4,938 research outputs found
Effects of Disease Type and Latency on the Value of Mortality Risk
We evaluate the effects of disease type and latency on willingness to pay (WTP) to reduce environmental risks of chronic, degenerative disease. Using contingent-valuation data collected from approximately 1,200 respondents in Taiwan, we find that WTP declines with latency between exposure to environmental contaminants and manifestation of any resulting disease, at a 1.5 percent annual rate for a 20 year latency period. WTP to reduce the risk of cancer is estimated to be about one-third larger than WTP to reduce risk of a similar chronic, degenerative disease. The value of risk reduction also depends on the affected organ, environmental pathway, or payment mechanism: estimated WTP to reduce the risk of lung disease due to industrial air pollution is twice as large as WTP to reduce the risk of liver disease due to contaminated drinking water.
Valuation of the Risk of SARS in Taiwan
Two surveys conducted in Taiwan during the spring 2003 SARS epidemic reveal a high degree of concern about the threat posed by SARS to Taiwan and to residents, although respondents believe they are knowledgeable about the risk of SARS and that it is susceptible to individual control. WTP to reduce the risk of infection and death from SARS is elicited using contingent valuation methods. Estimated WTP is high, implying values per statistical life of US$3 to 12 million. While consistent with estimates for high-income countries, these values are substantially larger than previous estimates for Taiwan and may be attributable to the high degree of concern about SARS at the time the data were collected.
Evaluation of Sandwich Structure Bonding In Out-of-Autoclave Processing
The out-of-autoclave-vacuum-bag-only (OOA-VBO) process is low in capital expenditures compared to the traditional autoclave, however, the material challenges for OOA-VBO workable material systems are high. Presently there are few such aerospace grade prepreg materials available commercially. In this study, we evaluated processing and properties of honeycomb sandwich structure (HC/SS) panels fabricated by co-curing composite face sheet with adhesives by the OOA-VBO process in an oven. The prepreg materials were IM7/MTM 45-1 and T40-800B/5320. Adhesives studied were AF-555M, XMTA-241/PM15, FM-309-1M and FM-300K. Aluminum H/C cores with and without perforations were included. It was found that adhesives in IM7/MTM 45-1/AF-555M, T40-800B/5320/FM 309-1M and T40-800B/5320/FM-300K panels all foamed but yielded high flatwise tensile (FWT) strength values above 8,275 kPA (1,200 psi). IM7/MTM 45-1/XMTA-241/PM15 did not foam, yet yielded a low FWT strength. SEM photomicrographs revealed that the origin of this low strength was poor adhesion in the interfaces between the adhesive and face sheet composite due to poor wetting associated with the high initial viscosity of the XMTA-241/PM15 adhesive
Long-range forces between two excited mercury atoms and associative ionization
The long-range quadrupole-quadrupole () and leading dispersion
() interactions between all pairs of excited Hg() ,
, , and atoms are determined. The quadrupole moments are
calculated using the {\it ab initio} relativistic configuration-interaction
method coupled with many-body perturbation theory. The van der Waals
coefficients are approximated using previously calculated static
polarizabilities and expressions for the dispersion energy that are validated
with similar systems. The long-range interactions are critical for associative
ionization in thermal and cold collisions, and are found to be quite different
for different pairs of interacting states. Based on this knowledge and the
short-range parts of previously calculated potential curves, improved estimates
of the chemi-ionization cross sections are obtained.Comment: accepted in Phys Rev
In vivo and ex vivo regulation of visfatin production by leptin in human and murine adipose tissue : role of mitogen-activated protein kinase and phosphatidylinositol 3-kinase signaling pathways
Visfatin is an adipogenic adipokine with increased levels in obesity, properties common to leptin. Thus, leptin may modulate visfatin production in adipose tissue (AT). Therefore, we investigated the effects of leptin on visfatin levels in 3T3-L1 adipocytes and human/murine AT, with or without a leptin antagonist. The potential signaling pathways and mechanisms regulating visfatin production in AT was also studied. Real-time RT-PCR and Western blotting were used to assess the relative mRNA and protein expression of visfatin. ELISA was performed to measure visfatin levels in conditioned media of AT explants, and small interfering RNA technology was used to reduce leptin receptor expression. Leptin significantly (P < 0.01) increased visfatin levels in human and murine AT with a maximal response at leptin 10–9 M, returning to baseline at leptin 10–7 M. Importantly, ip leptin administration to C57BL/6 ob/ob mice further supported leptin-induced visfatin protein