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There is much variation in ownership concentration among entrepreneurial firms cross-sectionally and over time. Growth potential, risk-sharing, and demand for external capital seem to be the main reasons behind the choice of low ownership concentration, and firms with diluted ownership show strong growth. After controlling for the firm fixed effects or the sample selection bias, we do not find any evidence suggesting a link between ownership concentration and other dimensions of firm performance. Therefore, the trade-off between growth aspiration and retention of dominant control of the firms may be critical in ownership structure decisions among entrepreneurial firms.

[EN] The use of decision trees considerably improves the discriminating capacity of ensemble classifiers. However, this process results in the classifiers no longer being interpretable, although comprehensibility is a desired trait of decision trees. Consolidation (consolidated tree construction algorithm, CTC) was introduced to improve the discriminating capacity of decision trees, whereby a set of samples is used to build the consolidated tree without sacrificing transparency. In this work, PCTBagging is presented as a hybrid approach between bagging and a consolidated tree such that part of the comprehensibility of the consolidated tree is maintained while also improving the discriminating capacity. The consolidated tree is first developed up to a certain point and then typical bagging is performed for each sample. The part of the consolidated tree to be initially developed is configured by setting a consolidation percentage. In this work, 11 different consolidation percentages are considered for PCTBagging to effectively analyse the trade-off between comprehensibility and discriminating capacity. The results of PCTBagging are compared to those of bagging, CTC and C4.5, which serves as the base for all other algorithms. PCTBagging, with a low consolidation percentage, achieves a discriminating capacity similar to that of bagging while maintaining part of the interpretable structure of the consolidated tree. PCTBagging with a consolidation percentage of 100% offers the same comprehensibility as CTC, but achieves a significantly greater discriminating capacity. This work was funded by the Department of Education, Universities and Research of the Basque Government (ADIAN, IT980-16); and by the Ministry of Economy and Competitiveness of the Spanish Government and the European Regional Development Fund -ERDF (PhysComp, TIN2017-85409-P). We would also like to thank our former undergraduate student Ander Otsoa de Alda, who participated in the implementation of the PCTBagging algorithm for the WEKA platform.

Eusocial insect societies possess complex multilevel disease defences, including individual level protection conferred by physical (e.g. cuticle) and immunological obstacles and colony level protection mediated by collective behaviours (social immunity). It remains unclear whether and how these two levels of disease protection are related to one another in jointly driving colonies’ susceptibility to disease. Here, we examine whether a relationship exists between individual worker survival after exposure to a fungal pathogen (a proxy for immunity) and corpse removal (a colony level social immunity metric) in the acorn ant Temnothorax curvispinosus. Since behavioural avoidance is the first line of defence against infection, we also tested whether individual ants exhibited parasite avoidance behaviour during exploration and whether colonies exhibit avoidance behaviour during foraging. We found that individual level and colony level immunity were negatively correlated: colonies that removed corpses more rapidly contained workers with weaker individual defences. We did not detect parasite avoidance behaviour by individual workers or whole colonies, nor were these two factors related. These data suggest that individual immunity and social immunity may trade off, regulating overall parasite protection. Alternatively, optimized social immunity at the colony level may compensate for disease vulnerability to infection at the individual level, and thus provide a protective benefit in overall colony defence in the absence of pathogen avoidance.

The proximate and ultimate mechanisms behind individual behavioural phenotypes are still only partially understood, with studies often focusing on a single or a few factor(s) that affect behaviour in a controlled environment. To understand the development and consequences of individual behavioural phenotypes in their complexity, a comprehensive approach is needed that analyses the effects of a broad spectrum of factors and their interactions on behaviour within the natural environment. We used focal observations to quantify four key behavioural components of Gala = pagos sea lion, Zalophus wollebaeki, pups under natural conditions: general social interactions, swimming, resting and social play behaviour. We then investigated the influence and interplay of age, sex, body condition, basal cortisol and testosterone levels, personality scores and the social environment on the observed behaviour. We identified significant correlations between all measured factors and behaviour. Complex interactions between testosterone, boldness and social play especially stand out, with the effect of boldness on social play being dependent on testosterone levels. We also demonstrate the importance of the early social environment, defined as local population density, for social play and, interestingly, time spent swimming. This could have consequences for the development of social and hunting skills, crucial for later stages of ontogeny. For this endangered pinniped, a decline in the diversity of social environments due to dwindling population numbers could lead to a decline in behavioural diversity and lower coping abilities towards future changes in their environment. Our study reveals important factors for the development of individual behavioural phenotypes of young Gala = pagos sea lions and elucidates some aspects of the architecture behind this individual variation in behaviour. (c) 2021 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

In this study, we investigated which strategy Macrobrachium amazonicum populations use to survive in river and estuary environments. In each environment, abiotic factors were analyzed in situ, and ovigerous females and males of M. amazonicum specimens were captured. To determine ovarian maturity and morphotypes, gonads were removed and processed histologically, and the gonadosomatic index and condition factor (K) were determined. Ovigerous females were analyzed to determine the relationship between ovarian maturation and the embryonic phases of eggs in the brood pouch. Precipitation, turbidity and dissolved oxygen showed differences between the estuary and river. The population of ovigerous females showed that ovarian maturation was simultaneous with embryonic development. However, the freshwater prawn populations in the river were smaller and consisted of a greater number of ovigerous females with maturing and mature ovaries. In the estuary, ovigerous females with spawned and reorganized ovaries were observed more frequently. In males, the GC morphotype was absent in the river, where the TC morphotype predominated and showed similar reproductive conditions as the GC morphotype in the estuary. M. amazonicum has strategies for allocating energy for reproduction or growth in different environments. This description established the trade-off as a strategy used by M. amazonicum to maintain the population in adverse environments.

Behavioural thermoregulation can ameliorate thermal stress but is costly. For species that court in a thermally stressful microhabitat, sexual selection via endurance rivalry favours individuals that are able and willing to endure harsh conditions in the courtship habitat, as retreats to a thermal refuge will reduce mating opportunities. The relative costs and benefits of refuge use versus continued courtship in the face of thermal risk, which vary across abiotic and biotic contexts, determine the optimal behavioural strategy. We examined the social and abiotic factors driving behavioural decisions related to thermoregulatory retreat in the fiddler crab Austruca mjoebergi. Male fiddler crabs perform a courtship display on the thermally stressful intertidal sediment surface. Time on the surface, and thus time available for display, was limited by high temperatures; as temperature increased, surface time decreased. Yet when presented with a stimulus female, males were more likely to perform the courtship display, displayed at a higher rate and increased time spent on the surface. These results demonstrate that behavioural decisions related to thermal retreat depend both on the abiotic conditions that influence the degree of thermal stress and on the social conditions that influence the reproductive prospects of the individual.

