Lianas associated with continued forest biomass losses following large‐scale disturbances

Lianas are important to rainforest ecosystems but often impede tree growth and increase tree mortality and stem damage after disturbances that favor their growth. Understanding how lianas affect biomass recovery and rates of carbon sequestration following disturbance is therefore of crucial importance. In this study, we determine how a tropical forest recovers biomass following a large‐scale disturbance, and test how this varies with liana dominance and stem damage. We use remote sensing methods to develop a model, validated by field data from 40 20 7 20 m vegetation plots, to measure change in tree aboveground biomass 8 years after Tropical Cyclone Yasi damaged logged forests in the Australian Wet Tropics. We related tree biomass changes to field measures of current liana dominance over trees, expressed as liana: tree basal area ratio, and assessed how these measures related to tree stem damage. Biomass declined in 34 of the 40 plots during the 8 years post‐disturbance, with loss rates and proportions of damaged tree stems increasing with the liana: tree ratio. From spatial upscaling, we found a net loss in biomass across the study landscape over the same period. Our results show that, following disturbances, lianas not only limit tree biomass recovery but also are associated with further biomass declines, most likely through their contribution to stem damage and delayed mortality. Furthermore, our finding of net biomass loss across the landscape since the cyclone shows that, post‐disturbance, rainforests can act as a carbon source with consequences for the global carbon sink

A calibration protocol for population-specific accelerometer cut-points in children

PurposeTo test a field-based protocol using intermittent activities representative of children\u27s physical activity behaviours, to generate behaviourally valid, population-specific accelerometer cut-points for sedentary behaviour, moderate, and vigorous physical activity.MethodsTwenty-eight children (46% boys) aged 10&ndash;11 years wore a hip-mounted uniaxial GT1M ActiGraph and engaged in 6 activities representative of children\u27s play. A validated direct observation protocol was used as the criterion measure of physical activity. Receiver Operating Characteristics (ROC) curve analyses were conducted with four semi-structured activities to determine the accelerometer cut-points. To examine classification differences, cut-points were cross-validated with free-play and DVD viewing activities.ResultsCut-points of &le;372, &gt;2160 and &gt;4806 counts&bull;min&minus;1 representing sedentary, moderate and vigorous intensity thresholds, respectively, provided the optimal balance between the related needs for sensitivity (accurately detecting activity) and specificity (limiting misclassification of the activity). Cross-validation data demonstrated that these values yielded the best overall kappa scores (0.97; 0.71; 0.62), and a high classification agreement (98.6%; 89.0%; 87.2%), respectively. Specificity values of 96&ndash;97% showed that the developed cut-points accurately detected physical activity, and sensitivity values (89&ndash;99%) indicated that minutes of activity were seldom incorrectly classified as inactivity.ConclusionThe development of an inexpensive and replicable field-based protocol to generate behaviourally valid and population-specific accelerometer cut-points may improve the classification of physical activity levels in children, which could enhance subsequent intervention and observational studies.<br /

Acquisition of naturally occurring antibody responses to recombinant protein domains of Plasmodium falciparum erythrocyte membrane protein 1

Background: Antibodies targeting variant antigens expressed on the surface of Plasmodium falciparum infected erythrocytes have been associated with protection from clinical malaria. The precise target for these antibodies is unknown. The best characterized and most likely target is the erythrocyte surface-expressed variant protein family Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1). Methods: Using recombinant proteins corresponding to five domains of the expressed A4 var gene, A4 PfEMP1, the naturally occurring antibody response was assessed, by ELISA, to each domain in serum samples obtained from individuals resident in two communities of differing malaria transmission intensity on the Kenyan coast. Using flow cytometry, the correlation in individual responses to each domain with responses to intact A4-infected erythrocytes expressing A4 PfEMP1 on their surface as well as responses to two alternative parasite clones and one clinical isolate was assessed. Results: Marked variability in the prevalence of responses between each domain and between each transmission area was observed, as wasa strong correlation between age and reactivity with some but not all domains. Individual responses to each domain varied strikingly, with some individuals showing reactivity to all domains and others with no reactivity to any, this was apparent at all age groups. Evidence for possible cross-reactivity in responses to the domain DBL4γ was found. Conclusion: Individuals acquire antibodies to surface expressed domains of a highly variant protein. The finding of potential cross-reactivity in responses to one of these domains is an important initial finding in the consideration of potential vaccine targets

Research-policy partnerships - experiences of the Mental Health and Poverty Project in Ghana, South Africa, Uganda and Zambia

Background: Partnerships are increasingly common in conducting research. However, there is little published evidence about processes in research-policy partnerships in different contexts. This paper contributes to filling this gap by analysing experiences of research-policy partnerships between Ministries of Health and research organisations for the implementation of the Mental Health and Poverty Project in Ghana, South Africa, Uganda and Zambia. Methods: A conceptual framework for understanding and assessing research-policy partnerships was developed and guided this study. The data collection methods for this qualitative study included semi-structured interviews with Ministry of Health Partners (MOHPs) and Research Partners (RPs) in each country. Results: The term partnership was perceived by the partners as a collaboration involving mutually-agreed goals and objectives. The principles of trust, openness, equality and mutual respect were identified as constituting the core of partnerships. The MOHPs and RPs had clearly defined roles, with the MOHPs largely providing political support and RPs leading the research agenda. Different influences affected partnerships. At the individual level, personal relationships and ability to compromise within partnerships were seen as important. At the organisational level, the main influences included the degree of formalisation of roles and responsibilities and the internal structures and procedures affecting decision-making. At the contextual level, political environment and the degree of health system decentralisation affected partnerships. Conclusions: Several lessons can be learned from these experiences. Taking account of influences on the partnership at individual, organisation and contextual/system levels can increase its effectiveness. A common understanding of mutually-agreed goals and objectives of the partnership is essential. It is important to give attention to the processes of initiating and maintaining partnerships, based on clear roles, responsibilities and commitment of parties at different levels. Although partnerships are often established for a specific purpose, such as carrying out a particular project, the effects of partnership go beyond a particular initiative