production in omental AT (P < 0.05). Additionally, soluble leptin receptor levels rose with concentration dependency to a maximal response at leptin 10–7 M (P < 0.01). The use of a leptin antagonist negated the induction of visfatin and soluble leptin receptor by leptin. Furthermore, leptin-induced visfatin production was significantly decreased in the presence of MAPK and phosphatidylinositol 3-kinase inhibitors. Also, when the leptin receptor gene was knocked down using small interfering RNA, leptin-induced visfatin expression was significantly decreased. Thus, leptin increases visfatin production in AT in vivo and ex vivo via pathways involving MAPK and phosphatidylinositol 3-kinase signaling. The pleiotropic effects of leptin may be partially mediated by visfatin
The Effect of Prenatal Exposure to Radiation on Birth Outcomes: Exploiting a Natural Experiment in Taiwan
We estimate the effect of prenatal exposure to radiation on infant health. By exploiting the 1983 Taiwanese radiation-contaminated buildings (RCBs) accident as a natural experiment, we compare birth outcomes between siblings and cousins exposed to different radiation levels. Given the 1983 accident was unanticipated and exposed cohorts were unaware of the risk until 1992, our design isolates the effect of radiation exposure during pregnancy from other effects. We provide the first evidence that prenatal exposure to a continuous low-level dose of radiation significantly reduces gestational length and increases the probabilities of prematurity and low birth weight
Gene validation and remodelling using proteogenomics of Phytophthora cinnamomi, the causal agent of Dieback
Phytophthora cinnamomi is a pathogenic oomycete that causes plant dieback disease
across a range of natural ecosystems and in many agriculturally important crops on a
global scale. An annotated draft genome sequence is publicly available (JGI Mycocosm)
and suggests 26,131 gene models. In this study, soluble mycelial, extracellular
(secretome), and zoospore proteins of P. cinnamomi were exploited to refine the genome
by correcting gene annotations and discovering novel genes. By implementing the
diverse set of sub-proteomes into a generated proteogenomics pipeline, we were
able to improve the P. cinnamomi genome annotation. Liquid chromatography mass
spectrometry was used to obtain high confidence peptides with spectral matching
to both the annotated genome and a generated 6-frame translation. Two thousand
seven hundred sixty-four annotations from the draft genome were confirmed by spectral
matching. Using a proteogenomic pipeline, mass spectra were used to edit the
P. cinnamomi genome and allowed identification of 23 new gene models and 60
edited gene features using high confidence peptides obtained by mass spectrometry,
suggesting a rate of incorrect annotations of 3% of the detectable proteome. The
novel features were further validated by total peptide support, alongside functional
analysis including the use of Gene Ontology and functional domain identification. We
demonstrated the use of spectral data in combination with our proteogenomics pipeline
can be used to improve the genome annotation of important plant diseases and identify
missed genes. This study presents the first use of spectral data to edit and manually
annotate an oomycete pathogen
Development and external validation of an acute kidney injury risk score for use in the general population
Background: Improving recognition of patients at increased risk of acute kidney injury (AKI) in the community may facilitate earlier detection and implementation of proactive prevention measures that mitigate the impact of AKI. The aim of this study was to develop and externally validate a practical risk score to predict the risk of AKI in either hospital or community settings using routinely collected data. Methods: Routinely collected linked datasets from Tayside, Scotland, were used to develop the risk score and datasets from Kent in the UK and Alberta in Canada were used to externally validate it. AKI was defined using the Kidney Disease: Improving Global Outcomes serum creatinine–based criteria. Multivariable logistic regression analysis was performed with occurrence of AKI within 1 year as the dependent variable. Model performance was determined by assessing discrimination (C-statistic) and calibration. Results: The risk score was developed in 273 450 patients from the Tayside region of Scotland and externally validated into two populations: 218 091 individuals from Kent, UK and 1 173 607 individuals from Alberta, Canada. Four variables were independent predictors for AKI by logistic regression: older age, lower baseline estimated glomerular filtration rate, diabetes and heart failure. A risk score including these four variables had good predictive performance, with a C-statistic of 0.80 [95% confidence interval (CI) 0.80–0.81] in the development cohort and 0.71 (95% CI 0.70–0.72) in the Kent, UK external validation cohort and 0.76 (95% CI 0.75–0.76) in the Canadian validation cohort.
