164 research outputs found
Unbounded Solutions to Systems of Differential Equations at Resonance
We deal with a weakly coupled system of ODEs of the type xj\u2032\u2032+nj2xj+hj(x1,\u2026,xd)=pj(t),j=1,\u2026,d,with hj locally Lipschitz continuous and bounded, pj continuous and 2 \u3c0-periodic, nj 08 N (so that the system is at resonance). By means of a Lyapunov function approach for discrete dynamical systems, we prove the existence of unbounded solutions, when either global or asymptotic conditions on the coupling terms h1, \u2026 , hd are assumed
Radiation and Scattering of EM Waves in Large Plasmas Around Objects in Hypersonic Flight
Hypersonic flight regime is conventionally defined for Mach larger than 5; in
these conditions, the flying object becomes enveloped in a plasma. This plasma
is densest in thin surface layers, but in typical situations of interest it
impacts electromagnetic wave propagation in an electrically large volume. We
address this problem with a hybrid approach. We employ Equivalence Theorem to
separate the inhomogeneous plasma region from the surrounding free space via an
equivalent (Huygens) surface, and the Eikonal approximation to Maxwell
equations in the large inhomogeneous region for obtaining equivalent currents
on the separating surface. Then, we obtain the scattered field via (exact) free
space radiation of these surface equivalent currents. The method is extensively
tested against reference results and then applied to a real-life re-entry
vehicle with full 3D plasma computed via Computational Fluid Dynamic (CFD)
simulations. We address both scattering (RCS) from the entire vehicle and
radiation from the on-board antennas. From our results, significant radio link
path losses can be associated with plasma spatial variations (gradients) and
collisional losses, to an extent that matches well the usually perceived
blackout in crossing layers in cutoff. Furthermore, we find good agreement with
existing literature concerning significant alterations of the radar response
(RCS) due to the plasma envelope
Concurrency in leukocyte vascular recognition: developing the tools for a predictive computer model
Leukocyte recruitment has a crucial role in inflammation and immunity. An interplay between adhesion molecules and pro-adhesive agonists generates a complex molecular network controlling tissue-specific and inflammation-dependent leukocyte vascular recognition. Recent findings highlight the importance of quantitative parameters in controlling the specificity of leukocyte vascular recognition. Introduction of quantitative parameters demonstrates the non-linear behavior of the process and suggests the necessity for a revision of the traditional model. We propose a formalization of the original multi-step model of leukocyte vascular recognition by introducing the notion of concurrency that explains how the quantitative variation of pro-adhesive parameters might control the specificity and the sensitivity of this process. Moreover, we discuss how concurrency, by integrating quantitative parameters, constitutes a central concept for the implementation of a predictive computer modeling of leukocyte vascular recognition
CP Violation in Supersymmetry with Effective Minimal Flavour Violation
We analyze CP violation in supersymmetry with Effective Minimal Flavour
Violation, as recently proposed in arXiv:1011.0730. Unlike the case of standard
Minimal Flavour Violation, we show that all the phases allowed by the flavour
symmetry can be sizable without violating existing Electric Dipole Moment
constraints, thus solving the SUSY CP problem. The EDMs at one and two loops
are precisely analyzed as well as their correlations with the expected CP
asymmetries in B physics.Comment: 22 pages, 7 figures. v2: Discussion in section 2 extended,
conclusions unchanged. Matches published versio
Search for Gravitational Waves from Primordial Black Hole Binary Coalescences in the Galactic Halo
We use data from the second science run of the LIGO gravitational-wave
detectors to search for the gravitational waves from primordial black hole
(PBH) binary coalescence with component masses in the range 0.2--.
The analysis requires a signal to be found in the data from both LIGO
observatories, according to a set of coincidence criteria. No inspiral signals
were found. Assuming a spherical halo with core radius 5 kpc extending to 50
kpc containing non-spinning black holes with masses in the range 0.2--, we place an observational upper limit on the rate of PBH coalescence
of 63 per year per Milky Way halo (MWH) with 90% confidence.Comment: 7 pages, 4 figures, to be submitted to Phys. Rev.
