3,208 research outputs found
INVESTMENT IN ANTIVIRAL DRUGS:A REAL OPTIONS APPROACH
Real options analysis is a promising approach to model investment under uncertainty. We employ this approach to value stockpiling of antiviral drugs as a precautionary measure against a possible influenza pandemic. Modifications of the real options approach to include risk attitude and deviations from expected utility are presented. We show that risk aversion counteracts the tendency to delay investment for this case of precautionary investment, which is in contrast to earlier applications of risk aversion to real options analysis. Moreover, we provide a numerical example using real world data and discuss the implications of real options analysis for health policy. Suggestions for further extensions of the model and a comparison with the expected value of information analysis are put forward. Copyright (C) 2009 John Wiley & Sons, Ltd
The Iowa Homemaker vol.5, no.11
Table of Contents
Choosing the Profession of Homemaking by Anna E. Richardson, page 1
Opportunities Offered in Hospital Dietetics by Grace Magee, page 2
Selecting Your Spring Wardrobe by Betty Barker, page 2
Soft Water for the Housewife by Arthur W. Turner, page 3
Do You Have a Tea Room Complex? by Gladys Branson, page 4
The Designer â Her Place by Helen Dahl, page 4
Girlsâ 4-H Page, page 5
With the Iowa State Home Economics Association, page 6
Editorial, page 7
Whoâs There and Where, page 8
Marketing as a Business Proposition by Ruetta Day Blinks, page 9
The Eternal Question, page 10
Are You Furnishing Your Home?, page 11
The Heart of the Home by Frances Jones, page 1
A Three-Domain Structure for the delta Subunit of the DNA Polymerase III Holoenzyme delta Domain III Binds delta\u27 and Assembles Into the DnaX Complex
Using Ï-BLAST, we have developed a method for identifying the poorly conserved ÎŽ subunit of the DNA polymerase III holoenzyme from all sequenced bacteria. This approach, starting withEscherichia coli ÎŽ, leads not only to the identification of ÎŽ but also to the DnaX and ÎŽâČ subunits of the DnaX complex and other AAA+-class ATPases. This suggests that, although not an ATPase, ÎŽ is related structurally to the other subunits of the DnaX complex that loads the ÎČ sliding clamp processivity factor onto DNA. To test this prediction, we aligned ÎŽ sequences with those of ÎŽâČ and, using the start of ÎŽâČ Domain III established from its x-ray crystal structure, predicted the juncture between Domains II and III of ÎŽ. This putative ÎŽ Domain III could be expressed to high levels, consistent with the prediction that it folds independently. ÎŽ Domain III, like Domain III of DnaX and ÎŽâČ, assembles by itself into a complex with the other DnaX complex components. Cross-linking studies indicated a contact of ÎŽ with the DnaX subunits. These observations are consistent with a model where two Ï subunits and one each of the Îł, ÎŽâČ, and ÎŽ subunits mutually interact to form a pentameric functional core for the DnaX complex
Application of novel analytical ultracentrifuge analysis to solutions of fungal mannans
Polysaccharides, the most abundant biopolymers, are required for a host of activities in lower organisms, animals, and plants. Their solution characterization is challenging due to their complex shape, heterogeneity, and size. Here, recently developed data analysis approaches were applied for traditional sedimentation equilibrium and velocity methods in order to investigate the molar mass distribution(s) of a subtype of polysaccharide, namely, mannans from four Candida spp. The molecular weight distributions of these mannans were studied using two recently developed equilibrium approaches: SEDFIT-MSTAR and MULTISIG, resulting in corroboratory distribution profiles. Additionally, sedimentation velocity data for all four mannans, analyzed using ls-g*(s) and Extended Fujita approaches, suggest that two of the fungal mannans (FM-1 and FM-3) have a unimodal distribution of molecular species whereas two others (FM-2 and FM-4) displayed bi-modal and broad distributions, respectively: this demonstrates considerable molecular heterogeneity in these polysaccharides, consistent with previous observations of mannans and polysaccharides in general. These methods not only have applications for the characterization of mannans but for other biopolymers such as polysaccharides, DNA, and proteins (including intrinsically disordered proteins)
Significant association between host transcriptomeâderived HPV oncogene E6* influence score and carcinogenic pathways, tumor size, and survival in head and neck cancer
