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Conservative Assumptions (conservative + assumption)

Distribution by Scientific Domains

Business, Economics, Finance and Accounting	50%

Selected Abstracts

Modeling the effect of high dead-space syringes on the human immunodeficiency virus (HIV) epidemic among injecting drug users

ADDICTION, Issue 8 2010
Georgiy V. Bobashev
ABSTRACT Aims To illustrate the impact of different proportions of injecting drug users (IDUs) sharing high dead-space syringes (HDSS) or low dead-space syringes (LDSS) on the probability of human immunodeficiency virus (HIV) transmission; and thus the impact on injection-related HIV prevalence and incidence. Design A stochastic mathematical model was used to evaluate the impact of HDSS use in high- and low-risk IDU populations. Model parameters were obtained from peer-reviewed publications. Analytical solutions of a simplified deterministic model were obtained to explain the effect of HDSS on HIV endemic states. Findings Simulation analysis shows that the HIV epidemic could be sustained even when a small percentage of sharing (10%) involved HDSS. The effect is much stronger in high-risk compared with low-risk populations. Steady state HIV prevalence increases with the proportion of HDSS, and for high- and low-risk populations reaches around 80% and 20%, respectively. For low-risk populations, the use of LDSS could result in the virtual elimination of HIV. These results are dependent upon an evidence-supported assumption of a significant difference in HIV transmission risk associated with HDSS versus LDSS. Conclusions Our models suggest that injection-related HIV epidemics may not occur when most (e.g. 95% or more) IDUs use LDSS. While these results are based on indirect risk measures and a number of simplifying assumptions, the effect of blood retained in high dead-space syringes on HIV prevalence seems to be very strong, even using relatively conservative assumptions. The findings have potential implications for needle exchange programs and the types of syringes produced and distributed world-wide. [source]

Karakorum,Hindukush,western Himalaya: assessing high-altitude water resources

HYDROLOGICAL PROCESSES, Issue 12 2005
M. Winiger
Abstract The high mountains of Central and South Asia provide irrigation water for their adjacent lowlands. The Indus Irrigation Scheme depends on approximately 50% of its runoff originating from snowmelt and glacier melt from the eastern Hindukush, Karakorum and western Himalaya. The Atlas of Pakistan indicates that these mountains gain a total annual rainfall of between 200 and 500 mm, amounts that are generally derived from valley-based stations and not representative for elevated zones. High-altitude snowfall seems to be neglected and is obviously still rather unknown. Estimates derived from accumulation pits runoff above 4000 m range from 1000 mm to more than 3000 mm, depending on the site and time of investigation, as well as on the method applied. To assess the vertical spatio-temporal distribution of total annual precipitation, a combined approach is presented. This approach links in situ measurements of snow depth and water equivalent (10-year time series derived from automatic weather stations at elevations between 1500 and 4700 m a.s.l.), the spatial distribution and period of snow coverage (remotely sensed data and digital elevation models), and the runoff characteristics of streams originating from snow or snow/ice-covered watersheds (modified snowmelt runoff model, including intermediate snowfall and glacier runoff). Based on conservative assumptions, the vertically changing seasonal ratio between liquid and solid precipitation is calculated. Using a combined snow cover and ablation model, total annual amounts of precipitation are derived for different altitudinal zones. Amounts of modelled and measured runoff complement the investigation. Horizontal gradients along the Indus,Gilgit,Hunza transect indicate the varying dominance of seasonal precipitation regimes (monsoonal, Mediterranean and continental disturbances) south of Nanga Parbat, between Nanga Parbat and Batura Wall (=West Karakorum rainfall regime: 1500,1800 mm year,1 at 5000 m) and areas north of Batura (=Central Asian rainfall regime: ,600 mm year,1 at 5000 m). Copyright © 2005 John Wiley & Sons, Ltd. [source]

Participation and study decisions in a public system of higher education

JOURNAL OF APPLIED ECONOMETRICS, Issue 3 2010
Stijn Kelchtermans
We analyze the decision whether to participate and where and what to study in a public system of higher education, based on a unique dataset of all eligible high school pupils in an essentially closed region (Flanders). We find that pupils perceive the available institutions and programs as close substitutes relative to the outside option. This implies an ambiguous role for travel costs: they hardly affect the participation decision, but have a strong impact on the decision where and what to study. To illustrate how our empirical results can inform the debate on reforming public systems, we assess the effects of tuition fee increases. Uniform cost-based tuition fee increases achieve most of the welfare gains; the additional gains from fee differentiation are relatively limited. These welfare gains are quite large under conservative assumptions on the social cost of public funds, and there is a substantial redistribution from students to outsiders. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Some Economics of Safe Injecting Rooms

THE AUSTRALIAN ECONOMIC REVIEW, Issue 1 2001
Harry Clarke
Provision of safe injecting rooms (SIRs), needle exchanges and other harm minimisation schemes reduce mortality and other health risks that illicit drug users experience. However, SIRs diminish incentives to refrain from the use of drugs by reducing the risk of a key harmful consequence of use, namely the user's death. Moreover, such harm minimisation efforts are socially costly. Economic approaches to drug management balance benefits from harm minimisation against policy costs and the costs associated with a failure of community drug abstinence. This article shows that the economic case for SIRs disappears with conservative assumptions about adverse incentive effects of reduced mortality risks even when only modest weight is placed on drug abstinence objectives. [source]