Wnt signaling is essential for neuronal development and the maintenance of the developing nervous system. Recent studies indicated that Wnt signaling modulates long term potentiation in adult ...hippocampal slices. We report here that different Wnt ligands are present in hippocampal neurons of rat embryo and adult rat, including Wnt-4, -5a, -7a, and -11. Wnt-7a acts as a canonical Wnt ligand in rat hippocampal neurons, stimulates clustering of presynaptic proteins, and induces recycling and exocytosis of synaptic vesicles as studied by FM dyes. Wnt-3a has a moderate effect on recycling of synaptic vesicles, and no effect of Wnt-1 and Wnt-5a was detected. Electrophysiological analysis on adult rat hippocampal slices indicates that Wnt-7a, but not Wnt-5a, increases neurotransmitter release in CA3-CA1 synapses by decreasing paired pulse facilitation and increasing the miniature excitatory post-synaptic currents frequency. These results indicate that the presynaptic function of rat hippocampal neurons is modulated by the canonical Wnt signaling.
The increased incidence of drug-resistant tuberculosis has created an urgent necessity for the development of new and effective anti-tuberculosis drugs and for alternative therapeutic regimens. ...Clofazimine (CFZ) is a fat-soluble riminophenazine dye used in the treatment of leprosy worldwide. CFZ has also been used as a Group 5 drug in the treatment of tuberculosis (TB). A large cohort study from Bangladesh published in 2010 described a treatment regimen for multidrug-resistant tuberculosis (MDR-TB) including CFZ as being highly effective against MDR-TB. We searched multiple databases for studies published through February 2012 that reported use of CFZ in MDR- and extensively drug-resistant TB (XDR-TB) treatment regimens. We identified nine observational studies (6 MDR-TB and 3 XDR-TB) including patients with drug-resistant TB treated with CFZ. Overall, 65% (95% confidence interval 95%CI 54-76) of the patients experienced favorable outcomes, defined as either cure or treatment completion. Using random effects meta-analysis, 65% (95%CI 52-79) of those with MDR-TB and 66% (95%CI 42-89) of those with XDR-TB experienced favorable treatment outcomes. High-quality prospective cohort studies and clinical trials examining the effect of CFZ as part of drug-resistant TB treatment regimens are needed.
Ecosystem services are typically valued for their immediate material or cultural benefits to human wellbeing, supported by regulating and supporting services. Under climate change, with more frequent ...stresses and novel shocks, 'climate adaptation services', are defined as the benefits to people from increased social ability to respond to change, provided by the capability of ecosystems to moderate and adapt to climate change and variability. They broaden the ecosystem services framework to assist decision makers in planning for an uncertain future with new choices and options. We present a generic framework for operationalising the adaptation services concept. Four steps guide the identification of intrinsic ecological mechanisms that facilitate the maintenance and emergence of ecosystem services during periods of change, and so materialise as adaptation services. We applied this framework for four contrasted Australian ecosystems. Comparative analyses enabled by the operational framework suggest that adaptation services that emerge during trajectories of ecological change are supported by common mechanisms: vegetation structural diversity, the role of keystone species or functional groups, response diversity and landscape connectivity, which underpin the persistence of function and the reassembly of ecological communities under severe climate change and variability. Such understanding should guide ecosystem management towards adaptation planning.
The standard neoclassical approach to economic theorising excludes, by definition, economic emergence and the related phenomenon of entrepreneurship. We explore how the most economic of human ...behaviours, entrepreneurship, came to be largely excluded from mainstream economic theory. In contrast, we report that evolutionary economists have acknowledged the importance of understanding emergence and we explore the advances that have been made in this regard. We go on to argue that evolutionary economics can make further progress by taking a more ‘naturalistic’ approach to economic evolution. This requires that economic analysis be fully embedded in complex economic system theory and that associated understandings as to how humans react to states of uncertainty be explicitly dealt with. We argue that ‘knowledge,’ because of the existence of uncertainty is, to a large degree ‘conjectural’ and, thus, is closely linked to our emotional states. Our economic behaviour is also influenced by the reality that we, and the systems that we create, are dissipative structures. Thus, we introduce the notions of ‘energy gradients’ and ‘knowledge gradients’ as essential concepts in understanding economic emergence and resultant economic growth.
Unhealthy dietary intake among American children and adults is of great concern to public health practitioners, nutritional scientists, and child development experts. Cooking skills are related to ...healthier dietary intake among Americans of all ages, but remain a substantial barrier for many parents who want to serve healthy meals for their families at home. Culinary education interventions are effective solutions for many parents who do not know how to cook, but issues with participation bias mean that these programs are not effective solutions for all individuals. The food industry should develop solutions to help those parents for whom learning cooking skills is not an option – specifically through the development of healthier pre-assembled or prepared foods that do not require cooking skills to make. In the future, the research community should also strive to collect comprehensive population-based data on the state of cooking skills in the United States.
Ecosystem resilience depends on functional redundancy (the number of species contributing similarly to an ecosystem function) and response diversity (how functionally similar species respond ...differently to disturbance). Here, we explore how land-use change impacts these attributes in plant communities, using data from 18 land-use intensity gradients that represent five biomes and > 2800 species. We identify functional groups using multivariate analysis of plant traits which influence ecosystem processes. Functional redundancy is calculated as the species richness within each group, and response diversity as the multivariate within-group dispersion in response trait space, using traits that influence responses to disturbances. Meta-analysis across all datasets showed that land-use intensification significantly reduced both functional redundancy and response diversity, although specific relationships varied considerably among the different land-use gradients. These results indicate that intensified management of ecosystems for resource extraction can increase their vulnerability to future disturbances. Ecology Letters (2010) 13: 76-86
Summary
Background
There is limited understanding of how maternal diet affects breastmilk food allergen concentrations, and whether exposure to allergens through this route influences the development ...of infant oral tolerance or sensitization.
