126 research outputs found
Algebraic extensions of Gaudin models
We perform a In\"on\"u--Wigner contraction on Gaudin models, showing how the
integrability property is preserved by this algebraic procedure. Starting from
Gaudin models we obtain new integrable chains, that we call Lagrange chains,
associated to the same linear -matrix structure. We give a general
construction involving rational, trigonometric and elliptic solutions of the
classical Yang-Baxter equation. Two particular examples are explicitly
considered: the rational Lagrange chain and the trigonometric one. In both
cases local variables of the models are the generators of the direct sum of
interacting tops.Comment: 15 pages, corrected formula
Chasing the cuprates with dilatonic dyons
Magnetic field and momentum dissipation are key ingredients in describing
condensed matter systems. We include them in gauge/gravity and systematically
explore the bottom-up panorama of holographic IR effective field theories based
on bulk Einstein-Maxwell Lagrangians plus scalars. The class of solutions here
examined appear insufficient to capture the phenomenology of charge transport
in the cuprates. We analyze in particular the temperature scaling of the
resistivity and of the Hall angle. Keeping an open attitude, we illustrate weak
and strong points of the approach.Comment: 30 pages, 2 figures, Version to appear in JHE
B\"acklund transformations for the rational Lagrange chain
We consider a long--range homogeneous chain where the local variables are the
generators of the direct sum of interacting Lagrange
tops. We call this classical integrable model rational ``Lagrange chain''
showing how one can obtain it starting from rational Gaudin
models. Moreover we construct one- and two--point integrable maps (B\"acklund
transformations).Comment: 12 page
Modeling of a Non-Rigid Passive Exoskeleton-Mathematical Description and Musculoskeletal Simulations
There is a growing application of passive exoskeletons in the industrial sector with the purpose to reduce the incidence of work-related musculoskeletal disorders (MSDs). Nowadays, while many passive shoulder exoskeletons have been developed to support overhead tasks, they present limitations in supporting tasks such as load lifting and carrying. Further developments are therefore needed to have a wider application of these devices in the industrial sector. This paper presents a modelling procedure of a passive non-rigid exoskeleton for shoulder support that can be used to evaluate the device in its development phase. The modelling began with the definition of the equations to describe the exoskeleton kinematics and dynamics to obtain the support force profile provided by the device over the shoulder flexion angle. A musculoskeletal simulation software was then used to evaluate the effect of the device on the human body. The computed support force profile is in agreement with the purpose of the device, with the maximal support force obtained for a shoulder flexion angle of 85–90°. The maximum support force value had the same magnitude as the one reported by the device user manual (3.5 kg). In particular, for a determined exoskeleton configuration, the maximum support force value computed was 34.3 N, equal to the reported by the manufacturer. The subsequent musculoskeletal simulation showed the ability of the device to reduce the muscular activation of agonist muscles such as the anterior deltoid (−36.01%) compared to the case when the exoskeleton is not used. The musculoskeletal results showed a positive effect of the device on the joint reaction forces at the glenohumeral joint with a reduction up to 41.91%. Overall the methodology and the mathematical model proposed can be used to further develop these devices, making them suitable for a wider range of tasks
Gaudin models with {\CU}_q(\mathfrak{osp}(1 | 2)) symmetry
We consider a Gaudin model related to the q-deformed superalgebra
{\CU}_q(\mathfrak{osp}(1 | 2)). We present an exact solution to that system
diagonalizing a complete set of commuting observables, and providing the
corresponding eigenvectors and eigenvalues. The approach used in this paper is
based on the coalgebra supersymmetry of the model.Comment: 10 page
A First Assessment of Carbon Nanotubes Grown on Oil-Well Cement via Chemical Vapor Deposition
In this study, carbon nanotubes (CNTs) were synthesized on an oil-well cement substrate using the chemical vapor deposition (CVD) method. The effect of synthesis process on cement was investigated in depth. In this regard, FE-SEM, RAMAN and X-Ray spectroscopy were used to characterize the cement before and after the synthesis process to reveal the modifications to the cementitious matrix and some unique morphological features of CNTs
An integrable discretization of the rational su(2) Gaudin model and related systems
The first part of the present paper is devoted to a systematic construction
of continuous-time finite-dimensional integrable systems arising from the
rational su(2) Gaudin model through certain contraction procedures. In the
second part, we derive an explicit integrable Poisson map discretizing a
particular Hamiltonian flow of the rational su(2) Gaudin model. Then, the
contraction procedures enable us to construct explicit integrable
discretizations of the continuous systems derived in the first part of the
paper.Comment: 26 pages, 5 figure
An EBC/Plasma miRNA Signature Discriminates Lung Adenocarcinomas From Pleural Mesothelioma and Healthy Controls
Background: Despite significant improvement in screening programs for cancers of the respiratory district, especially in at-risk subjects, early disease detection is still a major issue. In this scenario, new molecular and non-invasive biomarkers are needed to improve early disease diagnosis.
Methods: We profiled the miRNome in exhaled breath condensate (EBC) and plasma samples from fourteen patients affected by lung AdCa, nine healthy subjects. miRNA signatures were then analyzed in another neoplasia of the respiratory district, i.e. pleural mesothelioma (n = 23) and subjects previously exposed to asbestos were used as controls for this cohort (n = 19). Selected miRNAs were analyzed in purified pulmonary neoplastic or normal epithelial and stromal cell subpopulation from AdCa patients. Finally, the plasmatic miRNA signature was analyzed in a publicly available cohort of NSCLC patients for data validation and in silico analysis was performed with predicted miRNA targets using the multiMiR tool and STRING database.
Results: miR-597-5p and miR-1260a are significantly over-expressed in EBC from lung AdCa and are associated with AdCa. Similarly, miR-1260a is also up-regulated in the plasma of AdCa patients together with miR-518f-3p and correlates with presence of lung cancer, whereas let-7f-5p is under-expressed. Analysis of these circulating miRNAs in pleural mesothelioma cases confirmed that up-regulation of miR-518f-3p, -597-5p and -1260a, is specific for lung AdCa. Lastly, quantification of the miRNAs in laser-assisted microdissected lung tissues revealed that miR-518f-3p, 597-5p and miR-1260a are predominantly expressed in tumor epithelial cells. Validation analysis confirmed miR-518f-3p as a possible circulating biomarker of NSCLC. In silico analysis of the potentially modulated biological processes by these three miRNAs, shows that tumor bioenergetics are the most affected pathways.
Conclusions: Overall, our data suggest a 3-miRNAs signature as a non-invasive and accurate biomarker of lung AdCa. This approach could supplement the current screening approaches for early lung cancer diagnosis
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