Potential ecosystem-level effects of genetic variation among populations of Metrosideros polymorpha from a soil fertility gradient in Hawaii.

This study assessed intrinsic differences in tissue quality and growth rate among populations of Metrosideros polymorpha native to sites with a range of soil fertilities. We collected seedlings from three Hawaiian mesic forests that were either phosphorus-limited, nitrogen-limited, or relatively fertile. These individuals were grown in a common garden under a factorial high/low, N/P fertilization regime for 1.5 years and then harvested to determine genetic divergence; aboveground growth rate; and lignin, N, and P concentrations in leaves and roots. Allozyme analyses indicated that the three groups had genetically diverged to some degree (genetic distance = 0.036-0.053 among populations). Relative growth rate did not differ significantly among the populations. Senescent leaves from the fertile-site population had the highest N concentrations (due to low N resorption) and had lower lignin concentrations than plants from the N-limited site. Across treatments, P concentrations in senescent leaves were highest in plants from the fertile and P-limited site. Root tissue quality did not generally differ significantly among populations. Since decomposition rate of senescent leaves in this system is related positively to N concentration and negatively to lignin concentration, senescent leaves from the fertile-site population may have a genetic tendency toward faster decay than the others. The intrinsic qualities of the three populations may provide positive feedbacks on nutrient cycling at each site-nutrient availability may be raised to some degree at the fertile site, and reduced at the N- or P-limited sites. Our results suggest that even a small degree of genetic differentiation among groups can influence traits related to nutrient cycling

Feeling good about being hungry: food-related thoughts in eating disorder

Objectives: This study explores the relationships to food and hunger in women living with anorexic type eating difficulties and asks how imagery-based elaborations of food and eating thoughts are involved in their eating restraint, and recovery. Design: The qualitative idiographic approach of Interpretative Phenomenological Analysis (IPA) was used. Four in-depth semi-structured interviews were conducted with women self-selected as having experienced anorexia or anorexic like behaviour. Methods: The data was analysed using IPA and an audit of the analysis was conducted to ensure that the process followed had been systematic and rigorous and appropriately considered reflexivity. Results: Hunger was perceived positively by participants as confirmation that they were achieving their goal of losing weight, or avoiding weight gain. Hunger conferred a sense of being in control for the participants. Intrusive thoughts about food were reported as being quickly followed by elaborative mental imagery of the positive aspects of weight loss, and the negative consequences of eating. Imagery appeared to serve to maintain anorexic behaviours rather than to motivate food seeking. However, negative imagery of the consequences of anorexia were also described as supporting recovery. Conclusions: The finding that physiological sensations of hunger were experienced as positive confirmation of maintaining control has potentially important clinical and theoretical implications. It suggests further attention needs to be focused upon how changes in cognitive elaboration, involving mental imagery, are components of the psychological changes in the development of, maintenance of, and recovery from, anorexia

Changes in the sense of agency : Implications for the psychotherapy of bulimia nervosa- A case study

A sense of agency is a transtheoretical concept that increases our understanding of important processes in psychotherapy. Agency can be described in terms of how strongly the person believes that she can have an impact on her problematic experiences and behaviors. In this case study, a patient's sense of agency in relation to symptoms of bulimia nervosa was assessed during 3 years of psychotherapy. Five distinct phases of agency in relation to eating disorder symptoms were identified: A false sense of agency or no agency at all, a weak sense of agency, a nascent sense of agency, a wavering sense of agency, and a strong sense of agency. A better understanding of patient agency can facilitate adapting approaches and methods best suited for the patient's capacity for change throughout treatment.Peer reviewe

Nitrogen stable isotopic composition of leaves and soil: Tropical versus temperate forests