Using the data from two leading online lending platforms in the US and China, Lending Club and Renrendai, respectively, we compare the behaviors of risk aversion and risk-return trade-off among US and Chinese online lending investors. We use the event of the implementation of “de-guarantee” policy as a quasi-natural experiment to evaluate the impact of the policy on the behaviors of online lending investors. The results of our study show that prior to 2018, the seemingly irrational behavior of Chinese lenders – blindly pursuing high interest rates regardless of default risk – is a rational response to the fact that the loans they invest in are guaranteed, and after the implementation of the “de-guarantee” policy, Chinese online lending investors exhibit similar risk-averse behaviors as US investors. In addition, we find that lenders on the US online platform consistently exhibit risk aversion behaviors and risk-return trade-off on the interest rate, while Chinese lenders do not demonstrate this trade-off before the implementation of the “de-guarantee” policy.

Studies suggest that many species are already living close to their upper physiological thermal limits. Phenotypic plasticity is thought to be an important mechanism for species to counter rapid environmental change, yet the extent to which plastic responses may buffer projected climate change - and what limits the evolution of plasticity - is still unclear. The tolerance-plasticity trade-off hypothesis predicts that the evolution of plasticity may be constrained by a species' thermal tolerance. Empirical evidence is equivocal, but we argue that inconsistent patterns likely reflect problems in experimental design/analysis, limiting our ability to detect and interpret trade-off patterns. Here, we address why we may, or may not see tolerance-plasticity trade-offs and outline a framework addressing current limitations, focusing on understanding the underlying mechanisms.

The pervasiveness of Internet of Things results in vast volumes of personal data generated by smart devices of users (data producers) such as smart phones, wearables and other embedded sensors. It is a common requirement, especially for Big Data analytics systems, to transfer these large in scale and distributed data to centralized computational systems for analysis. Nevertheless, third parties that run and manage these systems (data consumers) do not always guarantee users’ privacy. Their primary interest is to improve utility that is usually a metric related to the performance, costs and the quality of service. There are several techniques that mask user-generated data to ensure privacy, e.g. differential privacy. Setting up a process for masking data, referred to in this paper as a ‘privacy setting’, decreases on the one hand the utility of data analytics, while, on the other hand, increases privacy. This paper studies parameterizations of privacy settings that regulate the trade-off between maximum utility, minimum privacy and minimum utility, maximum privacy, where utility refers to the accuracy in the estimations of aggregation functions. Privacy settings can be universally applied as system-wide parameterizations and policies (homogeneous data sharing). Nonetheless they can also be applied autonomously by each user or decided under the influence of (monetary) incentives (heterogeneous data sharing). This latter diversity in data sharing by informational self-determination plays a key role on the privacy-utility trajectories as shown in this paper both theoretically and empirically. A generic and novel computational framework is introduced for measuring privacy-utility trade-offs and their Pareto optimization. The framework computes a broad spectrum of such trade-offs that form privacy-utility trajectories under homogeneous and heterogeneous data sharing. The practical use of the framework is experimentally evaluated using real-world data from a Smart Grid pilot project in which energy consumers protect their privacy by regulating the quality of the shared power demand data, while utility companies make accurate estimations of the aggregate load in the network to manage the power grid. Over 20,000 differential privacy settings are applied to shape the computational trajectories that in turn provide a vast potential for data consumers and producers to participate in viable participatory data sharing systems., Future Generation Computer Systems, 109, ISSN:0167-739X, ISSN:1872-7115

Disease exposure is a threat to all organisms, but there are a number of methods of self-defence. First, individuals can proactively prevent disease through avoidance behaviours. If they become infected, individuals can activate an immune response to control the infection. A trade-off between avoidance behaviours and immune response activation has been hypothesized to occur because of costs associated with each strategy. Individuals may balance behavioural and immunological strategies to provide optimal protection against disease. To test this hypothesis in a captive population of zebra finches, Taeniopygia guttata, we conducted behavioural trials to determine how much time focal birds associated with stimulus birds that were either healthy or displayed sickness behaviours. We then inoculated focal birds with lipopolysaccharide (LPS) and measured levels of natural antibodies, complement and haptoglobin. One physiological mechanism that may mediate the proposed trade-off between behavioural and immunological defences is the glucocorticoid hormone corticosterone (CORT). Therefore, we experimentally manipulated CORT in another subset of birds. Finally, it is unknown whether individuals are consistent in their strategy choice over time or whether strategy choice changes based on environmental context or life history stage. Thus, we tested behavioural and immunological responses multiple times. We found limited evidence that zebra finches trade off between behavioural avoidance and immune responses as protection against infection, instead these defences were unrelated or positively correlated in control birds. CORT changed the relationships between behavioural and immunological defences and these defences were traded-off after acute CORT exposure. Some behavioural and immunological defences were repeatable over three months. Thus, even though individuals may be consistent in behavioural and immunological defence strategies, these defences are not generally traded off. Further research is encouraged to determine whether behavioural and immunological trade-offs persist across contexts, life history stages, or in wild populations, and the degree to which strategies are influenced by selection.