Conclusion
We have devised and externally validated a simple risk score from routinely collected data that can aid both primary and secondary care physicians in identifying patients at high risk of AKI
Deep proteogenomics; high throughput gene validation by multidimensional liquid chromatography and mass spectrometry of proteins from the fungal wheat pathogen Stagonospora nodorum
Background
Stagonospora nodorum, a fungal ascomycete in the class dothideomycetes, is a damaging pathogen of wheat. It is a model for necrotrophic fungi that cause necrotic symptoms via the interaction of multiple effector proteins with cultivar-specific receptors. A draft genome sequence and annotation was published in 2007. A second-pass gene prediction using a training set of 795 fully EST-supported genes predicted a total of 10762 version 2 nuclear-encoded genes, with an additional 5354 less reliable version 1 genes also retained.
Results
In this study, we subjected soluble mycelial proteins to proteolysis followed by 2D LC MALDI-MS/MS. Comparison of the detected peptides with the gene models validated 2134 genes. 62% of these genes (1324) were not supported by prior EST evidence. Of the 2134 validated genes, all but 188 were version 2 annotations. Statistical analysis of the validated gene models revealed a preponderance of cytoplasmic and nuclear localised proteins, and proteins with intracellular-associated GO terms. These statistical associations are consistent with the source of the peptides used in the study. Comparison with a 6-frame translation of the S. nodorum genome assembly confirmed 905 existing gene annotations (including 119 not previously confirmed) and provided evidence supporting 144 genes with coding exon frameshift modifications, 604 genes with extensions of coding exons into annotated introns or untranslated regions (UTRs), 3 new gene annotations which were supported by tblastn to NR, and 44 potential new genes residing within un-assembled regions of the genome.
Conclusion
We conclude that 2D LC MALDI-MS/MS is a powerful, rapid and economical tool to aid in the annotation of fungal genomic assemblies
Is survival a luxury good? Income elasticity of the value per statistical life
The value of a change in mortality risk is conventionally described by the marginal rate of substitution between income and mortality risk—the value per statistical life (VSL). The income elasticity of VSL is important for estimating how the value of mortality risk varies with time (for evaluating programs with long-lived effects) and across populations with different income levels (for evaluating programs with international consequences). Previous estimates of income elasticity based on meta-analysis of wage-differential studies and cross-sectional comparisons in stated-preference studies suggest values between about one-half and one. We present new estimates based on a 16-year series of wage-differential estimates in Taiwan. Between 1982 and 1997, estimated VSL increased by a factor of five while household labor earnings increased by 60 percent, per capita GDP increased two-and-a-half fold, and the occupational fatality rate in manufacturing and service industries decreased by half. Comparing the growth of VSL with that of household income implies the income elasticity is between about two and five but this estimate may be biased by the endogeneity of VSL, which is affected by workers’ job choices. Using a two-stage approach to control for endogeneity yields estimates of the income elasticity of VSL between two-thirds and one, consistent with estimates from other approaches
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