662 research outputs found
Addressing urban social and spatial stratification: testing the potential for integration of public housing
The legacy of public housing in the American city is dominated by a condition of social and spatial stratification. In New York City, inadequate funding exacerbates the conditions of isolated public housing residents, raising questions about the stability and sustainability of public housing. At a time when a severe housing crisis is impacting on the affordability of and access to urban housing generally, addressing this legacy of public housing can be the impetus for a long-term vision that integrates public housing into the fabric of the city, providing new housing options for public housing residents while merging them into mixed-income neighbourhoods with redefined public spaces and increased services and amenities. This approach to a long-term vision, built around high-density mid-rise development, contrasts with the incremental approach currently expedient due to the social and political climate surrounding public housing. However, current resistance to an aggressive strategy belies another part of the legacy of public housing: the major demolition of city streets and blocks that made possible the anti-urban planning that undergirds this isolation and stratification. Empirical evidence supports urban design that builds on the nineteenth-century city’s urban form of small blocks and active streets as the foundation for vital urban neighbourhoods. This study of the political and urban design efforts to address the severe challenges facing public housing tests the potential for a path, when the political and social climate allows, for an aggressive strategy to preserve public housing that centres on social and spatial integration
Almost all trees are almost graceful
The Graceful Tree Conjecture of Rosa from 1967 asserts that the vertices of each tree T of order n can be injectively labeled by using the numbers {1,2,…,n} in such a way that the absolute differences induced on the edges are pairwise distinct. We prove the following relaxation of the conjecture for each γ>0 and for all n>n 0(γ). Suppose that (i) the maximum degree of T is bounded by (Formula presented.)), and (ii) the vertex labels are chosen from the set {1,2,…,⌈(1+γ)n⌉}. Then there is an injective labeling of V(T) such that the absolute differences on the edges are pairwise distinct. In particular, asymptotically almost all trees on n vertices admit such a labeling. The proof proceeds by showing that a certain very natural randomized algorithm produces a desired labeling with high probability
cMET inhibitor crizotinib impairs angiogenesis and reduces tumor burden in the C3(1)-Tag model of basal-like breast cancer
Epidemiologic studies have associated obesity with increased risk of the aggressive basal-like breast cancer (BBC) subtype. Hepatocyte growth factor (HGF) signaling through its receptor, cMET, is elevated in obesity and is a pro-tumorigenic pathway strongly associated with BBC. We previously reported that high fat diet (HFD) elevated HGF, cMET, and phospho-cMET in normal mammary gland, with accelerated tumor development, compared to low fat diet (LFD)-fed lean controls in a murine model of BBC. We also showed that weight loss resulted in a significant reversal of HFD-induced effects on latency and elevation of HGF/cMET signaling in normal mammary and cMET in normal mammary and tumors. Here, we sought to inhibit BBC tumor progression in LFD- and HFD-fed C3(1)-Tag BBC mice using a small molecule cMET inhibitor, and began crizotinib treatment (50 mg/kg body weight by oral gavage) upon identification of the first palpable tumor. We next investigated if administering crizotinib in a window prior to tumor development would inhibit or delay BBC tumorigenesis. Treatment: Crizotinib significantly reduced mean tumor burden by 27.96 and 37.29 %, and mean tumor vascularity by 35.04 and 33.52 %, in our LFD- and HFD-fed C3(1)-Tag BBC mice, respectively. Prevention: Crizotinib significantly accelerated primary tumor progression in both diet groups but had no effect on total tumor progression or total tumor burden. In sum, cMET inhibition by crizotinib limited tumor development and microvascular density in basal-like tumor-bearing mice but did not appear to be an effective preventive agent for BBC
Hopf algebras and Markov chains: Two examples and a theory
The operation of squaring (coproduct followed by product) in a combinatorial
Hopf algebra is shown to induce a Markov chain in natural bases. Chains
constructed in this way include widely studied methods of card shuffling, a
natural "rock-breaking" process, and Markov chains on simplicial complexes.
Many of these chains can be explictly diagonalized using the primitive elements
of the algebra and the combinatorics of the free Lie algebra. For card
shuffling, this gives an explicit description of the eigenvectors. For
rock-breaking, an explicit description of the quasi-stationary distribution and
sharp rates to absorption follow.Comment: 51 pages, 17 figures. (Typographical errors corrected. Further fixes
will only appear on the version on Amy Pang's website, the arXiv version will
not be updated.
Model-based investigation into atmospheric freeze drying assisted by power ultrasound
Atmospheric freeze drying consists of a convective drying process using air at a temperature below the
freezing point of the processed product, and with a very low relative humidity content. This paper focuses
on the use of a simple one-dimensional model considering moving boundary vapor diffusion to describe
the ultrasonic assisted atmospheric freeze-drying of foodstuffs. The case study is the drying of apple
cubes (8.8 mm) at different air velocities (1, 2, 4 and 6 m/s), temperatures ( 5, 10 and 15 C), without
and with (25, 50 and 75 W) power ultrasound application. By fitting the proposed diffusion model to the
experimental drying kinetics, the effective diffusivity of water vapor in the dried product was estimated.
The model was successfully validated by drying apple samples of different size and geometry (cubes and
cylinders). Finally, a 23 factorial design of experiments revealed that the most relevant operating parameter
affecting the drying time was the applied ultrasound power level.The authors acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad (MINECO) and of the European Regional Development Fund (ERDF) through the project DPI2012-37466-CO3-03, the FPI fellowship (BES-2010-033460) and the EEBB-I-14-08572 fellowship granted to J.V. Santacatalina for a short stay at Politecnico di Torino.Santacatalina Bonet, JV.; Fissore, D.; Cárcel Carrión, JA.; Mulet Pons, A.; García Pérez, JV. (2015). Model-based investigation into atmospheric freeze drying assisted by power ultrasound. Journal of Food Engineering. 151:7-15. https://doi.org/10.1016/j.jfoodeng.2014.11.013S71515
Safety and efficacy of eculizumab in the prevention of antibody-mediated rejection in living-donor kidney transplant recipients requiring desensitization therapy: A randomized trial
We report results of a phase 2, randomized, multicenter, open‐label, two‐arm study
evaluating the safety and efficacy of eculizumab in preventing acute antibody‐
mediated rejection (AMR) in sensitized recipients of living‐donor kidney transplants
requiring pretransplant desensitization (NCT01399593). In total, 102 patients under‐
went desensitization. Posttransplant, 51 patients received standard of care (SOC)
and 51 received eculizumab. The primary end point was week 9 posttransplant treat‐
ment failure rate, a composite of: biopsy‐proven acute AMR (Banff 2007 grade II or
III; assessed by blinded central pathology); graft loss; death; or loss to follow‐up. Eculizumab was well tolerated with no new safety concerns. No significant difference
in treatment failure rate was observed between eculizumab (9.8%) and SOC (13.7%;
P = .760). To determine whether data assessment assumptions affected study out‐
come, biopsies were reanalyzed by central pathologists using clinical information. The
resulting treatment failure rates were 11.8% and 21.6% for the eculizumab and SOC
groups, respectively (nominal P = .288). When reassessment included grade I AMR,
the treatment failure rates were 11.8% (eculizumab) and 29.4% (SOC; nominal
P = .048). This finding suggests a potential benefit for eculizumab compared with
SOC in preventing acute AMR in recipients sensitized to their living‐donor kidney
transplants (EudraCT 2010‐019630‐28)
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