Functional trait variation of plant species includes both inter- and intraspecific variation; however, trait-based plant ecology generally considers only interspecific variation while ignoring intraspecific variation. One reason for this neglect is that intraspecific variation may be negligible when compared to interspecific variation; however, direct comparisons between inter- and intraspecific variation of plant species are lacking, especially in tropical forests. Here we investigated intraspecific leaf trait variation (leaf area, specific leaf area, leaf thickness, leaf density, leaf chlorophyll content) of Pittosporopsis kerrii Craib (Icacinaceae), the most abundant tree species in the Xishuangbanna tropical seasonal rainforest in southwestern China, along an elevational gradient (703–824 m). We found a substantial range of intraspecific variation in P. kerrii that was never less than 22.1% of range of the interspecific variation among 462 tree species reported before in the same community. Moreover, with increased elevation, both leaf thickness and density increased and specific leaf area decreased significantly. It could be more important for the individuals of P. kerrii to produce thicker and denser leaves to tolerate environmental stress (e.g. soil water availability) rather than having high growth rates at the places with higher elevation in the Xishuangbanna tropical seasonal rainforest. Keywords: Functional traits, Intraspecific variation, Trade-off, Tropical seasonal rainforest, Xishuangbanna

The demand for sustainable replacements for fossil-based products is steadily increasing, especially now that the effects of climate change are becoming more prominent. Lignocellulose, which is a sustainable and abundant carbon source, is dubbed to be the perfect replacement. Lignocellulose consists of lignin, hemicellulose, and cellulose. During the Simultaneous Saccharification and Fermentation (SSF) of cellulose, the hydrolysis and fermentation of the produced C6-sugars occurs simultaneously in the same vessel. The SSF process has mainly been developed to circumvent inhibitory effect and increase the overall product yield. Although the concept of the SSF process is promising, the applications are still limited. This contribution presents the trade-off-based multi-objective optimisation of an SSF process. Multi-objective optimisation allows for optimising (bio-)process with respect to multiple, and often conflicting, objectives. These optimisation problems do not render a unique optimal solution but instead an infinite set of so-called Pareto-optimal solutions, the Pareto front. From the Pareto front, the decision maker should select one working point. To aid decision makers in this selection process, the application of a novel genetic optimisation algorithm is presented in this contribution, i.e., tDOM, that is capable of filtering solutions using t-domination. This results in a less dense Pareto front that only contains solutions that are of interest for the decision maker. Additionally, by extending the t-domination concept to two subsequent solution populations, a novel problem-relevant stopping criterion is developed, resulting in a significant gain in the required computational time. A comparison to the well known NSGA-II is provided.

The rational utilization of the characteristics of sediment resources to achieve the optimal allocation of sediment resources is a key problem that must be solved urgently for ecological governance. On the basis of determining the allocation mode of sediment resources, this study established the multi-objective optimal allocation model of sediment resources, which aimed at the maximum ecological, economic, and social benefits and used the e-constraint method and Kuhn–Tucker condition to obtain the non-inferior solution. Moreover, the optimal equilibrium solution of the model was obtained by using the subjective trade-off method from the perspective of preference. The Weishan and Bojili irrigation areas in China were then chosen as a case study to verify the feasibility and validity of the model. Results corroborate that, compared with the present situation, the proportions of sediment transport into the field in Weishan and Bojili irrigation areas are significantly increased and that the proportions of the main and branch canal sediment detention in the two irrigation areas are reduced. Compared with the results of the non-inferior solution, ecological and social benefits have been improved, and economic benefit has been decreased. The coordinated optimization of ecological, economic, and social benefits has been realized, instead of blindly pursuing economic benefit.

In a multi-state system with common bus performance sharing, the performance surplus from one element can be transmitted to other deficient elements as long as the total amount of transmission does not exceed the transmission capacity of the common bus. Existing literature fails to consider the transmission loss during the performance sharing process. Transmission loss widely exists in practice and is affected by many external factors. For example, the power transmission loss is affected by the distance, humility and temperature. In this research, we study a common bus performance sharing system consisting of N independent elements with consideration of performance loss during transmission. We propose three different transmission loss models that are frequently encountered in practice, and suggest their corresponding reliability evaluation algorithms. To improve the system availability, maintenance actions are taken to improve the component reliability, and protection is provided to defend the system against external impacts. We analyze the optimal trade-off between protection and maintenance by minimizing the system cost while satisfying a pre-specified system availability requirement. The proposed reliability models and algorithms are illustrated by a regional power distribution system. The numerical study has demonstrated the importance of considering transmission loss in reliability modeling and optimization.

International audience; In recent decades, increases in wheat yield have been achieved mainly through increases in grain number per m2 (GNM2) rather than through increases in average grain weight (AGW). Using AGW as a lever to increase yield would require avoidance of the negative relationship between GNM2 and AGW. It is usually supposed that this trade-off arises from an increase in the proportion of small grains as GNM2 rises. The proportional increase in small grains being the result either of (1) an increase in the proportion of secondary tillers in the spike population or (2) of an increase in the proportion of grains located in distal positions within each spike. Either or both of these two populational effects would tend to mask any true genotypic differences in AGW. The existence of these constitutive differences has already been proposed, but without considering the full extent of the populational confounding effects. Identification of a component of the constitutive genetic determinism of AGW - one that is truly independent of GNM2 - could contribute to cultivar developments that would lead to further increases in grain yield under future target environments. To address this question, we analysed populational effects on AGW in four, modern, well-adapted bread-wheat cultivars. The four chosen cultivars show similar grain yields but contrasting AGWs. The analysis of populational effects was carried out at three hierarchical levels (the plot, the spike and the single grain) and under two contrasting environmental conditions (well-watered vs waterdeficit conditions). Regardless of the environment, no (or only slight) differences in individual spike size were observed between cultivars. Furthermore the weak relationship between spike size and AGWdemonstrates that AGW differences between cultivars cannot be attributed to spike-level populational effects. Meanwhile, the analysis of individual grain mass distributions, showed that the differences in AGW between cultivars, originated from shifts in the whole grain-mass distribution, rather than from shape changes in the grain-mass distribution. This clearly indicates that AGW differences between cultivars cannot be attributed to populational effects at the individual grain level. The analysis carried out at both spike and individual grain levels indicates that the AGW differences between cultivars are largely constitutive, so that increases in grain yield through AGW may be considered independently of the GNM2 : AGW trade-off. Taken together, these findings offer a new perspective for the genetic improvement of wheat, and one that should lead to further increases in yield.

How society invests in human capital is important for economic growth and social welfare. The paper reports from the first experiment designed to elicit people’s preferences for how to prioritize educational resources, where 2,000 Americans trade off educational resources between quick and slow learners. I find that they give strong priority to slow learners and assign two thirds of the educational resources to this group. Both cost efficiency and the motivation of the learners causally affect the resource allocation. The findings provide important insights for the present policy debate on how to distribute educational resources in society.

