Fear in the dark? Community‐level effects of non‐lethal predators change with light regime

The total effect of predators on prey is a combination of direct consumption, and non‐consumptive effects (NCEs), such as predator‐induced changes to prey morphology, behaviour and life history. Past research into NCEs has tended to focus on pair‐wise interactions between predators and prey, while in natural ecosystems, species exist in complex communities with several trophic levels made up of multiple autotrophic and heterotropic species. To address how predator NCEs alter the photosynthetic and heterotrophic components of communities, we exposed microbial microcosms to one of three predator treatments: live predators (full predator effect), freeze‐killed predators (NCEs only) or no predators (control), and incubated them under either 12 h:12 h light:dark conditions or continual darkness. Under 12 h:12 h light:dark conditions, NCEs‐only communities never differed from predator‐free communities, but differed from live predator communities. Under conditions of continual darkness, the structure of NCEs‐only communities differed from predator‐free controls, but not from live predator communities, suggesting NCEs can be strong enough to structure communities. Predation threat may cause certain prey to induce defences, such as reductions in movement, which make them less competitive in a community setting. This reduction in competitive ability could lead to these species being driven to extinction through interspecific competition, resulting in similar communities to those in which live predators are present. Heterotrophic species whose rates of resource acquisition depend on movement rates may be affected to a greater extent than autotrophs by predator‐induced reductions in movement, accounting for our observed differences in predator NCEs in ‘dark’ and ‘light’ communities. Our results suggest that the community‐level consequences of fear are greater in the dark. Synthesis Predators affect prey through consumptive and non‐consumptive effects (NCEs) such as alterations to prey behaviour, morphology, and life history. However, predators and prey do not exist in isolated pairs, but in complex communities where they interact with many other species. Using a long term study (>10 predator generations), we show that predator NCEs alone can alter community structure under conditions of darkness, but not in a 12h:12h light:dark cycle. Our results demonstrate for the first time that although the community‐level consequences of predator NCEs may be dramatic, they depend upon the abiotic conditions of the ecosystem.     

Wading through the swamp: what does tropical peatland restoration mean to national‐level stakeholders in Indonesia?

Ecological restoration is considered to play an important role in mitigating climate change, protecting biodiversity, and preventing environmental degradation. Yet, there are often multiple perspectives on what outcomes restoration should be aiming to achieve, and how we should get to that point. In this study we interview a range of policymakers, academics, and non‐governmental organization (NGO) representatives to explore the range of perspectives on the restoration of Indonesia's tropical peatlands—key global ecosystems that have undergone large‐scale degradation. Thematic analysis suggests that participants agreed about the importance of restoration, but had differing opinions on how effective restoration activities to date have been and what a restored peatland landscape should look like. These results exemplify how ecological restoration can mean different things to different people, but also highlight important areas of consensus for moving forward with peatland restoration strategies.     

Trade‐offs in evolutionary immunology: just what is the cost of immunity?

It has become increasingly clear that life-history patterns among the vertebrates have been shaped by the plethora and variety of immunological risks associated with parasitic faunas in their environments. Immunological competence could very well be the most important determinant of life-time reproductive success and fitness for many species. It is generally assumed by evolutionary ecologists that providing immunological defences to minimise such risks to the host is costly in terms of necessitating trade-offs with other nutrient-demanding processes such as growth, reproduction, and thermoregulation. Studies devoted to providing assessments of such costs and how they may force evolutionary trade-offs among life-history characters are few, especially for wild vertebrate species, and their results are widely scattered throughout the literature. In this paper we attempt to review this literature to obtain a better understanding of energetic and nutritional costs for maintaining a normal immune system and examine how costly it might be for a host who is forced to up-regulate its immunological defence mechanisms. The significance of these various costs to ecology and life history trade-offs among the vertebrates is explored. It is concluded that sufficient evidence exists to support the primary assumption that immunological defences are costly to the vertebrate host.     

Deletion of the nicotinic acetylcholine receptor subunit gene Dα1 confers insecticide resistance,but at what cost?

