Comments on the role of diagonal dominance in implicit difference methods

Numerical tests were made for a model of the Navier-Stokes equations using a second-order accurate implicit scheme which guarantees diagonal dominance. The results suggest that the failure of implicit methods using large marching steps may not always be attributed to the lack of diagonal dominance in the coefficient matrix. In some cases the failure may be caused by a nonlinear instability associated with the solution method

Impulse oscillometry identifies peripheral airway dysfunction in children with adenosine deaminase deficiency.

Adenosine deaminase-deficient severe combined immunodeficiency (ADA-SCID) is characterized by impaired T-, B- and NK-cell function. Affected children, in addition to early onset of infections, manifest non-immunologic symptoms including pulmonary dysfunction likely attributable to elevated systemic adenosine levels. Lung disease assessment has primarily employed repetitive radiography and effort-dependent functional studies. Through impulse oscillometry (IOS), which is effort-independent, we prospectively obtained objective measures of lung dysfunction in 10 children with ADA-SCID. These results support the use of IOS in the identification and monitoring of lung function abnormalities in children with primary immunodeficiencies

Desenvolvimento de modelos de regressão como contribuição para a análise de risco de resíduos de pesticidas em maçã.

O Plano Nacional de Controle de Resíduos e Contaminantes (PNCRC) do Ministério da Agricultura Pecuária e Abastecimento (MAPA) é um programa federal de fiscalização de alimentos que visa quantificar resíduos químicos potencialmente nocivos à saúde do consumidor. Os dados coletados pelo PNCRC provêm de uma amostragem homogênea e aleatória, em âmbito nacional, de diversos produtos de origem vegetal e animal, seguida de análises em laboratórios oficiais e credenciados pelo MAPA. Este trabalho objetiva o tratamento dos dados gerados pelo PNCRC, coletados no período de 2008 a 2011, relativos à análise de risco de resíduos de pesticidas em maçã, visando evidenciar correlações espaço-temporais relevantes quanto à concentração de diferentes resíduos químicos.CIIC 2014. Nº 14604

Simulating the Mechanics of Protein-Induced DNA Looping and Protein-Constrained DNA Buckling.

The bending and twisting mechanics of DNA are known to play a crucial role in many biological processes, yet fundamental details, even in relatively simple systems, remain unclear. The overall objective of this dissertation is to advance this knowledge in the context of two important systems including 1) the role of protein flexibility in an elementary gene regulatory protein that loops DNA, and 2) the structure and biological function(s) of DNA buckling during packaging and ejection in bacterial viruses. To address this objective, we contribute new modeling techniques by extending an elastic rod model for DNA. For protein-induced DNA looping, we use the model to reinterpret two seminal studies on Lac repressor looped DNA including the stability and topology of loops. For viral packaging, we contribute a model for mechanical contact between DNA and a cavity of arbitrary geometry, and also the first multi-scale model for DNA under extreme compression, to examine a buckled DNA toroid recently discovered in a protein cavity below the bacteriophage phi29 viral capsid. This example further motivates an extensive study of the mechanics of constrained DNA buckles inside the portal cavities of a family of viruses. The theoretical results for looped DNA successfully predict experimental observations and reveal that an extended protein conformation was active, yet overlooked, in classic experiments by the Muller-Hill laboratory. A detailed analysis of phi29 reveals that a DNA toroid can form under biologically-relevant force levels supplied by a packing motor. Computed DNA density maps compare favorably with the experimental data. Upon simulating the dynamic ejection of the toroid from the cavity, we reveal that large reaction forces/torques develop at the portal that could be used to signal genome release. Using Greenhill's equation, we show that DNA buckling is also feasible in a number of other bacteriophages including T7 and P22 that contain large portal cavities. Simulating DNA buckles in these cavities shows that large reaction forces develop on the portal walls that could signal a motor to terminate packing. Despite differences in size and shape, the cavities possess the same energy density.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/99845/1/adhirsh_1.pd

Magnon-Paramagnon Effective Theory of Itinerant Ferromagnets

The present work is devoted to the derivation of an effective magnon-paramagnon theory starting from a microscopic lattice model of ferromagnetic metals. For some values of the microscopic parameters it reproduces the Heisenberg theory of localized spins. For small magnetization the effective model describes the physics of weak ferromagnets in accordance with the experimental results. It is written in a way which keeps O(3) symmetry manifest,and describes both the order and disordered phases of the system. Analytical expression for the Curie temperature,which takes the magnon fluctuations into account exactly, is obtained. For weak ferromagnets $T_c$ is well below the Stoner's critical temperature and the critical temperature obtained within Moriya's theory.Comment: 14 pages, changed content,new result

