... Original article Effects of Cry1Ab protoxin, deltamethrin and imidacloprid on the foraging ac... more ... Original article Effects of Cry1Ab protoxin, deltamethrin and imidacloprid on the foraging activity and the learning performances of the honeybee Apis mellifera, a comparative approach1 RicardoRAMIREZ-ROMEROa,c*, Josette CHAUFAUXb, Minh-Hà PHAM-DELÈGUEa ...
It is physically possible to capture CO2 directly from the air and immobilize it in geological st... more It is physically possible to capture CO2 directly from the air and immobilize it in geological structures. Air capture differs from conventional mitigation in three key aspects. First, it removes emissions from any part of the economy with equal ease or difficulty, so its cost provides an absolute cap on the cost of mitigation. Second, it permits reduction in concentrations faster than the natural carbon cycle: the effects of irreversibility are thus partly alleviated. Third, because it is weakly coupled to existing energy infrastructure, air capture may offer stronger economies of scale and smaller adjustment costs than the more conventional mitigation technologies. We assess the ultimate physical limits on the amount of energy and land required for air capture and describe two systems that might achieve air capture at prices under 200 and 500 $/tC using current technology. Like geoengineering, air capture limits the cost of a worst-case climate scenario. In an optimal sequential decision framework with uncertainty, existence of air capture decreases the need for near-term precautionary abatement. The long-term effect is the opposite; assuming that marginal costs of mitigation decrease with time while marginal climate change damages increase, then air capture increases long-run abatement. Air capture produces an environmental Kuznets curve, in which concentrations are returned to preindustrial levels.
In the climate change issue, the environmental irreversibility (risk of an acceleration of mitiga... more In the climate change issue, the environmental irreversibility (risk of an acceleration of mitigation policies if the worse happen) has to be balanced with the investment irreversibility (risk of over-cautious policies). To explore this balance, we define an option value for a precautionary climate policy. Using the simplest decision-making model, we expose how option value relates to the expected value of future information. Using quantitative data from an integrated assessment model, we find that most of the times the environmental irreversibility dominates the investment irreversibility. For all cases explored here, the order of magnitude of the option value was significant, about 50% of the opportunity cost.
Combined electrophysiological recordings (EAG) and gas chromatographic separation were performed ... more Combined electrophysiological recordings (EAG) and gas chromatographic separation were performed in order to investigate which volatile chemical components of a sunflower extract could be detected by honeybee workers and thus are likely to trigger the foraging behavior. A direct coupling device allowed for the stimulation of the antennal receptors with individual constituents of a polar fraction of the flower aroma shown to be attractive to bees. More than 100 compounds were separated from the extract. Twenty-four compounds elicited clear EAG responses. These compounds were identified by mass spectrometry (electronic impact and chemical ionisation). Both short- and long-chain aliphatic alcohols, one short-chain aliphatic aldehyde, one acid, two esters, and terpenic compounds were found to stimulate the antennal receptors. Six compounds identified in previous behavioral experiments were found to exhibit EAG activity. The chemicals screened by this method may be used for recognition of the plant odor and the selective behavior of honeybees.
The aim of this study was to assess the potential effect of a transgenic line of oilseed rape exp... more The aim of this study was to assess the potential effect of a transgenic line of oilseed rape expressing oryzacystatin I (OCI) on two strains of cabbage seed weevil. The level of OCI expression in seeds was approximately 0.05% of total soluble proteins. The insects were field-collected in two different locations, and their progeny was analyzed after a 3 week-development in pods. Both strains showed a similar pattern of proteolytic activity, and similar levels of OCI-sensitive proteinase activity in vitro. However, the larvae showed differential susceptibility to the transgenic plants. Despite inhibition of digestive proteinases in vitro by OCI in both strains, one strain showed an increased growth rate when fed the transgenic seeds, while the other strain remained unaffected. While suggesting the importance of studying individuals from different populations when assessing the effect of proteinase inhibitorexpressing plants on insect growth, our results also point out the necessity of studying the biochemical interactions taking place in vivo between the recombinant inhibitors and their target proteinases.