Allocating the overall budget to projects is a major decision for an organization. Taking that decision by looking at the overall profit only may result in an unfair treatment of departments, with some departments overloaded and others underemployed (and dissatisfied). We consider an alternative approach, where the budget allocation is accomplished by aiming at fairness as well as profit. We adopt a knapsack-type Integer Linear Programming formulation to optimize both quality indicators of budget allocation, employing a fairly wide selection of fairness measures. The resulting optimization routines are applied to a representative selection of instances generated through Monte Carlo simulation. We show that high levels of fairness can be achieved for realistic scenarios with only a moderate loss of profit. Large companies appear to be able to achieve a better trade-off between fairness and profit. Striving for fairness also leads to funding more projects, thus increasing the usage level of the organization's human and material resources.

Mountain ecosystems provide a variety of important ecosystem services (ESs) to humanity; however, the variation in multiple mountain ESs and the trade-off relationships among mountain ESs remain largely unknown. In this study, we took the Taihang Mountains as the study area and used the root mean square error (RMSE) method to quantify the trade-offs among multiple mountain ESs. Our results showed that net primary production (NPP), soil conservation (SC) and habitat quality (HQ) increased significantly with increasing elevation and vegetation cover fraction (VCF), whereas water yield (WY) did not. In addition, the trade-offs among different ES pairs had different sensitivities to changes in elevation, VCF and precipitation. As the elevation and VCF increased, the trade-offs between WY and NPP and WY and HQ increased significantly. As the precipitation increased, the trade-offs between SC and NPP, WY and NPP, HQ and SC, and WY and HQ all decreased significantly. In addition, the trade-offs among these four ESs were lowest in mid-elevation, high-VCF and low-mean annual precipitation (MAP) areas. This study could improve our current understanding of mountain ESs and help ES management for the Taihang Mountains.

Environmental temperature, particularly in habitats with extreme temperature fluctuations, may shape selection pressures on life history traits. Especially in ectotherms, temperature affects performance, physiology, and in some species, skin color. Skin color can be a sexual ornament signaling the bearer's ability to resist infections, when only high-quality individuals are able to invest both in high immune defense and elaborate ornament expression. However, how the information content of these sexual traits may vary with environmental conditions has been less studied. Dickerson's collared lizard (Crotaphytus dickersonae) males are blue and have a black and white collar. This conspicuous coloration signals performance and immune response, and is related to body temperature. Here, by maintaining males at higher, lower, and mean environmental temperatures we evaluated whether temperature variation influences color and constitutive innate humoral immunity (agglutination and lysis titers, estimated through hemolysis-hemagglutination assays), and whether extreme temperatures impose trade-offs between color and humoral immunity. We found that at low and high temperature treatments males had lower agglutination and lysis titers, and at low temperature, blue chroma from the dorsum declined and males became greener. Interestingly, at low and control temperature treatments, agglutination titer and blue coloration were positively correlated, whereas high temperatures revealed a trade-off between increasing agglutination titers and displaying bluer skin color. Our results suggest that in the Dickerson collared lizard even short-term variation of environmental temperature affects performance of constitutive innate humoral immunity and the brilliant blue skin color. Particularly, high temperatures may compromise some components of male's immunity and sexual signaling.

We investigate how macroeconomic and financial uncertainty impacts the behavior of hedge fund strategy higher moments—i.e., co-skewness and co-kurtosis—and their respective cross-sectional dispersions. Consistent with theoretical models, we find that strategy managers trade off these two higher moments when building optimal portfolios. Moreover, these trade-offs depend on the kind of strategy. Our experiments show that the VIX and its conditional variance are the most important factors affecting higher moment risk in the hedge fund industry. They also reveal that the behavior of hedge fund strategies is very asymmetric depending on the phase of the business cycle. In contrast to studies which rely on the mean-variance setting, we find that systemic risk—as measured by the cross-sectional dispersions of higher moments—tends to decrease in the low regime. The indicators of market volatility play a decisive role to explain this decline in systemic risk.

© 2019 Elsevier Ltd This paper addresses the proactive resource-constrained project scheduling problem, aiming to explore better surrogate robustness measures for project managers that want to generate robust baseline schedules under uncertain environments. The contribution of this paper is threefold. First, we propose a general framework of slack-based surrogate robustness measures and introduce three parameters to distinguish different alternative calculations of the measure. A computational experiment based on reactive simulation is constructed where the performance of the surrogate measures is evaluated by the reactive cost and two types of uncertain environments, i.e. stochastic resource availabilities and stochastic activity durations, are taken into account. Second, we analyze the impact of the three parameters as well as the two uncertain environments on the surrogate robustness measures and find the best measures for different situations. The proposed surrogate robustness measures are shown to be effective. Compared with benchmark measures, the improvements are respectively 2.67% and 13.79% under the two uncertain environments. Third, we investigate the difference of buffering strategies between the two uncertain environments. For the environment of stochastic resource availabilities, it turns out to be better to have a uniform distribution of time buffers throughout the schedule, while the reverse is true for the environment of stochastic activity durations. ispartof: COMPUTERS & INDUSTRIAL ENGINEERING vol:131 pages:382-390 status: published

There have been a number of scholarly works investigating the energy-pollutant-human development nexus, however, they have failed to fully investigate the simultaneous effects of energy consumption, human development and carbon dioxin emissions. These effects need to be understood with proper consideration for the level of economic development. To fill this gap, this paper collectively estimates three simultaneous equations of human development, energy consumption and carbon dioxin emissions, employing a system-generalized method of moment approach (SGMM) covering ninety countries over the period 1990–2014. Results indicate that increased human development leads to reduced carbon emissions for the global sample and development countries. However, no significant relationship between carbon emissions and human development is found in developed countries. The results show no significant causal relationship between energy consumption and human development, neither for the global sample nor the subpanels. Given the incorporation of the non-linear term of human development in environmental equations, a U-Shape hypothesis is not valid in this study. Hence, despite some positive findings, the study shows that environmental policies related to controlling carbon emissions and energy usage are likely to have no impact on human development at any stage of economic development.

