Genetic Engineering in Agriculture: Who Stands to Benefit?

The use of genetic engineering inagriculture has been the source of much debate. Todate, arguments have focused most strongly on thepotential human health risks, the flow of geneticmaterial to related species, and ecologicalconsequences. Little attention appears to have beengiven to a more fundamental concern, namely, who willbe the beneficiaries of this technology? Given the prevalence of chronic hunger and thestark economics of farming, it is arguable thatfarmers and the hungry should be the mainbeneficiaries of agricultural research. However, theapplication of genetic engineering appears unlikely tobenefit either of these two groups. This technology islargely controlled by the private sector, and itscontinued development hinges on its profitability.Thus, the only likely beneficiaries of the applicationof genetic engineering in agriculture are companieswith the capacity to use it.     

Handedness, Hand Roles, and Hand Injuries at Work

Hand injuries form a significant proportion of all workplace injuries. They are costly to treat, and lead to significant loss of time at work. This paper has two parts. First, there is a review of the literature that discusses prevalence of hand injury, and the significance of hand roles and handedness in industrial injuries. The second part represents an initial attempt to document the roles of the two hands in a particular industry, the metal manufacturing industry. The purpose of this survey of 30 different work stations in seven different industrial plants was to see whether there is a significant bias in terms of movement requirements for one or the other hand, leading to a possible differential risk of injury for the left and right hands. Overall, there was no clear bias favoring the right hand in activities assigned to the hands in seven different movement categories (MTM). However, the location of emergency controls favored the right hand unequivocally. The implications of biases favoring the left/right hand for safety of machine operation are discussed in the light of current findings on left/right hand performance in right- and lefthanders.     

Semicontinuous PM2.5 sulfate and nitrate measurements at an urban and a rural location in New York: PMTACS-NY summer 2001 and 2002 campaigns

Several collocated semicontinuous instruments measuring particulate matter with particle sizes < or =2.5 microm (PM2.5) sulfate (SO4(2-)) and nitrate (NO3-) were intercompared during two intensive field campaigns as part of the PM2.5 Technology Assessment and Characterization Study. The summer 2001 urban campaign in Queens, NY, and the summer 2002 rural campaign in upstate New York (Whiteface Mountain) hosted an operation of an Aerosol Mass Spectrometer, Ambient Particulate Sulfate and Nitrate Monitors, a Continuous Ambient Sulfate Monitor, and a Particle-Into-Liquid Sampler with Ion Chromatographs (PILS-IC). These instruments provided near real-time particulate SO4(2-) and NO3- mass concentration data, allowing the study of particulate SO4(2-)/NO3- diurnal patterns and detection of short-term events. Typical particulate SO4(2-) concentrations were comparable at both sites (ranging from 0 to 20 microg/m3), while ambient urban particulate NO3- concentrations ranged from 0 to 11 microg/m3 and rural NO3- concentration was typically less than 1 microg/m3. Results of the intercomparisons of the semicontinuous measurements are presented, as are results of the comparisons between the semicontinuous and time-integrated filter-based measurements. The comparisons at both sites, in most cases, indicated similar performance characteristics. In addition, charge balance calculations, based on major soluble ionic components of atmospheric aerosol from the PILS-IC and the filter measurements, indicated slightly acidic aerosol at both locations.     

The role of algae (Isochrysis galbana) enrichment on the bioaccumulation of benzo[a]pyrene and its effects on the blue mussel Mytilus edulis

