Early prosociality is conditional on opportunity cost and familiarity with the target

Developmental research in the past decade has painted the picture of a gregarious child ready to engage in a range of prosocial behavior, but less is known about the situational factors that moderate this behavior. The present study investigated the effects of cost and familiarity on children's readiness to help the victim of a moral transgression. Opportunity cost was operationalized as the time and effort expended on providing help, that could otherwise be used to earn a reward from a productive task. Familiarity varied as a function of whether there was prior contact between the child and victim. Five- and six-year-olds in Singapore (N = 120) witnessed an adult transgressor destroy the victim's tower of blocks, responded to the victim's pleas for help in rebuilding her tower, and shared resources with both actresses. Contrary to our initial predictions, children helped a familiar victim less when cost was high as opposed to low, but helped an unfamiliar victim equally regardless of cost. Additionally, helping rates were low (30–60%) except in the least prohibitive condition (> 80%; Low-Cost, Familiar Victim), stemming from a combination of not having a productive task to occupy one's time and energy, and simultaneously a familiar target which increased one's intrinsic motivation to help. The conditional limits imposed on children's decision to help thus appear to be, “I'll help, if I know you and have nothing better to do!” In terms of resource sharing, children behaved selfishly toward both the victim and transgressor regardless of their familiarity with the victim. Altogether, our findings suggest that children consider self-interest when deciding whether to help and share with others.     

The impact of climatic variation on the opportunity for sexual selection

Many studies have demonstrated influences of climatic variation on a variety of ecological processes, however, its impact on the potent evolutionary force of sexual selection has largely been ignored. The intensity of sexual selection is a fundamental parameter in animal populations, which depends upon the degree of polygamy and will probably be influenced by the impact of local climatic variation upon 'environmental potential for polygamy'. Here, we provide evidence of a direct effect of local climatic variation on the intensity of sexual selection, by showing a clear correlation between local weather conditions and inter-annual changes in the degree of polygamy in a long-term study of colonially breeding grey seals (Halichoerus grypus). Our results show that changes in local weather conditions alter the annual proportion of males contributing to the effective population size (Ne) by up to 61%. Consequently, over the 'lifetime' of a cohort, a broader range of individuals will contribute genetically to the next generation if local weather conditions are variable. In the context of predicted future changes in climatic variation, these findings have broad implications for population genetics of socially structured animal systems through the major influence that the degree of polygamy has upon Ne.     

On the opportunity cost of the photosynthate invested in stem elongation reactions mediated by phytochrome

Summary Seedlings of shade-intolerant species react to alterations of the light climate caused by their neighbors with morphological changes that may influence the pattern of resource acquisition and utilization at the whole-canopy level. One such change, the increased stem elongation rate that is triggered by low red (R, 660 nm) to far-red (FR, 730 nm) ratios (R:FR) in dense canopies, might reduce the amount of assimilates available for leaf area expansion or root growth, and in that way affect resource capture by the canopy. We have tested this hypothesis by comparing the growth of both isolated individuals and canopies of the weed Amaranthus quitensis under conditions differing only in the spectral distribution of the incident light. When canopies received the full spectrum of sunlight, the stems were a large proportion (40–57%) of total biomass. Filtering the FR waveband (and hence raising the R:FR ratio to eliminate the neighbors' proximity-signal) resulted in shorter canopies with lighter stems. However, the growth of leaves and roots was not promoted by this treatment, indicating that the opportunity cost of the assimilates invested in the stems was nil or very small. Filtering the FR had no effect on biomass accumulation when plants were grown as isolated individuals. The higher growth of the canopics under full spectrum could be due to a higher light interception or to a higher efficiency of light conversion into biomass. The first possibility is weakened by the observation that filtering the FR had no effect on the dynamics of soil covering by the crops. The second is indirectly strengthened by results of an experiment with isolated plants showing that stem elongation, stem growth, and total plant biomass can be increased by reducing the flux of R light received by the stems without affecting the light climate of the leaves. Further work is needed to distinguish between these two possibilities; whatever the cause, our results show that the elongation responses to decreased R:FR may lead to a net increase in canopy productivity, and do not necessarily have a negative impact on the growth of resource-harvesting organs.     

Impact beyond the impact factor

The journal impact factor is an annually calculated number for each scientific journal, based on the average number of times its articles published in the two preceding years have been cited. It was originally devised as a tool for librarians and publishers to provide information about the citation performance of a journal as a whole, but over the last few decades it has increasingly been used to assess the quality of specific articles and the research performance of individual investigators, institutions, and countries. In addition to this clear abuse of the journal impact factor, several conceptual and technical issues limit its usability as a measure of journal reputation, especially when journals are compared across different fields. An author’s decision regarding the suitability of a scholarly journal for publication should, therefore, be based on the impact that this journal makes in the field of research, rather than on the journal impact factor.     

Performance-gated deliberation: A context-adapted strategy in which urgency is opportunity cost

Finding the right amount of deliberation, between insufficient and excessive, is a hard decision making problem that depends on the value we place on our time. Average-reward, putatively encoded by tonic dopamine, serves in existing reinforcement learning theory as the opportunity cost of time, including deliberation time. Importantly, this cost can itself vary with the environmental context and is not trivial to estimate. Here, we propose how the opportunity cost of deliberation can be estimated adaptively on multiple timescales to account for non-stationary contextual factors. We use it in a simple decision-making heuristic based on average-reward reinforcement learning (AR-RL) that we call Performance-Gated Deliberation (PGD). We propose PGD as a strategy used by animals wherein deliberation cost is implemented directly as urgency, a previously characterized neural signal effectively controlling the speed of the decision-making process. We show PGD outperforms AR-RL solutions in explaining behaviour and urgency of non-human primates in a context-varying random walk prediction task and is consistent with relative performance and urgency in a context-varying random dot motion task. We make readily testable predictions for both neural activity and behaviour.     

