The high sex ratio in China: what do the Chinese think?

High sex ratios are well documented in many Asian countries, including China. This study was conducted in three Chinese provinces to explore awareness of the high sex ratios and its effects. Questionnaires were completed by 7435 respondents; 46% were urban and 53% were female. Sixty-four per cent were aware of the high sex ratio, and the majority were able to identify a range of consequences both for society and for unmarried men. These high levels of awareness of the negative impacts of high sex ratios should ultimately help to reduce the sex ratio at birth.     

Individual-based modelling in ecology: what makes the difference?

Is individual-based modelling really a new approach in ecology? A large part of the uncertainty surrounding this question is a consequence of imprecisely delimited boundaries between classical and individual-based modelling. Genuine 'individual-based' models describe a population made up of individuals that may differ from one another; they also describe changes in numbers of individuals rather than in the population density, and take resource dynamics explicitly into account. Individual-based models that fulfil these criteria will not characterize ecological systems as 'stable' systems in their ideal form, with equilibrium states represented by points in the phase space.     

Where's the ecology in molecular ecology?

Molecular techniques have had a profound impact in biology. Major disciplines, including evolutionary biology, now consistently utilize molecular tools. In contrast, molecular techniques have had a more limited impact in ecology. This discrepancy is surprising. Here, we describe the unexpected paucity of ecological research in the field colloquially referred to as 'molecular ecology.' Publications over the past 15 years from the journals Ecology , Evolution and Molecular Ecology reveal that much of the research published under the molecular ecology banner is in fact evolutionary in nature, and that comparatively little ecological research incorporates molecular tools. This failure to more broadly utilize molecular techniques in ecology is alarming because several promising lines of ecological inquiry could benefit from molecular approaches. Here we summarize the use of molecular tools in ecology and evolution, and suggest several ways to renew the ecological focus in 'molecular ecology'.     

Cardiovascular risk and attitudes to lifestyle: what do patients think?

OBJECTIVE--To examine the relation between subjects'' level of cardiovascular risk and their beliefs about the harmfulness of their smoking habit, current diet, and level of exercise, together with their stated desire to modify such behaviour. DESIGN--Self administered postal health and life-style questionnaire followed by a structured health check conducted by a nurse. SETTING--Five general practices in Luton and Dunstable, Bedfordshire. SUBJECTS--5803 people aged 35-64 years enrolled in the OXCHECK trial who attended for a health check before 1 March 1992. MAIN OUTCOME MEASURES--Perceived risk to health of lifestyle behaviours, desire to modify behaviour, and a reported serious attempt to modify behaviour in the preceding year. RESULTS--A high proportion of smokers and those who were physically inactive perceived their behaviour to be harmful (1020; (76%; 95% confidence interval 74% to 79%) and 350 (74%; 70% to 78%) respectively) and wished to modify it (1212 (79%; 77% to 81%) and 375 (74%; 71% to 78%) respectively). In contrast, only 289 (45%; 41% to 48%) of obese people and 188 (14%; 12% to 16%) of people with a high dietary fat intake perceived their current diet to be harmful. The more cardiovascular risk factors present, the more likely subjects were to perceive a health risk attached to their diet and lack of exercise (p < 0.01 in both cases) and to want to improve their diet. CONCLUSION--Awareness of the health risk from smoking and motivation to stop is high. Further efforts are required, however, to educate the public about the risks associated with a high dietary fat intake. Although the health risks of inactivity were widely recognised, motivation to take more exercise needs to be increased.     

POPP the question: what do LEA proteins do?

Late embryogenesis abundant (LEA) proteins are produced in maturing seeds and anhydrobiotic plants, animals and microorganisms, in which their expression correlates with desiccation tolerance. However, their function has remained obscure for 20 years. We argue that novel computational tools devised for non-globular proteins might now overcome this problem. Predictions arising from bioinformatics fit well with recent data on Group 3 proteins, which potentially form cytoskeletal filaments, and suggest experimentally testable functions for these and other LEA protein groups.     

The role of ecological feedbacks in the evolution of host defence: what does theory tell us?

Hosts have evolved a diverse range of defence mechanisms in response to challenge by infectious organisms (parasites and pathogens). Whether defence is through avoidance of infection, control of the growth of the parasite once infected, clearance of the infection, tolerance to the disease caused by infection or innate and/or acquired immunity, it will have important implications for the population ecology (epidemiology) of the host-parasite interaction. As a consequence, it is important to understand the evolutionary dynamics of defence in the light of the ecological feedbacks that are intrinsic to the interaction. Here, we review the theoretical models that examine how these feedbacks influence the nature and extent of the defence that will evolve. We begin by briefly comparing different evolutionary modelling approaches and discuss in detail the modern game theoretical approach (adaptive dynamics) that allows ecological feedbacks to be taken into account. Next, we discuss a number of models of host defence in detail and, in particular, make a distinction between 'resistance' and 'tolerance'. Finally, we discuss coevolutionary models and the potential use of models that include genetic and game theoretical approaches. Our aim is to review theoretical approaches that investigate the evolution of defence and to explain how the type of defence and the costs associated with its acquisition are important in determining the level of defence that evolves.     

Emerging infectious disease: what are the relative roles of ecology and evolution?

The increasing threat of infectious diseases in humans has renewed interest in factors leading to the emergence of new diseases and the re-emergence of familiar diseases. Examples of seemingly novel diseases currently spreading in human populations include HIV, dengue hemorrhagic fever and Lyme disease; drug-resistant forms of well-known diseases such as tuberculosis are also increasing. The problem of disease emergence also extends to other animal and plant populations. In most current epidemics, ecological factors (e.g. migration, climate, agricultural practices) play a more significant role in disease emergence than evolutionary changes in pathogens or hosts. Evolutionary biologists and ecologists have much to offer to the development of strategies for the control of emerging diseases.     

