Evolutionary stable strategy application of Nash equilibrium in biology

Every behaviourally responsive animal (including us) make decisions. These can be simple behavioural decisions such as where to feed, what to feed, how long to feed, decisions related to finding, choosing and competing for mates, or simply maintaining one's territory. All these are conflict situations between competing individuals, hence can be best understood using a game theory approach. Using some examples of classical games, we show how evolutionary game theory can help understand behavioural decisions of animals. Game theory (along with its cousin, optimality theory) continues to provide a strong conceptual and theoretical framework to ecologists for understanding the mechanisms by which species coexist

The value of urban and peri-urban conservation efforts within a global biodiversity hotspot

Background: Systematic conservation planning (SCP) is a key tool in conservation prioritisation. It has recently been applied within the eThekwini Municipal Area (EMA), South Africa, a rapidly developing metro located within a biodiversity hotspot. Most vegetation types within this region are threatened, yet have received limited scientific attention. Objectives: To assess forb biodiversity of coastal and near-coastal grasslands and contextualise potential drivers of species variation to the EMA context. Method: We quantified forb species richness, frequency and species composition, determined the variation of these amongst plots and sites, and assessed which variables were responsible for this variation. Results: Site forb species richness ranged from 33 to 84 species per site, with the most frequent species differing across the seven sites. Beta diversity was higher across than within sites. Distance to the closest traditional medicine market and site perimeter-to-area ratio were the greatest drivers of species richness, whilst altitude, aspect, mean temperature and rainfall seasonality were the main contributors to species composition patterns. Conclusion: SCP can use key environmental and climatic categories to improve selection of grasslands to maximise both species richness and variation in species composition. A more fine-scale systematic conservation plan will, in turn, provide a more robust basis for development decisions. The outcomes illustrate the importance of urban and peri-urban conservation efforts, including fine-scale conservation planning, in contributing to regional, national conservation targets

Perceived Risk of Predation Affects Reproductive Life - History Traits in Gambusia holbrooki, but Not in Heterandria formosa

Key to predicting impacts of predation is understanding the mechanisms through which predators impact prey populations. While consumptive effects are well-known, non-consumptive predator effects (risk effects) are increasingly being recognized as important. Studies of risk effects, however, have focused largely on how trade-offs between food and safety affect fitness. Less documented, and appreciated, is the potential for predator presence to directly suppress prey reproduction and affect life-history characteristics. For the first time, we tested the effects of visual predator cues on reproduction of two prey species with different reproductive modes, lecithotrophy (i.e. embryonic development primarily fueled by yolk) and matrotrophy (i.e. energy for embryonic development directly supplied by the mother to the embryo through a vascular connection). Predation risk suppressed reproduction in the lecithotrophic prey (Gambusia holbrokii) but not the matrotroph (Heterandria formosa). Predator stress caused G. holbrooki to reduce clutch size by 43%, and to produce larger and heavier offspring compared to control females. H. formosa, however, did not show any such difference. In G. holbrooki we also found a significantly high percentage (14%) of stillbirths in predator-exposed treatments compared to controls (2%). To the best of our knowledge, this is the first direct empirical evidence of predation stress affecting stillbirths in prey. Our results suggest that matrotrophy, superfetation (clutch overlap), or both decrease the sensitivity of mothers to environmental fluctuation in resource (food) and stress (predation risk) levels compared to lecithotrophy. These mechanisms should be considered both when modeling consequences of perceived risk of predation on prey-predator population dynamics and when seeking to understand the evolution of reproductive modes

Impact of schizophrenia and schizophrenia treatment-related adverse events on quality of life: direct utility elicitation

