Role of GBV-C and human herpes virus coinfections in AIDS development in HIV-1 seroconverters

Background: GB virus type C (GBV-C) co-infection prolongs survival among Human Immunodeficiency Virus (HIV) infected individuals. Chronic immune activation is associated with HIV-1 disease progression. Objective: To investigate the effect of GBV-C coinfection and herpes virus reactivation on AIDS development in HIV-1 seroconverters. Methods: A total of 272 men HIV-1 seroconverters were included for the analysis. Cox proportional hazards (PH) regression models were employed to evaluate the effects of GBV-C and herpes viruses (CMV, EBV, HHV6, HHV8) on time from HIV-1 seroconversion to AIDS development. In addition, Gray’s piecewise constant time-varying coefficient (PC-TVC) model that accounts for varying covariate effects over time was employed to estimate the effects for the variables that did not follow PH assumption. Results: In Cox PH model analysis, GBV-C coinfection delayed AIDS development statistically significant in HIV-1 seroconverters. The log10 GBV-C RNA increase was associated with a 15% decrease in AIDS development, while the high HHV8 and CMV reactivation increased AIDS development respectively. The effects of HHV6 and EBV on AIDS development were not statistically significant. Using Gray PC-TVC model, GBV-C coinfection was associated with delaying AIDS development, especially starting from year 3 of HIV-1 infection, then the hazard ratios decreased over time until 10 years, and kept in low level after 10 years of infection. HHV8 reactivation increased the chance of AIDS development, especially after 3 years of HIV-1 infection. The effect of CMV reactivation was constant with a hazard ratio of 1.38. In addition, two variables, age and baseline CD4+ T cell counts, which were not statistically significant in Cox PH regression model analysis, were statistically significant in Gray PC-TVC model. Similar to Cox PH analysis, the effects of HHV6 and EBV were not statistically significant either on AIDS development. Conclusion: GBV-C co-infection delayed HIV-1 disease progression. HHV8 and CMV accelerated AIDS development. The effects of HHV6 and EBV were not statistically significant on AIDS development. Public health importance: This study has important implications for investigating viral coinfections on AIDS development and providing alternative ideas to delay HIV disease progression

The Pleiotropic Mutant R50 (\u3cem\u3esym16\u3c/em\u3e): A Link Between Cytokinin and Starch Metabolism May Explain Its Seed Phenotype

Cytokinins are a class of adenine-based plant hormones that stimulate cell divisions and are therefore essential for organ growth and development. The role that cytokinin plays in nodulation and that of R50 (syml6) in particular is very complex. In this study, a cytokinin antagonist and a cytokinin oxidase (CKX) inhibitor were used as tools to study the effects of cytokinin perception or cytokinin degradation on nodulation in pea, the cytokinin transduction pathway, especially that induced by CRE1/AHK4, and CKX play a significant role in pea nodulation. Comparison of the full length sequences PsCKX2 cDNAs from Sparkle and R50 indicated that PsCKX2 is likely not syml6. The availability of the full length PsCKX2 cDNA facilitated the assessment of PsCKX1 and PsCKX2 expression profiles in seedling development using semi-quantitative RT-PCR. Along with a morphological study (dry weight of R50 cotyledons are not decreasing as fast as those of wild type) and microscopic studies (R50 starch grains within the cotyledons are not digested as fast as those of wild type) of seedling development, a workmg model which integrates cytokinm and starch metabolism is proposed to explain the seedlmg phenotype of R50

Electrochemical, resonance Raman, and surface enhanced Raman spectroscopic study of biomolecules: cytochrome c and its mutants

In this work, conventional electrochemical methods were coupled with structure sensitive techniques, resonance Raman and surface-enhanced resonance Raman spectroscopies to study the electrochemical behavior, electron transfer mechanisms and configuration of the cytochrome c at modified metal electrode surfaces. Four studies were undertaken. The first one reevaluated two promoters which were studied by other research groups and a new electrode modification procedure was used. It was determined that both 2,2\u27-bipyridine and pyrazine act as promoters. The strengths of adsorption were found to be a very important factor which affects the promoter performance. A new idea about the structure requirement of the promoter was proposed. The second study found that thiophene, carbazole and pyridine whose molecules contain only one functional group, are all effective promoters which supported the previously proposed idea in the first study. The crucial role of these three promoters may be prevent denaturation and/or irreversible adsorption of cytochrome c or the deaminated and oligomeric components, which results in irreversible electrochemistry. In the third study, Quasi-reversible and direct electron transfer was observed between an iodide-modified gold electrode and cytochrome c. The results suggest that an electrostatic interaction between cytochrome c and the iodide-modified electrode surface plays an important role in the electrochemical response. Results obtained by surface enhanced resonance Raman scattering (SERRS) spectroscopy indicate that the heme group of the adsorbed cytochrome c is in the native low spin, six coordinate configuration at the iodide-modified Ag electrode, whereas at the bare Ag electrode a mixture of both low spin, six coordinate and high spin, five coordinate heme is present on the surface. In the forth study, several cytochrome c mutants were characterized by using cyclic voltammetry, resonance Raman and surface-enhanced resonance Raman spectroscopies to investigate how the mutations affect the redox potential, electron transfer kinetics and the stability of cytochrome. The results show that the mutations for the water mutants decrease the redox potentials which indicates that the mutation increases the stability of the protein. The RR results indicate that the heme environment is strongly perturbed by the mutation

