14,584 research outputs found
Tissue-Engineered Larynx: Future Applications in Laryngeal Cancer
PURPOSE OF REVIEW: This article reviews the latest developments in tissue engineering for the larynx with a specific focus on the treatment of laryngeal cancer. RECENT FINDINGS: Challenges in tissue engineering a total larynx can be divided into scaffold design, methods of re-mucosalization, and how to restore laryngeal function. The literature described a range of methods to deliver a laryngeal scaffold including examples of synthetic, biomimetic, and biological scaffolds. Methods to regenerate laryngeal mucosa can be divided into examples that use a biological dressing and those that engineer a new mucosal layer de novo. Studies aiming to restore laryngeal function have been reported, but to date, the optimum method for achieving this as part of a total laryngeal transplant is yet to be determined. SUMMARY: There is great potential for tissue engineering to improve the treatments available for laryngeal cancer within the next 10 years. A number of challenges exist however and advances in restoring function must keep pace with developments in scaffold design
Remarks on the extension of the Ricci flow
We present two new conditions to extend the Ricci flow on a compact manifold
over a finite time, which are improvements of some known extension theorems.Comment: 9 pages, to appear in Journal of Geometric Analysi
A galaxy-halo model of large-scale structure
We present a new, galaxy-halo model of large-scale structure, in which the
galaxies entering a given sample are the fundamental objects. Haloes attach to
galaxies, in contrast to the standard halo model, in which galaxies attach to
haloes. The galaxy-halo model pertains mainly to the relationships between the
power spectra of galaxies and mass, and their cross-power spectrum. With
surprisingly little input, an intuition-aiding approximation to the
galaxy-matter cross-correlation coefficient R(k) emerges, in terms of the halo
mass dispersion. This approximation seems valid to mildly non-linear scales (k
< ~3 h/Mpc), allowing measurement of the bias and the matter power spectrum
from measurements of the galaxy and galaxy-matter power spectra (or correlation
functions). This is especially relevant given the recent advances in precision
in measurements of the galaxy-matter correlation function from weak
gravitational lensing. The galaxy-halo model also addresses the issue of
interpreting the galaxy-matter correlation function as an average halo density
profile, and provides a simple description of galaxy bias as a function of
scale.Comment: 13 pages, 9 figures, submitted to MNRAS. Minor changes, suggested by
  refere
The Ricci flow on noncommutative two-tori
In this paper we construct a version of Ricci flow for noncommutative 2-tori,
based on a spectral formulation in terms of the eigenvalues and eigenfunction
of the Laplacian and recent results on the Gauss-Bonnet theorem for
noncommutative tori.Comment: 18 pages, LaTe
The three-dimensional geometry and merger history of the massive galaxy cluster MACS J0358.8-2955
We present results of a combined X-ray/optical analysis of the dynamics of
the massive cluster MACS J0358.8-2955 (z=0.428) based on observations with the
Chandra X-ray Observatory, the Hubble Space Telescope, and the Keck-I telescope
on Mauna Kea. MACS J0358.8-2955 is found to be one of the most X-ray luminous
clusters known at z>0.3, featuring L_X(<r_500) = 4.24*10^45 erg/s, kT = (9.55
+0.58/-0.37) keV, M^{3D}_{gas}(<r_500) = (9.18+/-1.45)*10^13 M_sun, and
M^{3D}_{tot}(<r_500) = (1.12+/-0.18)*10^15 M_sun. The system's high velocity
dispersion of (1440 +130/-110) km/s (890 km/s when the correct relativistic
equation is used), however, is inflated by infall along the line of sight, as
the result of a complex merger of at least three sub-clusters. One collision
proceeds close to head-on, while the second features a significant impact
parameter. The temperature variations in the intra-cluster gas, two tentative
cold fronts, the radial velocities measured for cluster galaxies, and the small
offsets between collisional and non-collisional cluster components all suggest
that both merger events are observed close to core passage and along axes that
are greatly inclined with respect to the plane of the sky. A strong-lensing
analysis of the system anchored upon three triple-image systems (two of which
have spectroscopic redshifts) yields independent constraints on the mass
distribution. For a gas fraction of 8.2%, the resulting strong-lensing mass
profile is in good agreement with our X-ray estimates, and the details of the
mass distribution are fully consistent with our interpretation of the
three-dimensional merger history of this complex system.Comment: 17 pages, 17 figures, and 4 tables. Accepted for publication in MNRA
The Postoperative Morbidity Survey was validated and used to describe morbidity after major surgery.
