The benefits of item-method-directed forgetting

The present experiments examined the encoding and retrieval conditions in an item-method-directed forget (IMDF) study that included a novel control condition. In the IMDF condition, half of the items were followed by a remember cue whereas the other half were followed by a forget cue. In a remember-both control condition, half of the items were followed by an item identifier called Set A; whereas the other half of the items were followed by a Set B identifier. At the test, items were recalled as a function of the instruction cue or the set identifier. Across two experiments, directed-forgetting effects and associated benefits were found. Further, results from both studies revealed a new way to demonstrate the benefit of IMDF - directed-forgetting participants made more correct source attributions compared to remember-both participants. These benefits were obtained using a within-subjects IMDF paradigm (Experiment 1) as well as a between-subjects IMDF paradigm (Experiment 2). These patterns of results are consistent with several current theories of item-method-directed forgetting.

Emerging Trends in Ant-Pollinator Conflict in Extrafloral Nectary-Bearing Plants

The net outcomes of mutualisms are mediated by the trade-offs between the costs and benefits provided by both partners. Our review proposes the existence of a trade-off in ant protection mutualisms between the benefits generated by the ants' protection against the attack of herbivores and the losses caused by the disruption of pollination processes, which are commonly not quantified. This trade-off has important implications for understanding the evolution of extrafloral nectaries (EFNs), an adaptation that has repeatedly evolved throughout the flowering plant clade. We propose that the outcome of this trade-off is contingent on the specific traits of the organisms involved. We provide evidence that the protective mutualisms between ants and plants mediated by EFNs have optimal protective ant partners, represented by the optimum point of the balance between positive effects on plant protection and negative effects on pollination process. Our review also provides important details about a potential synergism of EFN functionality; that is, these structures can attract ants to protect against herbivores and/or distract them from flowers so as not to disrupt pollination processes. Finally, we argue that generalizations regarding how ants impact plants should be made with caution since ants' effects on plants vary with the identity of the ant species in their overall net outcome.

Multiple modes of selection can influence the role of phenotypic plasticity in species' invasions: Evidence from a manipulative field experiment

In exploring the roles of phenotypic plasticity in the establishment and early evolution of invading species, little empirical attention has been given to the importance of correlational selection acting upon suites of functionally related plastic traits in nature. We illustrate how this lack of attention has limited our ability to evaluate plasticity's role during invasion and also, the costs and benefits of plasticity. We addressed these issues by transplanting clones of European-derived Plantago lanceolata L. genotypes into two temporally variable habitats in the species' introduced range in North America. Phenotypic selection analyses were performed for each habitat to estimate linear, quadratic, and correlational selection on phenotypic trait values and plasticities in the reproductive traits: flowering onset and spike and scape lengths. Also, we measured pairwise genetic correlations for our "colonists." Results showed that (a) correlational selection acted on trait plasticity after transplantation, (b) selection favored certain combinations of genetically correlated and uncorrelated trait values and plasticities, and (c) using signed, instead of absolute, values of plasticity in analyses facilitated the detection of correlational selection on trait value-plasticity combinations and their adaptive value. Based on our results, we urge future studies on species invasions to (a) measure correlational selection and (b) retain signed values of plasticity in order to better discriminate between adaptive and maladaptive plasticity.

Costs and Benefits of Transgenerational Induced Resistance in Arabidopsis

Recent evidence suggests that stressed plants employ epigenetic mechanisms to transmit acquired resistance traits to their progeny. However, the evolutionary and ecological significance of transgenerational induced resistance (t-IR) is poorly understood because a clear understanding of how parents interpret environmental cues in relation to the effectiveness, stability, and anticipated ecological costs of t-IR is lacking. Here, we have used a full factorial design to study the specificity, costs, and transgenerational stability of t-IR following exposure of Arabidopsis thaliana to increasing stress intensities by a biotrophic pathogen, a necrotrophic pathogen, and salinity. We show that t-IR in response to infection by biotrophic or necrotrophic pathogens is effective against pathogens of the same lifestyle. This pathogen-mediated t-IR is associated with ecological costs, since progeny from biotroph-infected parents were more susceptible to both necrotrophic pathogens and salt stress, whereas progeny from necrotroph-infected parents were more susceptible to biotrophic pathogens. Hence, pathogen-mediated t-IR provides benefits when parents and progeny are in matched environments but is associated with costs that become apparent in mismatched environments. By contrast, soil salinity failed to mediate t-IR against salt stress in matched environments but caused non-specific t-IR against both biotrophic and necrotrophic pathogens in mismatched environments. However, the ecological relevance of this non-specific t-IR response remains questionable as its induction was offset by major reproductive costs arising from dramatically reduced seed production and viability. Finally, we show that the costs and transgenerational stability of pathogen-mediated t-IR are proportional to disease pressure experienced by the parents, suggesting that plants use disease severity as an environmental proxy to adjust investment in t-IR.