Nicotinic acetylcholine receptors (nAChRs) have vital functions in processes of neurotransmission that underpin key behaviors. These pentameric ligand-gated ion channels have been used as targets for insecticides that constitutively activate them, causing the death of insect pests. In examining a knockout of the Dα1 nAChR subunit gene, our study linked this one subunit with multiple traits. We were able to confirm previous work that had identified Dα1 as a target of the neonicotinoid class of insecticides. Further, we uncovered roles for the gene in influencing mating behavior and patterns of sleep. The knockout mutant was also observed to have a significant reduction in longevity. This study highlighted the severe fitness costs that appear to be associated with the loss of function of this gene in natural populations in the absence of insecticides targeting the Dα1 subunit. Such a fitness cost could explain why target site resistances to neonicotinoids in pest insect populations have been associated specific amino acid replacement mutations in nAChR subunits, rather than loss of function. That mutant phenotypes were observed for the two behaviors examined indicates that the functions of Dα1, and other nAChR subunits, need to be explored more broadly. It also remains to be established whether these phenotypes were due to loss of the Dα1 receptor and/or to compensatory changes in the expression levels of other nAChR subunits.     

Hormone-mediated maternal effects in birds: mechanisms matter but what do we know of them?

Over the past decade, birds have proven to be excellent models to study hormone-mediated maternal effects in an evolutionary framework. Almost all these studies focus on the function of maternal steroid hormones for offspring development, but lack of knowledge about the underlying mechanisms hampers further progress. We discuss several hypotheses concerning these mechanisms, point out their relevance for ecological and evolutionary interpretations, and review the relevant data. We first examine whether maternal hormones can accumulate in the egg independently of changes in hormone concentrations in the maternal circulation. This is important for Darwinian selection and female physiological trade-offs, and possible mechanisms for hormone accumulation in the egg, which may differ among hormones, are reviewed. Although independent regulation of plasma and yolk concentrations of hormones is conceivable, the data are as yet inconclusive for ovarian hormones. Next, we discuss embryonic utilization of maternal steroids, since enzyme and receptor systems in the embryo may have coevolved with maternal effect mechanisms in the mother. We consider dose-response relationships and action pathways of androgens and argue that these considerations may help to explain the apparent lack of interference of maternal steroids with sexual differentiation. Finally, we discuss mechanisms underlying the pleiotropic actions of maternal steroids, since linked effects may influence the coevolution of parent and offspring traits, owing to their role in the mediation of physiological trade-offs. Possible mechanisms here are interactions with other hormonal systems in the embryo. We urge endocrinologists to embark on suggested mechanistic studies and behavioural ecologists to adjust their interpretations to accommodate the current knowledge of mechanisms.     

Debate: at what level of coronary heart disease risk should a statin be prescribed?

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) are effective treatments for the primary and secondary prevention of coronary heart disease, but an outstanding issue is determining who should have such treatment. The benefit from treatment with statins appears to be proportional to the underlying risk of coronary heart disease and independent of the factors increasing risk. Most benefit will therefore be achieved by treating people at increased risk of coronary heart disease. Statins reduce coronary morbidity even when the risk of coronary heart disease is relatively low (6% over 10 years), but reduction in all-cause mortality, the true measure of safety has been shown only when the risk of a major coronary heart disease event is 15% over 10 years or greater. At this level of risk patients appear willing to take treatment to gain the benefit expected from statin treatment, and the cost effectiveness of statin treatment is within the range accepted for other treatments. The major impediments to the systematic introduction of statin treatment at this level of risk are the very high overall cost and the large workload in countries like Britain, where the population risk of coronary heart disease is high. For this reason, recent British guidelines correctly advise statin treatment for secondary prevention and primary prevention when the 10 year coronary heart disease risk is 30% or greater as the first priority, moving to a lower coronary heart disease threshold for primary prevention only when resources permit.     

The hemolymph proteome of the honeybee: Gel‐based or gel‐free?

The honeybee has an invaluable economic impact and is a model for studying immunity, development and social behavior. The recent sequencing and annotation of the honeybee genome facilitates the study of its hemolymph, which reflects the physiological condition and mediates immune responses. We aimed at making a proteomic reference map of honeybee hemolymph and compared gel‐free and gel‐based techniques. One hundered and four 2‐DE spots corresponding to 62 different proteins were identified. Eight identical 2‐DLC experiments resulted in the identification of 32 unique proteins. One repeat was clearly not representative for the potential of the given 2‐DLC setup. Only 27% of the identified hemolymph proteins were found by both techniques. In addition, we found proteins of three different viruses which creates possibilities for biomarker design. Future hemolymph studies will benefit from this work.     

