459 research outputs found
On membrane interactions and a three-dimensional analog of Riemann surfaces
Membranes in M-theory are expected to interact via splitting and joining
processes. We study these effects in the pp-wave matrix model, in which they
are associated with transitions between states in sectors built on vacua with
different numbers of membranes. Transition amplitudes between such states
receive contributions from BPS instanton configurations interpolating between
the different vacua. Various properties of the moduli space of BPS instantons
are known, but there are very few known examples of explicit solutions. We
present a new approach to the construction of instanton solutions interpolating
between states containing arbitrary numbers of membranes, based on a continuum
approximation valid for matrices of large size. The proposed scheme uses
functions on a two-dimensional space to approximate matrices and it relies on
the same ideas behind the matrix regularisation of membrane degrees of freedom
in M-theory. We show that the BPS instanton equations have a continuum
counterpart which can be mapped to the three-dimensional Laplace equation
through a sequence of changes of variables. A description of configurations
corresponding to membrane splitting/joining processes can be given in terms of
solutions to the Laplace equation in a three-dimensional analog of a Riemann
surface, consisting of multiple copies of R^3 connected via a generalisation of
branch cuts. We discuss various general features of our proposal and we also
present explicit analytic solutions.Comment: 64 pages, 17 figures. V2: An appendix, a figure and references added;
various minor changes and improvement
Membranes from monopole operators in ABJM theory: large angular momentum and M-theoretic AdS_4/CFT_3
We consider states with large angular momentum to facilitate the study of the
M-theory regime of the AdS_4/CFT_3 correspondence. We study the duality between
M-theory in AdS_4xS^7/Z_k and the ABJM N=6 Chern-Simons-matter theory with
gauge group U(N)xU(N) and level k, taking N large and k of order 1. In this
regime the lack of an explicit formulation of M-theory in AdS_4xS^7/Z_k makes
the gravity side difficult, while the CFT is strongly coupled and the planar
approximation is not applicable. To overcome these difficulties, we focus on
states on the gravity side with large angular momentum J>>1 and identify the
dual operators in the CFT, thereby establishing the AdS/CFT dictionary in this
sector. Natural approximation schemes arise on both sides thanks to the
presence of the small parameter 1/J. On the AdS side, we use the matrix model
of M-theory on the maximally supersymmetric pp-wave background with matrices of
size J/k. A perturbative treatment of this matrix model provides a good
approximation to M-theory in AdS_4xS^7/Z_k when N^{1/3}<<J<<N^{1/2}. On the CFT
side, we study the theory on S^2xR with magnetic flux J/k. A Born-Oppenheimer
type expansion arises naturally for large J in spite of the theory being
strongly coupled. The energy spectra on the two sides agree at leading order.
This provides a non-trivial test of the AdS_4/CFT_3 correspondence including
near-BPS observables associated with membrane degrees of freedom, thus
verifying the duality beyond the previously studied sectors corresponding to
either BPS observables or the type IIA string regime.Comment: 67 pages, 5 figures; V2: minor changes, references adde
Diagnostic utility of measuring lactate dehydrogenase levels and its isoenzyme activities for the evaluation of malignancy in feline pleural effusion and ascitic fluid
Background: Lactate dehydrogenase (LDH) isoenzymes may be useful in the differential diagnosis of pleural effusion (PE) and ascitic fluid (AF) etiologies in cats since tissue damage induces their release, changing the pattern of their activity.
Aim: This study aimed to determine the diagnostic utility of measuring LDH levels and isoenzyme activities in PE or AF in cats with malignancy.
Methods: LDH levels and isoenzyme activities in the serum, PE, and AF were compared among cats in the malignant, infectious, and non-malignant, non-infectious groups. A receiver operating characteristic (ROC) analysis was performed to assess the accuracy in diagnosing feline malignancy.
Results: Significant differences in LDH level and LDH isoenzyme activities in the PE and AF were observed among the three groups. The combination of LDH level and LDH-1 activity in PE or AF had the highest area under the ROC (AUC) values for discriminating malignant effusion from non-malignant effusion. The AUC of the combination of LDH level and LDH-1 activity in PE or AF was 0.874. The sensitivity and specificity of using the combination of LDH level (cut-off: <2,269 U/l) and LDH-1 activity (cut-off: <4.8%) in PE or AF for predicting malignancy with the highest AUC value were 94.4% and 72.7%, respectively.