Several lines of evidence suggest that nitrogen in most tropical forests is relatively more available than N in most temperate forests, and even that it may function as an excess nutrient in many tropical forests. If this is correct, tropical forests should have more open N cycles than temperate forests, with both inputs and outputs of N large relative to N cycling within systems. Consequent differences in both the magnitude and the pathways of N loss imply that tropical forests should in general he more 15N enriched than are most temperate forests. In order to test this hypothesis, we compared the nitrogen stable isotopic composition of tree leaves and soils from a variety of tropical and temperate forests. Foliar δ15N values from tropical forests averaged 6.5‰ higher than from temperate forests. Within the tropics, ecosystems with relatively low N availability (montane forests, forests on sandy soils) were significantly more depleted in 15N than other tropical forests. The average δ15N values for tropical forest soils, either for surface or for depth samples, were almost 8‰ higher than temperate forest soils. These results provide another line of evidence that N is relatively abundant in many tropical forest ecosystems

A Systematic and Methodological Review of Attentional Biases in Eating Disorders: Food, Body, and Perfectionism

Objective: The current systematic and methodological review aimed to critically review existing literature utilizing implicit processing, or automatic approach- and/or avoidance-related attentional biases between eating disorder (ED) and nonclinical samples, which: (1) highlights how psychophysiological methods advance knowledge of ED implicit bias; (2) explains how findings fit into transdiagnostic versus disorder-specific ED frameworks; and (3) suggests how research can address perfectionism-related ED biases. Method: Three databases were systematically searched to identify studies: Pubmed, Scopus, and PsychInfo electronic databases. Peer-reviewed studies of 18-39-year-olds with both clinical ED and heathy samples assessing visual attentional biases using pictorial and/or linguistic stimuli related to food, body, and/or perfectionism were included. Results: Forty-six studies were included. While behavioral results were often similar across ED diagnoses, studies incorporating psychophysiological measures often revealed disease-specific attentional biases. Specifically, women with bulimia nervosa (BN) tend to approach food and other body types, whereas women with anorexia nervosa (AN) tend to avoid food as well as overweight bodies. Conclusions: Further integration of psychophysiological and behavioral methods may identify subtle processing variations in ED, which may guide prevention strategies and interventions, and provide important clinical implications. Few implicit bias studies include male participants, investigate binge eating disorder, or evaluate perfectionism-relevant stimuli, despite the fact that perfectionism is implicated in models of ED

The role of intraspecific competition in the dispersal of an invasive fish

1. Ponto‐Caspian gobies are among the most successful fish invaders in inland waters of Europe and in the Great Lakes of North America. Their invasions appear to comprise a combination of passive and active dispersal mechanisms, both natural and human‐mediated. Despite the significance of Ponto‐Caspian gobies as invasive species, there is little information about the mechanisms underpinning their dispersal. They are relatively small benthic fish, with high site affinity. Thus, actively dispersing individuals must express a behavioural motivation to engage in persistent directional movement. 2. Several recent studies have suggested that inter‐individual behavioural differences in boldness, activity level and tendency to explore might underpin dispersal. In addition, because males are highly territorial, intraspecific competition may lead to density‐dependent dispersal of subordinate individuals. To date, studies on this subject have focused mainly on comparisons between individuals from the core of established populations with those at the margins and, thus, address the outcome of dispersal rather than the mechanism itself. 3. We conducted a series of experiments on the racer goby Babka gymnotrachelus to address the question of what behavioural and physiological traits predict the tendency of an individual to perform dispersal behaviour, specifically considering the role of conspecifics in influencing the tendency to disperse. We used an artificial channel to measure dispersal tendency in this species in combination with behavioural trials. 4. Our results showed that fish with a greater tendency to disperse in an experimental channel grew more slowly and were bolder; that is displayed a greater propensity to emerge from a cryptic background onto a white background and performed worse in prey capture trials. As predicted, intraspecific competition played a primary role in the dispersal of the racer goby. Dominant males showed a tendency to monopolise limited shelters with an outcome that subordinates were forced to disperse upstream. The specific growth rate of individuals appeared to be a good indicator of social position. Subordinate males expressed the lowest rates of growth, probably as a result of long‐term deprivation of food in the presence of dominant conspecifics. They were also quicker to explore novel environments, possibly to search for food. Contrary to expectations, subordinate individuals performed relatively poorly in feeding trials when tested individually. 5. Our findings suggest that intraspecific competition in racer goby males is an important mechanism for active dispersal. It can also influence inter‐individual variation in traits such as boldness and tendency to explore novel environments. Similar responses to competitive interactions may have encouraged the invasive expansion of other Ponto‐Caspian gobies following establishment in new environments, as well as other fish species that exhibit territorial behaviour