BackgroundHuman papillomavirus (HPV) oncogenes E6, E7, and shorter isoforms of E6 (E6*) are known carcinogenic factors in head and neck squamous cell carcinoma (HNSCC). Little is known regarding E6* functions.MethodsWe analyzed RNAâseq data from 68 HNSCC HPV type 16âpositive tumors to determine host genes and pathways associated with E6+E7 expression (E6E7) or the percent of fullâlength E6 (E6%FL). Influence scores of E6E7 and E6%FL were used to test for associations with clinical variables.ResultsFor E6E7, we recapitulated all major known affected pathways and revealed additional pathways. E6%FL was found to affect mitochondrial processes, and E6%FL influence score was significantly associated with overall survival and tumor size.ConclusionsHPV E6E7 and E6* result in extensive, doseâdependent compensatory effects and dysregulation of key cancer pathways. The switch from E6 to E6* promotes oxidative phosphorylation, larger tumor size, and worse prognosis, potentially serving as a prognostic factor for HPVâpositive HNSCC.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156432/2/hed26244.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156432/1/hed26244_am.pd
Volatile profiling reveals intracellular metabolic changes in Aspergillus parasticus: veA regulates branched chain amino acid and ethanol metabolism
Background: Filamentous fungi in the genus Aspergillus produce a variety of natural products, including aflatoxin, the most potent naturally occurring carcinogen known. Aflatoxin biosynthesis, one of the most highly characterized secondary metabolic pathways, offers a model system to study secondary metabolism in eukaryotes. To control or customize biosynthesis of natural products we must understand how secondary metabolism integrates into the overall cellular metabolic network. By applying a metabolomics approach we analyzed volatile compounds synthesized by Aspergillus parasiticus in an attempt to define the association of secondary metabolism with other metabolic and cellular processes.
Results: Volatile compounds were examined using solid phase microextraction - gas chromatography/mass spectrometry. In the wild type strain Aspergillus parasiticus SU-1, the largest group of volatiles included compounds derived from catabolism of branched chain amino acids (leucine, isoleucine, and valine); we also identified alcohols, esters, aldehydes, and lipid-derived volatiles. The number and quantity of the volatiles produced depended on media composition, time of incubation, and light-dark status. A block in aflatoxin biosynthesis or disruption of the global regulator veA affected the volatile profile. In addition to its multiple functions in secondary metabolism and development, VeA negatively regulated catabolism of branched chain amino acids and synthesis of ethanol at the transcriptional level thus playing a role in controlling carbon flow within the cell. Finally, we demonstrated that volatiles generated by a veA disruption mutant are part of the complex regulatory machinery that mediates the effects of VeA on asexual conidiation and sclerotia formation.
Conclusions: 1) Volatile profiling provides a rapid, effective, and powerful approach to identify changes in intracellular metabolic networks in filamentous fungi. 2) VeA coordinates the biosynthesis of secondary metabolites with catabolism of branched chain amino acids, alcohol biosynthesis, and b-oxidation of fatty acids. 3) Intracellular chemical development in A. parasiticus is linked to morphological development. 4) Understanding carbon flow through secondary metabolic pathways and catabolism of branched chain amino acids is essential for controlling and customizing production of natural products
Volatile profiling reveals intracellular metabolic changes in Aspergillus parasiticus: veA regulates branched chain amino acid and ethanol metabolism
<p>Abstract</p> <p>Background</p> <p>Filamentous fungi in the genus <it>Aspergillus </it>produce a variety of natural products, including aflatoxin, the most potent naturally occurring carcinogen known. Aflatoxin biosynthesis, one of the most highly characterized secondary metabolic pathways, offers a model system to study secondary metabolism in eukaryotes. To control or customize biosynthesis of natural products we must understand how secondary metabolism integrates into the overall cellular metabolic network. By applying a metabolomics approach we analyzed volatile compounds synthesized by <it>Aspergillus parasiticus </it>in an attempt to define the association of secondary metabolism with other metabolic and cellular processes.</p> <p>Results</p> <p>Volatile compounds were examined using solid phase microextraction - gas chromatography/mass spectrometry. In the wild type strain <it>Aspergillus parasiticus </it>SU-1, the largest group of volatiles included compounds derived from catabolism of branched chain amino acids (leucine, isoleucine, and valine); we also identified alcohols, esters, aldehydes, and lipid-derived volatiles. The number and quantity of the volatiles produced depended on media composition, time of incubation, and light-dark status. A block in aflatoxin biosynthesis or disruption of the global regulator <it>veA </it>affected the volatile profile. In addition to its multiple functions in secondary metabolism and development, VeA negatively regulated catabolism of branched chain amino acids and synthesis of ethanol at the transcriptional level thus playing a role in controlling carbon flow within the cell. Finally, we demonstrated that volatiles generated by a <it>veA </it>disruption mutant are part of the complex regulatory machinery that mediates the effects of VeA on asexual conidiation and sclerotia formation.