and clinical fMRI dat from human finger tapping experiments. Different levels of noise were added to two waveforms of phantom data. No assumptions about specific frequency and amplitude of an activation signal were made prior to analysis. Detection was reliable for modest levels of random noise, but less precise at higher levels. For clinical fMRI data, activation maps were comparable to those of existing standard techniques.
N-site-lattice analogues of $V(x)=i x^3$
Creators: name: Znojil, Miloslav
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: 81Q12

description: Two discrete N-level alternatives to the popular imaginary cubic oscillator are proposed and studied. In a certain domain ${\cal D}$ of parameters $a$ and $z$ of the model, the spectrum of energies is shown real (i.e., potentially, observable) and the unitarity of the evolution is shown mediated by the construction of a (non-unique) physical, ad hoc Hilbert space endowed with a nontrivial, Hamiltonian-dependent inner-product metric $Θ$. Beyond ${\cal D}$ the complex-energy curves are shown to form a "Fibonacci-numbered" geometric pattern and/or a "topologically complete" set of spectral loci. The dynamics-determining construction of the set of the eligible metrics is shown tractable by a combination of the computer-assisted algebra with the perturbation and extrapolation techniques. Confirming the expectation that for the local potentials the effect of the metric cannot be short-ranged.
description: 28 pp, 17 figures, submitted (and presented also during the conference "Tercentenary of the Laplace-Runge-Lenz vector", Durban, November 23-27, 2011, http://math.ukzn.ac.za/~pllrl/)
Monitoring tuberculosis treatment response using molecular techniques
Creators: name: Farmer, Eoghan
Publisher: name: University of St Andrews
Year: 2019
Subjects: subject: QR201.T6F2
subject: Tuberculosis--Treatment
subject: Tuberculosis--Molecular aspects
subject: Biochemical markers

description: This study looks to monitor tuberculosis treatment response using molecular techniques. An assay for the detection and enumeration of Mycobacterium tuberculosis already existed in the form of the Mycobacterial Load Assay (MBL). This utilised reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) to detect M. tuberculosis 16S ribosomal RNA (rRNA) and thereby quantify bacillary loads in patient sputa. By measuring labile RNA the assay was thought to only measure viable bacilli. However, unpublished data from the Gillespie lab suggested that 16S rRNA remains stable even once cell are non-viable. Two new markers were sought to represent the viable bacilli: M. tuberculosis precursor 16S rRNA (pre-16S rRNA) and transfer- messenger RNA (tm-RNA). Both of these novel biomarkers were chosen because of their complex secondary structures giving them increased stability allowing for their detection in adverse environments. Development and of a multiplex assay using the same messenger RNA (mRNA) phyB internal control utilised by the MBL assay, then the fielding testing of these multiplex assays was performed with the subsequent failure of the phyB control. The internal control was then redesigned to be more robust and reproducible utilising a novel M. marinum control. The new multiplex assays with 16S rRNA, pre-16S rRNA and tm-RNA with the M. marinum internal control were then tested on 520 patient samples to demonstrate that the assays could be used for monitoring treatment response.
Magnitude correlations and criticality in a self-similar model of seismicity
Creators: name: Zambrano Moreno, Andres Felipe
Publisher: name: Science
Year: 2019
Subjects: subject: Emergence
subject: Seismicity
subject: Self-similarity
subject: Physics

description: We present an analysis of the statistical relation between subsequent magnitudes for a previously proposed self-similar aftershock rates model of seismicity whose main distinguishing feature arises as a consequence of the dependency of the rates on the magnitude difference between trigger-triggered events. By means of a particular statistical measure we studied the level of magnitude correlations among time-ordered subsequent events for various magnitude thresholds under specific types of time conditioning, explained their provenance through the model and found that the type of null model chosen in the analysis plays a pivotal role in the type of observed correlations. With particular time conditioning between subsequent events, we also analyzed and compared a model catalog to data from Southern California (SC), and found that model and real-world catalogues are consistent with each other within our statistical measure. When comparing a culled SC and the corresponding culled model catalogue under a specific type of time conditioning and magnitude thresholds, correlations do not significantly deviate from zero for the model but are present in the subset SC catalogue; these observed correlations in the SC catalogue we attributed to a process where a fraction of events are missed in the seismic recordings. The former was substantiated when we looked at the culled SC catalog for higher magnitude thresholds and saw no significant correlations, although the amount of data for this already shortened catalog is relatively low. By creating synthetic catalogues between 2 − 26 times the culled model catalogue, we estimated the length of a catalogue needed to begin to observe magnitude correlations at 3σ to be ∼ 15 times the current culled model catalogue ( ∼ 150 years worth of data) while the existence of magnitude correlations can be used in earthquake forecasting, only the time variations in the frequency-magnitude distribution might lead to a significant improvement in forecasting. We also studied the criticality of the self-similar model from the perspective of finite size effects through the introduction of an upper magnitude cut-off in the analysis and established that the model lies in the sub-critical regime for the SC parameters.
A steerable dyadic wavelet transform and interval wavelets for enhancement of digital mammography
Creators: name: Laine, Andrew F.
name: Koren, Iztok
name: Yang, Wuhai
name: Taylor, Fred
Publisher: name: Columbia University
Year: 1995
Subjects: Medicine
Biomedical engineering