OBJECTIVES: To describe the reliability and validity of the Postoperative Morbidity Survey (POMS). To describe the level and pattern of short-term postoperative morbidity after major elective surgery using the POMS. STUDY DESIGN AND SETTING: This was a prospective cohort study of 439 adults undergoing major elective surgery in a UK teaching hospital. The POMS, an 18-item survey that address nine domains of postoperative morbidity, was recorded on postoperative days 3, 5, 8, and 15. RESULTS: Inter-rater reliability was perfect for 11/18 items (Kappa=1.0), with Kappa=0.94 for 6/18 items. A priori hypotheses that the POMS would discriminate between patients with known measures of morbidity risk, and predict length of stay were generally supported through observation of data trends, and there was statistically significant evidence of construct validity for all but the wound and neurological domains. POMS-defined morbidity was present in 325 of 433 patients (75.1%) remaining in hospital on postoperative day 3 after surgery, 231 of 407 patients (56.8%) on day 5, 138 of 299 patients (46.2%) on day 8, and 70 of 111 patients (63.1%) on day 15. Gastrointestinal (47.4%), infectious (46.5%), pain-related (40.3%), pulmonary (39.4%), and renal problems (33.3%) were the most common forms of morbidity. CONCLUSION: The POMS is a reliable and valid survey of short-term postoperative morbidity in major elective surgery. Many patients remain in hospital without any morbidity as recorded by the POMS
Ricci flows, wormholes and critical phenomena
We study the evolution of wormhole geometries under Ricci flow using
numerical methods. Depending on values of initial data parameters, wormhole
throats either pinch off or evolve to a monotonically growing state. The
transition between these two behaviors exhibits a from of critical phenomena
reminiscent of that observed in gravitational collapse. Similar results are
obtained for initial data that describe space bubbles attached to
asymptotically flat regions. Our numerical methods are applicable to
"matter-coupled" Ricci flows derived from conformal invariance in string
theory.Comment: 8 pages, 5 figures. References added and minor changes to match
  version accepted by CQG as a fast track communicatio
Elliptic gradient estimates and Liouville theorems for a weighted nonlinear parabolic equation
Let  be a complete smooth metric measure space with
-Bakry-\'Emery Ricci tensor bounded from below. We derive elliptic
gradient estimates for positive solutions of a weighted nonlinear parabolic
equation \begin{align*} \displaystyle \Big(\Delta_f - \frac{\partial}{\partial
t}\Big) u(x,t) +q(x,t)u^\alpha(x,t) = 0, \end{align*} where  and  is an arbitrary constant. As
Applications we prove a Liouville-type theorem for positive ancient solutions
and Harnack-type inequalities for positive bounded solutions.Comment: 18 page
Evolutionary instability of Zero Determinant strategies demonstrates that winning isn't everything
Zero Determinant (ZD) strategies are a new class of probabilistic and
conditional strategies that are able to unilaterally set the expected payoff of
an opponent in iterated plays of the Prisoner's Dilemma irrespective of the
opponent's strategy, or else to set the ratio between a ZD player's and their
opponent's expected payoff. Here we show that while ZD strategies are weakly
dominant, they are not evolutionarily stable and will instead evolve into less
coercive strategies. We show that ZD strategies with an informational advantage
over other players that allows them to recognize other ZD strategies can be
evolutionarily stable (and able to exploit other players). However, such an
advantage is bound to be short-lived as opposing strategies evolve to
counteract the recognition.Comment: 14 pages, 4 figures. Change in title (again!) to comply with Nature
  Communications requirements. To appear in Nature Communication
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