Neural Circuits Underlying Rodent Sociality: A Comparative Approach

All mammals begin life in social groups, but for some species, social relationships persist and develop throughout the course of an individual’s life. Research in multiple rodent species provides evidence of relatively conserved circuitry underlying social behaviors and processes such as social recognition and memory, social reward, and social approach/avoidance. Species exhibiting different complex social behaviors and social systems (such as social monogamy or familiarity preferences) can be characterized in part by when and how they display specific social behaviors. Prairie and meadow voles are closely related species that exhibit similarly selective peer preferences but different mating systems, aiding direct comparison of the mechanisms underlying affiliative behavior. This chapter draws on research in voles as well as other rodents to explore the mechanisms involved in individual social behavior processes, as well as specific complex social patterns. Contrasts between vole species exemplify how the laboratory study of diverse species improves our understanding of the mechanisms underlying social behavior. We identify several additional rodent species whose interesting social structures and available ecological and behavioral field data make them good candidates for study. New techniques and integration across laboratory and field settings will provide exciting opportunities for future mechanistic work in non-model species

Polyamines and cancer: old molecules, new understanding

The amino-acid-derived polyamines have long been associated with cell growth and cancer, and specific oncogenes and tumour-suppressor genes regulate polyamine metabolism. Inhibition of polyamine synthesis has proven to be generally ineffective as an anticancer strategy in clinical trials, but it is a potent cancer chemoprevention strategy in preclinical studies. Clinical trials, with well-defined goals, are now underway to evaluate the chemopreventive efficacy of inhibitors of polyamine synthesis in a range of tissues

The Last Glacial Maximum in the central North Island, New Zealand: Palaeoclimate inferences from glacier modelling

© Author(s) 2016. Quantitative palaeoclimate reconstructions provide data for evaluating the mechanisms of past, natural climate variability. Geometries of former mountain glaciers, constrained by moraine mapping, afford the opportunity to reconstruct palaeoclimate, due to the close relationship between ice extent and local climate. In this study, we present results from a series of experiments using a 2-D coupled energy balance-ice flow model that investigate the palaeoclimate significance of Last Glacial Maximum moraines within nine catchments in the central North Island, New Zealand. We find that the former ice limits can be simulated when present-day temperatures are reduced by between 4 and 7°C, if precipitation remains unchanged from present. The spread in the results between the nine catchments is likely to represent the combination of chronological and model uncertainties. The majority of catchments targeted require temperature decreases of 5.1 to 6.3°C to simulate the former glaciers, which represents our best estimate of the temperature anomaly in the central North Island, New Zealand, during the Last Glacial Maximum. A decrease in precipitation of up to 25% from present, as suggested by proxy evidence and climate models, increases the magnitude of the required temperature changes by up to 0.8°C. Glacier model experiments using reconstructed topographies that exclude the volume of post-glacial (< 15 ka) volcanism generally increased the magnitude of cooling required to simulate the former ice limits by up to 0.5°C. Our palaeotemperature estimates expand the spatial coverage of proxy-based quantitative palaeoclimate reconstructions in New Zealand. Our results are also consistent with independent, proximal temperature reconstructions from fossil groundwater and pollen assemblages, as well as similar glacier modelling reconstructions from the central Southern Alps, which suggest air temperatures were ca. 6°C lower than present across New Zealand during the Last Glacial Maximum

Reward and punishment-based compound cue learning and generalization in opiate dependency

This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this recordSubstance dependence is thought to be mediated by abnormalities in cognitive abilities, but how this impacts decision-making remains unclear. This study aimed to test whether people who are opiate dependent differed from never-dependent controls in learning from reward and punishment or in the generalization of learning to novel conditions. Participants with opiate dependency consisted of 21 people who were outpatients in a methadone maintenance program; the control group consisted of 21 healthy participants with no histories of substance abuse. Subjects completed a computer-based task that involved two phases: the training phase involved participants being presented with compound stimulus (a shape and color) in each trial, with the goal of learning which compounds to 'pick' for rewards or 'skip' to avoid punishment. The test phase involved a transfer test, where stimuli from the first phase were combined together to form novel compounds without feedback. The control group demonstrated fewer errors compared to opiate-dependent individuals during the training phase. In the test phase, controls used prior knowledge of both shapes and colors in responding; however, opiate-dependent individuals used shapes but did not use their knowledge of color to modulate responding. When performance during training was equated in the groups using a learning threshold, this difference between groups on the generalization test remained. A deficit in learning generalization might be indicative of group differences in learning strategies in operation during training; however, future work is necessary to uncover the specific neural substrates in action during transfer tasks, and to determine the effects of acute methadone dosage on decision-making