description: This paper describes two approaches for accomplishing interactive feature analysis by overcomplete multiresolution representations. We show quantitatively that transform coefficients, modified by an adaptive non-linear operator, can make more obvious unseen or barely seen features of mammography without requiring additional radiation. Our results are compared with traditional image enhancement techniques by measuring the local contrast of known mammographic features. We design a filter bank representing a steerable dyadic wavelet transform that can be used for multiresolution analysis along arbitrary orientations. Digital mammograms are enhanced by orientation analysis performed by a steerable dyadic wavelet transform. Arbitrary regions of interest (ROI) are enhanced by Deslauriers-Dubuc interpolation representations on an interval. We demonstrate that our methods can provide radiologists with an interactive capability to support localized processing of selected (suspicion) areas (lesions). Features extracted from multiscale representations can provide an adaptive mechanism for accomplishing local contrast enhancement. By improving the visualization of breast pathology can improve changes of early detection while requiring less time to evaluate mammograms for most patients.
Comparative innate responses induced by Toll-like receptor (TLR)7 and 21 ligands against infectious bronchitis virus infection
Creators: name: De Silva Senapathi, Yaseshwari Upasama
Publisher: name: Veterinary Medicine
Year: 2019
Subjects: subject: In ovo; CpG oligonucleotide; resiquimod, infectious bronchitis virus; avian macrophage; CD4+ cell; CD8α+ cell; interleukin-1β; interferon-γ
subject: Veterinary Science
subject: Virology
subject: Immunology
subject: FOS: Clinical medicine

description: Toll-like receptor (TLR)7 and 21 ligands, resiquimod and cytosine-guanosine (CpG) oligonucleotides (ODNs) respectively have been used in ovo (pre-hatch) to enhance or prime an early immune response in chickens to provide protection against microbial pathogens. Yet, their protective efficacy against an infectious bronchitis virus (IBV) infection encountered post-hatch has not been evaluated. Thus, our objectives were to investigate the efficacy of resiquimod and CpG ODNs against a post-hatch IBV infection by delivering the ligands in ovo at embryo day (ED)18 and then, to determine possible mechanisms of protection. We found upregulation of interleukin (IL)-1β and interferon (IFN)-γ mRNA levels and considerable expansions of macrophage and cluster of differentiation (CD)8α+ T cell populations in lungs of chicken as early as day one post-hatch, following pre-hatch delivery of resiquimod. When the resiquimod pre-treated day-old chickens were infected with IBV, reduction in viral shedding via oral and fecal routes was observed at 3 days post-infection (dpi). Similarly, in CpG ODN pre-treated birds at 3 dpi, we found increased recruitment of macrophages, CD8α+ and CD4+ T lymphocytes in addition to up-regulation of IFN-γ and IL-1β mRNA concentrations in chicken lungs. However, only in ovo delivered CpG ODNs significantly reduced the morbidity and mortality associated with IBV infection. Overall, these studies bring us closer to understanding mechanisms behind CpG ODNs and resiquimod induced immune responses in chickens when used as stand-alone prophylactic agents in ovo.
Electrostatic shock dynamics in superthermal plasmas
Creators: name: Sultana, S.
name: Sarri, G.
name: Kourakis, I.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The propagation of ion acoustic shocks in nonthermal plasmas is investigated, both analytically and numerically. An unmagnetized collisionless electron-ion plasma is considered, featuring a superthermal (non-Maxwellian) electron distribution, which is modeled by a $κ$- (kappa) distribution function. Adopting a multiscale approach, it is shown that the dynamics of low-amplitude shocks is modeled by a hybrid Korteweg-de Vries -- Burgers (KdVB) equation, in which the nonlinear and dispersion coefficients are functions of the $κ$ parameter, while the dissipative coefficient is a linear function of the ion viscosity. All relevant shock parameters are shown to depend on $κ$: higher deviations from a pure Maxwellian behavior induce shocks which are narrower, faster and of larger amplitude. The stability profile of the kink-shaped solutions of the KdVB equation against external perturbations is investigated and the spatial profile of the shocks is found to depend upon and the role of the interplay between dispersion and dissipation is elucidated.
description: Accepted for publication in Physics of Plasmas
Fermi edge singularity and finite frequency spectral features in a semi-infinite 1D wire
Creators: name: Sheikhan, A.
name: Snyman, I.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We theoretically study a charge qubit interacting with electrons in a semi-infinite 1D wire. The system displays the physics of the Fermi edge singularity. Our results generalize known results for the Fermi-edge system to the regime where excitations induced by the qubit can resolve the spatial structure of the scattering region. We find resonant features in the qubit tunneling rate as a function of the qubit level splitting. They occur at integer multiples of h times v_F/l. Here v_F is the Fermi velocity of the electrons in the wire, and l is the distance from the tip of the wire to the point where it interacts with the qubit. These features are due to a single coherent charge fluctuation in the electron gas, with a half-wavelength that fits into l an integer number of times. As the coupling between the qubit and the wire is increased, the resonances are washed out. This is a clear signature of the increasingly violent Fermi-sea shake-up that accompanies strong coupling.
description: 11 pages
Kolorektale Neoplasien im Landkreis Aue-Schwarzenberg Analyse der Koloskopien am HELIOS Klinikum Aue im Zehnjahreszeitraum 1996 - 2005
Creators: name: Singer, Cornelia
Publisher: name: Universitäts- und Landesbibliothek Sachsen-Anhalt
Year: 2019
Subjects: subject: 610