Shovels and Swords: How realistic and fantastical themes affect children's word learning

Cataloged from PDF version of article.Research has shown that storybooks and play sessions help preschool children learn vocabulary, thereby benefiting their language and school readiness skills. But the kind of content that leads to optimal vocabulary learning – realistic or fantastical – remains largely unexplored. We investigate this issue as part of a large-scale study of vocabulary learning in low-income classrooms. Preschoolers (N = 154) learned 20 new words over the course of a two-week intervention. These words were taught using either realistic (e.g., farms) or fantastical (e.g., dragons) storybooks and toys. Children learned the new words in both conditions, and their comprehension knowledge did not differ across conditions. However, children who engaged in stories and play with a fantastical theme showed significantly greater gains in their production knowledge. Reasons for and implications of this result are discussed

Regulation of Reactive Oxygen Species and the Antioxidant Protein DJ-1 in Mastocytosis

Neoplastic accumulation of mast cells in systemic mastocytosis (SM) associates with activating mutations in the receptor tyrosine kinase KIT. Constitutive activation of tyrosine kinase oncogenes has been linked to imbalances in oxidant/antioxidant mechanisms in other myeloproliferative disorders. However, the impact of KIT mutations on the redox status in SM and the potential therapeutic implications are not well understood. Here, we examined the regulation of reactive oxygen species (ROS) and of the antioxidant protein DJ-1 (PARK-7), which increases with cancer progression and acts to lessen oxidative damage to malignant cells, in relationship with SM severity. ROS levels were increased in both indolent (ISM) and aggressive variants of the disease (ASM). However, while DJ-1 levels were reduced in ISM with lower mast cell burden, they rose in ISM with higher mast cell burden and were significantly elevated in patients with ASM. Studies on mast cell lines revealed that activating KIT mutations induced constant ROS production and consequent DJ-1 oxidation and degradation that could explain the reduced levels of DJ-1 in the ISM population, while IL-6, a cytokine that increases with disease severity, caused a counteracting transcriptional induction of DJ-1 which would protect malignant mast cells from oxidative damage. A mouse model of mastocytosis recapitulated the biphasic changes in DJ-1 and the escalating IL-6, ROS and DJ-1 levels as mast cells accumulate, findings which were reversed with anti-IL-6 receptor blocking antibody. Our findings provide evidence of increased ROS and a biphasic regulation of the antioxidant DJ-1 in variants of SM and implicate IL-6 in DJ-1 induction and expansion of mast cells with KIT mutations. We propose consideration of IL-6 blockade as a potential adjunctive therapy in the treatment of patients with advanced mastocytosis, as it would reduce DJ-1 levels making mutation-positive mast cells vulnerable to oxidative damage

Cost performance and risk in the construction of offshore and onshore wind farms

This article investigates the risk of cost overruns and underruns occurring in the construction of 51 onshore and offshore wind farms commissioned between 2000 and 2015 in 13 countries. In total, these projects required about $39 billion in investment and reached about 11 GW of installed capacity. We use this original dataset to test six hypotheses about construction cost overruns related to (i) technological learning, (ii) fiscal control, (iii) economies of scale, (iv) configuration, (v) regulation and markets and (vi) manufacturing experience. We find that across the entire dataset, the mean cost escalation per project is 6.5$63 million per windfarm, although 20 projects within the sample (39%) did not exhibit cost overruns. The majority of onshore wind farms exhibit cost underruns while for offshore wind farms the results have a larger spread. Interestingly, no significant relationship exists between the size (in total MWor per individual turbine capacity) of a windfarm and the severity of a cost overrun. Nonetheless, there is an indication that the risk increases for larger wind farms at greater distances offshore using new types of turbines and foundations. Overall, the mean cost escalation for onshore projects is 1.7% and 9.6% for offshore projects, amounts much lower than those for other energy infrastructure

C-axis Optical Sum Rule in Josephson Coupled Vortex State

Observed violations of the $c$-axis optical sum rule can give important information on deviations from in-plane Fermi liquid behavior and on the nature of interlayer coupling between adjacent copper oxide planes. Application of a magnetic field perpendicular to these planes is another way to probe in-plane dynamics. We find that the optical sum rule is considerably modified in the presence of the $c$-axis magnetic field. Interlayer correlation of pancake vortices is involved in the sum rule modification; however, details of the vortex distribution in the plane are less important.Comment: one figure. To be published in PRB (Sep. 20001