Mammals,agri‐environment schemes and set‐aside – what are the putative benefits?

• 1 The impacts of agricultural intensification on farmland wildlife have been the subject of increasing concern, particularly over the last two decades. Population declines have occurred for a number of mammalian species, sometimes drastically so, and changes in farming practice are believed to be significant contributory factors.
• 2 The major policy instruments for delivering environmental benefits on farmland are agri‐environment schemes. These encourage farmers to adopt more environmentally sensitive farming practices to promote farmland biodiversity. Additionally, compulsory set‐aside, which reduces agricultural surplus, could also have positive impacts on wildlife. In this paper we consider some of the putative benefits of agri‐environment schemes and set‐aside for mammals.
• 3 We review how establishment and management options within agri‐environment schemes and set‐aside might affect habitat resources for mammals. For example, conservation headlands increase plant and invertebrate resources within the crop edge for mammals such as wood mice. Grassy field margins can support communities of smaller mammals, and hedgerows may act as important commuting and hunting routes. Their potential will depend on factors such as seed mixtures used, timing and severity of cutting, and length of time they have been in place.
• 4 At a farm level, habitat heterogeneity may be increased through organic agriculture, which is supported by some agri‐environment schemes. Studies suggest significant benefits to mammals, including wood mice and bats. However, it is increasingly recognized that effective conservation of farmland mammals must seek solutions at the landscape scale, addressing such issues as habitat connectivity between farms. One approach may be the better targeting of scheme agreements.
• 5 We suggest that agri‐environment schemes and set‐aside can contribute to the conservation of mammals on farmland. Recent policy changes are likely to have further positive impacts on farmland wildlife but appropriate mammal monitoring programmes must be developed rigorously to assess their effects.

     

Shrub‐based plantings of woody perennial vegetation in temperate Australian agricultural landscapes: What benefits for native biodiversity?

Summary  In the highly fragmented agricultural landscapes of temperate southern Australia, fodder shrubs are being established as part of commercial grazing enterprises to fill the summer-autumn livestock feed gap. These woody perennial plantings have greater structural complexity than conventional grazing systems and may supplement resources for native fauna. However, to date the resources provided by these systems are poorly defined or documented. In this paper, we identify the potential environmental values of fodder shrub plantings by considering natural and planted shrub-based systems, with a particular focus on planted saltbush in non-saline lands. In marginal agricultural areas, shrub-based perennial fodder crops can not only provide economic benefits through improved livestock productivity, but also contribute to reducing soil erosion and offer potential carbon sequestration opportunities. We contend that these systems may also provide resources for a range of native fauna. More information is needed on the biodiversity value of grazing systems based on perennial shrubs so that their potential to contribute to conservation in multifunctional landscapes can be fully realised and appropriate management recommendations provided.     

Classifying the fire‐response traits of plants: How reliable are species‐level classifications?

Plant species in fire‐prone environments possess specific traits which allow them to survive fire. Species are commonly classified according to whether they survive fire and resprout or whether they are killed by fire and regenerate from seed. However, different populations of the same species have been shown to vary in their responses. Therefore, the classification of a species into a single category based on fire‐response traits may not necessarily be representative of every population under every circumstance. This study examined the extent of within‐species variation in fire‐response traits of woody plants in south‐eastern Australia after the 2003 fires. Species were then classified using two approaches: (i) using data from a field survey of fire‐response traits, taking into account within‐species variation; and (ii) using species' fire responses listed in a pre‐existing fire‐response database compiled from a variety of primary sources. Field data showed that the majority of species in the study area resprouted after fire with around one in 10 species variable in their resprouting response. Almost half of all species varied from site to site according to whether they regenerated from seed, either solely or in addition to resprouting. The numbers of species classified as resprouters and seed regenerators varied according to the classification method used. Differences were also found between the classification method when calculating the mean proportion of resprouters and seed regenerators across sites. The fire‐response traits for some species from the database were found to differ from the observed field responses. This study demonstrated that the application of a fire‐response trait, reported in a trait database, to an entire species, may not adequately represent the actual fire responses of the populations of interest. Rather than considering the fire‐response traits of a species, accurate prediction may be better achieved by considering how different populations of plants will respond to fire.     

The evidence‐based group‐level symptom‐reduction model as the organizing principle for mental health care: time for change?

