An Improved Tax Scheme for Selfish Routing

We study the problem of routing traffic for independent selfish users in a congested network to minimize the total latency. The inefficiency of selfish routing motivates regulating the flow of the system to lower the total latency of the Nash Equilibrium by economic incentives or penalties. When applying tax to the routes, we follow the definition of [Christodoulou et al, Algorithmica, 2014] to define ePoA as the Nash total cost including tax in the taxed network over the optimal cost in the original network. We propose a simple tax scheme consisting of step functions imposed on the links. The tax scheme can be applied to routing games with parallel links, affine cost functions and single-commodity networks to lower the ePoA to at most 4/3 - epsilon, where epsilon only depends on the discrepancy between the links. We show that there exists a tax scheme in the two link case with an ePoA upperbound less than 1.192 which is almost tight. Moreover, we design another tax scheme that lowers ePoA down to 1.281 for routing games with groups of links such that links in the same group are similar to each other and groups are sufficiently different

A mammalian Wnt5a-Ror2-Vangl2 axis controls the cytoskeleton and confers cellular properties required for alveologenesis.

Alveolar formation increases the surface area for gas-exchange and is key to the physiological function of the lung. Alveolar epithelial cells, myofibroblasts and endothelial cells undergo coordinated morphogenesis to generate epithelial folds (secondary septa) to form alveoli. A mechanistic understanding of alveologenesis remains incomplete. We found that the planar cell polarity (PCP) pathway is required in alveolar epithelial cells and myofibroblasts for alveologenesis in mammals. Our studies uncovered a Wnt5a-Ror2-Vangl2 cascade that endows cellular properties and novel mechanisms of alveologenesis. This includes PDGF secretion from alveolar type I and type II cells, cell shape changes of type I cells and migration of myofibroblasts. All these cellular properties are conferred by changes in the cytoskeleton and represent a new facet of PCP function. These results extend our current model of PCP signaling from polarizing a field of epithelial cells to conferring new properties at subcellular levels to regulate collective cell behavior

Phantom energy of a quenched, prethermal quantum many-body scar state

Strongly interacting quantum systems can exhibit emergent excitations that differ qualitatively from their microscopic degrees of freedom. Here we study an emergent phenomenon that is intrinsic to such systems far from equilibrium: Namely, the transmutation of attractive interactions into repulsive interactions. We initialize an attractively interacting Bose gas in a highly excited and correlated nonthermal state, quench the confining potential, and measure how the kinetic and total energies evolve after the quench. Although the bare interactions are attractive, the low-energy degrees of freedom evolve as if they repel each other: Thus, their kinetic energy paradoxically decreases as the gas is compressed. We quantify the missing ``phantom'' energy by benchmarking our experimental results against generalized hydrodynamics (GHD) calculations. We present evidence that the missing kinetic energy is stored in very high-momentum modes.Comment: 5 pages, 4 figures with 15-page supplement including 9 figure

Effectiveness of influenza vaccination in patients with end-stage renal disease receiving hemodialysis: a population-based study.

BackgroundLittle is known on the effectiveness of influenza vaccine in ESRD patients. This study compared the incidence of hospitalization, morbidity, and mortality in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD) between cohorts with and without influenza vaccination.MethodsWe used the insurance claims data from 1998 to 2009 in Taiwan to determine the incidence of these events within one year after influenza vaccination in the vaccine (N = 831) and the non-vaccine (N = 3187) cohorts. The vaccine cohort to the non-vaccine cohort incidence rate ratio and hazard ratio (HR) of morbidities and mortality were measured.ResultsThe age-specific analysis showed that the elderly in the vaccine cohort had lower hospitalization rate (100.8 vs. 133.9 per 100 person-years), contributing to an overall HR of 0.81 (95% confidence interval (CI) 0.72-0.90). The vaccine cohort also had an adjusted HR of 0.85 [95% CI 0.75-0.96] for heart disease. The corresponding incidence of pneumonia and influenza was 22.4 versus 17.2 per 100 person-years, but with an adjusted HR of 0.80 (95% CI 0.64-1.02). The vaccine cohort had lowered risks than the non-vaccine cohort for intensive care unit (ICU) admission (adjusted HR 0.20, 95% CI 0.12-0.33) and mortality (adjusted HR 0.50, 95% CI 0.41-0.60). The time-dependent Cox model revealed an overall adjusted HR for mortality of 0.30 (95% CI 0.26-0.35) after counting vaccination for multi-years.ConclusionsESRD patients with HD receiving the influenza vaccination could have reduced risks of pneumonia/influenza and other morbidities, ICU stay, hospitalization and death, particularly for the elderly