The role of algal concentration in the transfer of organic contaminants in a food chain has been studied using the ubiquitous model polycyclic aromatic hydrocarbon benzo[a]pyrene (BaP) as the contaminant, Isochrysis galbana as the phytoplankton food source, and the common mussel (Mytilus edulis) as the primary consumer. The effect of algal concentration on BaP uptake by M. edulis was determined by feeding M. edulis daily with I. galbana which had previously been kept in the presence of BaP for 24 h. Four combinations of concentrations of algae and BaP were used to give final exposure concentrations of 30,000 or 150,000 algal cells ml(-1) in combination with either 2 or 50 microg BaP l(-1). BaP concentrations were determined fluorometrically in rest tissues (excluding digestive glands) and digestive gland microsomal fractions of M. edulis after 1, 7 and 15 days exposure, and also in isolated algae. Potentially toxic effects of BaP on M. edulis were examined in terms of blood cell lysosomal membrane damage (neutral red dye retention assay) and induction of digestive gland microsomal mixed-function oxygenase (MFO) parameters [BaP hydroxylase (BPH) and NADPH-cytochrome c (P450) reductase activities]. BaP bioaccumulation in rest tissues (and to a lesser extent in digestive gland microsomes) of M. edulis increased with both increasing BaP and algal exposure concentrations, and over time, producing maximal bioconcentration factors in rest tissues after 15 days exposure to 150,000 algal cells ml(-1) and 50 microg BaP l(-1) of 250,000. The five-fold higher concentration of algae increased BaP bioaccumulation by a factor of approximately 2 for 50 microg BaP l(-1) at day 15. Blood cell neutral red dye retention time decreased linearly with increasing log(10) tissue BaP body burden, indicating an increased biological impact on M. edulis with increasing BaP exposure possibly due to a direct effect of BaP on blood cell lysosomal membrane integrity. An increase was seen in NADPH-cytochrome c reductase activity, and indicated in BPH activity, with 1 but not 7 or 15 days exposure to BaP, indicating a transient response of the digestive gland microsomal MFO system to BaP exposure.     

Which visibility indicators best represent a population’s preference for a level of visual air quality?

Several studies have been carried out over the past 20 or so years to assess the level of visual air quality that is judged to be acceptable in urban settings. Groups of individuals were shown slides or computer-projected scenes under a variety of haze conditions and asked to judge whether each image represented acceptable visual air quality. The goal was to assess the level of haziness found to be acceptable for purposes of setting an urban visibility regulatory standard. More recently, similar studies were carried out in Beijing, China, and the more pristine Grand Canyon National Park and Great Gulf Wilderness. The studies clearly showed that when preference ratings were compared to measures of atmospheric haze such as atmospheric extinction, visual range, or deciview (dv), there was not a single indicator that represented acceptable levels of visual air quality for the varied urban or more remote settings. For instance, using a Washington, D.C., setting, 50% of the observers rated the landscape feature as not having acceptable visual air quality at an extinction of 0.19 km^?1 (21 km visual range, 29 dv), while the 50% acceptability point for a Denver, Colorado, setting was 0.075 km^?1 (52 km visual range, 20 dv) and for the Grand Canyon it was 0.023 km^?1 (170 km visual range, 7 dv). Over the past three or four decades, many scene-specific visibility indices have been put forth as potential indicators of visibility levels as perceived by human observers. They include, but are not limited to, color and achromatic contrast of single landscape features, average and equivalent contrast of the entire image, edge detection algorithms such as the Sobel index, and just-noticeable difference or change indexes. This paper explores various scene-specific visual air quality indices and examines their applicability for use in quantifying visibility preference levels and judgments of visual air quality.

Implications: Visibility acceptability studies clearly show that visibility become more unacceptable as haze increases. However, there are large variations in the preference levels for different scenes when universal haze indicators, such as atmospheric extinction, are used. This variability is significantly reduced when the sky–landscape contrast of the more distant landscape features in the observed scene is used. Analysis suggest that about 50% of individuals would find the visibility unacceptable if at any time the more distant landscape features nearly disappear, that is, they are at the visual range. This common metric could form the basis for setting an urban visibility standard.     

Life cycle of <Emphasis Type="Italic">Pseudocalanus acuspes</Emphasis> Giesbrecht (Copepoda,Calanoida) in the Central Baltic Sea: II. Reproduction,growth and secondary production

The population dynamics of Pseudocalanus acuspes in the Central Baltic Sea were studied from March 2002 to May 2003 on a monthly basis. All stages were present year round with a stage shift from nauplii to older copepodite stages over the course of the year. Biomass, estimated from prosome length, peaked between May and September with maximum recorded values of 594 and 855 mg C m⁻² in May 2002 and 2003, respectively. Differences in biomass between stations up to a factor of 20 were observed especially in April/May and October. Mean egg production rate (EPR) showed a seasonal course and was highest in April 2002 and 2003 with 3.6 and 2.1 eggs f⁻¹ day⁻¹, respectively, corresponding to a mean weight-specific egg production rate (SEPR) of 0.13 and 0.04. Egg production seems to be limited by food from May on. Stage durations determined from moulting experiments turned out to be extremely long. Maximum growth rates based on stage durations of 15–25 days at 4°C in May and July 2003 amounted for 0.03–0.05 day⁻¹ in CI-CIV. Comparing these rates with rates derived from temperature–development relationships for P. acuspes from the literature resulted in five times higher growth rates for the latter case. Secondary production reached values up to 9.1 mg C m⁻² day⁻¹ (method for continuously reproducing populations) and 10.5 mg C m⁻² day⁻¹ (increment summation).     

