Where science starts: Spontaneous experiments in preschoolers’ exploratory play

Probabilistic models of expected information gain require integrating prior knowledge about causal hypotheses with knowledge about possible actions that might generate data relevant to those hypotheses. Here we looked at whether preschoolers (mean: 54 months) recognize “action possibilities” (affordances) in the environment that allow them to isolate variables when there is information to be gained. By manipulating the physical properties of the stimuli, we were able to affect the degree to which candidate variables could be isolated; by manipulating the base rate of candidate causes, we were able to affect the potential for information gain. Children’s exploratory play was sensitive to both manipulations: given unambiguous evidence children played indiscriminately and rarely tried to isolate candidate causes; given ambiguous evidence, children both selected (Experiment 1) and designed (Experiment 2) informative interventions.National Science Foundation (U.S.) (NSF Faculty Early Career Development Award)Templeton Foundation (Award)James S. McDonnell Foundation (Collaborative Interdisciplinary Grant on Causal Reasoning

Neural Activity, Neural Connectivity, and the Processing of Emotionally-Valenced Information in Older Adults: Links with Life Satisfaction

This study examines whether differences in late-life well-being are linked to how older adults encode emotionally-valenced information. Using fMRI with 39 older adults varying in life satisfaction, we examined how viewing positive and negative images affected activation and connectivity of an emotion-processing network. Participants engaged most regions within this network more robustly for positive than for negative images, but within the PFC this effect was moderated by life satisfaction, with individuals higher in satisfaction showing lower levels of activity during the processing of positive images. Participants high in satisfaction showed stronger correlations among network regions – particularly between the amygdala and other emotion processing regions – when viewing positive as compared to negative images. Participants low in satisfaction showed no valence effect. Findings suggest that late-life satisfaction is linked with how emotion-processing regions are engaged and connected during processing of valenced information. This first demonstration of a link between neural recruitment and late-life well-being suggests that differences in neural network activation and connectivity may account for the preferential encoding of positive information seen in some older adults

Neural Activity, Neural Connectivity, and the Processing of Emotionally-Valenced Information in Older Adults: Links with Life Satisfaction

This study examines whether differences in late-life well-being are linked to how older adults encode emotionally-valenced information. Using fMRI with 39 older adults varying in life satisfaction, we examined how viewing positive and negative images affected activation and connectivity of an emotion-processing network. Participants engaged most regions within this network more robustly for positive than for negative images, but within the PFC this effect was moderated by life satisfaction, with individuals higher in satisfaction showing lower levels of activity during the processing of positive images. Participants high in satisfaction showed stronger correlations among network regions – particularly between the amygdala and other emotion processing regions – when viewing positive as compared to negative images. Participants low in satisfaction showed no valence effect. Findings suggest that late-life satisfaction is linked with how emotion-processing regions are engaged and connected during processing of valenced information. This first demonstration of a link between neural recruitment and late-life well-being suggests that differences in neural network activation and connectivity may account for the preferential encoding of positive information seen in some older adults

The biology of the blackening phenomenon in cut carrots

A financially crippling blackening phenomenon of unknown cause has appeared in Scottish cut carrots in recent years. Full grown carrots are stored underground by the producers. They are covered in black plastic tarpaulin and straw throughout the harvesting year to prevent sprouting. The harvested carrots are then cut into batons and distributed to supermarkets and other outlets. Thereafter, blackening can occur within hours to days. Blackening is observed only in mature carrots that are over 1 year old and that have been stored underground until the end of the annual harvest period. This observation suggests that organ aging and/or length of storage underground are important factors contributing to the blackening. However, the environmental, metabolic and molecular triggers for blackening remain poorly characterised. An analysis of environmental conditions of carrot fields revealed that some fields yield carrots that show a higher level of blackening than others. The geographical locations of the fields or the local environmental conditions may enhance susceptibility to blackening. Metabolite profiling analysis revealed that the levels of amino acids and sugars were decreased in the blackened regions of the carrot batons, while fatty acids and phenolic compounds were increased. Immunofluorescence microscopy and a carbohydrate analysis revealed that pectin was less abundant in the cell walls in the blackened regions, which show high autofluorescence suggesting increased polyphenol accumulation. Moreover, lignin levels were higher in blackened regions. Transcript profiling analysis revealed that transcripts encoding proteins involved in phytohormone signalling were more abundant in the blacked regions. In particular, transcripts associated with auxin signalling and ethylene-responsive transcription factors were higher in the blackened regions. In contrast, the levels of transcripts encoding proteins associated with secondary metabolism were decreased in the blackened regions. Taken together, these findings suggest that hormonal and metabolic changes that occur during long periods of storage underground prior to harvest and that are associated with a loss of bud dormancy may predispose the carrots to wound-induced blackening discolouration. These studies provide new insights into the molecular and metabolic mechanisms that underpin the blackening process and will facilitate more rapid progress to solutions to address the problem

