320 research outputs found
Black string first order flow in N = 2, d = 5 abelian gauged supergravity
We derive both BPS and non-BPS first-order flow equations for magnetically
charged black strings in five-dimensional N=2 abelian gauged supergravity,
using the Hamilton-Jacobi formalism. This is first done for the coupling to
vector multiplets only and U(1) Fayet-Iliopoulos (FI) gauging, and then
generalized to the case where also hypermultiplets are present, and abelian
symmetries of the quaternionic hyperscalar target space are gauged. We then use
these results to derive the attractor equations for near-horizon geometries of
extremal black strings, and solve them explicitely for the case where the
constants appearing in the Chern-Simons term of the supergravity action satisfy
an adjoint identity. This allows to compute in generality the central charge of
the two-dimensional conformal field theory that describes the black strings in
the infrared, in terms of the magnetic charges, the CY intersection numbers and
the FI constants. Finally, we extend the r-map to gauged supergravity and use
it to relate our flow equations to those in four dimensions.Comment: 21 pages, uses jheppub.sty. v2: Minor errors corrected, refs. added.
v3: Minor error corrected in app. B, small discussion of string theory
realization added in final remark
Persistent Homology analysis of Phase Transitions
Persistent homology analysis, a recently developed computational method in
algebraic topology, is applied to the study of the phase transitions undergone
by the so-called XY-mean field model and by the phi^4 lattice model,
respectively. For both models the relationship between phase transitions and
the topological properties of certain submanifolds of configuration space are
exactly known. It turns out that these a-priori known facts are clearly
retrieved by persistent homology analysis of dynamically sampled submanifolds
of configuration space.Comment: 10 pages; 10 figure
Homological scaffold via minimal homology bases
The homological scaffold leverages persistent homology to construct a topologically sound summary of a weighted network. However, its crucial dependency on the choice of representative cycles hinders the ability to trace back global features onto individual network components, unless one provides a principled way to make such a choice. In this paper, we apply recent advances in the computation of minimal homology bases to introduce a quasi-canonical version of the scaffold, called minimal, and employ it to analyze data both real and in silico. At the same time, we verify that, statistically, the standard scaffold is a good proxy of the minimal one for sufficiently complex networks
Magnetoliposomes: opportunities and challenges
Combining liposomes with magnetic nanoparticles is an intriguing approach to create multifunctional vesicles for medical applications, which range from controlled drug delivery vehicles to diagnostic imaging enhancers. Over the past decade, significant effort has been invested in developing such hybrids - widely known as magnetoliposomes - and has led to numerous new concepts. This review provides an overview on of the current state of the art in this field. The concept of magnetic fluid hyperthermia and stimuli-responsive nanoparticles for drug delivery is briefly recapitulated. The materials needed for these hybrids are addressed as well. The three typically followed approaches to associate magnetic nanoparticles to the liposomes are described and discussed more in detail. The final chapters are dedicated to the analytical methods used to characterize these hybrids and to theoretical considerations relevant for bilayer-embedded nanoparticle
The complexity of titin splicing pattern in human adult skeletal muscles
Background: Mutations in the titin gene (TTN) cause a large spectrum of diseases affecting skeletal and/or cardiac muscle. TTN includes 363 coding exons, a repeated region with a high degree of complexity, isoform-specific elements, and metatranscript-only exons thought to be expressed only during fetal development. Although three main classes of isoforms have been described so far, alternative splicing events (ASEs) in different tissues or in different developmental and physiological states have been reported. Methods: To achieve a comprehensive view of titin ASEs in adult human skeletal muscles, we performed a RNA-Sequencing experiment on 42 human biopsies collected from 12 anatomically different skeletal muscles of 11 individuals without any skeletal-muscle disorders. Results: We confirmed that the skeletal muscle N2A isoforms are highly prevalent, but we found an elevated number of alternative splicing events, some at a very high level. These include previously unknown exon skipping events and alternative 5' and 3' splice sites. Our data suggests the partial inclusion in the TTN transcript of some metatranscript-only exons and the partial exclusion of canonical N2A exons. Conclusions: This study provides an extensive picture of the complex TTN splicing pattern in human adult skeletal muscle, which is crucial for a proper clinical interpretation of TTN variants.Peer reviewe
A unified framework for Simplicial Kuramoto models
Simplicial Kuramoto models have emerged as a diverse and intriguing class of
models describing oscillators on simplices rather than nodes. In this paper, we
present a unified framework to describe different variants of these models,
categorized into three main groups: "simple" models, "Hodge-coupled" models,
and "order-coupled" (Dirac) models. Our framework is based on topology,
discrete differential geometry as well as gradient flows and frustrations, and
permits a systematic analysis of their properties. We establish an equivalence
between the simple simplicial Kuramoto model and the standard Kuramoto model on
pairwise networks under the condition of manifoldness of the simplicial
complex. Then, starting from simple models, we describe the notion of
simplicial synchronization and derive bounds on the coupling strength necessary
or sufficient for achieving it. For some variants, we generalize these results
and provide new ones, such as the controllability of equilibrium solutions.