Refrigerants can have potential adverse impacts on human health through their life cycles at a global scale. However, they may also lead to a health risk because of direct exposure at a local scale. A policy intervention aiming to reduce one effect might simultaneously affect another. To address risk transfer or transformation, the present study evaluated both the global impact potential and local risk of refrigerants used in household air conditioners using methods based on life cycle assessment (LCA) and risk assessment (RA). LCA results indicated that human health damage attributable to energy consumption was greater than that attributable to refrigerant emission. The former was dominated by the use phase while the latter was dominated by the disposal phase. RA results indicated that the margin of exposure of R-22, R-410a, and R-32 were greater than 106. When R-22 was replaced with R-410a, we identified a trade-off between local risk and global warming potential (also between ozone depletion potential and global warming potential) because of refrigerant emission. This study is a real-world synergistic application of LCA and RA. Complimentary application of these two approaches could contribute to broad decision making in green product development by employing a systemic view and transcending disciplines.

Prey species are often non-randomly distributed along predator gradients but according to how they trade off growth against predation risk. The foraging-mediated growth/predation risk trade-off is well established, with increased foraging accelerating growth but also increasing predator induced mortality. While adaptations in digestive physiology may partly modify the relationship between foraging and growth in response to predation risk, studies exploring the impact of digestive physiology on growth in prey subjected to predation risk are still scarce. Larvae of the dragonfly genus Leucorrhinia segregate at the species level between lakes either being dominated by predatory fish (fish-lakes) or predatory invertebrates (dragonfly-lakes). Predators of these two lake types differ dramatically in their hunting style like searching and pursuing mode causing different selection pressure on prey traits including foraging. In a laboratory experiment we estimated growth rate, digestive physiology (ingested food, growth efficiency, assimilation efficiency, conversion efficiency) and metabolic rate (oxygen consumption) in the presence and absence of predator cues. Whereas fish-lake and dragonfly-lake Leucorrhinia species did not differ in growth rate, they evolved different pathways of digestive physiology to achieve similar growth rate. Because fish-lake species expressed a higher metabolic rate than dragonfly-lake species, we assume energy to be differently allocated and used for metabolic demands between species of both predator environments. Further, growth rate, but not digestive physiology was plastic in response to the presence of predator cues. Our results highlight the impact of digestive physiology in shaping the foraging-mediated growth/predation risk trade-off, with digestive physiology contributing to species distribution patterns along predator gradients.

This study examines whether different income groups have different trade-off preferences between public transportation accessibility and income and economic power. In this study, apartments, the most typical housing type in Seoul, were categorized according to size (small, medium, and large) based on the premise that apartment size is a measure of the economic status of an individual or household. Subsequently, the effect of subway accessibility on apartment prices for the three types of apartments was examined through the conventional hedonic price model and the spatial autoregressive combined model, followed by an investigation of the spatial patterns of the effect with a focus on a geographically weighted regression. As a result, this study finds that, although subway accessibility serves as a positive factor in housing location decisions for most socioeconomic classes, the positive effect is not spatially unanimous, indicating that households with relatively robust economic stability preferred housing locations further away from subway stations in pursuit of a more attractive residential environment. Although high-income households trade greater accessibility to public transportation for a more attractive neighborhood environment, middle-income households more actively pursued convenience and the greenness of their neighborhoods. Households with less economic stability preferred neighborhoods featuring relatively low-cost housing and greater accessibility. These results confirm the prevalence of trade-off between public transportation accessibility and housing size in Seoul, Korea. This also verifies that the spatial division along economic class lines is intensifying, and that perspectives on subway accessibility vary depending on consumers' economic status. The results suggest the need for consumer-tailored public transportation policies that consider the residential location patterns of the socioeconomic classes that are dependent on public transportation. This perspective can improve our understanding of how to distribute mass transportation systems spaces in large cities, particularly where the wealth gap is relatively high.

As a part of the transition to a sustainable economy, China has set a cap on primary energy consumption for the first time, of 5.0 billion tonnes of standard coal equivalent by 2020. However, there is a debate on the cap feasibility and failure to adequately address the underlying equity-efficiency trade-off, which hampers achievement. This paper identifies some key challenges ahead, including the coal-dominant energy mix, declining financial support, inconsistent central-local goals, rising costs of energy-saving measures and quality of energy statistical data. By quantifying the preference of each providence toward equity-based or efficiency-based allocation schemes, the great disparity among provinces is revealed and the equity-efficiency trade-off relationship is confirmed. Developing regions, primarily located in central and western areas, tend to favor equity-based disaggregating schemes. Contrarily, developed coastal provinces strongly favor efficiency-based schemes. The present national disaggregation schemes are mainly based on historical energy consumption, but disregard the provincial development gap and efficiency factors. We conclude that this ambitious goal is likely within reach, but increased efforts and flexible instruments are needed.

Previous research has suggested that psychopathy may be involved in mating-parenting trade-off; furthermore, a harsh environment could facilitate this trade-off in psychopathy. We integrated these two hypotheses into a single research design. We hypothesized that psychopathy elevated mating but decreased parenting effort; in addition, we predicted that these associations were more pronounced in a harsh environment. We tested these hypotheses in a community sample of individuals who have children (N = 320). We measured harsh environment in childhood, psychopathy traits (Meanness, Boldness and Disinhibition); mate seeking, the duration of longest partner relationship, the onset of sexual behavior (as indicators of mating effort) and care for children (as a measure of parenting effort). The results showed that psychopathic individuals had earlier onset of sexual behavior, shorter partner relationships, and invested more in seeking new partners but had lower parental effort. Furthermore, significant interactions between the Meanness trait and childhood environmental harshness were found in predicting these outcomes: individuals higher in Meanness who lived in a harsh environment had especially high mate seeking, shorter relationships and lower parental effort. Findings have high heuristic power because they reveal two evolutionary mechanisms which maintain inter-individual variation in psychopathy: adaptive trade-offs and harsh environment as an extrinsic state condition.

Commercial salmon harvests have declined dramatically for all Pacific salmon species in British Columbia, mainly over the period 1995–2000. Much of this decline is attributable to declining abundance, but some of it has been due to deliberate reduction in allowable exploitation rates. Various reasons have been given for this reduction, but the main rationale appears to have been concern about declines in a few relatively small and unproductive stocks that are intercepted in mixed-stock fisheries. Reductions in exploitation rate have generally not been followed by the increases in stock size that would be expected if overfishing had been the main cause of the declines. Current procedures for setting exploitation rate goals do not appear to involve explicit analysis of the risk-reward trade off relationship between mixed stock exploitation rates and yields.