The content and organization of mental health care have been heavily influenced by the view that mental difficulties come as diagnosable disorders that can be treated by specialist practitioners who apply evidence‐based practice (EBP) guidelines of symptom reduction at the group level. However, the EBP symptom‐reduction model is under pressure, as it may be disconnected from what patients need, ignores evidence of the trans‐syndromal nature of mental difficulties, overestimates the contribution of the technical aspects of treatment compared to the relational and ritual components of care, and underestimates the lack of EBP group‐to‐individual generalizability. A growing body of knowledge indicates that mental illnesses are seldom “cured” and are better framed as vulnerabilities. Important gains in well‐being can be achieved when individuals learn to live with mental vulnerabilities through a slow process of strengthening resilience in the social and existential domains. In this paper, we examine what a mental health service would look like if the above factors were taken into account. The mental health service of the 21st century may be best conceived of as a small‐scale healing community fostering connectedness and strengthening resilience in learning to live with mental vulnerability, complemented by a limited number of regional facilities. Peer support, organized at the level of a recovery college, may form the backbone of the community. Treatments should be aimed at trans‐syndromal symptom reduction, tailored to serve the higher‐order process of existential recovery and social participation, and applied by professionals who have been trained to collaborate, embrace idiography and maximize effects mediated by therapeutic relationship and the healing effects of ritualized care interactions. Finally, integration with a public mental health system of e‐communities providing information, peer and citizen support and a range of user‐rated self‐management tools may help bridge the gap between the high prevalence of common mental disorder and the relatively low capacity of any mental health service.     

Is the structural and psittacofulvin‐based coloration of wild burrowing parrots Cyanoliseus patagonus condition dependent?

The bright colours of parrots are caused by psittacofulvin pigments, which appear unique to this Order, and by structural colours. We measured red (psittacofulvin), green (mixed) and blue (structural) colours of wild burrowing parrots Cyanoliseus patagonus of northeastern Patagonia, Argentina, and measured nestlings regularly to obtain data on breeding success and nestling growth. As adult feathers are moulted outside the breeding season, adult body condition could not be measured directly during feather growth, and climatic conditions were used as an indirect parameter. The colony of burrowing parrots is surrounded by Monte steppe habitat, the breeding success has been shown to depend strongly on the climatic patterns. The area experienced a drought with very poor breeding success as well as a year of above‐average precipitation during the study period, serving as a natural experiment. We thus analysed the variability of colouration within the population among and within breeding seasons. We observed strong inter‐annual differences in nestling and adult colouration. Nestlings grew blue feathers with lower achromatic brightness during better conditions, and when controlling for year effects, nestlings with higher mass and from more successful families also had blue feathers with lower achromatic brightness. Adult blue feathers showed the same trend, with lower achromatic brightness in the moult following breeding seasons of better conditions. In contrast, during better conditions, adults grew red feathers with higher achromatic brightness and the colour hue was also affected, and the hue of the red region of nestlings varied with the hatching order. The colour of all three regions of nestlings varied between nests, and the colour of the red region of adult males positively correlated with breeding success (clutch size, brood size). In summary, the present data suggest that environmental conditions contribute to variability in both structural and the psittacofulvin‐based colours of wild burrowing parrots.     

Avoiding risk at what cost? Putting use of medicines for breastfeeding women into perspective

Breastfeeding women often need to take medicines, and therefore health professionals need to consider the effects of medication on lactation and the breastfed infant, and any associated risks. This commentary discusses the tragic case of a young woman with a history of mental illness who committed suicide in the postpartum period. She was determined to be a 'good mother' and breastfeed, and to avoid any potential adverse effects of medication on her breastfed infant. The final outcome was fatal for both mother and child. We argue that if women require medication during lactation, all risks need to be considered ?C the risk of not treating the maternal medical condition may greatly outweigh the potential risk to the breastfed infant.     

The theoretical basis of cancer‐stem‐cell‐based therapeutics of cancer: can it be put into practice?