TRAM flap versus nonautologous breast reconstruction: what do patients really think?

Although there have been many reports of aesthetic outcomes after breast reconstruction, there have been comparatively few studies examining patient satisfaction and related subjective issues. The variables affecting satisfaction are only beginning to be understood, and patient satisfaction issues were explored in a more homogeneous patient population. A questionnaire surveying overall and aesthetic satisfaction, postoperative recuperation time, and symptoms was used to elicit candid patient responses. Fifty-seven patients replied (86 percent response rate), of whom 38 had undergone transverse rectus abdominis musculocutaneous (TRAM) flap (pedicled, n = 29; free, n = 9) reconstruction and 19 had undergone nonautologous reconstruction. Although the median patient satisfaction score was higher for the TRAM flap group, this was not statistically significant (p = 0.92). Recuperation was significantly longer for the TRAM flap group, with only 47 percent of patients being able to resume full activities within 2 months after the surgical procedure, compared with 95 percent of the implant group (p = 0.002). Of the TRAM flap-treated patients, 50 percent described some postoperative abdominal weakness, but only 5 percent of all TRAM flap-treated patients said that abdominal weakness was actually a functional problem. Our results suggest that patients may derive equal satisfaction with the two methods of reconstruction. The postoperative recuperation time after TRAM flap reconstruction is significantly longer than that after nonautologous procedures, although the postoperative abdominal weakness after TRAM flap reconstruction is not as significant a clinical problem as previously thought. The patient-derived information on satisfaction should assist both surgeons and patients in matching reconstructive options with patients' expectations and lifestyle.     

Thinking systemically about ecological interventions: what do system archetypes teach us?

To address the need for more holistic approaches to ecological management and restoration, we examine ecosystem interventions through the lens of systems thinking and in reference to systems archetypes, as developed in relation to organizational management in the business world. Systems thinking is a holistic approach to analysis that focuses on how a system's constituent parts interrelate and how systems work over time and within the context of larger systems. Systems archetypes represent patterns of behavior that have been observed repeatedly. These archetypes help relate commonly observed responses to environmental problems with their effect on important feedback processes to better anticipate connections between actions and results. They highlight situations where perceived solutions actually result in worse or unintended consequences, and where changing goals may be either appropriate or inappropriate. The archetypes can be applied to practical examples, and can provide guidance to help make appropriate intervention decisions in similar circumstances. Their use requires stepping back from immediately obvious management decisions and taking a more systemic view of the situation. A catalog of archetypes that describe common patterns of systems behavior may inform management by helping to diagnose system dynamics earlier and identifying interactions among them.     

Managing ecosystem services: what do we need to know about their ecology?

Human domination of the biosphere has greatly altered ecosystems, often overwhelming their capacity to provide ecosystem services critical to our survival. Yet ecological understanding of ecosystem services is quite limited. Previous work maps the supply and demand for services, assesses threats to them, and estimates economic values, but does not measure the underlying role of biodiversity in providing services. In contrast, experimental studies of biodiversity-function examine communities whose structures often differ markedly from those providing services in real landscapes. A bridge is needed between these two approaches. To develop this research agenda, I discuss critical questions and key approaches in four areas: (1) identifying the important 'ecosystem service providers'; (2) determining the various aspects of community structure that influence function in real landscapes, especially compensatory community responses that stabilize function, or non-random extinction sequences that rapidly erode it; (3) assessing key environmental factors influencing provision of services, and (4) measuring the spatio-temporal scale over which providers and services operate. I show how this research agenda can assist in developing environmental policy and natural resource management plans.     

Dimensions of rationing: who should do what?

Priority setting is a complex interaction of multiple decisions at various levels in the organisation and constrained by history. There is no self evident set of ethical principles or analytical tools to determine what decisions we should take at various levels, nor is there an obvious or easy way to resolve the clash of claims on resources. To make priority setting more "rational" we should concentrate on the processes and structure of decision making and the relation of macro and micro decisions. The debate should promote reasoned, informed, and open argument, draw on a variety of perspectives, and involve a plurality of interests. The aim must be to build up, over time, the capacity to engage in continuous, collective argument.     

Host specificity in ectomycorrhizal communities: what do the exceptions tell us?

Classic ectomycorrhizal symbioses are mutualisms that involvethe exchange of fixed carbon for mineral nutrients between plantroots and fungi. They are unique in the way they contain featuresof both intimate and diffuse symbioses. The degree of host specificityvaries, particularly among the fungi. Here we examine two exceptionalcases of specificity to see what they tell us about the advantagesof specificity, how it is initiated, and the potential rolethat it plays in complex ecosystems. The first case involvesnon-photosynthetic epiparasitic plants, which contrary to virtuallyall other plants, exhibit high levels of specificity towardtheir fungal hosts. The second case involves suilloid fungi;this is the largest monophyletic group of ectomycorrhizal fungithat is essentially restricted to associations with a singleplant family. In both cases, new symbioses are initiated bydormant propagules that are stimulated to germinate by chemicalcues from the host. This reduces the cost of wasting propaguleson non-hosts. The advantages of specificity remain unclear inboth cases, but we argue that increased benefit to the specialistmay result from specialized physiological adaptations. We reexaminethe idea that specialist fungi may help their hosts competein complex ecosystems by reducing facultative epiparasitismby other plants, and suggest an alternative hypothesis for theobserved pattern.