Quadtrees as an Abstract Domain

Quadtrees have proved popular in computer graphics and spatial databases as a way of representing regions in two dimensional space. This hierarchical data-structure is flexible enough to support non-convex and even disconnected regions, therefore it is natural to ask whether this datastructure can form the basis of an abstract domain. This paper explores this question and suggests that quadtrees offer a new approach to weakly relational domains whilst their hierarchical structure naturally lends itself to representation with boolean functions

Enhanced β(2)-adrenergic receptor (β(2)AR) signaling by adeno-associated viral (AAV)-mediated gene transfer

BACKGROUND: β(2)-Adrenergic receptors (β(2)AR) play important regulatory roles in a variety of cells and organ systems and are important therapeutic targets in the treatment of airway and cardiovascular disease. Prolonged use of β-agonists results in tolerance secondary to receptor down-regulation resulting in reduced therapeutic efficiency. The purpose of this work is to evaluate the signaling capabilities of the β(2)AR expressed by a recombinant adeno-associated viral (AAV) vector that also included an enhanced green fluorescent protein (EGFP) gene (AAV-β(2)AR/EGFP). RESULTS: By epifluorescence microscopy, ~40% of infected HEK 293 cells demonstrated EGFP expression. β(2)AR density measured with [(3)H]dihydroalprenolol ([(3)H]DHA) increased either 13- or 77-fold in infected cells compared to mock infected controls depending on the culture conditions used. The [(3)H]DHA binding was to a single receptor population with a dissociation constant of 0.42 nM, as would be expected for wild-type β(2)AR. Agonist competition assays with [(3)H]DHA showed the following rank order of potency: isoproterenol>epinephrine> norepinephrine, consistent with β(2)AR interaction. Isoproterenol-stimulated cyclic AMP levels were 5-fold higher in infected cells compared to controls (314 ± 43 vs. 63.4 ± 9.6 nmol/dish; n = 3). Receptor trafficking demonstrated surface expression of β(2)AR with vehicle treatment and internalization following isoproterenol treatment. CONCLUSIONS: We conclude that HEK 293 cells infected with AAV-β(2)AR/EGFP effectively express β(2)AR and that increased expression of these receptors results in enhanced β(2)AR signaling. This method of gene transfer may provide an important means to enhance function in in vivo systems

Education, income, and incident heart failure in post-menopausal women: the Women\u27s Health Initiative Hormone Therapy Trials

OBJECTIVES: The purpose of this study is to estimate the effect of education and income on incident heart failure (HF) hospitalization among post-menopausal women. BACKGROUND: Investigations of socioeconomic status have focused on outcomes after HF diagnosis, not associations with incident HF. We used data from the Women\u27s Health Initiative Hormone Trials to examine the association between socioeconomic status levels and incident HF hospitalization. METHODS: We included 26,160 healthy, post-menopausal women. Education and income were self-reported. Analysis of variance, chi-square tests, and proportional hazards models were used for statistical analysis, with adjustment for demographics, comorbid conditions, behavioral factors, and hormone and dietary modification assignments. RESULTS: Women with household incomes $50,000 a year (16.7/10,000 person-years; p \u3c 0.01). Women with less than a high school education had higher HF hospitalization incidence (51.2/10,000 person-years) than college graduates and above (25.5/10,000 person-years; p \u3c 0.01). In multivariable analyses, women with the lowest income levels had 56% higher risk (hazard ratio: 1.56, 95% confidence interval: 1.19 to 2.04) than the highest income women; women with the least amount of education had 21% higher risk for incident HF hospitalization (hazard ratio: 1.21, 95% confidence interval: 0.90 to 1.62) than the most educated women. CONCLUSIONS: Lower income is associated with an increased incidence of HF hospitalization among healthy, post-menopausal women, whereas multivariable adjustment attenuated the association of education with incident HF. Elsevier Inc. All rights reserved