Effects of Ischemia on Lung Macrophages

Angiogenesis after pulmonary ischemia is initiated by reactive O2 species and is dependent on CXC chemokine growth factors, and its magnitude is correlated with the number of lavaged macrophages. After complete obstruction of the left pulmonary artery in mice, the left lung is isolated from the peripheral circulation until 5–7 days later, when a new systemic vasculature invades the lung parenchyma. Consequently, this model offers a unique opportunity to study the differentiation and/or proliferation of monocyte-derived cells within the lung. In this study, we questioned whether macrophage subpopulations were differentially expressed and which subset contributed to growth factor release. We characterized the change in number of all macrophages (MHCII int, CD11C+), alveolar macrophages (MHCII int, CD11C+, CD11B−) and mature lung macrophages (MHCII int, CD11C+, CD11B+) in left lungs from mice immediately (0 h) or 24 h after left pulmonary artery ligation (LPAL). In left lung homogenates, only lung macrophages increased 24 h after LPAL (vs. 0 h; p<0.05). No changes in proliferation were seen in any subset by PCNA expression (0 h vs. 24 h lungs). When the number of monocytic cells was reduced with clodronate liposomes, systemic blood flow to the left lung 14 days after LPAL decreased by 42% (p<0.01) compared to vehicle controls. Furthermore, when alveolar macrophages and lung macrophages were sorted and studied in vitro, only lung macrophages secreted the chemokine MIP-2α (ELISA). These data suggest that ischemic stress within the lung contributes to the differentiation of immature monocytes to lung macrophages within the first 24 h after LPAL. Lung macrophages but not alveolar macrophages increase and secrete the proangiogenic chemokine MIP-2α. Overall, an increase in the number of lung macrophages appears to be critical for neovascularization in the lung, since clodronate treatment decreased their number and attenuated functional angiogenesis

Using nature to nurture: Breast milk analysis and fortification to improve growth and neurodevelopmental outcomes in preterm infants

Premature infants are born prior to a critical window of rapid placental nutrient transfer and fetal growth—particularly brain development—that occurs during the third trimester of pregnancy. Subsequently, a large proportion of preterm neonates experience extrauterine growth failure and associated neurodevelopmental impairments. Human milk (maternal or donor breast milk) is the recommended source of enteral nutrition for preterm infants, but requires additional fortification of macronutrient, micronutrient, and energy content to meet the nutritional demands of the preterm infant in attempts at replicating in utero nutrient accretion and growth rates. Traditional standardized fortification practices that add a fixed amount of multicomponent fortifier based on assumed breast milk composition do not take into account the considerable variations in breast milk content or individual neonatal metabolism. Emerging methods of individualized fortification—including targeted and adjusted fortification—show promise in improving postnatal growth and neurodevelopmental outcomes in preterm infants

Vertebrate Fauna: a Survey of Australia’s Oldest National Park and Adjoining Reserves

This study compiles an inventory of amphibians, reptiles, birds and mammals in Royal National Park, Garawarra State Conservation Area and Heathcote National Park. It investigates patterns of species occurrence and puts the results into a regional context. Systematic and targeted field surveys were undertaken and previously existing data were reviewed. The surveys detected 283 species. This high species richness can be attributed to the diversity of habitats present. The Rainforests and Heathlands vegetation formations each support a distinct suite of fauna, while many species only occur on the ocean and/or estuarine shoreline. Rainforests and Heathlands have a restricted distribution in the Sydney basin, and in that context the reserves support large numbers of heath-dependant fauna species. The reserves also have relatively high numbers of at least five threatened species. The field surveys detected seven species not previously documented, including Australasian bittern (Botaurus poiciloptilus) and eastern grass owl (Tyto longimembris). Also notable is the discovery of roosts of eastern horseshoe-bat (Rhinolophus megaphyllus) and little bent-wing-bat (Miniopterus australis). However, many species previously known from the reserves could not be found, such as ground parrot (Pezoporus wallicus), green and golden bell frog (Litoria aurea), parma wallaby (Macropus parma) and platypus (Ornithorhynchus anatinus)

