Plant intelligence

Intelligent behavior is a complex adaptive phenomenon that has evolved to enable organisms to deal with variable environmental circumstances. Maximizing fitness requires skill in foraging for necessary resources (food) in competitive circumstances and is probably the activity in which intelligent behavior is most easily seen. Biologists suggest that intelligence encompasses the characteristics of detailed sensory perception, information processing, learning, memory, choice, optimisation of resource sequestration with minimal outlay, self-recognition, and foresight by predictive modeling. All these properties are concerned with a capacity for problem solving in recurrent and novel situations. Here I review the evidence that individual plant species exhibit all of these intelligent behavioral capabilities but do so through phenotypic plasticity, not movement. Furthermore it is in the competitive foraging for resources that most of these intelligent attributes have been detected. Plants should therefore be regarded as prototypical intelligent organisms, a concept that has considerable consequences for investigations of whole plant communication, computation and signal transduction.     

Identification of sex pheromone components of the pea midge, Contarinia pisi (Diptera: Cecidomyiidae)

 Three components in extract of pheromone glands of female pea midges, Contarinia pisi, were found to be active on male pea midge antennae by coupled gas chromatographic-electroantennographic detection. The EAD active components were identified as 2-acetoxytridecane, (2S,11S)-diacetoxytridecane, and (2S,12S)-diacetoxytridecane. A blend of these compounds proved to be highly attractive to males in windtunnel experiments. Received: 12 November 1998 / Accepted in revised form: 26 january 1999     

Alternatives for Managing Drought: A Comparative Cost Analysis

The question addressed by this study is how a large urban water district can best respond to a drought. Using a computer model of a representative district, we find that a combination of conjunctive use and water marketing is well over an order of magnitude cheaper than the traditional alternative of constructing new storage capacity. The indicated cost saving can be explained by the intermittent nature of the transfer, corresponding to the intermittent demand. Comparing costs to benefits, the consumer-surplus loss otherwise entailed by raising prices to cut back on consumption in the event of a drought, we find that construction of new storage does not pass a benefit/cost test, but introduction of conjunctive use/water marketing does.     

First-trimester maternal serum alphafetoprotein and chorionic gonadotropin in aneuploid pregnancies

First-trimester maternal serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) levels were measured in samples from 29 women with cytogenetically abnormal pregnancies and 145 women with cytogenetically normal pregnancies matched for gestational age, race, and sample storage time. All patients had a risk of fetal aneuploidy greater than or equal to that of a mother 35 years of age. AFP was significantly lower in samples from pregnancies affected with trisomy 21 (0.67 MoM;p <0.05), while HCG values were no different from those of matched controls. Trisomies 13 and 18 could not be distinguished from matched controls by AFP. However, levels of HCG were significantly lower in such pregnancy samples, with median values of 0.65 MoM in trisomy 13 and 0.32 MoM in trisomy 18 (p<0.05). Variations in AFP and HCG levels suggest that expressed differences between autosomal aneuploidies include differences in fetal and placenta! protein production in the first trimester.     

Lake sediments record sensitivity of two hydrologically closed upland lakes in Mexico to human impact

We provide evidence of rapid, recent environmental change in two lakes in the highlands of central Mexico. Multiple sediment cores were obtained from Lago de Zirahuén (Michoacán) and Laguna de Juanacatlán (Jalisco). Analysis of diatom assemblages, magnetic susceptibility, and metal concentrations was carried out, with the chronology provided by 210Pb dating, 14C dating, and tephrochronology. There is evidence of catchment disturbance during the colonial period in both basins, but the most striking feature at both sites is the rapid change in diatom assemblages during the last 20 y, indicating the onset of eutrophication. Limnological data from Lago de Zirahuén support this interpretation, although none are available from Laguna de Juanacatlán. Paleolimnology is a powerful tool in tracking recent change, particularly in the absence of regular limnological monitoring programs. These lakes appear to be highly sensitive to changes in catchment exploitation, which must be considered in future drainage basin management.     

Financing remediation by delisting and selling clean portions of affected property

It is an established fact that property owners can face significant liabilities as a result of an on-site environmental contamination problem. This paper outlines a successful, innovative remedial strategy that, in conjunction with agency negotiation, afforded a property owner minimal financial expenditure and, at the same time, facilitated property cleanup and reuse. The strategy includes the delisting and sale of “clean” portions of the property to obtain the finances necessary to remediate the remaining “impacted” portion of the property. Previous investigations performed by EPA indicate the affected area to be a five to seven acre area located in the northeast portion of the property. Since a portion of the property was affected, significant restrictions for long-term use were placed on the entire property. A summary of environmental data generated for the property was prepared and submitted to the agency. This data summary communicated a strategy which was developed to delist and sell the “clean” portion of the property and to use the proceeds to clean up the affected property. To accomplish this, several tasks were outlined, including work-plan preparation and submittal, data collection, and interim remedial activities. In addition, a risk assessment is planned to identify potential threats to receptors downgradient of the impacted areas. This strategy allows the owner of an environmentally distressed property to use financial assets of the property to facilitate an acceptable solution with both regulatory agencies and the surrounding community.