Modeling costs and benefits of the organized colorectal cancer screening programme and its potential future improvements in Hungary

OBJECTIVE

The national population-based colorectal cancer screening programme in Hungary was initiated in December 2018. We aimed to evaluate the current programme and investigate the costs and benefits of potential future changes to overcome the low coverage of the target population.

METHODS

We performed an economic evaluation from a healthcare payer perspective using an established micro-simulation model (Microsimulation Screening Analysis-Colon). We simulated costs and benefits of screening with fecal immunochemical test in the Hungarian population aged 50-100, investigating also the impact of potential future scenarios which were assumed to increase invitation coverage: improvement of the IT platform currently used by GPs or distributing the tests through pharmacies instead of GPs.

RESULTS

The model predicted that the current screening programme could lead to 6.2% colorectal cancer mortality reduction between 2018 and 2050 compared to no screening. Even higher reductions, up to 16.6%, were estimated when tests were distributed through pharmacies and higher coverage was assumed. This change in the programme was estimated to require up to 26 million performed fecal immunochemical tests and 1 million colonoscopies for the simulated period. These future scenarios have acceptable cost-benefit ratios of €8000-€8700 per life-years gained depending on the assumed adherence of invited individuals.

CONCLUSIONS

With its limitations, the current colorectal cancer screening programme in Hungary will have a modest impact on colorectal cancer mortality. Significant improvements in mortality reduction could be made at acceptable costs, if the tests were to be distributed by pharmacies allowing the entire target population to be invited.

Individual willingness to leave a safe refuge and the trade-off between food and safety: a test with social fish

Refuges offer prey animals protection from predation, but increased time spent hiding can reduce foraging opportunities. Within social groups, individuals vary in their refuge use and willingness to forage in the presence of a predator. Here, we examine the relative foraging benefits and mortality costs associated with individual refuge use and foraging behaviour within groups of goldfish (Carassius auratus) under predation risk from an avian predator (little egret-Egretta garzetta). We assessed individual order of emergence from the refuge and participation over 15 group foraging outings, and assigned each fish a daily outing index score. The individual fish that emerged from the refuge earlier than the other group members and that participated in more outings received high outing index scores and consumed more food compared with fish that tended to emerge in posterior positions and participate in fewer outings. However, individual fish that attained high outing index scores suffered a higher risk of predation. Furthermore, the amount of time the egret spent at the pool affected group foraging behaviour: as predation risk increased, groups of fish consumed significantly less food. Our results exemplify the trade-off between foraging success and safety from predation that prey species regularly experience.

Lights Off for Arbuscular Mycorrhiza: On Its Symbiotic Functioning under Light Deprivation

Plants are often exposed to shade over different time scales and this may substantially affect not only their own growth, but also development and functioning of the energetically dependent organisms. Among those, the root symbionts such as arbuscular mycorrhizal (AM) fungi and rhizobia represent particularly important cases-on the one hand, they consume a significant share of plant carbon (C) budget and, on the other, they generate a number of important nutritional feedbacks on their plant hosts, often resulting in a net positive effect on their host growth and/or fitness. Here we discuss our previous results comparing mycorrhizal performance under different intensities and durations of shade (Konvalinková et al., 2015) in a broader context of previously published literature. Additionally, we review publicly available knowledge on the root colonization and mycorrhizal growth responses in AM plants under light deprivation. Experimental evidence shows that sudden and intensive decrease of light availability to a mycorrhizal plant triggers rapid deactivation of phosphorus transfer from the AM fungus to the plant already within a few days, implying active and rapid response of the AM fungus to the energetic status of its plant host. When AM plants are exposed to intensive shading on longer time scales (weeks to months), positive mycorrhizal growth responses (MGR) are often decreasing and may eventually become negative. This is most likely due to the high C cost of the symbiosis relative to the C availability, and failure of plants to fully compensate for the fungal C demand under low light. Root colonization by AM fungi often declines under low light intensities, although the active role of plants in regulating the extent of root colonization has not yet been unequivocally demonstrated. Quantitative information on the rates and dynamics of C transfer from the plant to the fungus is mostly missing, as is the knowledge on the involved molecular mechanisms. Therefore, these subjects deserve particular attention in the future.

