Time‐Dependent Health Risk from Contaminated Groundwater Including Use of Reliability,Resilience, and Vulnerability as Measures

Traditionally, assessment of human health risk caused by contamination of a water supply focuses on the maximum risk to an individual. Here, we introduce a time‐dependent risk assessment method and adapt and explore the reliability, resilience, and vulnerability (RRV) criteria from the surface‐water literature as possible tools for assessing this risk. Time‐dependent risk assessment, including RRV, is applied to two synthetic examples where water quality at a well varies over time. We calculate time‐dependent health risks for discrete periods of exposure to the contaminated water for a variable population. The RRV criteria provide information about time‐dependent risk: probability of an acceptable risk, probability of system recovery, maximum risk, and average exceedance of a prescribed risk threshold. The results demonstrate that episodic contamination events produce fundamentally different time‐dependent risks than long‐term events: these differences, such as generally lower risks for the episodic contamination, can be captured via plots of the risk and the RRV criteria. Furthermore, the evaluation of time‐dependent health risk and the RRV criteria demonstrates significant sensitivity to the shape of the contaminant breakthrough curve, length of exposure, and variability within the population. Overall, analysis of time‐dependent health risks provides substantial insight into the structure of risk, with RRV providing a reasonable framework for the evaluation of these risks.     

Sustainable consumption: the effects of knowledge,cultural values,environmental advertising,and demographics

As a result of human lifestyles and unsustainable consumption patterns, the environment continues to deteriorate and thus inhibit sustainable development. In order to curb this situation and promote a sustainable economy, one of the solution is to reduce conventional products consumption and shift to green products. Over the past 20 years, marketing managers keenly seek to understand the green market; however, inadequate information on how to promote consumers’ green behavioral intentions is slowing the growth of green markets and becomes a barrier for firms when developing segments and communicating strategies for effective promotion of green products in countries like Malaysia where the trend is fairly new. Therefore, this study attempts to examine the impact of environmental knowledge, cultural values, and environmental advertising and determine the moderating effect of income level, education level, and gender on consumers’ green purchase intentions. A survey was administered, and a total of 405 valid questionnaires were obtained. Structural equation modeling technique was used to evaluate the causal model by using SmartPLS 2.0 software. The finding results suggest that cultural values and environmental advertising are the main influences in building green purchase intentions, while environmental knowledge is not significantly related. The results also indicate that education level and gender have a significant positive moderation effect while income did not. This suggests that green purchase intentions’ motivational factors are greater among highly educated individuals, with females in particular. The discussions and implications of these findings are further elaborated.     

Analysing household decision-making on oil palm cultivation in Thailand

This paper analyses the dynamics of land use via the perspectives, motivations and behaviours of local landowners looking at land-use change (through the landowner’s eyes) in the way that the landowners would prefer to do and not to do in various situations. The dynamics are explored in the context of an oil-palm-based biodiesel development in Thailand where the advent of oil palm (OP) has caused the loss of paddy areas. A sequential mixed-method strategy, including 10 in-depth interviews and 180 responses to a questionnaire survey, indicates that the likelihood of a landowner switching traditional land for OP cultivation is affected by a number of factors including age and education of the head of household, number of household farming labourers, amount and source of income, land size and land right. Moreover, the results indicate that success of switching land to OP cultivation was determined by factors influencing willingness and capacity to change. Willingness-related factors are relevant to outcome expectation and social networks and connections while capacity-related factors are relevant to finance, labour, capital, land rights and transportation.     

Purification,characterization and toxicity of a mannose-binding lectin from the seeds of Treculia africana plant

In this study, a mannose-specific, homodimeric lectin from the seeds of Treculia africana was purified, characterized and its adverse effects were investigated in mice. The purification protocol involved anionic exchange chromatography on DEAE-Cellulose followed by gel filtration on Sephadex G-100. The hemagglutinating activity of lectin towards human erythrocytes was sensitive to inhibition by D-mannose. Treatment of the protein with EDTA exerted no inhibitory effect; however, analysis of metal content by atomic absorption spectroscopy revealed the presence of Cu²⁺, Fe³⁺, and Mg²⁺. The results obtained showed that the lectin possesses maximum hemagglutinating activity towards human erythrocytes activity over the pH range 3–7.2 and is relatively thermostable up to 50°C. Periodic acid Schiff's (PAS) reagent staining showed that the protein was non-glycosylated while its amino acid composition analysis revealed that the protein contained 155 residues per subunit. The subunit had a minimal molecular weight of 22,139 Daltons, while the native molecular weight was estimated to be 41,000 Daltons. The lectin was found to be moderately toxic to mice with an LD₅₀ of 47.21 µg g^?1 body weight while, histopathological analysis showed no treatment related effects in any of the organs examined.     