Objective
To investigate how maternal dietary egg ingestion during early lactation influences egg protein (ovalbumin) levels detected in human breastmilk.
Methods
In a randomized controlled trial, women were allocated to a dietary group for the first six weeks of lactation: high‐egg diet (> 4 eggs per week), low‐egg diet (one‐three eggs per week) or an egg‐free diet. Breastmilk samples were collected at 2, 4 and 6 weeks of lactation for the measurement of ovalbumin. The permeability of the mammary epithelium was assessed by measuring the breastmilk sodium : potassium ratio. Egg‐specific IgE and IgG4 were measured in infant plasma at 6 weeks, and prior to the introduction of egg in solids at 16 weeks.
Results
Average maternal egg ingestion was associated with breastmilk ovalbumin concentration. Specifically, for each additional egg ingested per week, there was an average 25% increase in ovalbumin concentration (95% CI: 5–48%, P = 0.01). Breastmilk ovalbumin concentrations were significantly higher in the ‘high‐egg’ group (> 4 eggs per week) compared with the ‘egg‐free’ group (P = 0.04). However, one‐third of women had no breastmilk ovalbumin detected. No detectable associations were found between mammary epithelium permeability and breastmilk ovalbumin concentrations. Infant plasma egg‐specific IgG4 levels were also positively associated with maternal egg ingestion, with an average 22% (95% CI: 3–45%) increase in infant egg‐specific IgG4 levels per additional egg consumed per week (P = 0.02).
Conclusions and Clinical Relevance
Increased maternal egg ingestion is associated with increased breastmilk ovalbumin, and markers of immune tolerance in infants. These results highlight the potential for maternal diet to benefit infant oral tolerance development during lactation.
► Ecosystem services are useful for assessing trade-offs in water quality management. ► We trialled the approach in the Tully–Murray catchment, Great Barrier Reef and found. ► Trade-offs between food ...production, water quality regulation, tourism and fisheries. ► Symmetry between private stakeholders: farmers, tour operators, tourists and fishermen. ► Scale mis-matches between ecosystem service flows and water quality governance.
The Great Barrier Reef (GBR), Australia, is threatened by declining water quality largely derived from agricultural run-off. Water quality planning aims to mitigate pollutant run-off through land management, including riparian and wetland restoration, but no tools exist to assess trade-offs in land use change across the catchment-to-reef continuum. We adapted the Millennium Ecosystem Assessment framework in the GBR's Tully–Murray catchment to identify trade-offs between linked ecosystem services and stakeholders. Applying four land use scenarios we assessed outcomes for the ecosystem service of water quality regulation, and trade-offs with six floodplain services and four GBR services. Based on statistical correlations between ecosystem services’ status under the scenarios, we identified trade-offs and thresholds between services and associated stakeholders. The most direct trade-off in floodplain services (and primary stakeholders) was food and fibre production (farmers) versus water quality regulation (community, GBR tourists, tour operators and fishermen). There were synergies between water quality regulation (community, GBR tourists, tour operators and fishermen) and floodplain recreational and commercial fisheries (fishermen). Scale mis-matches between water quality management structures and ecosystem service flows were also evident. We discuss the strengths and weaknesses of this ecosystem services approach, and its potential application in the GBR and other catchment-to-reef social–ecological systems.
Value of long-term ecological studies LINDENMAYER, DAVID B.; LIKENS, GENE E.; ANDERSEN, ALAN ...
Austral ecology,
November 2012, Letnik:
37, Številka:
7
Journal Article
Recenzirano
Long‐term ecological studies are critical for providing key insights in ecology, environmental change, natural resource management and biodiversity conservation. In this paper, we briefly discuss ...five key values of such studies. These are: (1) quantifying ecological responses to drivers of ecosystem change; (2) understanding complex ecosystem processes that occur over prolonged periods; (3) providing core ecological data that may be used to develop theoretical ecological models and to parameterize and validate simulation models; (4) acting as platforms for collaborative studies, thus promoting multidisciplinary research; and (5) providing data and understanding at scales relevant to management, and hence critically supporting evidence‐based policy, decision making and the management of ecosystems. We suggest that the ecological research community needs to put higher priority on communicating the benefits of long‐term ecological studies to resource managers, policy makers and the general public. Long‐term research will be especially important for tackling large‐scale emerging problems confronting humanity such as resource management for a rapidly increasing human population, mass species extinction, and climate change detection, mitigation and adaptation. While some ecologically relevant, long‐term data sets are now becoming more generally available, these are exceptions. This deficiency occurs because ecological studies can be difficult to maintain for long periods as they exceed the length of government administrations and funding cycles. We argue that the ecological research community will need to coordinate ongoing efforts in an open and collaborative way, to ensure that discoverable long‐term ecological studies do not become a long‐term deficiency. It is important to maintain publishing outlets for empirical field‐based ecology, while simultaneously developing new systems of recognition that reward ecologists for the use and collaborative sharing of their long‐term data sets. Funding schemes must be re‐crafted to emphasize collaborative partnerships between field‐based ecologists, theoreticians and modellers, and to provide financial support that is committed over commensurate time frames.
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