Efficiency Costs of Meeting Industry-Distributional Constraints under Environmental Permits and Taxes

A politically realistic approach to environmental policy seems to require avoiding significant profit-losses in major pollution-related industries. The government can avoid such losses by freely allocating some emissions permits or by exempting some inframarginal emissions from a pollution tax. However, preventing profit-losses in this way involves an efficiency cost because it compels the government to forego especially efficient sources of revenue and to rely more heavily on ordinary, distortionary taxes. Using analytically and numerically solved equilibrium models, we analyze these efficiency costs. We find that when the required amount of abatement is small, the efficiency cost implied by the profits-constraint dwarfs the other efficiency costs of pollution-control. When the abatement requirement becomes more extensive, the cost of this constraint diminishes relative to the other efficiency costs. We also calculate and analyze the determinants of the gross compensation ratio' the share of pollution permits that must be freely allocated to prevent profit-losses in the targeted industries. Numerical simulations of sulfur dioxide pollution-control suggest that the Bush Administration's Clear Skies Initiative would exceed this ratio, freely allocating more permits than necessary to preserve profits.

Teacher and student perceptions of the development of learner autonomy : a case study in the biological sciences

Biology teachers in a UK university expressed a majority view that student learning autonomy increases with progression through university. A minority suggested that pre-existing diversity in learning autonomy was more important and that individuals not cohorts differ in their learning autonomy. They suggested that personal experience prior to university and age were important and that mature students are more autonomous than 18-20 year olds. Our application of an autonomous learning scale (ALS) to four year-groups of biology students confirmed that the learning autonomy of students increases through their time at university but not that mature students are necessarily more autonomous than their younger peers. It was evident however that year of study explained relatively little

Sustainability and the Measurement of Wealth

We develop a consistent and comprehensive theoretical framework for assessing whether economic growth is compatible with sustaining well-being over time. The framework focuses on whether a comprehensive measure of wealth – one that accounts for natural capital and human capital as well as reproducible capital – is maintained through time. Our framework also integrates population growth, technological change, and changes in health. We apply the framework to five countries that differ significantly in stages of development and resource bases: the United States, China, Brazil, India, and Venezuela. With the exception of Venezuela, significant increases in human capital enable comprehensive wealth to be maintained (and sustainability to be achieved) despite significant reductions in the natural resource base. We find that the value of “health capital” is very large relative to other forms of capital. As a result, its growth rate critically influences the growth rate of per-capita comprehensive wealth.

An HIV-1 Nef genotype that diminishes immune control mediated by protective human leucocyte antigen alleles

Objectives: Certain human leucocyte antigen (HLA)-B alleles (protective alleles) associate with durable immune control of HIV-1, but with substantial heterogeneity in the level of control. It remains elusive whether viral factors including Nef-mediated immune evasion function diminish protective allele effect on viral control. / Design: The naturally occurring non-Ser variant at position 9 of HIV-1 subtype C Nef has recently exhibited an association with enhanced HLA-B downregulation function and decreased susceptibility to recognition by CD8+ T cells. We therefore hypothesized this Nef genotype leads to diminished immune control mediated by protective HLA alleles. / Methods: Nef sequences were isolated from HIV-1 subtype C-infected patients harboring protective alleles and several Nef functions including downregulation of HLA-A, HLA-B, CD4, and SERINC5 were examined. Association between Nef non-Ser9 and plasma viral load was examined in two independent South African and Botswanan treatment-naïve cohorts. / Results: Nef clones isolated from protective allele+ individuals encoding Nef non-Ser9 variant exhibited greater ability to downregulate HLA-B when compared with the Ser9 variant, while other Nef functions including HLA-A, CD4, and SERINC5 downregulation activity were unaltered. By analyzing a cohort of South African participants chronically infected with subtype C HIV-1, Nef non-Ser9 associated with higher plasma viral load in patients harboring protective alleles. Corroboratively, the Nef non-Ser9 correlated with higher plasma viral load in an independent cohort in Botswana. / Conclusion: Taken together, our study identifies the Nef genotype, non-Ser9 that subverts host immune control in HIV-1 subtype C infection

Post-treatment control or treated controllers? Viral remission in treated and untreated primary HIV infection

OBJECTIVE(S): An HIV cure will impose aviraemia which is sustained following the withdrawal of antiretroviral therapy (ART). Understanding the efficacy of novel interventions aimed at curing HIV requires characterisation of both natural viral control and the effect of ART on viral control after treatment interruption. DESIGN: Analysis of transient viral control in recent seroconverters in the SPARTAC trial. METHODS: We compared untreated and treated HIV seroconverters (n = 292) and identified periods of control (plasma VL<400 copies/mL for ≥16 weeks off therapy) in 7.9% of ART-naive participants, and in 12.0% overall. HIV DNA was measured by qPCR and HIV-specific CD8 responses were measured by ELISpot. T cell activation and exhaustion were measured by flow cytometry. RESULTS: At baseline, future controllers had lower HIV DNA, lower plasma VLs, higher CD4:CD8 ratios (all p < 0.001), and higher CD4 counts (p < 0.05) than non-controllers. Among controllers, the only difference between the untreated and those who received ART was higher baseline VLs in the latter (p = 0.003), supporting an added ART effect. CONCLUSIONS: Consideration of spontaneous remission in untreated individuals will be critical to avoid overestimating the effect size of new interventions used in HIV cure studies