description: Für die Region Aue-Schwarzenberg (Sachsen, Deutschland) liegt bisher keine systematische Auswertung der in der Region durchgeführten Koloskopien vor. Daten bezüglich Komplikationsraten für ein überwiegend stationäres Patientengut sind kaum verfügbar. Die vorliegende Arbeit umfasst eine retrospektive Auswertung aller im Zeitraum von 1996 bis 2005 am HELIOS Klinikum Aue durchgeführten Koloskopien. Bei den insgesamt 10.771 Koloskopien konnte in 3.106 Untersuchungen mindestens ein histopathologischer Befund erfasst werden. Komplikationen traten bei 64 Koloskopien (0,6%) auf. Untersuchungen mit spezifischer Indikation hatten ein 6-fach erhöhtes Risiko für Blutungskomplikationen. Die erhobenen Häufigkeiten kolorektaler Neoplasien stehen in Übereinstimmung mit bisherigen Studien. Die Komplikationsraten sind auch bei stationären Patienten mit 0,6% niedrig. Die vorliegende Arbeit präsentiert einen Vorschlag zur Vereinheitlichung der Klassifizierung und Erfassung von Blutungskomplikationen und empfiehlt die Etablierung eines Qualitätssicherungsbogens.
description: A systematic analysis of colonoscopies in the district of Aue-Schwarzenberg, Saxony, Germany is not yet available. Data regarding complication rates of colonoscopies for in-patient setting is sparse. The following study provides a retrospective analysis of all colonoscopies performed at the HELIOS Klinikum Aue between 1996 and 2005. In 3.106 of 10.771 colonoscopies (28.8%) polyps and / or carcinomas were detected. Complications could be observed in 64 colonoscopies (0,6%) and involved mainly bleeding complications. Colonoscopies with specific indications had a 6-fold increased risk of bleeding as compared with colonoscopies with non-specific indications. Frequencies of colorectal neoplasia were comparable with former studies. The observed complication rate of 0.6% was also low for in-patient setting and comparable to data already reported for out-patient setting. The study presents a proposal for the classification and registration of bleeding complications and suggests the use of a quality assurance bow for all colonoscopies.
A wavelet based mammographic system
Creators: name: Laine, Andrew F.
name: Lewis, Michael
name: Taylor, Fred
Publisher: name: Columbia University
Year: 1994
Subjects: Medicine
Biomedical engineering