<b>Objective</b>: To examine the impact of schizophrenia, its treatment and treatment-related adverse events related to antipsychotics, on quality of life from the perspective of schizophrenia patients and laypersons. <b>Methods</b>: Health state descriptions for stable schizophrenia, extra pyramidal symptoms (EPS), hyperprolactinemia, diabetes, weight gain and relapse were developed based on a review of the literature and expert opinion. The quality of life impact of each health state was elicited using a time trade-off instrument administered by interview to 49 stable schizophrenia patients and 75 laypersons. Regression techniques were employed to examine the importance of subject characteristics on health-related utility scores. <b>Results</b>: Patients and laypersons completed the interview in similar times. Stable schizophrenia had the highest mean utility (0.87 and 0.92 for laypersons and patients respectively), while relapse (0.48 and 0.60) had the lowest mean utility. Of the treatment-related adverse events, EPS had the lowest mean utility (0.57 and 0.72, respectively). Age, gender and PANSS score did not influence the utility results independently of health state. On average, patient utilities are 0.077 points higher than utilities derived from laypersons, although the ranking was similar between the two groups. <b>Conclusion</b>: Events associated with schizophrenia and treatment of schizophrenia can bring about a significant detriment in patient quality of life, with relapse having the largest negative impact. Results indicate that patients with stable schizophrenia are less willing to trade years of life to avoid schizophrenia-related symptoms compared to laypersons. Both sets of respondents showed equal ability to complete the questionnaire

Follow-up household survey in Agra District

This follow-up household survey in Agra District, India, was conducted with funding from USAID under the Population Council’s Asia and Near East Operations Research and Technical Assistance (ANE OR/TA) Project. The main objective of this study, as noted in this report, is to assess changes in the program indicators of family welfare activities, including some of the selected reproductive health indicators, from 1995 (before method-specific targets were withdrawn) and 1997 (30 months after targets were withdrawn). The study’s objectives are to detect changes in FP knowledge and use among currently married women in rural areas; detect changes in level of unmet need for spacing and limiting births; detect changes in use of health services by pregnant and postpartum women; identify the differential use of FP methods, antenatal and postnatal services, child immunization, and other reproductive health services; assess reproductive tract infections among ever-married women in rural areas as reported by them; and assess the level of unwanted pregnancies, incidence of abortions, and post-abortion services

The value of urban and peri-urban conservation efforts within a global biodiversity hotspot

Conservation planning and sustainable environmental management have limited resources for implementation owing to competition with other socio-economic imperatives (Heywood & Iriondo 2003; Shankaran 2009; Schneider et al. 2011). Prioritisation of areas for conservation, through systematic conservation planning (SCP), has become a key tool in conservation resource allocation (Heywood & Iriondo 2003; Margules & Pressey, 2000; Pressey, Cowling & Rouget 2003). These algorithm-based planning tools use available data on habitats, species and ecosystem services to select priority sites based on important criteria (Margules & Pressey 2000). However, SCP outputs are only as good as the input data (Heywood & Iriondo 2003; Margules & Pressey 2000; Smith, Goodman & Matthews 2006), and conservation plans are often based on limited data, which requires conservation planners to define different environmental features by using environmental breaks or changes (termed mesofilters; Crous, Samways & Pryke 2013). These ‘surrogate’ habitats are then assumed to be representative of a set of species known to occur within them (Crous et al. 2013; Smith et al. 2006). Incorrect selection of surrogates may result in inaccurate SCP that does not sufficiently represent reality, leading to potentially wasted resource expenditure on marginal areas (Crous et al. 2013) and inappropriate protection for the species that need it most (Coppolillo et al., 2004). The eThekwini Municipal Area (EMA), whic

Restoration planning for climate change mitigation and adaptation in the city of Durban, South Africa

Peer reviewe

Health-related quality-of-life implications of cardiovascular events in individuals with type 2 diabetes mellitus: A subanalysis from the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus (SAVOR)-TIMI 53 trial.

BACKGROUND: The impact of cardiovascular complications on health-related quality-of-life (HRQoL) in type 2 diabetes mellitus has not been clearly established. Using EQ5D utility data from SAVOR-TIMI 53, a large phase IV trial of saxagliptin versus placebo, we quantified the impact of cardiovascular and other major events on HRQoL. METHODS: EQ5D utilities were recorded annually and following myocardial infarction (MI) or stroke. Utilities among patients experiencing major cardiovascular events were analyzed using linear mixed-effects regression, adjusting for baseline characteristics (including EQ5D utility), and compared to those not experiencing major cardiovascular events. Mean utility decrements with standard errors (SE) were estimated as the difference in utility before and after the event. FINDINGS: The mean EQ5D utility of the sample was 0.776 at all time points, and did not differ by treatment. However, mean baseline and month 12 utilities among those with a major cardiovascular event were 0.751 and 0.714. Mean utilities were 0.691 within 3months of, 0.691 3-6months after, and 0.714 6-12months after, a major cardiovascular event. Cardiovascular event-specific utility decrements were 0.05 (0.007) for major cardiovascular events over the same time periods. Decrements of 0.051 (0.012; myocardial infarction), 0.111 (0.022; stroke), 0.065 (0.014; hospitalization for heart failure) 0.019 (0.024; hospitalization for hypoglycemia) were estimated; all coefficients were statistically significant. INTERPRETATION: Consistent with clinical outcomes reported elsewhere, saxagliptin did not improve HRQoL. Cardiovascular complications were associated with significantly decreased HRQoL, most substantial earlier after the event. FUNDING: BMS/AZ

