Moving Toward A Consensus on Climate Policy: The Essential Role of Global Public Disclosure

Among climate scientists, there is no longer any serious debate about whether greenhouse gas emissions from human activity are altering the earth’s climate. There is also a broad consensus on two issues related to reducing emissions. First, developing countries must be full participants in global emissions control, because they will be most heavily impacted by global warming, and because they are rapidly approaching parity with developed countries in the scale of their emissions. Second, efficient emissions control will require carbon pricing via market-based instruments (charges or cap-and-trade). These points of consensus are sufficient to establish a clear way forward, despite continued disagreements over the choice of specific instrument and the appropriate carbon charge level. Since all market-based systems that regulate emissions sources require the same emissions information, the international community should immediately establish an institution mandated to collect, verify and publicly disclose information about emissions from all significant global carbon sources. Its mandate should extend to best-practice estimation and disclosure of emissions sources in countries that initially refuse to participate. This institution will serve four purposes. First, it will lay the necessary foundation for implementing any market-based system of emissions source regulation. Second, it will provide an excellent credibility test, since a country’s acceptance of full disclosure will signal its true willingness to participate in globally-efficient emissions reduction. Third, global public disclosure will itself reduce carbon emissions, by focusing stakeholder pressure on major emitters and providing reputational rewards for clean producers. Fourth, disclosure will make it very hard to cheat once market-based instruments are implemented. This will be essential for preserving the credibility of an international agreement to reduce emissions.climate change

Heard Island and the McDonald Islands: a window into the Kerguelen Plateau

The modern phase of volcanism on Heard Island probably is younger than one million years and is responsible for building Big Ben, the bulk of the island. The nearby McDonald Islands are less than 100 000 years old and are volcanically active. Big Ben sits on the Drygalski Formation, a Late Miocene-Early Pliocene volcanic/marine sediment with glacial influence, which occurs as a generally flat-lying, cliff forming unit over most of Heard Island. The "basement" of Palaeogene limestone crops out mainly on Laurens Peninsula but also sporadically beneath Big Ben and occurs as clasts in volcanics. Historical eruptions of Heard Island, most recently from 1985 to at least 1992 and probably later, have occurred from Mawson Peak, the summit cone built upon Big Ben, but young lavas and ash cones are widespread around the island. Recent volcanic activity is summarised. Heard Island and the McDonald Islands, with the Kerguelen Islands, are exposed parts of the Kerguelen Plateau, possibly the largest submarine plateau on earth, and provide geochemical and isotopic insights into the formation of oceanic plateaux, mantle plume development and the separation of Australia, India and Africa from Antarctica. The Plateau has a complex history that commenced with subaerial basaltic volcanism at 115 Ma, about 10 million years after India and Antarctica separated. It sank below sea level in the mid-Cretaceous, and subsided to its present setting as Broken Ridge and Kerguelen Plateau separated at 43 Ma when the Southeast Indian Ridge came between Australia and Antarctica. It is likely that, during its entire existence, some part of the plateau has been volcanically active, yielding a long-term geochemical record of large-scale crust-mantle evolution

Herbicide Evaluation in Arkansas Rice, 1997

Weed control is economically important for production of rice, a major crop in Arkansas. These findings summarize efforts of the team of Arkansas scientists working on weed control strategies for rice during 1997. Various technologies were evaluated in field studies at five locations involving the major weed problems and rice production systems used in the state. Results from these studies will add to the arsenal of weed control options for producers. Highlights include synergists and safeners for herbicides to aid in control of propanil-resistant barnyardgrass; herbicides and flooding techniques for control of red rice and other weeds; and the use of transgenic rice cultivars for broadspectrum weed control. The preliminary results reported here generally warrant further testing for more advanced findings and for the labeling of new technologies, and finally are the basis for updating safe, effective, and economical recommendations to Arkansas rice producers

The effect of phenethyl alcohol, and other antimetabolites, on growth and extracellular protein production in Staphylococcus aureus

Staphylococcus aureus can excrete at least 31 different proteins which are either wholly extracellular or cell-associated to some degree. Conditions required for production of the two classes are likely to be different since the former are produced late in the growth cycle whereas the latter are probably constitutive. Two proteins were chosen to represent each class and the effect of various antimetabolites on their production was investigated. Particular attention was paid to the effect of phenethyl alcohol since it was hoped to clarify its mode of action. Acid phosphatase was chosen as the example of a cell-associated protein. Since its degree of association was uncertain this was investigated in two ways. A culture which had been grown, overnight was separated by centrifugation and the phosphatase activity in the supernatant and in the cells was determined. Activity associated with the cells was fractionated by washing to remove loosely bound enzyme, protoplasting to determine activity in the wall and periplasm, and lysis to determine activity in the membranes and cytoplasm. It was found that 40% of the total activity was extracellular, 35% was associated with the outer layers of the cell and the remainder was in the protoplast. Electron microscopy revealed considerable activity in the cytoplasm, membranes and walls much of which could be easily washed out. The phosphatase activity appeared to have three pH optima at 6.1, 6.8 and 7.8. These results confirmed that the acid phosphatase was largely cell-associated. Alpha-haemolysin was the other protein chosen, since it was widely accepted to be a wholly extracellular enzyme. Production of the two proteins under different conditions was assessed. In rich media, such as the glucose-casamino acids-yeast extract diffusate medium most commonly used in these experiments, alpha-haemolysin activity was first detected at a population density of 0.68+/- 0.11 measured by extinction at E600nm. Evidence of growth linking; indeed production of the haemolysin increased most markedly while the culture was slowing down at the end of log phase. In poorer media with lower nitrogen content or with alternative carbon sources production of alpha-haemolysin began much later and yield was greatly reduced. Some other extracellular proteins were' assessed in a few experiments and seemed to parallel the appearance of the alpha-haemolysin. Acid phosphatase activity was always detected and its production appeared to be proportional to the population density, although it was not directly growth-linked. The effect of phenethyl alcohol on growth and extracellular protein production was examined by varying concentration of inhibitor and by varying either the time of addition or the cell number. Concentrations of phenethyl alcohol above about 25mM were totally inhibitory to growth due to damage to membrane. Analysis of the results indicated that the effect on growth was competitive up to 25mM and non-competitive above this concentration. Production of alpha-haemolysin was delayed until an E600nm +/- 0.2 and the yield was reduced by 80%, when treated with phenethyl alcohol at 15mM. Above this concentration it was not detected. Acid phosphatase production was inhibited in line with growth inhibition. Inhibition of both growth and extracellular protein production was independent of growth rate and population density, although if inhibitor was added when the culture was nearing stationary phase and maximum protein level this was not always easy to detect. Certain amino acids had been suggested to be involved in alpha-haemolysin production. Phenethyl alcohol did not directly mimic the effect of phenylalanine analogues but addition of excess histidine to complex media did partially reverse the inhibition of alpha-haemolysin production. A comparison of the effect of phenethyl alcohol analogues indicated that the inhibitory effects increased with decreased polarity of the side chain, suggesting that membrane penetration might be involved. (Abstract shortened by ProQuest.)

