Targeted gene flow and rapid adaptation in an endangered marsupial

Targeted gene flow is an emerging conservation strategy. It involves translocating individuals with favorable genes to areas where they will have a conservation benefit. The applications for targeted gene flow are wide-ranging but include preadapting native species to the arrival of invasive species. The endangered carnivorous marsupial, the northern quoll (Dasyurus hallucatus), has declined rapidly since the introduction of the cane toad (Rhinella marina), which fatally poisons quolls that attack them. There are, however, a few remaining toad-invaded quoll populations in which the quolls survive because they know not to eat cane toads. It is this toad-smart behavior we hope to promote through targeted gene flow. For targeted gene flow to be feasible, however, toad-smart behavior must have a genetic basis. To assess this, we used a common garden experiment, comparing offspring from toad-exposed and toad-naïve parents raised in identical environments, to determine whether toad-smart behavior is heritable. Offspring from toad-exposed populations were substantially less likely to eat toads than those with toad-naïve parents. Hybrid offspring showed similar responses to quolls with 2 toad-exposed parents, indicating the trait may be dominant. Together, these results suggest a heritable trait and rapid adaptive response in a small number of toad-exposed populations. Although questions remain about outbreeding depression, our results are encouraging for targeted gene flow. It should be possible to introduce toad-smart behavior into soon to be affected quoll populations.     

Effects of learning and adaptation on population viability

Cultural adaptation is one means by which conservationists may help populations adapt to threats. A learned behavior may protect an individual from a threat, and the behavior can be transmitted horizontally (within generations) and vertically (between generations), rapidly conferring population-level protection. Although possible in theory, it remains unclear whether such manipulations work in a conservation setting; what conditions are required for them to work; and how they might affect the evolutionary process. We examined models in which a population can adapt through both genetic and cultural mechanisms. Our work was motivated by the invasion of highly toxic cane toads (Rhinella marina) across northern Australia and the resultant declines of endangered northern quolls (Dasyurus hallucatus), which attack and are fatally poisoned by the toxic toads. We examined whether a novel management strategy in which wild quolls are trained to avoid toads can reduce extinction probability. We used a simulation model tailored to quoll life history. Within simulations, individuals were trained and a continuous evolving trait determined innate tendency to attack toads. We applied this model in a population viability setting. The strategy reduced extinction probability only when heritability of innate aversion was low (<20%) and when trained mothers trained >70% of their young to avoid toads. When these conditions were met, genetic adaptation was slower, but rapid cultural adaptation kept the population extant while genetic adaptation was completed. To gain insight into the evolutionary dynamics (in which we saw a transitory peak in cultural adaptation over time), we also developed a simple analytical model of evolutionary dynamics. This model showed that the strength of natural selection declined as the cultural transmission rate increased and that adaptation proceeded only when the rate of cultural transmission was below a critical value determined by the relative levels of protection conferred by genetic versus cultural mechanisms. Together, our models showed that cultural adaptation can play a powerful role in preventing extinction, but that rates of cultural transmission need to be high for this to occur.     

Behavioral responses of territorial red squirrels to natural and experimental variation in population density

The relative scarcity of studies at the intersection of behavioral and population ecology is surprising given the presumed importance of behavior in density-dependent population regulation. Here we tested whether North American red squirrels (Tamiasciurus hudsonicus) adjust their behavior in response to local population density and whether they use rates of territorial vocalizations in their local neighborhood to assess density. We examined these relationships using 18?years of live trapping and 20?years of behavioral data that were collected across natural variation in local population density. To disentangle the effects of population density on behavior from those due to changes in per capita food abundance or changes in the frequency of antagonistic interactions with neighbors, we also experimentally manipulated population density with long-term food supplementation as well as perceived population density with long-term playbacks of territorial vocalizations. The frequency with which squirrels emitted territorial vocalizations was positively associated with local population density. In contrast, antagonistic physical interactions observed between squirrels and territorial intrusions were rare and the frequency of intrusions was weakly and negatively, not positively, associated with population density. Squirrels experiencing naturally and experimentally high density conditions spent less time in the nest and feeding but more time being vigilant. Similar density-dependent changes in behavior were observed in response to our manipulations of perceived population density, indicating that vocalization rates and not physical interactions or food abundance were the mechanism by which squirrels assessed and responded behaviorally to changes in local density.     