How to build science-action partnerships for local land-use planning and management: Lessons from Durban, South Africa

The gap between scientific knowledge and implementation in the fields of biodiversity conservation, environmental management, and climate change adaptation has resulted in many calls from practitioners and academics to provide practical solutions responding effectively to the risks and opportunities of global environmental change, e.g., Future Earth. We present a framework to guide the implementation of science-action partnerships based on a real-world case study of a partnership between a local municipality and an academic institution to bridge the science-action gap in the eThekwini Municipal Area, South Africa. This partnership aims to inform the implementation of sustainable land-use planning, biodiversity conservation, environmental management, and climate change adaptation practice and contributes to the development of human capacity in these areas of expertise. Using a transdisciplinary approach, implementation-driven research is being conducted to develop several decision-making products to better inform land-use planning and management. Lessons learned through this partnership are synthesized and presented as a framework of enabling actions operating at different levels, from the individual to the interorganizational. Enabling actions include putting in place enabling organizational preconditions, assembling a functional well-structured team, and actively building interpersonal and individual collaborative capacity. Lessons learned in the case study emphasize the importance of building collaborative capacity and social capital, and paying attention to the process of transdisciplinary research to achieve more tangible science, management, and policy objectives in science-action partnerships. By documenting and reflecting on the process, this case study provides conceptual and practical guidance on bridging the science-action gap through partnerships

Evaluating Native Wheatgrasses for Restoration of Sagebrush Steppes

Pseudoroegneria spicata and Elymus wawawaiensis are two native perennial bunchgrasses of North America\u27s Intermountain West. Frequent drought, past overgrazing practices, subsequent weed invasions, and increased wildfire frequency have combined to severely degrade natural landscapes in the region, leading to a decline in the abundance of native vegetation. Being formerly widespread throughout the region, P. spicata is a favorite for restoration purposes in the Intermountain West. Elymus wawawaiensis, which occupies a more restricted distribution in the Intermountain West, is often used as a restoration surrogate for P. spicata. However, since most restoration sites are outside the native range of E. wawawaiensis and as the use of native plant material may be more desirable than a surrogate, the use of E. wawawaiensis as a restoration plant material has been somewhat controversial. The main goal of my research was to identify plant materials of these species with superior seedling growth, drought tolerance, and defoliation tolerance, traits that may contribute to enhanced ecological function in restored rangeland plant communities. I conducted a growth-chamber study to evaluate morphological and growth-related traits of germinating seedlings of these two species. My study suggested that, while the two bunchgrasses are similar in many ways, they display fundamentally different strategies at the very-young seedling stage. While P. spicata exhibited greater shoot and root biomass to enhance establishment, E. wawawaiensis displayed high specific leaf area (SLA) and specific root length (SRL), two traits commonly associated with faster growth. According to the eco-physiology literature, plants with greater stress tolerance display lesser growth potential. However, my greenhouse study showed that E. wawawaiensis was relatively more drought tolerant than P. spicata, despite higher expression of growth-related traits, e.g., SLA and SRL. While the two species displayed similar water use efficiency when water was abundant, E. wawawaiensis was also more efficient in its water use when drought stress was imposed. In a field study, I found E. wawawaiensis to be twice as defoliation tolerant as P. spicata. This study showed that P. spicata is typically more productive in the absence of defoliation, but E. wawawaiensis was more productive after defoliation due to its superior ability to recover and hence is a better candidate for rangelands that will be grazed. Hence, my study showed that E. wawawaiensis, despite being regarded as a surrogate for P. spicata, exhibits superior seedling establishment, drought tolerance, and defoliation tolerance. Therefore, E. wawawaiensis has advantages as a restoration species for the Intermountain West