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Selected AbstractsThe prevalence of methamphetamine and amphetamine abuse in North America: a review of the indicators, 1992,2007DRUG AND ALCOHOL REVIEW, Issue 3 2008JANE CARLISLE MAXWELL PhD Senior Research Scientist Abstract Introduction. This paper reviews epidemiological information about methamphetamine production and use in North America. Methods. Information is drawn from a range of sources, including, but not limited to, historical accounts, peer-reviewed papers, population surveys and large national databases. Results. Methamphetamine and amphetamine use in North America is characterised by geographic variations, with different types of the drug, different routes of administration and different types of users at various times. Unlike some other drug use patterns in North America, the nature of methamphetamine use in Canada, Mexico and the United States has been linked closely in terms of production and supply of the drug. According to their national household surveys, the annual prevalence for ,speed' use in Canada was 0.8% in 2004, 0.3% for ,anfetaminas' and 0.1% for ,metanfetaminas' in Mexico in 2002, and 1.4% for ,stimulants' in the United States in 2006. Discussion. Although the data sources in the three North American countries are not consistent in methodology, terminology or frequency of reporting, all show similar trends. The type of stimulant most used has shifted from non-medical use of pharmaceutical amphetamine to use of powder methamphetamine and then to use of ,ice'. The indicators show the problem is greatest in the western parts of the countries and is moving eastward, but the decreased availability of pseudoephedrine may have a significant impact on the nature of the epidemic in the future. Nevertheless, use of methamphetamine poses a number of risks for users and specialised treatment resources for these various populations are needed. [source] Application of a habitat-based model to estimate effective longline fishing effort and relative abundance of Pacific bigeye tuna (Thunnus obesus)FISHERIES OCEANOGRAPHY, Issue 3 2002Keith A. Bigelow A new habitat-based model is developed to improve estimates of relative abundance of Pacific bigeye tuna (Thunnus obesus). The model provides estimates of `effective' longline effort and therefore better estimates of catch-per-unit-of-effort (CPUE) by incorporating information on the variation in longline fishing depth and depth of bigeye tuna preferred habitat. The essential elements in the model are: (1) estimation of the depth distribution of the longline gear, using information on gear configuration and ocean currents; (2) estimation of the depth distribution of bigeye tuna, based on habitat preference and oceanographic data; (3) estimation of effective longline effort, using fine-scale Japanese longline fishery data; and (4) aggregation of catch and effective effort over appropriate spatial zones to produce revised time series of CPUE. Model results indicate that effective effort has increased in both the western and central Pacific Ocean (WCPO) and eastern Pacific Ocean (EPO). In the WCPO, effective effort increased by 43% from the late 1960s to the late 1980s due primarily to the increased effectiveness of effort (deeper longline sets) rather than to increased nominal effort. Over the same period, effective effort increased 250% in the EPO due primarily to increased nominal effort. Nominal and standardized CPUE indices in the EPO show similar trends , a decline during the 1960s, a period of stability in the 1970s, high values during 1985,1986 and a decline thereafter. In the WCPO, nominal CPUE is stable over the time-series; however, standardized CPUE has declined by ,50%. If estimates of standardized CPUE accurately reflect relative abundance, then we have documented substantial reductions of bigeye tuna abundance for some regions in the Pacific Ocean. A decline in standardized CPUE in the subtropical gyres concurrent with stability in equatorial areas may represent a contraction in the range of the population resulting from a decline in population abundance. The sensitivity of the results to the habitat (temperature and oxygen) assumptions was tested using Monte Carlo simulations. [source] A laboratory study of seismic velocity and attenuation anisotropy in near-surface sedimentary rocksGEOPHYSICAL PROSPECTING, Issue 5 2007Angus I. Best ABSTRACT The laboratory ultrasonic pulse-echo method was used to collect accurate P- and S-wave velocity (±0.3%) and attenuation (±10%) data at differential pressures of 5,50 MPa on water-saturated core samples of sandstone, limestone and siltstone that were cut parallel and perpendicular to the vertical borehole axis. The results, when expressed in terms of the P- and S-wave velocity and attenuation anisotropy parameters for weakly transversely isotropic media (,, ,, ,Q, ,Q) show complex variations with pressure and lithology. In general, attenuation anisotropy is stronger and more sensitive to pressure changes than velocity anisotropy, regardless of lithology. Anisotropy is greatest (over 20% for velocity, over 70% for attenuation) in rocks with visible clay/organic matter laminations in hand specimens. Pressure sensitivities are attributed to the opening of microcracks with decreasing pressure. Changes in magnitude of velocity and attenuation anisotropy with effective pressure show similar trends, although they can show different signs (positive or negative values of ,, ,Q, ,, ,Q). We conclude that attenuation anisotropy in particular could prove useful to seismic monitoring of reservoir pressure changes if frequency-dependent effects can be quantified and modelled. [source] Biomanufacturing process analytical technology (PAT) application for downstream processing: Using dissolved oxygen as an indicator of product quality for a protein refolding reactionBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2009Shelly A. Pizarro Abstract Process analytical technology (PAT) is an initiative from the US FDA combining analytical and statistical tools to improve manufacturing operations and ensure regulatory compliance. This work describes the use of a continuous monitoring system for a protein refolding reaction to provide consistency in product quality and process performance across batches. A small-scale bioreactor (3,L) is used to understand the impact of aeration for refolding recombinant human vascular endothelial growth factor (rhVEGF) in a reducing environment. A reverse-phase HPLC assay is used to assess product quality. The goal in understanding the oxygen needs of the reaction and its impact to quality, is to make a product that is efficiently refolded to its native and active form with minimum oxidative degradation from batch to batch. Because this refolding process is heavily dependent on oxygen, the % dissolved oxygen (DO) profile is explored as a PAT tool to regulate process performance at commercial manufacturing scale. A dynamic gassing out approach using constant mass transfer (kLa) is used for scale-up of the aeration parameters to manufacturing scale tanks (2,000,L, 15,000,L). The resulting DO profiles of the refolding reaction show similar trends across scales and these are analyzed using rpHPLC. The desired product quality attributes are then achieved through alternating air and nitrogen sparging triggered by changes in the monitored DO profile. This approach mitigates the impact of differences in equipment or feedstock components between runs, and is directly inline with the key goal of PAT to "actively manage process variability using a knowledge-based approach." Biotechnol. Bioeng. 2009; 104: 340,351 © 2009 Wiley Periodicals, Inc. [source] | ||||||||||