Impurities such as particulates and some dissolved salts present in the water used for cleaning o... more Impurities such as particulates and some dissolved salts present in the water used for cleaning of a polysulphone ultra®ltration membrane have been found to affect the ef®ciency of the cleaning. A cationic surfactant, CTAB (cetyltrimethyl-ammonium bromide), was used for membrane cleaning after ultra®ltration of a 0.1 wt% reconstituted whey protein solution. Colloidal-free water used for cleaning was doped with a known amount of the ions: calcium, sodium, chloride, nitrate and sulphate. The presence of calcium in water, at the usual concentrations found in tap water, did not greatly affect cleaning ef®ciency while chloride was found to reduce cleaning ef®ciency. Sodium, nitrate and sulphate appeared to improve the¯ux recovery during membrane cleaning. The cleaning ef®ciency was also improved at higher ionic strengths. Calculations were carried out to demonstrate that the differences were statistically signi®cant. # 1998 Elsevier Science B.V.
Dealing consistently with risk and uncertainty across the IPCC reports is a difficult challenge. ... more Dealing consistently with risk and uncertainty across the IPCC reports is a difficult challenge. Huge practical difficulties arise from the Panel's scale and interdisciplinary context, the complexity of the climate change issue and its political context. The key question of this paper is if the observed differences in the handling of uncertainties by the three IPCC Working Groups can be clarified. To address this question, the paper reviews a few key issues on the foundations of uncertainty analysis, and summarizes the history of the treatment of uncertainty by the IPCC. One of the key findings is that there is reason to agree to disagree: the fundamental differences between the issues covered by the IPCC's three interdisciplinary Working Groups, between the type of information available, and between the dominant paradigms of the practitioners, legitimately lead to different approaches. We argue that properly using the IPCC's Guidance Notes for Lead Authors for addressing uncertainty, adding a pedigree analysis for key findings, and particularly communicating the diverse nature of uncertainty to the users of the assessment would increase the quality of the assessment. This approach would provide information about the nature of the uncertainties in addition to their magnitude and the confidence assessors have in their findings.
... Original article Effects of Cry1Ab protoxin, deltamethrin and imidacloprid on the foraging ac... more ... Original article Effects of Cry1Ab protoxin, deltamethrin and imidacloprid on the foraging activity and the learning performances of the honeybee Apis mellifera, a comparative approach1 RicardoRAMIREZ-ROMEROa,c*, Josette CHAUFAUXb, Minh-Hà PHAM-DELÈGUEa ...
It is physically possible to capture CO2 directly from the air and immobilize it in geological st... more It is physically possible to capture CO2 directly from the air and immobilize it in geological structures. Air capture differs from conventional mitigation in three key aspects. First, it removes emissions from any part of the economy with equal ease or difficulty, so its cost provides an absolute cap on the cost of mitigation. Second, it permits reduction in concentrations faster than the natural carbon cycle: the effects of irreversibility are thus partly alleviated. Third, because it is weakly coupled to existing energy infrastructure, air capture may offer stronger economies of scale and smaller adjustment costs than the more conventional mitigation technologies. We assess the ultimate physical limits on the amount of energy and land required for air capture and describe two systems that might achieve air capture at prices under 200 and 500 $/tC using current technology. Like geoengineering, air capture limits the cost of a worst-case climate scenario. In an optimal sequential decision framework with uncertainty, existence of air capture decreases the need for near-term precautionary abatement. The long-term effect is the opposite; assuming that marginal costs of mitigation decrease with time while marginal climate change damages increase, then air capture increases long-run abatement. Air capture produces an environmental Kuznets curve, in which concentrations are returned to preindustrial levels.
In the climate change issue, the environmental irreversibility (risk of an acceleration of mitiga... more In the climate change issue, the environmental irreversibility (risk of an acceleration of mitigation policies if the worse happen) has to be balanced with the investment irreversibility (risk of over-cautious policies). To explore this balance, we define an option value for a precautionary climate policy. Using the simplest decision-making model, we expose how option value relates to the expected value of future information. Using quantitative data from an integrated assessment model, we find that most of the times the environmental irreversibility dominates the investment irreversibility. For all cases explored here, the order of magnitude of the option value was significant, about 50% of the opportunity cost.