Children balance theories and evidence in exploration, explanation, and learning

We look at the effect of evidence and prior beliefs on exploration, explanation and learning. In Experiment 1, we tested children both with and without differential prior beliefs about balance relationships (Center Theorists, mean: 82 months; Mass Theorists, mean: 89 months; No Theory children, mean: 62 months). Center and Mass Theory children who observed identical evidence explored the block differently depending on their beliefs. When the block was balanced at its geometric center (belief-violating to a Mass Theorist, but belief-consistent to a Center Theorist), Mass Theory children explored the block more, and Center Theory children showed the standard novelty preference; when the block was balanced at the center of mass, the pattern of results reversed. The No Theory children showed a novelty preference regardless of evidence. In Experiments 2 and 3, we follow-up on these findings, showing that both Mass and Center Theorists selectively and differentially appeal to auxiliary variables (e.g., a magnet) to explain evidence only when their beliefs are violated. We also show that children use the data to revise their predictions in the absence of the explanatory auxiliary variable but not in its presence. Taken together, these results suggest that children’s learning is at once conservative and flexible; children integrate evidence, prior beliefs, and competing causal hypotheses in their exploration, explanation, and learning.American Psychological Foundation (Elizabeth Munsterberg Koppitz Fellowship)James S. McDonnell Foundation (Collaborative Interdisciplinary Grant on Causal Reasoning)National Science Foundation (U.S.) (NSF Faculty Early Career Development Award)Templeton Foundation (Award

Infection by a foliar endophyte elicits novel arabidopside-based plant defence reactions in its host, Cirsium arvense

Endophytic fungi live asymptomatically within plants. They are usually regarded as non-pathogenic or even mutualistic, but whether plants respond antagonistically to their presence remains unclear, particularly in the little-studied associations between endophytes and nong-raminoid herbaceous plants. We investigated the effects of the endophyte Chaetomium cochlioides on leaf chemistry in Cirsium arvense. Plants were sprayed with spores; leaf material from both subsequent new growth and the sprayed leaves was analysed 2 wk later. Infection frequency was 91% and63% for sprayed and new growth, respectively, indicating that C. cochlioides rapidly infects new foliage. Metabolomic analyses revealed marked changes in leaf chemistry with infection, especially in new growth. Changes in several novel oxylipin metabolites were detected, including arabi-dopsides reported here for the first time in a plant species other than Arabidopsis thaliana,and a jasmonate-containing galactolipid. The production of these metabolites in response to endophyte presence, particularly in newly infected foliage, suggests that endophytes elicit similar chemical responses in plants to those usually produced following wounding, herbivory and pathogen invasion. Whether en-dophytes benefit their hosts may depend on a complex series of chemically mediated interactions between the plant, the endophyte, other microbial colonists and natural enemies

The Double-edged Sword of Pedagogy: Modeling the Effect of Pedagogical Contexts on Preschoolers’ Exploratory Play

URL to paper from conference siteHow does explicit instruction affect exploratory play and learning? We present a model that captures pedagogical assumptions (adapted from Shafto and Goodman, 2008) and test the model with a novel experiment looking at 4-year-olds’ exploratory play in pedagogical and non-pedagogical contexts. Our findings are consistent with the model predictions: preschool children limit their exploration in pedagogical contexts, spending most of their free play performing only the demonstrated action. By contrast, children explore broadly both at baseline and after an accidental demonstration. Thus pedagogy constrains children’s exploration for better and for worse; children learn the demonstrated causal relationship but are less likely than children in non-pedagogical contexts to discover and learn other causal relationships.American Psychological Foundation (Elizabeth Munsterberg Koppitz Fellowship)Templeton FoundationJames S. McDonnell Foundatio