Differentiated Anti-Predation Responses in a Superorganism

Insect societies are complex systems, displaying emergent properties much greater than the sum of their individual parts. As such, the concept of these societies as single 'superorganisms' is widely applied to describe their organisation and biology. Here, we test the applicability of this concept to the response of social insect colonies to predation during a vulnerable period of their life history. We used the model system of house-hunting behaviour in the ant Temnothorax albipennis. We show that removing individuals from directly within the nest causes an evacuation response, while removing ants at the periphery of scouting activity causes the colony to withdraw back into the nest. This suggests that colonies react differentially, but in a coordinated fashion, to these differing types of predation. Our findings lend support to the superorganism concept, as the whole society reacts much like a single organism would in response to attacks on different parts of its body. The implication of this is that a collective reaction to the location of worker loss within insect colonies is key to avoiding further harm, much in the same way that the nervous systems of individuals facilitate the avoidance of localised damage

Computational model of collective nest selection by ants with heterogeneous acceptance thresholds

Collective decision-making is a characteristic of societies ranging from ants to humans. The ant Temnothorax albipennis is known to use quorum sensing to collectively decide on a new home; emigration to a new nest site occurs when the number of ants favouring the new site becomes quorate. There are several possible mechanisms by which ant colonies can select the best nest site among alternatives based on a quorum mechanism. In this study, we use computational models to examine the implications of heterogeneous acceptance thresholds across individual ants in collective nest choice behaviour. We take a minimalist approach to develop a differential equation model and a corresponding non-spatial agent-based model. We show, consistent with existing empirical evidence, that heterogeneity in acceptance thresholds is a viable mechanism for efficient nest choice behaviour. In particular, we show that the proposed models show speed–accuracy trade-offs and speed–cohesion trade-offs when we vary the number of scouts or the quorum threshold

A social mechanism facilitates ant colony emigrations overdifferent distances

Behavioural responses enable animals to react rapidly to fluctuating environments. In eusocial organisms, such changes are often enacted at the group level, but may be organised in a decentralised fashion by the actions of individuals. However, the contributions of different group members are rarely homogeneous, and there is evidence to suggest that certain ‘keystone’ individuals are important in shaping collective responses. Accordingly, investigations of the dynamics and structuring of behavioural changes at both the group and individual level are crucial for evaluating the relative influence of different individuals. Here, we examined the composition of tandem running behaviour during colony emigrations in the ant species Temnothorax albipennis. Tandem running is modulated in response to emigration distance, with more runs being conducted when a more distant nest site must be reached. We show that certain individuals are highly active in the tandem running process, attempting significantly more work in thetask. Contrary to expectations, however, such individuals are in fact no more successful at conducting tandem runs than their less active nest mates. Instead, it seems that when more tandem runs are required, colonies rely on greater recruitment of workers into the process. The implications of our study are that in some cases, even when apparently ‘key’ individuals exist within a group, their relative contribution to task performance may be far from decisive

Creative Exchange 'Mapping Emergence' In Progress Report

This report highlights the progress and current outputs of the funded Creative Exchange collaborative research project 'Mapping Emergence'. This art / science collaboration set out to conduct an experimental creative exchange with social insects, mapping their colonies’ emergent properties. During 2023 the project evaluated the meaning of ‘creative exchange’ from a non-anthropocentric perspective, and indeed to consider the boundaries of human | non-human collaboration

Ants show a leftward turning bias when exploring unknown nest sites

Behavioural lateralization in invertebrates is an important field of study because it may provide insights into the early origins of lateralization seen in a diversity of organisms. Here, we present evidence for a leftward turning bias in Temnothorax albipennis ants exploring nest cavities and in branching mazes, where the bias is initially obscured by thigmotaxis (wall-following) behaviour. Forward travel with a consistent turning bias in either direction is an effective nest exploration method, and a simple decision-making heuristic to employ when faced with multiple directional choices. Replication of the same bias at the colony level would also reduce individual predation risk through aggregation effects, and may lead to a faster attainment of a quorum threshold for nest migration. We suggest the turning bias may be the result of an evolutionary interplay between vision, exploration and migration factors, promoted by the ants' eusociality