Weighted composition operators on the Dirichlet space: boundedness and spectral properties

Boundedness of weighted composition operators W u,φ acting on the classical Dirichlet space D as W u,φ f=u(f∘φ) is studied in terms of the multiplier space associated to the symbol φ , i.e., M(φ)={u∈D:W u,φ is bounded on D} . A prominent role is played by the multipliers of the Dirichlet space. As a consequence, the spectrum of W u,φ in D whenever φ is an automorphism of the unit disc is studied, extending a recent work of Hyvärinen et al. (J. Funct. Anal. 265:1749–1777, 2013) to the context of the Dirichlet space

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

Did smokefree legislation in England reduce exposure to secondhand smoke among nonsmoking adults? Cotinine analysis from the Health Survey for England.

Background: On 1 July 2007, smokefree legislation was implemented in England, which made virtually all enclosed public places and workplaces smokefree. Objectives: We examined trends in and predictors of secondhand smoke exposure among nonsmoking adults to determine whether exposure changed after the introduction of smokefree legislation and whether these changes varied by socioeconomic status (SES) and by household smoking status. Methods: We analyzed salivary cotinine data from the Health Survey for England that were collected in 7 of 11 annual surveys undertaken between 1998 and 2008. We conducted multivariate regression analyses to examine secondhand smoke exposure as measured by the proportion of nonsmokers with undetectable levels of cotinine and by geometric mean cotinine. Results: Secondhand smoke exposure was higher among those exposed at home and among lower-SES groups. Exposure declined markedly from 1998 to 2008 (the proportion of participants with undetectable cotinine was 2.9 times higher in the last 6 months of 2008 compared with the first 6 months of 1998 and geometric mean cotinine declined by 80%). We observed a significant fall in exposure after legislation was introduced—the odds of having undetectable cotinine were 1.5 times higher [95% confidence interval (CI): 1.3, 1.8] and geometric mean cotinine fell by 27% (95% CI: 17%, 36%) after adjusting for the prelegislative trend and potential confounders. Significant reductions were not, however, seen in those living in lower-social class households or homes where smoking occurs inside on most days. Conclusions: We found that the impact of England’s smokefree legislation on secondhand smoke exposure was above and beyond the underlying long-term decline in secondhand smoke exposure and demonstrates the positive effect of the legislation. Nevertheless, some population subgroups appear not to have benefitted significantly from the legislation. This finding suggests that these groups should receive more support to reduce their exposure

Preparing for The Inevitable: Ecological and Indigenous Community Impacts of Oil Spill-Related Mortality in The United States’ Arctic Marine Ecosystem

While hydrocarbon exploration and extraction in the Arctic ebb and flow, reduced sea ice has opened new travel routes across the Arctic. The opening of the Northwest Passage has allowed larger ships (including oil tankers) and higher traffic into remote regions. More ice loss is expected in the future. With this comes the potential for hydrocarbon spills. To quantify the ecosystem impacts of a spill in the Alaska North Slope region, an Ecospace model using the Ecopath with Ecosim software was developed. We highlight the impacts of four potential hydrocarbon contamination scenarios: a subsurface crude oil pipeline release, a surface platform oil spill, a surface cruise ship diesel spill, and a surface tanker oil spill. Hydrocarbon contamination was modeled using SIMAP (Spill Impact Model Analysis Package), which was developed from the oil fate sub-model in the Natural Resource Damage Assessment Model for the US Department of the Interior and under the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA). Spatial-temporal SIMAP results were coupled to the Ecospace model. We show that in all four hydrocarbon contamination scenarios, there are spatial changes in harvested species resulting in long-term declines in harvest levels for the communities within the model area (Nuiqsut, Kaktovik, and Barrow Alaska), depending on the severity of the scenario. Responses to hydrocarbon events are likely to be slow in the Arctic, limited by the ice-free season. We highlight this area for scenario testing as ecological impacts are also an issue of food security to the local communities and human health issue

Genome-wide association analysis of coffee drinking suggests association with CYP1A1/CYP1A2 and NRCAM

Coffee consumption is a model for addictive behavior. We performed a meta-analysis of genome-wide association studies (GWASs) on coffee intake from 8 Caucasian cohorts (N = 18 176) and sought replication of our top findings in a further 7929 individuals. We also performed a gene expression analysis treating different cell lines with caffeine. Genome-wide significant association was observed for two single-nucleotide polymorphisms (SNPs) in the 15q24 region. The two SNPs rs2470893 and rs2472297 (P-values = 1.6 x 10(-11) and 2.7 x 10(-11)), which were also in strong linkage disequilibrium (r(2) = 0.7) with each other, lie in the 23-kb long commonly shared 5' flanking region between CYP1A1 and CYP1A2 genes. CYP1A1 was found to be downregulated in lymphoblastoid cell lines treated with caffeine. CYP1A1 is known to metabolize polycyclic aromatic hydrocarbons, which are important constituents of coffee, whereas CYP1A2 is involved in the primary metabolism of caffeine. Significant evidence of association was also detected at rs382140 (P-value = 3.9 x 10(-09)) near NRCAM-a gene implicated in vulnerability to addiction, and at another independent hit rs6495122 (P-value = 7.1 x 10(-09))-an SNP associated with blood pressure-in the 15q24 region near the gene ULK3, in the meta-analysis of discovery and replication cohorts. Our results from GWASs and expression analysis also strongly implicate CAB39L in coffee drinking. Pathway analysis of differentially expressed genes revealed significantly enriched ubiquitin proteasome (P-value = 2.2 x 10(-05)) and Parkinson's disease pathways (P-value = 3.6 x 10(-05)). Molecular Psychiatry (2012) 17, 1116-1129; doi: 10.1038/mp.2011.101; published online 30 August 201