Control of reproduction in social insect colonies: individual and collective relatedness preferences in the paper wasp, Polistes annularis

Social insect colonies often have one or a few queens. How these queens maintain their reproductive monopoly, when other colony members could gain by sharing in the reproduction, is not generally known. DNA microsatellite genotyping is used to determine reproductive interests of various classes of colony members in the paper wasp, Polistes annularis. The relatedness estimates show that the best outcome for most individuals is to be the reproductive egg-layer. For workers, this depends on the sex of offspring: they should prefer to lay their own male eggs, but are indifferent if the queen lays the female eggs. The next-best choice is usually to support the current queen. As a rule, subordinates and workers should prefer the current queen to reproduce over other candidates (though subordinates have no strong preference for the queen over other subordinates, and workers may prefer other workers as a source of male eggs). This result supports the theory that reproductive monopoly stems from the collective preferences of non-reproductives, who suppress each other in favor of the queen. However, we reject the general hypothesis of collective worker control in this species because its predictions about who should succeed after the death of the present queen are not upheld. The first successor is a subordinate foundress even though workers should generally prefer a worker successor. If all foundresses have died, an older worker succeeds as queen, in spite of a collective worker preference for a young worker. The results support the previous suggestion that age serves as a conventional cue serving to reduce conflict over queen succession. Received: 3 May 1996 / Accepted after revision: 22 September 1996     

Evaporation of solutes from water

A model is developed to define the evaporation rates of solutes from water. The rate equation, similar in form to the Knudsen equation, takes into consideration the effect of air and subwater turbulences on the evaporation loss. At given system conditions, the factor accounting for the air turbulence appears to be essentially constant and independent of temperature (3.5–25°C) for various organic chemicals and water. These characteristics allow one to study the rate of evaporation from water and the relative enhancement by subwater mixing for different solutes. This report shows that the volatilization loss of pure substances and solutes with low Henry's law constants is enhanced by air turbulence, not by subwater mixing. However, the loss of volatile solutes (high Henry's law constants) may be promoted both by air turbulence and by subwater mixing, in which the extent of enhancement by liquid mixing is determined primarily by the Henry's law constant. The present model provides a theoretical basis to explain these effects and others, which appear to be important for assessment of pollutant evaporative transport in the environment.     

Hydrologic monitoring tools for freshwater municipal planning in the Arctic: the case of Iqaluit,Nunavut, Canada

Freshwater and the services it provides are vital to both natural ecosystems and human needs; however, extreme climates and their influence on freshwater availability can be challenging for municipal planners and engineers to manage these resources effectively. In Arctic Canada, financial and human capital limitations have left a legacy of freshwater systems that underserve current communities and may be inadequate in the near future under a warming climate, growing population, and increasing demand. We address this challenge to community water resource planning by applying several novel water supply forecasting methods to evaluate the Apex River as an alternative freshwater source for Iqaluit, Nunavut (Canada). Surveys of water isotope composition of the Apex River and tributaries indicated that rainfall is the main source of water replenishment. This information was utilized to calibrate a water resource assessment that considered climate forecasting scenarios and their influence on supply, and alternative scenarios for freshwater management to better adapt to a changing climate. We found that under current climate and demand conditions, the freshwater supply of Iqaluit would be in a perpetual state of drawdown by 2024. Analysis of current infrastructure proposals revealed significant deficiencies in the supply extensions proposed whereby the Apex replenishment pipeline would only provide a 2-year extension to current municipal supply. Our heuristic supply forecast methods allowed for several alternative supply strategies to be rapidly evaluated, which will aid the community planning process by specifically quantifying the service life of the city’s current and future primary water supply.