Studying the trade-off between developing new products that exploit a focal firm's familiar current knowledge resources and developing new products that explore knowledge resources that are new to the firm, we show that new products perform better when the new products are neither too familiar nor new to the firm, in contrast to the findings reported in prior research indicating that both types of new products are positively related to new product performance. The results were consistent for the familiarity and newness of both technological and market knowledge. In addition, the study revealed that while focal firms' inter-organizational network ties involving their supplier firms attenuated the potential negative impacts of technological familiarity and newness, their inter-organizational network ties involving their buyer firms lessened the potential negative impacts of the familiarity and newness of market knowledge that their new products required.

Personal carbon trading is a downstream version of the cap and trade approaches to mitigating carbon emissions from individual energy use. Although there are studies that investigate the theoretical and implementation issues, there is little evidence over the potential ways people could reduce their emissions when subject to a PCT policy. Especially little is understood about how people make tradeoff between or complement reducing emissions from transport and in-home energy use. This paper addresses this gap by reporting the findings of a questionnaire survey of stated intentions under the policy. Results show that, more people (53.6%) preferred to reduce their emissions from both transport and in-home energy use compared to from only one of these. This shows the flexibility offered by a cap including transport and in-home energy use is more efficient compared to a PCT covering either of these separately. Nearly three-fourths (76.2%) opted to reduce their emissions following a PCT policy. However, among those with above-budget initial emissions, a large share (79.6%) still could not reduce their emissions to below the budget and opted to purchase at least some permits to cover their emissions, indicating the difficulty in reducing emissions at the personal and household level.

Understanding causes and consequences of behavioural plasticity is a major focus in animal behaviour studies for its importance to any population's ability to persist under changing environments. However, behavioural plasticity in traits linked to reproduction has received surprisingly limited attention, especially in species exhibiting alternative reproductive tactics (ARTs). In this study, we explored how behavioural plasticity in ARTs varies in response to social conditions in male guppies, Poecilia reticulata, an internally fertilizing fish in which males can switch between two ARTs to achieve matings. Males can either court receptive females using elaborate mating displays (courtship), or attempt forced copulations without prior display or female cooperation (sneaking). Although males have a genetic predisposition to engage predominantly in one tactic over the other, the extent to which social experience shapes individual plasticity in these tactics is unknown. We observed that between-individual variation in mating effort and preferred ARTs was repeatable over time and largely explained by variation in body size and coloration between individuals. Moreover, we showed experimentally that males exposed to social cues rapidly developed a preference towards either sneaking or courting, resulting in a rapid decline in individual plasticity compared to their socially deprived counterparts. These findings accord with the theoretical predictions that behavioural plasticity should decline as individuals incrementally adjust to local environmental conditions and, thus, when environmental uncertainty is reduced.

A comprehensive understanding of the relationships among ecosystem services (ES) is important for landscape management, decision-making and policy development, but interactions among multiple ES remain under-researched. In particular, earlier studies often did not clearly distinguish between supply, flow and demand. Furthermore, the underlying mechanisms in complex socio-ecological systems remain less examined. In this study, we therefore aimed to assess interactions among eight key ES, adopting a multistep approach. For all ES, we mapped ES supply, flow and demand at the municipality level in the Alpine Space area. We applied correlation analysis and cluster analysis in order to analyse the linkages between ES and to identify bundles of ES. We used random forest analysis to explain the distribution of the ES bundles and to identify important drivers based on socio-ecological variables (e.g. land use/cover, climate, topography and population density). Our results demonstrate that trade-offs and synergies varied greatly for supply, flow and demand. We identified five ES bundles, distinguishing hotspots of ES supply and demand. Twelve socio-ecological variables correctly predicted the membership of 81% of the municipalities to the ES bundles. Our results suggest that a limited number of socio-ecological variables can explain the majority of the distribution of ES bundles in the landscape. Considering the spatial relationships between mountain regions and their surrounding lowlands, regional and transnational governance frameworks need to connect areas of multiple ES supply to areas of ES demand, and should account for the different levels and types of ES relationships.

In many species, males follow alternative reproductive tactics (ARTs), where one tactic (called bourgeois) has much higher reproductive success than alternative tactics followed by males with lower competitive ability. The extent to which ARTs differ in energetic costs is unknown, but it is important to understand the fitness payoffs of ARTs. We studied male African striped mice (Rhabdomys pumilio) which follow one of three ARTs: heavy bourgeois males defend harems of females and have 10 times higher reproductive success than smaller roamers, which have ten times higher reproductive success than philopatric males, which remain in their natal group and are the smallest males. Bourgeois and philopatric males live in social groups that defend one territory, while roamers are solitary and roam over larger areas. We predicted that roamers will face higher energetic costs compared to group-living males because they do not gain thermoregulatory benefits of huddling in groups and might travel larger distances as they have larger home ranges. We measured daily energy expenditure (DEE) of 30 males, resting metabolic rate (RMR) of 79 males, travel distances and daily ranges of 31 males and changes in body mass of 51 males. Roamers had higher DEE and higher RMR than both types of group-living males. Philopatric males had shorter travel distances and smaller daily ranges than both roamers and bourgeois males, which did not differ from each other. This indicates that the higher DEE of roamers compared to bourgeois males cannot be explained by larger travel distances. Philopatrics gained body mass faster than bourgeois males and roamers, thereby increasing their competitive ability and thus the probability of later switching to a tactic of higher reproductive success. Our results suggest that roamers suffer energetic costs that might reduce their ability of gaining body mass and thus the likelihood of switching to the bourgeois tactic, indicating evolutionary trade-offs between investing energy into roaming versus gaining body mass.