The roles of competition and environmental heterogeneity in the maintenance of behavioral variation and covariation

Many models of selection predict that populations will lose variation in traits that affect fitness. Nonetheless, phenotypic variation is commonly observed in natural populations. We tested the influences of competition and spatial heterogeneity on behavioral variation within and among populations of Merriam's kangaroo rats (Dipodomys merriami) and tested for the differential expression of trait correlations. We found that populations of D. merriami exhibited more aggression at sites with more competition. Contrary to theoretical predictions and empirical results in other systems, the sites with the greatest spatial heterogeneity and highest levels of competition did not exhibit the most behavioral variation among individuals. However, the greatest within-individual behavioral variability in boldness (response to cues of predator presence) was exhibited where spatial heterogeneity was highest. Aggression and boldness of D. merriami were highly repeatable, that is, individuals behaved in a consistent manner over time, and the two behaviors were also highly correlated. Interestingly, the strength of this correlation was greatest where the competitive community was least diverse. These findings add to increasing evidence that natural populations of animals exhibit patterns of behavioral covariance, or personality structure, and suggest that competitive variation may act to erode personality structure.     

Making a stand: five centuries of population growth in colonizing populations of Pinus ponderosa

The processes underlying the development of new populations are important for understanding how species colonize new territory and form viable long-term populations. Life-history-mediated processes such as Allee effects and dispersal capability may interact with climate variability and site-specific factors to govern population success and failure over extended time frames. We studied four disjunct populations of ponderosa pine in the Bighorn Basin of north-central Wyoming to examine population growth spanning more than five centuries. The study populations are separated from continuous ponderosa pine forest by distances ranging from 15 to >100 km. Strong evidence indicates that the initial colonizing individuals are still present, yielding a nearly complete record of population history. All trees in each population were aged using dendroecological techniques. The populations were all founded between 1530 and 1655 cal yr CE. All show logistic growth patterns, with initial exponential growth followed by a slowing during the mid to late 20th century. Initial population growth was slower than expectations from a logistic regression model at all four populations, but increased during the mid-18th century. Initial lags in population growth may have been due to strong Allee effects. A combination of overcoming Allee effects and a transition to favorable climate conditions may have facilitated a mid-18th century pulse in population growth rate.     

Fine-scale distribution of juvenile Atlantic and Mediterranean loggerhead turtles (Caretta caretta) in the Mediterranean Sea

Loggerhead turtles nesting in the Mediterranean Sea exhibit remarkable genetic structuring. This paper tests the hypothesis that young loggerhead turtles from different rookeries do not distribute homogeneously among the major Mediterranean foraging grounds, due to a complex pattern of surface currents. We extracted long fragments of mitochondrial DNA from 275 stranded or bycaught juvenile turtles from six foraging grounds (Catalano-Balearic Sea, Algerian basin, Tyrrhenian Sea, Adriatic Sea, northern Ionian Sea and southern Levantine Sea). We used a Bayesian mixed-stock analysis to estimate the contributions from rookeries in the Mediterranean, the North-west Atlantic and Cape Verde to the studied foraging grounds. Differences were found in the relative contribution of juvenile turtles of Atlantic and Mediterranean origin to each foraging ground. A decreasing proportion of Atlantic juveniles was detected along the main surface current entering the Mediterranean, with a high prevalence of turtles from eastern Florida in the Algerian basin and lower numbers elsewhere. In regard to the turtles of Mediterranean origin, juveniles from Libya prevailed in central and western Mediterranean foraging grounds other than the Algerian basin. Conversely, the Adriatic Sea was characterised by a large presence of individuals from western Greece, while the southern Levantine Sea was inhabited by a heterogeneous mix of turtles from the eastern Mediterranean rookeries (Turkey, Lebanon and Israel). Overall, the distribution of juveniles may be related to surface circulation patterns in the Mediterranean and suggests that fisheries might have differential effects on each population depending on the overlap degree between foraging and fishing grounds.     

Behavioral transitions with the evolution of cooperative nest founding by harvester ant queens

Research on the evolution of cooperative groups tends to explore the costs and benefits of cooperation, with less focus on the proximate behavioral changes necessary for the transition from solitary to cooperative living. However, understanding what proximate changes must occur, as well as those pre-conditions already in place, is critical to understanding the origins and evolution of sociality. The California harvester ant Pogonomyrmex californicus demonstrates population-level variation in colony founding over a close geographic range. In adjacent populations, queens either found nests as single individuals (haplometrosis) or form cooperative groups of nonrelatives (pleometrosis). We compared aggregation, aggression, and tolerance of queens from one pleometrotic and two haplometrotic populations during nest initiation, to determine which behaviors show an evolutionary shift and which are present at the transition to pleometrosis. Surprisingly, within-nest aggregative behavior was equally present among all populations. In nesting boxes with multiple available brood-rearing sites, both queen types readily formed and clustered around a single common brood pile, suggesting that innate attraction to brood (offspring) facilitates the transition to social aggregation. In contrast, queens from the three populations differed in their probabilities of attraction on the ground to nest sites occupied by other queens and in levels of aggression. Our results suggest that some key behavioral mechanisms facilitating cooperation in P. californicus are in place prior to the evolution of pleometrosis and that the switch from aggression to tolerance is critical for the evolution of stable cooperative associations.