A
bstract
In this paper we conjecture that the generating function of the intersection numbers on the moduli spaces of Riemann surfaces with boundary, constructed recently by R. Pandharipande, J. ...Solomon and R. Tessler and extended by A. Buryak, is a tau-function of the KP integrable hierarchy. Moreover, it is given by a simple modification of the Kontsevich matrix integral so that the generating functions of open and closed intersection numbers are described by the MKP integrable hierarchy. Virasoro constraints for the open intersection numbers naturally follow from the matrix integral representation.
A
bstract
In this paper we revisit several recent results on monotone and strictly monotone Hurwitz numbers, providing new proofs. In particular, we use various versions of these numbers to discuss ...methods of derivation of quantum spectral curves from the point of view of KP integrability and derive new examples of quantum curves for the families of double Hurwitz numbers.
The KP and 2D Toda
τ
-functions of hypergeometric type that serve as generating functions for weighted single and double Hurwitz numbers are related to the topological recursion programme. A ...graphical representation of such weighted Hurwitz numbers is given in terms of weighted constellations. The associated classical and quantum spectral curves are derived, and these are interpreted combinatorially in terms of the graphical model. The pair correlators are given a finite Christoffel–Darboux representation and determinantal expressions are obtained for the multipair correlators. The genus expansion of the multicurrent correlators is shown to provide generating series for weighted Hurwitz numbers of fixed ramification profile lengths. The WKB series for the Baker function is derived and used to deduce the loop equations and the topological recursion relations in the case of polynomial weight functions.
. Alexandrov AV (University of Alabama Hospital, Birmingham, AL, USA). Current and future recanalization strategies for acute ischemic stroke (Review). J Intern Med 2010; 267: 209–219.
In a quest ...for stroke treatment, reperfusion proved to be the first key to the puzzle. Systemic tissue plasminogen activator (tPA), the first and currently the only approved treatment, is also the fastest way to initiate thrombolyis for acute ischemic stroke. tPA works by induction of mostly partial recanalization since stroke patients often have large thrombus burden. Thus, early augmentation of fibrinolysis and multi‐modal approach to improve recanalization are desirable. This review focuses on the following strategies available to clinicians now or being tested in clinical trials: (a) faster initiation of tPA infusion; (b) sonothrombolysis; (c) intra‐arterial revascularization, bridging intravenous and intra‐arterial thrombolysis, mechanical thrombectomy and aspiration; and (d) novel experimental approaches. Despite these technological advances, no single strategy was yet proven to be a ‘silver bullet’ solution to reverse acute ischemic stroke. Better outcomes are expected with faster treatment leading to early, at times just partial flow improvement rather than achieving complete recanalization with lengthy procedures. Arterial re‐occlusion can occur with any of these approaches, and it remains a challenge since it leads to poor outcomes and no clinical trial data are available yet to determine safe strategies to prevent or reverse re‐occlusion.
Complete genomic and epigenetic maps of human centromeres Altemose, Nicolas; Logsdon, Glennis A; Bzikadze, Andrey V ...
Science (American Association for the Advancement of Science),
04/2022, Letnik:
376, Številka:
6588
Journal Article
Recenzirano
Odprti dostop
Existing human genome assemblies have almost entirely excluded repetitive sequences within and near centromeres, limiting our understanding of their organization, evolution, and functions, which ...include facilitating proper chromosome segregation. Now, a complete, telomere-to-telomere human genome assembly (T2T-CHM13) has enabled us to comprehensively characterize pericentromeric and centromeric repeats, which constitute 6.2% of the genome (189.9 megabases). Detailed maps of these regions revealed multimegabase structural rearrangements, including in active centromeric repeat arrays. Analysis of centromere-associated sequences uncovered a strong relationship between the position of the centromere and the evolution of the surrounding DNA through layered repeat expansions. Furthermore, comparisons of chromosome X centromeres across a diverse panel of individuals illuminated high degrees of structural, epigenetic, and sequence variation in these complex and rapidly evolving regions.