A Mathematical Study of Competition and Adoption of Two Consumer Products

A mathematical model describing the competition between two consumer products in the market is constructed based on the Bass Diffusion Model and the competitive Lotka-Volterra model. Using this proposed model, the long-term behaviors of the two competing products can be forecasted. The model is analyzed and categorized into eight different cases with different settings of parameters, and under any of those cases, the two products are proved to co-exist in the long term

Allocation of risk capital based on iso-entropic coherent risk measure

Journal of Industrial Engineering and Management OmniaScience User Username Password Remember me Scholar Sponsorship - UPC BarcelonaTech - Beijing Jiaotong University - UPV - UPCT Article Tools Indexing metadata Supplementary files Finding References Review policy Email this article (Login required) Email the author (Login required) Printed Edition News Indexing SJR (Scopus) SCImago Journal & Country Rank See more: DOAJ, InRecs... Journal Content Search Browse By Issue By Author By Title Information For Readers For Authors For Librarians Visitors Locations of visitors to this page Home About Log In Archives Submissions Publication fee Indexing & Statistics Home > Vol 8, No 2 (2015) > Zheng Allocation of risk capital based on iso-entropic coherent risk measure Chengli Zheng, Yan Chen Abstract Purpose: The potential of diversified portfolio leads to the risk capital allocation problem. There are many kinds of methods or rules to allocate risk capital. However, they have flaws, such as non-continuity, unfairness. In order to get a better method, we propose a new risk measure to be the base of risk capital allocation rule. Design/methodology/approach: We proposed two kinds of allocation methods: one is marginal risk contribution based on iso-entropic coherent risk measure(IE), the other one is to combine the minimal excess allocation(EBA) principle and IE into risk capital allocation. The iso-entropic coherent risk measure has many advantages over others; it is continuous and more powerful in distinguishing risks, consistent with higher-order stochastic dominances than other risk measures. And EBA is consistent with the amount of risk, which means fairness for risk capital allocation. Findings: Through cases, simulations and empirical application, it shows that these two allocation rules satisfy some good properties, can be more efficient, more precise and fairer. And the EBA based on IE may be the better one. Research limitations/implications: However, there are some problems still open. One is how to treat the negative value of allocation. Second is that the consistence between the allocated risk capital and the amount of the risk needs to be studied further. Originality/value: A good risk measure is very important for risk capital allocation. We proposed two methods to deal with risk capital allocation based on a new coherent risk measure called iso-entropic risk measure, which is smooth and consistent with higher-order stochastic dominance and has higher resolution of risk. It shows that the risk capital allocation rules based on iso-entropic risk measure are better than the other rules.Peer Reviewe

Allocation of risk capital based on iso-entropic coherent risk measure

Journal of Industrial Engineering and Management OmniaScience User Username Password Remember me Scholar Sponsorship - UPC BarcelonaTech - Beijing Jiaotong University - UPV - UPCT Article Tools Indexing metadata Supplementary files Finding References Review policy Email this article (Login required) Email the author (Login required) Printed Edition News Indexing SJR (Scopus) SCImago Journal & Country Rank See more: DOAJ, InRecs... Journal Content Search Browse By Issue By Author By Title Information For Readers For Authors For Librarians Visitors Locations of visitors to this page Home About Log In Archives Submissions Publication fee Indexing & Statistics Home > Vol 8, No 2 (2015) > Zheng Allocation of risk capital based on iso-entropic coherent risk measure Chengli Zheng, Yan Chen Abstract Purpose: The potential of diversified portfolio leads to the risk capital allocation problem. There are many kinds of methods or rules to allocate risk capital. However, they have flaws, such as non-continuity, unfairness. In order to get a better method, we propose a new risk measure to be the base of risk capital allocation rule. Design/methodology/approach: We proposed two kinds of allocation methods: one is marginal risk contribution based on iso-entropic coherent risk measure(IE), the other one is to combine the minimal excess allocation(EBA) principle and IE into risk capital allocation. The iso-entropic coherent risk measure has many advantages over others; it is continuous and more powerful in distinguishing risks, consistent with higher-order stochastic dominances than other risk measures. And EBA is consistent with the amount of risk, which means fairness for risk capital allocation. Findings: Through cases, simulations and empirical application, it shows that these two allocation rules satisfy some good properties, can be more efficient, more precise and fairer. And the EBA based on IE may be the better one. Research limitations/implications: However, there are some problems still open. One is how to treat the negative value of allocation. Second is that the consistence between the allocated risk capital and the amount of the risk needs to be studied further. Originality/value: A good risk measure is very important for risk capital allocation. We proposed two methods to deal with risk capital allocation based on a new coherent risk measure called iso-entropic risk measure, which is smooth and consistent with higher-order stochastic dominance and has higher resolution of risk. It shows that the risk capital allocation rules based on iso-entropic risk measure are better than the other rules.Peer Reviewe