In spite of the advances in our knowledge of cancer biology, most cancers remain not curable with present therapies. Current treatments consider cancer as resulting from uncontrolled proliferation and are non-specific. Although they can reduce tumour burden, relapse occurs in most cases. This was long attributed to incomplete tumour elimination, but recent developments indicate that different types of cells contribute to the tumour structure, and that the tumour's cellular organization would be analogous to that of a normal tissue, with a main mass of differentiating cells sensitive to anti proliferative agents, together with a small percentage of quiescent, resistant stem cells responsible for replenishing the tumour: the Cancer Stem Cells (CSCs). Anti-CSCs targeted therapeutic agents would prevent tumour regeneration. New mouse models tailored to exploit this novel concept will be critical to develop CSC-based anti-cancer therapies. Here we review the biological basis and the therapeutic implications of the stem-cell model of cancer.     

Genomic‐scale comparison of sequence‐ and structure‐based methods of function prediction: Does structure provide additional insight?

A function annotation method using the sequence-to-structure-to-function paradigm is applied to the identification of all disulfide oxidoreductases in the Saccharomyces cerevisiae genome. The method identifies 27 sequences as potential disulfide oxidoreductases. All previously known thioredoxins, glutaredoxins, and disulfide isomerases are correctly identified. Three of the 27 predictions are probable false-positives. Three novel predictions, which subsequently have been experimentally validated, are presented. Two additional novel predictions suggest a disulfide oxidoreductase regulatory mechanism for two subunits (OST3 and OST6) of the yeast oligosaccharyltransferase complex. Based on homology, this prediction can be extended to a potential tumor suppressor gene, N33, in humans, whose biochemical function was not previously known. Attempts to obtain a folded, active N33 construct to test the prediction were unsuccessful. The results show that structure prediction coupled with biochemically relevant structural motifs is a powerful method for the function annotation of genome sequences and can provide more detailed, robust predictions than function prediction methods that rely on sequence comparison alone.     

Dynamic models of immune responses: what is the ideal level of detail?

Background  

One of the goals of computational immunology is to facilitate the study of infectious diseases. Dynamic modeling is a powerful tool to integrate empirical data from independent sources, make novel predictions, and to foresee the gaps in the current knowledge. Dynamic models constructed to study the interactions between pathogens and hosts' immune responses have revealed key regulatory processes in the infection.     

From cells to colonies: at what levels of body organization does the ‘temperature‐size rule’ apply?

SUMMARY An inverse relationship between temperature during ontogeny and final body size is widespread in ectotherms, but poorly understood. Evidence suggests that within organs, this “temperature‐size rule” (TSR) may also apply to cell size with no change in numbers. So how closely do reductions in size and number of cells and other repeated structures correlate with size reduction at higher levels of organization? We examine this in the context of a proposal that size and/or number changes at various organizational levels are adaptive responses to temperature‐ and size‐dependent oxygen supply. We subjected two clones of the modular colonial bryozoan, Celleporella hyalina, to orthogonal combinations of two temperatures and two oxygen concentrations during ontogeny, observing effects on sizes of colonies and larvae, and sizes and numbers of cells, tentacles, and modules (autozooids). We found that the size:number responses varied among cell types and among structures at different levels of organization, with the inverse temperature‐size relationship applying only to larval parenchymal cells and colony modules. Using our findings and other evidence we propose a unifying adaptive hypothesis that predicts how temperature affects the sizes of mitochondria, cells, organs, modules and organisms, and their relationships with processes that determine the functional capacity of aerobic metabolism.     

Kernel weight per spike: what contributes to it at the individual QTL level?

Spike length (SL), spikelet number (SPN) per spike, kernel number per spike (KNPS), and thousand-kernel weight (TKW) have strong genetic associations with kernel weight per spike (KWPS) in wheat. To investigate their genetic relationships at the individual quantitative trait locus (QTL) level, both unconditional and conditional QTL mapping for KWPS with respect to SL, SPN, KNPS, and TKW were conducted. Two related F_8:9 recombinant inbred line populations, comprising 485 and 229 lines, respectively, were used. The trait phenotypic performances of each population were evaluated in four different environments. Unconditional QTL mapping analysis identified 22 putative additive QTL for KWPS, five of which were stable QTL, and only QKwps-WJ-1B.2 showed significant additive-by-environment interaction effects. In comparison with unconditional QTL mapping analysis, conditional QTL mapping analysis indicated that, at the QTL level, KNPS and TKW contributed more to KWPS than did SL and SPN. Any unconditional QTL for KWPS detected in this study was associated with at least one of its four related traits. The present study will provide assistance in the understanding of the genetic relationships between KWPS and its related traits.