Conclusion: Our results suggest that the combination of LDH level and LDH-1 activity in PE or AF is a potential factor for diagnosing malignancy. Considering that LDH isoenzymes can be measured inexpensively and easily, LDH tests can be readily accommodated in veterinary clinical practice
Socially Anxious Tendencies Affect Impressions of Others’ Positive and Negative Emotional Gazes
Socially anxious tendencies have potential to become social anxiety disorder (SAD), which is characterized by fear of social situations associated with being evaluated or embarrassed by others. In particular, others’ gazes induce social anxiety. People with SAD have a negative interpretation bias toward ambiguous emotions in others’ faces; however, negative interpretation bias toward ambiguous emotions in others’ gazes has not been fully investigated. We used an impression judgment task to examine negative interpretation bias toward others’ gazes among people with socially anxious tendencies. We generated emotionally ambiguous gazes (positive, negative, and neutral) using a morphing technique with 10% steps (neutral, 10–100% negative, and 10–100% positive). Participants (all male) were asked to judge whether the stimulus was positive or negative. Each participant’s level of social anxiety was examined using the Japanese version of the Social Phobia Inventory (SPIN-J), which measures three symptom dimensions: fear, avoidance, and physiological arousal. To examine the influence of socially anxious tendencies in the impression judgment task, we calculated the point of subjective equality (PSE) using a two-step logistic curve fitted to individual participant’s responses. The negative emotional intensity of the PSE became lower as the fear score became higher (p < 0.05). This result suggests individuals with a high tendency toward social anxiety tend to interpret subtle negative emotional gazes as a negative emotion and regard these gazes as a threat
Towards a tensionless string field theory for the N=(2,0) CFT in d=6
We describe progress in using the field theory of tensionless strings to arrive at a Lagrangian for the six-dimensional N=(2,0) conformal theory. We construct the free part of the theory and propose an ansatz for the cubic vertex in light-cone superspace. By requiring closure of the (2,0) supersymmetry algebra, we fix the cubic vertex up to two parameters
An Empirical Study of Electric Power Demand Control by Real-time Feedback of Consumption Levels: Case of Nushima Island Households
AbstractElectric power demand management will play an important role in the creation of smart-energy communities. We are conducting a field experiment on the real-time feedback of electric power consumption via smart meters and tablet PCs with the participation of 51 households on Nushima Island, one of Japan's remote islands. Our estimate of the effect of feedback in reducing power demand by panel data analysis has revealed that such feedback achieves a saving of 7.6 percent in electric power demand
Evaluation of Patient Positioning during Digital Tomosynthesis and Reconstruction Algorithms for Ilizarov Frames: A Phantom Study
Aim: Metallic components from circular external fixators, including the Ilizarov frame, cause artefacts on X-rays and obstruct clear visualisation of bone detail. We evaluated the ability of tomosynthesis to reduce interference on radiographs caused by metal artefacts and developed an optimal image acquisition method for such cases.
Materials and methods: An Ilizarov frame phantom was constructed using rods placed on the bone for the purpose to evaluate the benefits of tomosynthesis. Distances between the rod and bone and the angle between the rod and X-ray tube orbit were set at three different levels. Filtered backprojection images were reconstructed using two different features of the reconstruction function: THICKNESS−− (CONTRAST4) and THICKNESS++ (METAL4); the first is suitable for improving contrast and the second is suitable for metal artefacts. The peak signal-to-noise ratio (PSNR) was used during image evaluation to determine the influence of the metallic rod on bone structure visibility.
Results: The PSNR increased as the angle between the metal rod and the X-ray tube orbit and the distance between the metallic rod and bone increased. The PSNR was larger when using THICKNESS−− (CONTRAST4) than when using THICKNESS++ (METAL4).
Conclusion: The optimal reconstruction function and image acquisition determined using the metallic rod in this study suggest that quality equal to that without the metallic rod can be obtained.
Clinical significance: We describe an optimised method for image acquisition without unnecessary acquisition repetition and unreasonable posture changes when the bone cannot be adequately visualised
An Attention-based Approach to Hierarchical Multi-label Music Instrument Classification
Although music is typically multi-label, many works have studied hierarchical
music tagging with simplified settings such as single-label data. Moreover,
there lacks a framework to describe various joint training methods under the
multi-label setting. In order to discuss the above topics, we introduce
hierarchical multi-label music instrument classification task. The task
provides a realistic setting where multi-instrument real music data is assumed.
Various hierarchical methods that jointly train a DNN are summarized and
explored in the context of the fusion of deep learning and conventional
techniques. For the effective joint training in the multi-label setting, we
propose two methods to model the connection between fine- and coarse-level
tags, where one uses rule-based grouped max-pooling, the other one uses the
attention mechanism obtained in a data-driven manner. Our evaluation reveals
that the proposed methods have advantages over the method without joint
training. In addition, the decision procedure within the proposed methods can
be interpreted by visualizing attention maps or referring to fixed rules.Comment: To appear at ICASSP 202
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