Most Earth system models agree that land will continue to store carbon due to the physiological effects of rising CO
concentration and climatic changes favoring plant growth in temperature-limited ...regions. But they largely disagree on the amount of carbon uptake. The historical CO
increase has resulted in enhanced photosynthetic carbon fixation (Gross Primary Production, GPP), as can be evidenced from atmospheric CO
concentration and satellite leaf area index measurements. Here, we use leaf area sensitivity to ambient CO
from the past 36 years of satellite measurements to obtain an Emergent Constraint (EC) estimate of GPP enhancement in the northern high latitudes at two-times the pre-industrial CO
concentration (3.4 ± 0.2 Pg C yr
). We derive three independent comparable estimates from CO
measurements and atmospheric inversions. Our EC estimate is 60% larger than the conventionally used multi-model average (44% higher at the global scale). This suggests that most models largely underestimate photosynthetic carbon fixation and therefore likely overestimate future atmospheric CO
abundance and ensuing climate change, though not proportionately.
Background and purpose
Blood pressure (BP) variability has been associated with worse neurological outcomes in acute ischaemic stroke (AIS) patients receiving treatment with intravenous thrombolysis ...(IVT). However, no study to date has investigated whether pulse pressure (PP) variability may be a superior indicator of the total cardiovascular risk, as measured by clinical outcomes.
Methods
Pulse pressure variability was calculated from 24‐h PP measurements following tissue plasminogen activator bolus in AIS patients enrolled in the Combined Lysis of Thrombus using Ultrasound and Systemic Tissue Plasminogen Activator for Emergent Revascularization (CLOTBUST‐ER) trial. The outcomes of interest were the pre‐specified efficacy and safety end‐points of CLOTBUST‐ER. All associations were adjusted for potential confounders in multivariable regression models.
Results
Data from 674 participants was analyzed. PP variability was identified as the BP parameter with the most parsimonious fit in multivariable models of all outcomes, and was independently associated (P < 0.001) with lower likelihood of both 24‐h neurological improvement and 90‐day independent functional outcome. PP variability was also independently related to increased odds of any intracranial bleeding (P = 0.011) and 90‐day mortality (P < 0.001). Every 5‐mmHg increase in the 24‐h PP variability was independently associated with a 36% decrease in the likelihood of 90‐day independent functional outcome (adjusted odds ratio 0.64, 95% confidence interval 0.52–0.80) and a 60% increase in the odds of 90‐day mortality (adjusted odds ratio 1.60, 95% confidence interval 1.23–2.07). PP variability was not associated with symptomatic intracranial bleeding at either 24 or 36 h after IVT administration.
Conclusions
Increased PP variability appears to be independently associated with adverse short‐term and long‐term functional outcomes of AIS patients treated with IVT.
On KP-integrable Hurwitz functions Alexandrov, A.; Mironov, A.; Morozov, A. ...
The journal of high energy physics,
11/2014, Letnik:
2014, Številka:
11
Journal Article
Recenzirano
Odprti dostop
A
bstract
There is now a renewed interest
1
–
4
to a Hurwitz
τ
-function, counting the isomorphism classes of Belyi pairs, arising in the study of equilateral triangulations and Grothiendicks’s
...dessins d
’
enfant
. It is distinguished by belonging to a particular family of Hurwitz
τ
-functions, possessing conventional Toda/KP integrability properties. We explain how the variety of recent observations about this function fits into the general theory of matrix model
τ
-functions. All such quantities possess a number of different descriptions, related in a standard way: these include Toda/KP integrability, several kinds of
W
-representations (we describe four), two kinds of integral (multi-matrix model) descriptions (of Hermitian and Kontsevich types), Virasoro constraints, character expansion, embedding into generic set of Hurwitz
τ
-functions and relation to knot theory. When approached in this way, the family of models in the literature has a natural extension, and additional integrability with respect to associated new time-variables. Another member of this extended family is the Itsykson-Zuber integral.
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