Drought resistance is required in rice breeding to address the challenge of frequent droughts. However, the evolutionary mechanism of rice drought resistance is not fully understood. We investigated the genetic differentiation between upland and lowland rice domesticated in agro-ecosystems with contrasting water–soil conditions using genome-wide SNPs. We estimated morphological differences among upland and lowland rice in drought resistance and productivity through common garden experiments. Upland rice had better drought resistance but poorer productivity. The negative correlations between traits of drought resistance and productivity are attributed to the underlying genetic trade-offs through tight linkages (e.g., DCA1 and OsCesA7) or pleiotropic effects (e.g., LAX1). The genetic trade-offs are common and greatly shape the evolution of drought resistance in upland rice. In genomic regions associated with both productivity and drought resistance, signs of balancing selection were detected in upland rice, while signs of directional selection were detected in lowland rice, potentially contributing to their adaptive differentiation. Signs of balancing selection in upland rice resulted from bi-directional selection during its domestication in drought-prone upland agro-ecosystems. Using genome-wide association analysis, we identified several valuable quantitative trait loci associated with drought resistance, for which highly differentiated genes should be considered candidates. Bi-directional selection breaking tight linkages by accumulating recombination events would be applicable in breeding water-saving and drought-resistance rice.

The American lobster supports the most economically valuable fishery in the Gulf of Maine and Atlantic Canada. Across much of its range, ocean temperatures have increased at rates faster than almost anywhere in the world. Studies of warming effects on larvae have largely focused on survival and development, but rarely have examined sub-lethal effects that could influence settlement and subsequent recruitment to the fishery. We explored how warming influences rate of development, survival, stress, and developmental stability of larval lobsters reared under four nominal temperatures: 14, 16, 18, and 22 °C. Our study is the first to evaluate the use of fluctuating asymmetry as a biomarker for developmental instability in larval American lobster. We also recorded total hemocyte counts in postlarvae as an indicator of stress, a novel technique for work in larval lobster. Development proceeded significantly faster as temperature increased, and cumulative survival was significantly positively correlated with temperature. However, postlarvae reared under temperature extremes exhibited elevated hemocyte counts and had significantly lower levels of variance in midline asymmetry compared to intermediate temperature groups. Together, this suggests that warmer temperatures may facilitate faster growth at the expense of increased physiological stress and a loss of genetic diversity, potentially affecting the species’ ability to adapt to changing environmental conditions. Fluctuating asymmetry could prove to be a useful bioindicator for population resilience.

Owing to major technological advances, bioacoustics has become a burgeoning field in\ud ecological research worldwide. Autonomous passive acoustic recorders are becoming widely\ud used to monitor aerial insectivorous bats, and automatic classifiers have emerged to aid\ud researchers in the daunting task of analyzing the resulting massive acoustic datasets.\ud However, the scarcity of comprehensive reference call libraries still hampers their wider\ud application in highly diverse tropical assemblages. Capitalizing on a unique acoustic dataset\ud of more than 650,000 bat call sequences collected over a 3-year period in the Brazilian\ud Amazon, the aims of this study were (a) to assess how pre-identified recordings of free-flying\ud and hand-released bats could be used to train an automatic classification algorithm (random\ud forest), and (b) to optimize acoustic analysis protocols by combining automatic classification\ud with visual post-validation, whereby we evaluated the proportion of sound files to be postvalidated\ud for different thresholds of classification accuracy. Classifiers were trained at species\ud or sonotype (group of species with similar calls) level. Random forest models confirmed the\ud reliability of using calls of both free-flying and hand-released bats to train custom-built\ud automatic classifiers. To achieve a general classification accuracy of ~85%, random forest\ud had to be trained with at least 500 pulses per species/sonotype. For seven out of 20 sonotypes,\ud the most abundant in our dataset, we obtained high classification accuracy (>90%). Adopting\ud a desired accuracy probability threshold of 95% for the random forest classifier, we found that\ud the percentage of sound files required for manual post-validation could be reduced by up to\ud 75%, a significant saving in terms of workload. Combining automatic classification with\ud manual ID through fully customizable classifiers implemented in open-source software as\ud demonstrated here shows great potential to help overcome the acknowledged risks and biases\ud associated with the sole reliance on automatic classification.

This study uses an organizational change perspective to analyze firms' export market selection (EMS) to adapt to home country market pressures. We argue that firms' strategic objectives influence whether they will enter institutionally proximal or distal markets. A model with two curvilinear (U-shaped and inverted U-shaped) relationships is found by testing 1940 Taiwanese export firms based on two official datasets. The model shows that firms are more likely to increase their exports to institutionally proximal markets and to decrease their exports to institutionally distal markets if they have an increasing but still controllable degree of competitive and marketing pressures in the home country. This response represents an incremental change by exporting firms. However, firms increase their exports to institutionally distal markets while decreasing their exports to institutionally proximal markets if they have an excessively increasing degree of competitive and marketing pressures in the home country. This response represents a radical change by exporting firms. We find that export firms' strategic objectives in choosing different organizational change styles (incremental or radical) are highly related to this trade-off in their EMS decision making.

In the management of natural resources, regulation often induces behavioral responses by resource users that ultimately undermine stated policy objectives. Examples of these unintended consequences have been associated with regulations ranging from the Endangered Species Act to laws governing clean air. In this paper we investigate an unintended behavioral response that can be triggered by conservation measures in multispecies fishery management, which leads to increased targeting of the species the conservation measures are meant to protect. Harvest is subject to stochastic variation, with output partially determined by the probability of encountering species of interest, either due to targeting or avoidance. Given the right conditions, an intertemporal arbitrage opportunity arises due to the fact that by targeting a stock in the current period, the probability of encountering that stock in the next period, when announced conservation measures are implemented, decreases. We present an empirical case study that supports the findings of the theoretical model. The results indicate that, by targeting so called weak stocks, some New England fishermen are willing to trade off increased costs today for increased expected profits in the future. To prevent the potentially harmful effects of this behavioral response, a manager may adopt precautionary provisions at the time a quota reduction is announced, or alternatively allow the industry to bank part of its current season's quota in order to alleviate the consequences of the reduction in the ensuing period. These results highlight the challenge of developing effective conservation strategies.

When shortening a project's duration, activity crashing, fast-tracking and substitution are the three most commonly employed compression techniques. Crashing generally involves allocating extra resources to an activity with the intention of reducing its duration. To date, the activity time-cost relationship has for the most part been assumed to be linear, however, a few studies have suggested that this is not necessarily the case in practice. This paper proposes two non-linear theoretical models which assume either collaborative or non-collaborative resources. These models closely depict the two most common situations occurring during construction projects. The advantages of these models are that they allow for both discrete and continuous, as well as deterministic and stochastic configurations. Additionally, the quantity of resources required for crashing the activity can be quantified. Comparisons between the models and another recent fast-tracking model from the literature are discussed, and a Genetic Algorithm is implemented for a fictitious application example involving both compression techniques.