Combined effects of resource heterogeneity and simulated herbivory on plasticity of clonal integration in a rhizomatous perennial herb

Previous lines of investigation assuming potential advantage of clonal integration generally have neglected its plasticity in complex heterogeneous environments. Clonal plants adaptively respond to abiotic heterogeneity (patchy resource distribution) and herbivory-induced heterogeneity (within-clone heterogeneity in ramet performance), but to date little is known about how resource heterogeneity and simulated herbivory jointly affect the overall performance of clones. Partial damage within a clone caused by herbivory might create herbivory-induced heterogeneity in a resource-homogeneous environment, and might also decrease or increase the extent of heterogeneity under resource-heterogeneous conditions. We conducted a greenhouse experiment in which target-ramets of Leymus chinensis segments within homogeneous or heterogeneous nutrient treatments were subject to clipping (0% or 75% shoot removal). In homogeneous environments with high (9:9) nutrient availability, ramet biomass of L. chinensis with intact or severed rhizomes is 0.70 or 0.69 g. Conversely, target-ramet biomass with intact rhizomes is obviously lower than that of the severed target-ramets in the homogeneous environments with medium (5:5) and low (1:1) nutrient availability. High resource availability and the presence of herbivory can alleviate negative effects of rhizome connection under homogeneous conditions, by providing copious resource or creating herbivory-induced heterogeneity respectively. Herbivory tolerance of clonal fragments with connected rhizomes was higher than that of fragments with severed rhizomes under heterogeneous conditions. These findings confirmed the unconditional advantage of clonal integration on reproduction under the combined influence of resource heterogeneity and simulated herbivory. Moreover, our results made clear the synergistically interactive effects of resource heterogeneity and simulated herbivory on costs and benefits of clonal integration. This will undoubtedly advance our understanding on the plasticity of clonal integration under complex environmental conditions.

Screening for gastric cancer and surveillance of premalignant lesions: a systematic review of cost-effectiveness studies

BACKGROUND

Cost-effectiveness studies are highly dependent on the models, settings, and variables used and should be based on systematic reviews. We systematically reviewed cost-effectiveness studies that address screening for gastric cancer and/or surveillance of precancerous conditions and lesions.

MATERIALS AND METHODS

A systematic review of cost-effectiveness studies was performed by conducting a sensitive search in seven databases (PubMed, Scopus, Web of Science, Current Contents Connect, Centre for Reviews and Dissemination, Academic Search Complete, and CINAHL Plus), independently evaluated by two investigators. Articles were evaluated for type of study, perspective, model, intervention, incremental cost-effectiveness ratio, clinical or cost variables, and quality, according to published guidelines.

RESULTS

From 2395 abstracts, 23 articles were included: 19 concerning population screening and 4 on following up premalignant lesions. Studies on Helicobacter pylori screening concluded that serology was cost-effective, depending on cancer incidence and endoscopy cost (incremental cost-effectiveness ratio: 6264-25,881), and eradication after endoscopic resection was also cost-effective (dominant) based on one study. Studies on imaging screening concluded that endoscopy was more cost-effective than no screening (incremental cost-effectiveness ratio: 3376-26,836). Articles on follow-up of premalignant lesions reported conflicting results (incremental cost-effectiveness ratio: 1868-72,519 for intestinal metaplasia; 18,600-39,800 for dysplasia). Quality assessment revealed a unanimous lack of a detailed systematic review and fulfillment of a median number of 23 items (20-26) of 35 possible ones.

CONCLUSIONS

The available evidence shows that Helicobacter pylori serology or endoscopic population screening is cost-effective, while endoscopic surveillance of premalignant gastric lesions presents conflicting results. Better implementation of published guidelines and accomplishment of systematic detailed reviews are needed.

Cost-Effectiveness Analysis of Omalizumab for the Treatment of Severe Asthma in Japan and the Value of Responder Prediction Methods Based on a Multinational Trial

OBJECTIVES

Omalizumab improves health outcomes for patients with severe asthma. The purpose of this study was to conduct a cost-utility analysis of omalizumab from a societal perspective by using the results from a randomized controlled trial in Japan, and explore the efficient use of omalizumab.

METHODS

We developed a Markov model to compare omalizumab add-on therapy with standard therapy. Patients transitioned between symptom-free, day-to-day, and exacerbation states. Our model had a lifetime horizon in which 5-year omalizumab add-on therapy was followed by standard therapy. Preference-based utilities were extracted from another study. We estimated the expected value of perfect information for patients' response to omalizumab.

RESULTS

In the base case, incremental cost-effectiveness ratio (ICER) for omalizumab add-on therapy was US $755,200 (95% credible interval [CI] $614,200-$1,298,500) per quality-adjusted life-year gained, compared with standard therapy alone. One-way sensitivity analyses indicated that the results were sensitive to asthma-related mortality, exacerbation risk, and omalizumab cost. The ICER for a responder subgroup was 22% lower than that in the base case. Individual and population expected value of perfect informations for the response were $4100 (95% CI $2500-$6000) and $28 million (95% CI $17 million-$42 million) per year, respectively.

CONCLUSIONS

With a willingness-to-pay of $45,000 per quality-adjusted life-year, omalizumab was not cost-effective in Japan. Confining omalizumab therapy to previously predicted responders, however, may be a reasonable strategy to reduce the ICER, as the cost-effectiveness was observed to improve for these patients. Further studies should be conducted to explore responder prediction methods. Decreasing the price of omalizumab would improve cost-effectiveness.