Synthesis of Recommendations From 25 Countries and 31 Oncology Societies: How to Navigate Through Covid-19 Labyrinth
Introduction: Pandemic COVID-19 is an unexpected challenge for the oncological community, indicating potential detrimental effects on cancer patients. Our aim was to summarize the converging key points providing a general guidance in order to support decision making, pertaining to the oncologic care in the middle of a global outbreak.
Methods: We did an international online search in twenty five countries that have managed a surge in cancer patient numbers. We collected the recommendations from thirty one medical oncology societies.
Results: By synthesizing guidelines for a) oncology service delivery adjustments, b) general and specific treatment adaptations, and c) discrepancies from guidelines comparison, we present a clinical synopsis with the forty more crucial statements. A Covid-19 risk stratification base was also created in order to obtain a quick, objective patient assessment and a risk-benefit evaluation on a case-by-case basis.
Conclusions: In an attempt to face these complex needs and due to limited understanding of COVID-19, a variability of recommendations based on general epidemiological and infectious disease principles rather than definite cancer-related evidence has evolved. Additionally, the absence of an effective treatment or vaccine requires the development of cancer management guidance, capitalizing on comprehensive COVID-19 oncology experience globally
Dental Health and Mortality in People With End-Stage Kidney Disease Treated With Hemodialysis: A Multinational Cohort Study
Background Dental disease is more extensive in adults with chronic kidney disease, but whether dental health and behaviors are associated with survival in the setting of hemodialysis is unknown. Study Design Prospective multinational cohort. Setting & Participants 4,205 adults treated with long-term hemodialysis, 2010 to 2012 (Oral Diseases in Hemodialysis [ORAL-D] Study). Predictors Dental health as assessed by a standardized dental examination using World Health Organization guidelines and personal oral care, including edentulousness; decayed, missing, and filled teeth index; teeth brushing and flossing; and dental health consultation. Outcomes All-cause and cardiovascular mortality at 12 months after dental assessment. Measurements Multivariable-adjusted Cox proportional hazards regression models fitted with shared frailty to account for clustering of mortality risk within countries. Results During a mean follow-up of 22.1 months, 942 deaths occurred, including 477 cardiovascular deaths. Edentulousness (adjusted HR, 1.29; 95% CI, 1.10-1.51) and decayed, missing, or filled teeth score ≥ 14 (adjusted HR, 1.70; 95% CI, 1.33-2.17) were associated with early all-cause mortality, while dental flossing, using mouthwash, brushing teeth daily, spending at least 2 minutes on oral hygiene daily, changing a toothbrush at least every 3 months, and visiting a dentist within the past 6 months (adjusted HRs of 0.52 [95% CI, 0.32-0.85], 0.79 [95% CI, 0.64-0.97], 0.76 [95% CI, 0.58-0.99], 0.84 [95% CI, 0.71-0.99], 0.79 [95% CI, 0.65-0.95], and 0.79 [95% CI, 0.65-0.96], respectively) were associated with better survival. Results for cardiovascular mortality were similar. Limitations Convenience sample of clinics. Conclusions In adults treated with hemodialysis, poorer dental health was associated with early death, whereas preventive dental health practices were associated with longer survival
Flavor Symmetric Sectors and Collider Physics
We discuss the phenomenology of effective field theories with new scalar or
vector representations of the Standard Model quark flavor symmetry group,
allowing for large flavor breaking involving the third generation. Such field
content can have a relatively low mass scale \lesssim TeV and O(1) couplings to
quarks, while being naturally consistent with both flavor violating and flavor
diagonal constraints. These theories therefore have the potential for early
discovery at LHC, and provide a flavor safe "tool box" for addressing anomalies
at colliders and low energy experiments. We catalogue the possible flavor
symmetric representations, and consider applications to the anomalous Tevatron
t-tbar forward backward asymmetry and B_s mixing measurements, individually or
concurrently. Collider signatures and constraints on flavor symmetric models
are also studied more generally. In our examination of the t-tbar forward
backward asymmetry we determine model independent acceptance corrections
appropriate for comparing against CDF data that can be applied to any model
seeking to explain the t-tbar forward backward asymmetry.Comment: 71 pages, 14 Figures, 12 Table
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
Meeting abstrac
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