The global oscillation network group site survey. II. Results

The Global Oscillation Network Group (GONG) Project will place a network of instruments around the world to observe solar oscillations as continuously as possible for three years. The Project has now chosen the six network sites based on analysis of survey data from fifteen sites around the world. The chosen sites are: Big Bear Solar Observatory, California; Mauna Loa Solar Observatory, Hawaii; Learmonth Solar Observatory, Australia; Udaipur Solar Observatory, India; Observatorio del Teide, Tenerife; and Cerro Tololo Interamerican Observatory, Chile. Total solar intensity at each site yields information on local cloud cover, extinction coefficient, and transparency fluctuations. In addition, the performance of 192 reasonable components analysis. An accompanying paper describes the analysis methods in detail; here we present the results of both the network and individual site analyses. The selected network has a duty cycle of 93.3%, in good agreement with numerical simulations. The power spectrum of the network observing window shows a first diurnal sidelobe height of 3 × 10⁻⁴ with respect to the central component, an improvement of a factor of 1300 over a single site. The background level of the network spectrum is lower by a factor of 50 compared to a single-site spectrum

Toward Innovative, Cost-Effective, and Systemic Solutions to Improve Outcomes and Well-Being of Military Families Affected by Autism Spectrum Disorder

The burdens faced by military families who have a child with autism are unique. The usual challenges of securing diagnostic, treatment, and educational services are compounded by life circumstances that include the anxieties of war, frequent relocation and separation, and a demand structure that emphasizes mission readiness and service. Recently established military autism-specific health care benefits set the stage for community-viable and cost-effective solutions that can achieve better outcomes for children and greater well-being for families. Here we argue for implementation of evidence-based solutions focused on reducing age of diagnosis and improving access to early intervention, as well as establishment of a tiered menu of services, individualized to the child and family, that fit with the military ethos and system of health care. Absence of this new model of care could compromise the utility and sustainability of the autism-specific benefit

Analysis of Intraseasonal and Interannual Variability of the Asian Summer Monsoon Using a Hidden Markov Model

Intraseasonal and interannual variability of Asian summer monsoon rainfall in pentad precipitation data is examined using a hidden Markov model (HMM). The spatial patterns of discrete rainfall states derived with the HMM and the associated transition probabilities between the states are shown to represent well the principal Asian summer monsoon intraseasonal oscillation (ISO), propagating eastward and northward with a period of 40–50 days. Stochastic simulations made with the HMM reasonably reproduce the canonical ISO propagation and its observed statistics such as the frequency of ISO events. The interannual modulation of the ISO associated with El Niño–Southern Oscillation (ENSO) is assessed by employing a nonhomogeneous HMM (NHMM) with summer-mean Niño-3.4 index prescribed as an input variable. ENSO influence on the ISO is found to manifest as preferences toward particular ISO phases depending on the ENSO condition, thus adding an asymmetry to the ISO. In the presence of seasonal mean anomalies, it is shown that the El Niño seasonal mean rainfall anomaly pattern is identified by the HMM as a distinct state, in addition to the ISO states, whereas the La Niña seasonal mean rainfall anomaly pattern does not appear distinct from the ISO states

Book reviews

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45936/1/357_2005_Article_BF01896816.pd

Permafrost and Climate Change: Carbon Cycle Feedbacks From the Warming Arctic

Rapid Arctic environmental change affects the entire Earth system as thawing permafrost ecosystems release greenhouse gases to the atmosphere. Understanding how much permafrost carbon will be released, over what time frame, and what the relative emissions of carbon dioxide and methane will be is key for understanding the impact on global climate. In addition, the response of vegetation in a warming climate has the potential to offset at least some of the accelerating feedback to the climate from permafrost carbon. Temperature, organic carbon, and ground ice are key regulators for determining the impact of permafrost ecosystems on the global carbon cycle. Together, these encompass services of permafrost relevant to global society as well as to the people living in the region and help to determine the landscape-level response of this region to a changing climate