Assessing the impacts of establishing MPAs on fishermen and fish merchants: the case of Lyme Bay, UK

Shortly after the implementation of a marine protected area (MPA) in Lyme Bay in 2008, inside which scallop dredging and bottom trawling is prohibited, a socio-economic impact assessment was initiated. This article presents the initial findings from this study. The aim was to understand the costs and benefits to fishermen and fish merchants of establishing the MPA. These were assessed using a combination of primary and secondary data. The results indicate that the impacts of the closure differ according to the gear type and the fishing location used by the fishermen. Static gear fishermen who fish inside the closed area have seen changes in terms of increased fishing effort, mostly because they have been able to increase the number of crab and whelk pots they deploy. The effects of the closure on static gear fishermen who fish outside the closed area has been reported in terms of increased conflicts with towed gear fishermen who now fish regularly in their traditional grounds. Fishermen using towed gear on the other hand have been impacted through displacement effects as they have been forced to look for other fishing grounds outside the closed area. Most fish merchants and processors initially claimed that they were heavily impacted by the closure but when they were interviewed 1 year after the closure they suggested a more stable picture. Preliminary analyses of landings data indicate that the introduction of the MPA has so far had minimal impacts on the average incomes and financial profits of fishermen and fish merchants. This conclusion, however, reflects a short-term view as the impacts of the closure of Lyme Bay are likely to be felt for a long time to come.

Consumption and response output as a function of unit price: manipulation of cost and benefit components

We conducted preference assessments with 4 typically developing children to identify potential reinforcers and assessed the reinforcing efficacy of those stimuli. Next, we tested two predictions of economic theory: that overall consumption (reinforcers obtained) would decrease as the unit price (response requirement per reinforcer) increased and that the cost and benefit components that defined unit price would not influence overall consumption considerably when unit price values were equal. We tested these predictions by arranging unit price such that the denominator was one (e.g., two responses produced one reinforcer) or two (e.g., four responses produced two reinforcers). Results showed that consumption decreased as unit price increased and that unit price values with different components produced similar consumption.

Defining "adverse environmental impact" and making paragraph 316(b) decisions: a fisheries management approach

The electric utility industry has developed an approach for decisionmaking that includes a definition of Adverse Environmental Impact (AEI) and an implementation process. The definition of AEI is based on lessons from fishery management science and analysis of the statutory term "adverse environmental impact" and is consistent with current natural resource management policy. The industry has proposed a definition focusing on "unacceptable risk to the population"s ability to sustain itself, to support reasonably anticipated commercial or recreational harvests, or to perform its normal ecological function." This definition focuses not on counting individual fish or eggs cropped by the various uses of a water body, but on preserving populations of aquatic organisms and their functions in the aquatic community. The definition recognizes that assessment of AEI should be site-specific and requires both a biological decision and a balancing of diverse societal values. The industry believes that the definition of AEI should be implemented in a process that will maximize the overall societal benefit of the paragraph 316(b) decision by considering the facility"s physical location, design, and operation, as well as the local biology. The approach considers effects on affected fish and shellfish populations and the benefits of any necessary best technology available (BTA) alternatives. This is accomplished through consideration of population impacts, which conversely allows consideration of the benefits of any necessary BTA modifications. This in turn allows selection of BTAs that will protect potentially affected populations in a cost-effective manner. The process also employs risk assessment with stakeholder participation, in accordance with EPA's Guidelines for Ecological Risk Assessment. The information and tools are now available to make informed decisions about site-specific impacts that will ensure protection of aquatic ecosystems and best serve the public interest.

Measuring investment in carnivory: seasonal and individual variation in trap number and biomass in Utricularia vulgaris L

The partitioning of biomass between traps and leaves is a measure of the investment in carnivory of Utricularia vulgaris and is dependent on the relative values of three attributes: trap size, trap number and leaf size. Marked seasonal and individual variations in trap size, trap number and leaf size occur within a small population of U. vulgaris at Wicken Fen, Cambridgeshire, UK, with some plants consistently having fewer traps per leaf than others, and some smaller leaves than others, throughout the growing season. However, the three attributes vary independently, so that all combinations over the observed ranges of trap size, trap number and leaf size occur simultaneously in the population. In spite of the variation in the three constituent factors, the proportion of biomass invested in traps is close to 50% in the majority of plants and throughout most of the growing season. The contribution of traps to total biomass cannot be predicted from the number of traps per leaf. Although the proportion of biomass represented by traps is the most useful measure of a plant's investment in carnivory, the precise way in which the biomass is partitioned between a variable number of traps of different sizes may also be an important consideration in cost-benefit analyses.