description: Mammography's role in the detection of breast cancer at early stages is well known. Although more accurate than other existing techniques, mammography still only finds 80 to 90 percent of breast cancers. It has been suggested that mammograms, as normally viewed, display only about 3% of the total information detected. The general inability to detect small tumors and other salient features within mammograms motivates our investigation of a system we call the Mammogram Display System (MDS). The core technology used for MDS image enhancement is the wavelet transform.
Time evolution of ground motion-dependent depolarisation at linear colliders
Creators: name: Bailey, I.
name: Bartels, C.
name: Beckmann, M.
name: Hartin, A.
name: Helebrant, C.
name: Kaefer, D.
name: List, J.
name: Moortgat-Pick, G.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: Future linear colliders plan to collide polarised beams and the planned physics reach requires knowledge of the state of polarisation as precisely as possible. The polarised beams can undergo depolarisation due to various mechanisms. In order to quantify the uncertainty due to depolarisation, spin tracking simulations in the International Linear Collider (ILC) Beam Delivery System (BDS) and at the Interaction Point (IP) have been performed. Spin tracking in the BDS was achieved using the BMAD subroutine library, and the CAIN program was used to do spin tracking through the beam-beam collision. Assuming initially aligned beamline elements in the BDS, a ground motion model was applied to obtain realistic random misalignments over various time scales. Depolarisation at the level of 0.1% occurs within a day of ground motion at a noisy site. Depolarisation at the IP also exceeds 0.1% for the nominal parameter sets for both the ILC and for the Compact Linear Collider (CLIC). Theoretical work is underway to include radiative corrections in the depolarisation processes and simulation of the depolarisation through the entire collider is envisaged.
description: 8 pages, 4 figures, PST09 proceedings; Proceedings of the 13th International Workshop on Polarised Sources, Targets and Polarimetry 2009, World Scientific 2011
Adaptive multiscale processing for contrast enhancement
Creators: name: Laine, Andrew F.
name: Song, Shuwu
name: Fan, Jian
name: Huda, Walter
name: Honeyman, Janice
name: Steinbach, Barbara
Publisher: name: Columbia University
Year: 1993
Subjects: Medicine
Biomedical engineering

description: This paper introduces a novel approach for accomplishing mammographic feature analysis through overcomplete multiresolution representations. We show that efficient representations may be identified from digital mammograms within a continuum of scale space and used to enhance features of importance to mammography. Choosing analyzing functions that are well localized in both space and frequency, results in a powerful methodology for image analysis. We describe methods of contrast enhancement based on two overcomplete (redundant) multiscale representations: (1) Dyadic wavelet transform (2) (phi) -transform. Mammograms are reconstructed from transform coefficients modified at one or more levels by non-linear, logarithmic and constant scale-space weight functions. Multiscale edges identified within distinct levels of transform space provide a local support for enhancement throughout each decomposition. We demonstrate that features extracted from wavelet spaces can provide an adaptive mechanism for accomplishing local contrast enhancement. We suggest that multiscale detection and local enhancement of singularities may be effectively employed for the visualization of breast pathology without excessive noise amplification.
Hexagonal wavelet processing of digital mammography
Creators: name: Laine, Andrew F.
name: Schuler, Sergio
name: Huda, Walter
name: Honeyman, Janice
name: Steinbach, Barbara
Publisher: name: Columbia University
Year: 1993
Subjects: Medicine
Biomedical engineering

description: This paper introduces a novel approach for accomplishing mammographic feature analysis through overcomplete multiresolution representations. We show that efficient representations may be identified from digital mammograms and used to enhance features of importance to mammography within a continuum of scale-space. We present a method of contrast enhancement based on an overcomplete, non-separable multiscale representation: the hexagonal wavelet transform. Mammograms are reconstructed from transform coefficients modified at one or more levels by local and global non-linear operators. Multiscale edges identified within distinct levels of transform space provide local support for enhancement. We demonstrate that features extracted from multiresolution representations can provide an adaptive mechanism for accomplishing local contrast enhancement. We suggest that multiscale detection and local enhancement of singularities may be effectively employed for the visualization of breast pathology without excessive noise amplification.
On discrete dyadic wavelets for contrast enhancement
Creators: name: Laine, Andrew F.
name: Fan, Jian
name: Schuler, Sergio
Publisher: name: Columbia University
Year: 1994
Subjects: Medicine
Biomedical engineering

description: In this paper, we establish a mathematical connection between dyadic-wavelet-based contrast enhancement and traditional unsharp masking. Our derivation is completely based in the discrete domain. These findings may provide a better theoretical understanding of these algorithms, and facilitate the acceptance of multiscale enhancement techniques applied to medical imaging.