Obesity impact on the attentional cost for controlling posture

Background

This study investigated the effects of obesity on attentional resources allocated to postural control in seating and unipedal standing.

Methods

Ten non obese adults (BMI = 22.4±1.3, age = 42.4±15.1) and 10 obese adult patients (BMI = 35.2±2.8, age = 46.2±19.6) maintained postural stability on a force platform in two postural tasks (seated and unipedal). The two postural tasks were performed (1) alone and (2) in a dual-task paradigm in combination with an auditory reaction time task (RT). Performing the RT task together with the postural one was supposed to require some attentional resources that allowed estimating the attentional cost of postural control. 4 trials were performed in each condition for a total of 16 trials.

Findings

(1) Whereas seated non obese and obese patients exhibited similar centre of foot pressure oscillations (CoP), in the unipedal stance only obese patients strongly increased their CoP sway in comparison to controls. (2) Whatever the postural task, the additional RT task did not affect postural stability. (3) Seated, RT did not differ between the two groups. (4) RT strongly increased between the two postural conditions in the obese patients only, suggesting that body schema and the use of internal models was altered with obesity.

Interpretation

Obese patients needed more attentional resources to control postural stability during unipedal stance than non obese participants. This was not the case in a more simple posture such as seating. To reduce the risk of fall as indicated by the critical values of CoP displacement, obese patients must dedicate a strong large part of their attentional resources to postural control, to the detriment of non-postural events. Obese patients were not able to easily perform multitasking as healthy adults do, reflecting weakened psycho-motor abilities.     

基于机会成本法的海洋保护区生态保护补偿标准

建立海洋保护区已被公认为维持海洋生物多样性和防止海洋生态环境恶化的重要途径,而合理实施生态保护补偿是确保海洋保护区建设和管理成效、促进区域经济发展机会公平的关键手段。以土地、海域为载体,从机会成本补偿的角度出发,分别设置了机会成本补偿基数、区域调整系数、分区补偿系数和开发限度补偿系数,构建了海洋保护区生态保护补偿标准测算方法,并选取全国8个省(市)14个国家级海洋自然保护区开展了实证分析。结果表明:2015年案例区的机会成本补偿测算结果介于0.66×10⁴—10.69×10⁴元/km²之间,河北昌黎黄金海岸国家级自然保护区和天津古海岸与湿地国家级自然保护区的补偿金额显著高于其他保护区,分别为10.69×10⁴元/km²和10.47×10⁴元/km²,相比之下,其余12个保护区的平均补偿金额为1.70×10⁴元/km²。     

Microbiological high throughput screening: an opportunity for the lead discovery process

Microbial HTS has been implemented at Rh?ne-Poulenc Rorer through the development of a dedicated robotic platform. This robot (Turbo) has been designed with the aim of fully integrating microbial HTS into the lead discovery processes. Innovative solutions have been found to reach high throughput as well as flexibility. This opens up new prospects for solid-phase microbial screening, taking advantage of the easy implementation and the very low costs of such screens. The different types of microbial screens done in our laboratory, as well as the throughputs and outputs obtained, are described. Some of the specific aspects of microbial HTS, as compared to biochemical and cell-based assays, are also discussed.     

Comparison of environmental impact and external cost assessment methods

Background, aim, and scope  

Impact assessment can be completed with the help of Life Cycle Impact Assessment (LCIA) as a part of Life Cycle Assessment (LCA) and External Cost Assessment methods. These methods help, for project and product classifications, to protect human health and the environment. Comparison of different impact assessment methods along parallel evaluations of real air pollution case studies helps to detect similarities and dependencies between them. The comparison helps and supports the work in both areas by mutually exploiting the merits of both methods. On the other hand, the detected similarities and dependencies also support the accuracy of the assessment work.     

Sometimes the impact factor outshines the H index

Human immunodeficiency virus type 2 (HIV-2) emerged following cross-species transmission of simian immunodeficiency virus (SIV) from sooty mangabeys to humans several decades ago. The epidemic groups of HIV-2 have been established in the human population for at least 50 years. However, it is likely that new divergent SIVs can infect humans and lead to new outbreaks. We report the isolation of a new strain of HIV-2, HIV2-NWK08F, from an immunodeficient Sierra Leone immigrant. Health care providers in Sierra Leone and elsewhere need to be alerted that a subtype of HIV-2, which is not detected by PCR for epidemic HIV-2 strains, exists and can lead to immunosuppression.     

Conserving rare species can have high opportunity costs for common species

Conservation practitioners face difficult choices in apportioning limited resources between rare species (to ensure their existence) and common species (to ensure their abundance and ecosystem contributions). We quantified the opportunity costs of conserving rare species of migratory fishes in the context of removing dams and retrofitting road culverts across 1,883 tributaries of the North American Great Lakes. Our optimization models show that maximizing total habitat gains across species can be very efficient in terms of benefits achieved per dollar spent, but disproportionately benefits common species. Conservation approaches that target rare species, or that ensure some benefits for every species (i.e., complementarity) enable strategic allocation of resources among species but reduce aggregate habitat gains. Thus, small habitat gains for the rarest species necessarily come at the expense of more than 20 times as much habitat for common ones. These opportunity costs are likely to occur in many ecosystems because range limits and conservation costs often vary widely among species. Given that common species worldwide are declining more rapidly than rare ones within major taxa, our findings provide incentive for triage among multiple worthy conservation targets.