Combined electrophysiological recordings (EAG) and gas chromatographic separation were performed ... more Combined electrophysiological recordings (EAG) and gas chromatographic separation were performed in order to investigate which volatile chemical components of a sunflower extract could be detected by honeybee workers and thus are likely to trigger the foraging behavior. A direct coupling device allowed for the stimulation of the antennal receptors with individual constituents of a polar fraction of the flower aroma shown to be attractive to bees. More than 100 compounds were separated from the extract. Twenty-four compounds elicited clear EAG responses. These compounds were identified by mass spectrometry (electronic impact and chemical ionisation). Both short- and long-chain aliphatic alcohols, one short-chain aliphatic aldehyde, one acid, two esters, and terpenic compounds were found to stimulate the antennal receptors. Six compounds identified in previous behavioral experiments were found to exhibit EAG activity. The chemicals screened by this method may be used for recognition of the plant odor and the selective behavior of honeybees.
The aim of this study was to assess the potential effect of a transgenic line of oilseed rape exp... more The aim of this study was to assess the potential effect of a transgenic line of oilseed rape expressing oryzacystatin I (OCI) on two strains of cabbage seed weevil. The level of OCI expression in seeds was approximately 0.05% of total soluble proteins. The insects were field-collected in two different locations, and their progeny was analyzed after a 3 week-development in pods. Both strains showed a similar pattern of proteolytic activity, and similar levels of OCI-sensitive proteinase activity in vitro. However, the larvae showed differential susceptibility to the transgenic plants. Despite inhibition of digestive proteinases in vitro by OCI in both strains, one strain showed an increased growth rate when fed the transgenic seeds, while the other strain remained unaffected. While suggesting the importance of studying individuals from different populations when assessing the effect of proteinase inhibitorexpressing plants on insect growth, our results also point out the necessity of studying the biochemical interactions taking place in vivo between the recombinant inhibitors and their target proteinases.
Impurities such as particulates and some dissolved salts present in the water used for cleaning o... more Impurities such as particulates and some dissolved salts present in the water used for cleaning of a polysulphone ultra®ltration membrane have been found to affect the ef®ciency of the cleaning. A cationic surfactant, CTAB (cetyltrimethyl-ammonium bromide), was used for membrane cleaning after ultra®ltration of a 0.1 wt% reconstituted whey protein solution. Colloidal-free water used for cleaning was doped with a known amount of the ions: calcium, sodium, chloride, nitrate and sulphate. The presence of calcium in water, at the usual concentrations found in tap water, did not greatly affect cleaning ef®ciency while chloride was found to reduce cleaning ef®ciency. Sodium, nitrate and sulphate appeared to improve the¯ux recovery during membrane cleaning. The cleaning ef®ciency was also improved at higher ionic strengths. Calculations were carried out to demonstrate that the differences were statistically signi®cant. # 1998 Elsevier Science B.V.
Dealing consistently with risk and uncertainty across the IPCC reports is a difficult challenge. ... more Dealing consistently with risk and uncertainty across the IPCC reports is a difficult challenge. Huge practical difficulties arise from the Panel's scale and interdisciplinary context, the complexity of the climate change issue and its political context. The key question of this paper is if the observed differences in the handling of uncertainties by the three IPCC Working Groups can be clarified. To address this question, the paper reviews a few key issues on the foundations of uncertainty analysis, and summarizes the history of the treatment of uncertainty by the IPCC. One of the key findings is that there is reason to agree to disagree: the fundamental differences between the issues covered by the IPCC's three interdisciplinary Working Groups, between the type of information available, and between the dominant paradigms of the practitioners, legitimately lead to different approaches. We argue that properly using the IPCC's Guidance Notes for Lead Authors for addressing uncertainty, adding a pedigree analysis for key findings, and particularly communicating the diverse nature of uncertainty to the users of the assessment would increase the quality of the assessment. This approach would provide information about the nature of the uncertainties in addition to their magnitude and the confidence assessors have in their findings.
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