Managers of multiple projects with overly constrained resources face difficult decisions in how to allocate resources to minimize the average delay per project or the time to complete the whole set of projects. Our offer includes two stages decomposition approach for multi-project scheduling. The first stage of the approach aims to define the projects as aggregations. Each aggregation is determined by solving a resource availability cost problem (RACP) model to complete the project by his critical path. In the second stage, aggregations are used for its resource leveling scheduling to complete the multi-project by a pre-specified project duration. Both stages use priority rule (PR) heuristics. Both stages are based on two parallel schedule generation schemes (SGS) and resource criteria. Each SGS uses two PR. The first SGS, a set of demands must be developed as initial solution. The solutions obtained by the first SGS algorithm with the best resource allocation rule are used as a baseline to compare those obtained by the latter. The second, the initial solution must be optimized. The visualized results of the offered methodology are given.

Commuting has been found to be one of the least enjoyable activities. As it is a consequence of the choice of home and work location, the question arises as to how its disutility is compensated. Urban location theory suggests a compensation in the housing or the labor market. While this provides part of the explanation, individuals' personal networks may provide additional insights. Data from a social network survey were used to investigate proximity to social contacts as a factor in residential location choice. The results indicated that proximity to social contacts was an important factor and that it was traded off against commute time. The notion that the disutility of commuting is not compensated for may be a consequence of ignoring the effect of personal networks. The results contribute to the understanding of residential location choice and have implications for urban planning and policies that seek to reduce commuting.

Previous empirical studies find a negative and significant relation between risk measures and expected future stock returns. Using four risk measures, we document that the negative risk-return relation is more pronounced among firms that receive high levels of attention from investors, while a standard positive risk-return relation holds among stocks to which investors pay little attention. Regardless of our proxy for risk, we find that the magnitude and statistical significance of the risk-related puzzle monotonically decreases as we move from high to low levels of investor attention. These findings suggest that investor attention may play a central role in risk-related anomalies.

To investigate whether farm animal welfare comes at the cost of dairy farm performance, and the role that pasture-access thereby plays, we analyse a rich sample of 45 dairy farms in Germany with a scientific measure of farm animal welfare. Based on directional efficiency measure that acknowledges sequential preferences such that farm animal welfare becomes relevant after technical efficiency, we cannot find a trade-off between farm animal welfare and technical milk efficiency. Pasture-based production systems can be at least as efficient or even more efficient compared to confinement systems, despite lower milk yields. Neglecting sequential preferences would bias efficiency in provision of farm animal welfare by pasture-systems. Farms from all types of dairy systems determine the efficient frontier, where efficiency increases with herd size, and is linked with higher profits. We conclude that pasture-access may help but does not guarantee higher levels of animal welfare. These results question governmental support for pasture access regarding the provision of farm animal welfare.

Food resources can occur heterogeneously in space or time and differ in their abundances. A forager should be able to determine the value of a patch and choose optimally how to exploit it. However, patch choice and exploitation may be influenced by predation risk. Using the Giving up Densities (GUDs) technique, we evaluated goldfish patch assessment and choice in a binary patch choice experiment. We offered a pair of unequal food patches containing high and low food quantity. We quantified goldfish foraging behavior in the presence and absence of a predator. Goldfish groups equalized the GUDs in the two patches in safe environments but left higher GUDs in the rich patch under predation risk. The results suggest that goldfish can use both “patch assessment rule” and “fixed time rule” to exploit resource patches and trade off food and danger.

Integrating uncertainties into the optimization process is crucial to obtain solutions suitable for practical needs. In particular, the considered uncertainty set has a huge impact on the quality of the computed solutions. In this paper, we consider a storage loading problem in which a set of items must be loaded into a partly filled storage area, regarding stacking constraints and taking into account stochastic data of items arriving later. We propose a robust optimization approach dealing with the stochastic uncertainty. With a focus on constructing the uncertainty set, we offer a rule-based scenario generation approach to derive such a set from the stochastic data. To evaluate the robustness of stacking solutions, we introduce the concept of a security level, which is the probability that a stacking solution is feasible when the data of the uncertain items are realized. Computational results for randomly generated problem instances are presented showing the impact of various factors on the trade-off between robustness and cost of the stacking solutions.

Environmental pollution is known to adversely affect amphibian reproduction and survival, however, the knowledge of environmental heavy metal pollution on fitness of male amphibian is largely unknown. The present study aimed to explore the variation in fitness of male Bufo raddei, a widespread anuran in northwest China, subjected to long-term heavy metal stress in Baiyin (BY) city. BY is heavily polluted by heavy metals mainly copper, zinc, lead and cadmium; meanwhile, Liujiaxia (LJX), a relatively unpolluted area, was chosen as control. Differences in advertisement call, larynx size, breeding glands size, as well as forearm force during courtship and amplexus in male B. raddei between the two populations were analyzed. The results revealed a competitive advantage in advertisement call in BY population, together with larger breeding glands size and forearm force, which demonstrated a relatively higher fitness. Using skeletochronological analysis, we found that more than 40% of males from BY began to breed at 2 years old, which was only 6.93% for males from LJX. Correspondingly, the average age for all males participate in breeding was younger from BY than from LJX. Not surprisingly, males from BY showed a relatively lower body condition. All these results illustrated males from BY invested more in reproduction to increase fitness at the cost of health and survival. This reproductive trade-off might ultimately influence stability of B. raddei population because of the environmental heavy metal pollution.

We put forward a computational multi-agent model capturing the impact of social network structure on individuals’ social trust, willingness to cooperate, social utility and economic performance. Social network structure is modeled as four distinct social capital dimensions: degree, centrality, bridging and bonding social capital. Model setup draws from socio-economic theory and empirical findings based on our novel survey dataset. Results include aggregate-level comparative statics and individual-level correlations. We find, inter alia, that societies that either are better connected, exhibit a lower frequency of local cliques, or have a smaller share of family-based cliques, record relatively better aggregate economic performance. As long as family ties are sufficiently valuable, there is a trade-off between aggregate social utility and economic performance, and small world networks are then socially optimal. We also find that in dense networks and trustful societies, there is a trade-off between individual social utility and economic performance; otherwise both outcomes are positively correlated in the cross section.