Functional analysis of BARD1 missense variants in homology-directed repair and damage sensitivity

The BARD1 protein, which heterodimerizes with BRCA1, is encoded by a known breast cancer susceptibility gene. While several BARD1 variants have been identified as pathogenic, many more missense variants exist that do not occur frequently enough to assign a clinical risk. In this paper, whole exome sequencing of over 10,000 cancer samples from 33 cancer types identified from somatic mutations and loss of heterozygosity in tumors 76 potentially cancer-associated BARD1 missense and truncation variants. These variants were tested in a functional assay for homology-directed repair (HDR), as HDR deficiencies have been shown to correlate with clinical pathogenicity for BRCA1 variants. From these 76 variants, 4 in the ankyrin repeat domain and 5 in the BRCT domain were found to be non-functional in HDR. Two known benign variants were found to be functional in HDR, and three known pathogenic variants were non-functional, supporting the notion that the HDR assay can be used to predict the clinical risk of BARD1 variants. The identification of HDR-deficient variants in the ankyrin repeat domain indicates there are DNA repair functions associated with this domain that have not been closely examined. In order to examine whether BARD1-associated loss of HDR function results in DNA damage sensitivity, cells expressing non-functional BARD1 variants were treated with ionizing radiation or cisplatin. These cells were found to be more sensitive to DNA damage, and variations in the residual HDR function of non-functional variants did not correlate with variations in sensitivity. These findings improve the understanding of BARD1 functional domains in DNA repair and support that this functional assay is useful for predicting the cancer association of BARD1 variants.</div

Less Invasive Mitral Valve Surgery via Right Minithoracotomy

Background/PurposeCurrent trends in cardiac surgical intervention are moving toward less invasiveness, with smaller wound or sternum-sparing, less pump time or off-pump, and beating rather than arrested heart. Data on the efficacy and safety of these newer less invasive techniques, as well as their cosmetic results, are limited. This study analyzed the results of a sternum-sparing mitral valve operation.MethodsThirty patients with mitral valve diseases, including 20 who underwent mitral valve repair and 10 mitral valve replacement, were enrolled. Cardiopulmonary bypass was established via femoral cannu-lation, and blood cardioplegic arrest was induced by using a percutaneous, transthoracic cross-clamp. The main surgical wound was made over the lateral border of the right breast. Two additional small wounds were required for the transthoracic aortic clamp and the mitral retractor.ResultsThere was no operative mortality, and all patients had an uneventful recovery. Two patients underwent redo mitral surgery. Nine associated procedures were performed including tricuspid valve annulo-plasty in six patients, tricuspid valve replacement in two patients and atrial septal defect repair in one patient. The length of the main wound was between 5.8 and 7.8 cm (mean, 7.1 cm). The mean cardiopul-monary bypass time and cross-clamp time were 91.1 and 43.7 minutes, respectively. Although the length of stay was not significantly reduced compared with traditional median sternotomy, all patients had satisfactory results with good cosmesis.ConclusionSternum-sparing mitral valve surgery appears to be a safe and effective alternative to conventional mitral valve surgery; it is less invasive and provides superior cosmetic results for patients