Improving situational awareness through the design of offshore installations

Maintaining the situational awareness of control room operators on offshore installations contributes to the timely diagnosis of conditions and making appropriate decisions. This is particularly important when dealing with events and incidents. Recent initiatives aimed at reducing operators’ exposure to the hazards of working on offshore installations may have a negative impact upon situational awareness within the control room environment.This paper discusses mitigation of the negative impact through the design and operation of the installation and control system; either by improving the general level of situational awareness or by specifically targeting the areas affected by these initiatives.     

The decision gym: decision insurance for organizations

Conducting decision calisthenics can help an organization win competitive advantage through harnessing its tremendous knowledge, imagination, and staff experience. The paper explores how knowledge and experience mined and refined through innovative approaches like scenarios and war gaming can turn visionary ideas into successful, working realities. To fully appreciate the value of novel frameworks requires contextualizing their utility in what can be called the decision gym. The decision gym offers a way to build powerful consensus and commitment to decisions, methods to optimize processes, and a way to create, evaluate, and execute critical strategies in the face of heuristics and biases that can distort decision making.     

中国生态保护政策的县域经济效应——来自国家重点生态功能区的证据

为保障生态产品供给，中国设立了限制开发的国家重点生态功能区，建立了生态保护转移支付制度.本文首次在县域层面构建2002~2017年县级面板数据，运用倾向得分匹配法构造政策组的“反事实”情形，基于双重差分法评估重点生态功能区政策的县域经济效应.结果表明，该政策提高了县域财力、长期来看一定程度改善了产业结构；以标准财政缺口为主的资金分配机制弱化了县域经济发展激励，资金补助不能完全抵消限制开发对县域经济带来的负向影响；固定资产投资和内资企业受影响较大.随着投入资金累积、生态产品价值的转化，该负向效应随时间而减弱、经济促增效应逐渐显现.政策效应在不同生态功能和经济区位间表现出明显的异质性.建议持续增加生态转移支付资金、将生态产品供给数量和质量作为资金分配依据，考虑按生态功能类型设计差异化政策，更好激励县域生态产品高水平供给与经济价值实现的双赢，促进区域均衡发展.     

Estimating uncertainties in the life cycle assessment of composting household biowaste and urban green waste in Germany

Life cycle assessment (LCA) of waste treatment processes is often associated with considerable uncertainties. The aim of this study is to estimate the total uncertainty in the modelled composting system and the influence of material and process parameters on the uncertainty. Four composting combinations with fresh (FC) and mature substrate compost (MSC) from partially enclosed (PEC) and open composting (OC) were investigated. Perturbation analysis was used to determine the effect of parameters on the result and Monte Carlo simulation was used to estimate the total uncertainty. This study showed that the production of MSC using PEC had the lowest overall impacts across all impact categories except ozone depletion. Results of the Monte Carlo simulation showed that comparing composting options was challenging. The sensitivity ratios obtained from the perturbation analysis showed that the process parameter percentage of carbon fraction degraded was the most influential for FC. In MSC, the moisture content in the input material and the substitution factor used for peat were the most influential. Monte Carlo simulations demonstrated the overall uncertainty of the model and its relevance when comparing results between combinations. The perturbation analysis identified the parameters that required more accurate data to reduce the uncertainty in the model.

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Pyrolysis of lemon peel waste in a fixed-bed reactor and characterization of innovative pyrolytic products

Journal of Material Cycles and Waste Management - Lemon peel waste (LPW) were pyrolysed in a laboratory fixed-bed reactor at final temperature of 300&nbsp;°C, 400&nbsp;°C and...     

Extraction and characterization of chitin,chitosan, and protein hydrolysate from the invasive Pacific blue crab,Portunus segnis (Forskål, 1775) having potential biological activities

Environmental Science and Pollution Research - The diversity of marine biomasses is a set of exploitable and renewable resources with application in several sectors. In this context, a co-culture...     

Mechanical and thermo-physical characterization of mortars made with uncontaminated marine sediments

Journal of Material Cycles and Waste Management - In a context of sustainable development, civil engineering must increasingly use recyclable materials to preserve natural resources. Sediments...