Rates of species introduction to a remote oceanic island

The introduction of species to areas beyond the limits of their natural distributions has a major homogenizing influence, making previously distinct biotas more similar. The scale of introductions has frequently been commented on, but their rate and spatial pervasiveness have been less well quantified. Here, we report the findings of a detailed study of pterygote insect introductions to Gough Island, one of the most remote and supposedly pristine temperate oceanic islands, and estimate the rate at which introduced species have successfully established. Out of 99 species recorded from Gough Island, 71 are established introductions, the highest proportion documented for any Southern Ocean island. Estimating a total of approximately 233 landings on Gough Island since first human landfall, this equates to one successful establishment for every three to four landings. Generalizations drawn from other areas suggest that this may be only one-tenth of the number of pterygote species that have arrived at the island, implying that most landings may lead to the arrival of at least one alien. These rates of introduction of new species are estimated to be two to three orders of magnitude greater than background levels for Gough Island, an increase comparable to that estimated for global species extinctions (many of which occur on islands) as a consequence of human activities

Cosmic-ray strangelets in the Earth's atmosphere

If strange quark matter is stable in small lumps, we expect to find such lumps, called ``strangelets'', on Earth due to a steady flux in cosmic rays. Following recent astrophysical models, we predict the strangelet flux at the top of the atmosphere, and trace the strangelets' behavior in atmospheric chemistry and circulation. We show that several strangelet species may have large abundances in the atmosphere; that they should respond favorably to laboratory-scale preconcentration techniques; and that they present promising targets for mass spectroscopy experiments.Comment: 28 pages, 4 figures, revtex

A systematic review of adaptive wildlife management for the control of invasive, non-native mammals, and other human–wildlife conflicts

1.We are entering an era where species declines are occurring at their fastest ever rate, and the increased spread of non-native species is among the top causes. High uncertainty in biological processes makes the accurate prediction of the outcomes of management interventions very challenging. Adaptive management (AM) offers solutions to reduce uncertainty and improve predictability so that the outcomes of interventions can continuously improve. 2.We quantitatively assess the extent to which AM is used for managing vertebrates, with a focus on invasive non-native species (INNS). Using the Web of Science, we evaluated 3992 articles returned by the search terms ‘adaptive management’ or ‘adaptive harvest management’ against seven recommended elements of AM (engagement with stakeholders, defining objectives, forecasting and estimating uncertainty, implementing management, monitoring populations, adjusting management in response to monitoring, and improving forecasting and reducing uncertainty in response to monitoring populations). 3.The use of AM for vertebrates was reported in 56 (1%) of the evaluated studies; including four for managing INNS. Of these, ten studies excluding INNS and no studies of INNS management implemented all seven recommended elements of AM. Those elements infrequently implemented were: the use of analysis or models to forecast and represent uncertainty (44%) and the feedback of monitoring data to improve forecasting and reduce uncertainty (25%). 4.Complete active AM has rarely been implemented and reported for managing INNS, despite the significant advantages it offers. Among studies purporting to have implemented AM, most did not use analyses or models to forecast and represent uncertainty, while most defined objectives, implemented management, and monitored populations.5.Improvements to ongoing control programmes and much broader adoption of the AM approach are required to increase the efficiency and success of INNS management campaigns and reduce their negative impacts on native species