</p> <p>Conclusions</p> <p>1) Volatile profiling provides a rapid, effective, and powerful approach to identify changes in intracellular metabolic networks in filamentous fungi. 2) VeA coordinates the biosynthesis of secondary metabolites with catabolism of branched chain amino acids, alcohol biosynthesis, and ÎČ-oxidation of fatty acids. 3) Intracellular chemical development in <it>A. parasiticus </it>is linked to morphological development. 4) Understanding carbon flow through secondary metabolic pathways and catabolism of branched chain amino acids is essential for controlling and customizing production of natural products.</p
Pretreatment dietary intake is associated with tumor suppressor DNA methylation in head and neck squamous cell carcinomas
Diet is associated with cancer prognosis, including head and neck cancer (HNC), and has been hypothesized to influence epigenetic state by determining the availability of functional groups involved in the modification of DNA and histone proteins. The goal of this study was to describe the association between pretreatment diet and HNC tumor DNA methylation. Information on usual pretreatment food and nutrient intake was estimated via food frequency questionnaire (FFQ) on 49 HNC cases. Tumor DNA methylation patterns were assessed using the Illumina Goldengate Methylation Cancer Panel. First, a methylation score, the sum of individual hypermethylated tumor suppressor associated CpG sites, was calculated and associated with dietary intake of micronutrients involved in one-carbon metabolism and antioxidant activity, and food groups abundant in these nutrients. Second, gene specific analyses using linear modeling with empirical Bayesian variance estimation were conducted to identify if methylation at individual CpG sites was associated with diet. All models were controlled for age, sex, smoking, alcohol and HPV status. Individuals reporting in the highest quartile of folate, vitamin B12 and vitamin A intake, compared with those in the lowest quartile, showed significantly less tumor suppressor gene methylation, as did patients reporting the highest cruciferous vegetable intake. Gene specific analyses identified differential associations between DNA methylation and vitamin B12 and vitamin A intake when stratifying by HPV status. These preliminary results suggest that intake of folate, vitamin A and vitamin B12 may be associated with the tumor DNA methylation profile in HNC and enhance tumor suppression
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Pretreatment dietary intake is associated with tumor suppressor DNA methylation in head and neck squamous cell carcinomas
Diet is associated with cancer prognosis, including head and neck cancer (HNC), and has been hypothesized to influence epigenetic state by determining the availability of functional groups involved in the modification of DNA and histone proteins. The goal of this study was to describe the association between pretreatment diet and HNC tumor DNA methylation. Information on usual pretreatment food and nutrient intake was estimated via food frequency questionnaire (FFQ) on 49 HNC cases. Tumor DNA methylation patterns were assessed using the Illumina Goldengate Methylation Cancer Panel. First, a methylation score, the sum of individual hypermethylated tumor suppressor associated CpG sites, was calculated and associated with dietary intake of micronutrients involved in one-carbon metabolism and antioxidant activity, and food groups abundant in these nutrients. Second, gene specific analyses using linear modeling with empirical Bayesian variance estimation were conducted to identify if methylation at individual CpG sites was associated with diet. All models were controlled for age, sex, smoking, alcohol and HPV status. Individuals reporting in the highest quartile of folate, vitamin B12 and vitamin A intake, compared with those in the lowest quartile, showed significantly less tumor suppressor gene methylation, as did patients reporting the highest cruciferous vegetable intake. Gene specific analyses identified differential associations between DNA methylation and vitamin B12 and vitamin A intake when stratifying by HPV status. These preliminary results suggest that intake of folate, vitamin A and vitamin B12 may be associated with the tumor DNA methylation profile in HNC and enhance tumor suppression
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