1,313 research outputs found
Counting Arithmetical Structures on Paths and Cycles
Let G be a finite, connected graph. An arithmetical structure on G is a pair of positive integer vectors d, r such that (diag (d) - A) r=0 , where A is the adjacency matrix of G. We investigate the combinatorics of arithmetical structures on path and cycle graphs, as well as the associated critical groups (the torsion part of the cokernels of the matrices (diag (d) - A)). For paths, we prove that arithmetical structures are enumerated by the Catalan numbers, and we obtain refined enumeration results related to ballot sequences. For cycles, we prove that arithmetical structures are enumerated by the binomial coefficients ((2n-1)/(n-1)) , and we obtain refined enumeration results related to multisets. In addition, we determine the critical groups for all arithmetical structures on paths and cycles
Counting Arithmetical Structures on Paths and Cycles
Let G be a finite, connected graph. An arithmetical structure on G is a pair of positive integer vectors d, r such that (diag (d) - A) r=0 , where A is the adjacency matrix of G. We investigate the combinatorics of arithmetical structures on path and cycle graphs, as well as the associated critical groups (the torsion part of the cokernels of the matrices (diag (d) - A)). For paths, we prove that arithmetical structures are enumerated by the Catalan numbers, and we obtain refined enumeration results related to ballot sequences. For cycles, we prove that arithmetical structures are enumerated by the binomial coefficients ((2n-1)/(n-1)) , and we obtain refined enumeration results related to multisets. In addition, we determine the critical groups for all arithmetical structures on paths and cycles
More on -flux and General Hodge Cycles on the Fermat Sextic
We study M-Theory solutions with -flux on the Fermat sextic Calabi-Yau
fourfold, focussing on the relationship between the number of stabilized
complex structure moduli and the tadpole contribution of the flux. We use two
alternative approaches to define the fluxes: algebraic cycles and
(appropriately quantized) Griffiths residues. In both cases, we collect
evidence for the non-existence of solutions which stabilize all moduli and stay
within the tadpole boundComment: v2: typos corrected and references adde
The calcium goes meow : effects of ions and glycosylation on Fel d 1, the major cat allergen
The major cat allergen, Fel d 1, is a structurally complex protein with two N-glycosylation sites that may be filled by different glycoforms. In addition, the protein contains three putative Ca2+ binding sites. Since the impact of these Fel d 1 structure modifications on the protein dynamics, physiology and pathology are not well established, the present work employed computational biology techniques to tackle these issues. While conformational effects brought upon by glycosylation were identified, potentially involved in cavity volume regulation, our results indicate that only the central Ca2+ion remains coordinated to Fel d 1 in biological solutions, impairing its proposed role in modulating phospholipase A2 activity. As these results increase our understanding of Fel d 1 structural biology, they may offer new support for understanding its physiological role and impact into cat-promoted allergy
Shock-Boundary Layer Interactions in Supersonic Turbine Cascades
The physics of shock-boundary layer interactions in a supersonic turbine
cascade is investigated through a wall-resolved large eddy simulation. Special
attention is given to the characterization of the low-frequency dynamics of the
separation bubbles using flow visualization, spectral analysis, space-time
cross correlations, and flow modal decomposition. The mean flowfield shows
different shock structures formed on both sides of the airfoil. On the suction
side, an oblique shock impinges on the turbulent boundary layer, whereas a Mach
reflection interacts with the pressure side boundary layer. Instantaneous flow
visualizations illustrate elongated streamwise structures on the incoming
boundary layers and their interactions with the shocks and separation bubbles.
The passage of high-speed (low-speed) streaks through the recirculation bubbles
leads to the downstream (upstream) motion of the separation point on both
suction and pressure sides, resulting in spanwise modulation of the bubbles.
Space-time cross-correlations reveal that the near-wall streaks drive the
suction side separation bubble motion, which in turn promotes the oscillations
of the reattachment shock and shear layer flapping. Space-time correlations
also indicate the existence of a phase jump in the pressure fluctuations
along the separation bubble on the suction side. After this phase jump, a
downstream propagating pressure disturbance is observed, while prior to this
point, the pressure disturbances dominantly propagate in the upstream
direction. Finally, the organized motions in the shock-boundary layer
interactions and their corresponding characteristic frequencies are identified
using proper orthogonal decomposition.Comment: 40 pages, 19 figures. Submitted to Physical Review Fluid
UPPERCARE: a community aware environment for post-surgical musculoskeletal recovery of elderly patients
Trabalho apresentado na Conferência Internacional realizada em Wellington, Nova Zelândia, de 26-28 de abril de 2017Disability from musculoskeletal diseases and comorbidities may lead to the worsening of social and economic
well-being through a multitude of paths. Moreover since in European Union (EU) Member States it is projected that those aged 65 and over will become a much larger share (rising from 17% to 30% of the population), and those aged 80 and over (rising from 5% to 12%) will almost become as numerous as the young population in 2060, there is a great potential for Information and Communication Technologies (ICT) solutions for addressing the present and future living arrangements in older people.
The UPPERCARE system is meant to affect positively both the intergenerational and partners care since it contributes to decrease usability barriers and promote collaborative environments for informal and self-care. UPPERCARE is a new approach for integrated care supported by ICT systems and services, focusing
on post-operative rehabilitation of musculoskeletal pathologies, having as a case study the knee post-operative scenarios of prosthetic care. This paper presents the UPPERCARE system, that provides an integrated care solution, supported ICT, for empowering self-care and adherence to rehabilitation plans through natural interfaces, gamification and cross-modal paths for community care collaboration. The system addresses current barriers from technological, clinical, social and organisational perspectives in a multidisciplinary environment. Special attention is given to the patients’ needs and behaviours entailing the participation of a wide care community, including clinical and non-clinical people, associations, institutions and authorities)
through an user driven interaction within the system.This work was supported by Project ”NanoSTIMA: Macroto-Nano Human Sensing: Towards Integrated Multimodal Health Monitoring and Analytics/NORTE-01-0145-FEDER- 000016” financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio
Counting arithmetical structures on paths and cycles
Let G be a finite, connected graph. An arithmetical structure on G is a pair of positive integer vectors d, r such that (diag(d)-A)r = 0, where A is the adjacency matrix of G. We investigate the combinatorics of arithmetical structures on path and cycle graphs, as well as the associated critical groups (the torsion part of the cokernels of the matrices (diag(d)-A)). For paths, we prove that arithmetical structures are enumerated by the Catalan numbers, and we obtain refined enumeration results related to ballot sequences. For cycles, we prove that arithmetical structures are enumerated by the binomial coefficients C(2n-1,n-1), and we obtain refined enumeration results related to multisets. In addition, we determine the critical groups for all arithmetical structures on paths and cycles
Everyone Is a Protagonist : Residue Conformational Preferences in High-Resolution Protein Structures
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