Finally, we explore a potential application in the reconstruction of brain
functional connectivity from structural connectomes and find that simple
edge-based Kuramoto models perform competitively or even outperform complex
extensions of node-based models.Comment: 36 pages, 11 figure
ODIN AD: a framework supporting the life-cycle of time series anomaly detection applications
Anomaly detection (AD) in numerical temporal data series is a prominent task in many domains, including the analysis of industrial equipment operation, the processing of IoT data streams, and the monitoring of appliance energy consumption. The life-cycle of an AD application with a Machine Learning (ML) approach requires data collection and preparation, algorithm design and selection, training, and evaluation. All these activities contain repetitive tasks which could be supported by tools. This paper describes ODIN AD, a framework assisting the life-cycle of AD applications in the phases of data preparation, prediction performance evaluation, and error diagnosis
How important is the role of iterative liver direct surgery in patients with hepatocellular carcinoma for a transplant center located in an area with a low rate of deceased donation?
Introduction: Hepatocellular carcinoma (HCC) accounts for nearly 90% of primary liver cancers, with estimates of over 1 million people affected by 2025. We aimed to explore the impacting role of an iterative surgical treatment approach in a cohort of HCC patients within the Milan criteria, associated with clinical risk factors for tumor recurrence (RHCC) after liver transplant (LT) and loco-regional therapies (LRT), as well as liver resection (LR) and/or microwave thermal ablation (MWTA). Methods: We retrospectively analyzed our experience performed during an 8-year period between January 2013 and December 2021 in patients treated for HCC, focusing on describing the impact on preoperative end-stage liver disease severity, oncologic staging, tumor characteristics, and surgical treatments. The Cox model was used to evaluate variables that could predict relapse risks. Relapse risk curves were calculated according to the Kaplan-Meier method, and the log-rank test was used to compare them. Results: There were 557 HCC patients treated with a first-line approach of LR and/or LRTs (n = 335) or LT (n = 222). The median age at initial transplantation was 59 versus 68 for those whose first surgical approach was LR and/or LRT. In univariate analysis with the Cox model, nodule size was the single predictor of recurrence of HCC in the posttreatment setting (HR: 1.61, 95% CI: 1.05-2.47, p = 0.030). For the LRT group, we have enlightened the following clinical characteristics as significantly associated with RHCC: hepatitis B virus infection (which has a protective role with HR: 0.34, 95% CI: 0.13-0.94, p = 0.038), number of HCC nodules (HR: 1.54, 95% CI: 1.22-1.94, p < 0.001), size of the largest nodule (HR: 1.06, 95% CI: 1.01-1.12, p = 0.023), serum bilirubin (HR: 1.57, 95% CI: 1.03-2.40, p = 0.038), and international normalized ratio (HR: 16.40, 95% CI: 2.30-118.0, p = 0.006). Among the overall 111 patients with RHCC in the LRT group, 33 were iteratively treated with further curative treatment (12 were treated with LR, two with MWTA, three with a combined LR-MWTA treatment, and 16 underwent LT). Only one of 18 recurrent patients previously treated with LT underwent LR. For these RHCC patients, multivariable analysis showed the protective roles of LT for primary RHCC after IDLS (HR: 0.06, 95% CI: 0.01-0.36, p = 0.002), of the time relapsed between the first and second IDLS treatments (HR: 0.97, 95% CI: 0.94-0.99, p = 0.044), and the impact of previous minimally invasive treatment (HR: 0.28, 95% CI: 0.08-1.00, p = 0.051). Conclusion: The coexistence of RHCC with underlying cirrhosis increases the complexity of assessing the net health benefit of ILDS before LT. Minimally invasive surgical therapies and time to HCC relapse should be considered an outcome in randomized clinical trials because they have a relevant impact on tumor-free survival
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