#3 - Generation of SULT4A1 Gene Mutations in SH-SY5Y Cells

The cytosolic sulfotransferases (SULT) are a superfamily of enzymes that catalyze the metabolism of various substrates throughout the body. One member, SULT4A1, has no known substrates and is highly conserved among all vertebrates which is not a shared characteristic among the SULT family. Also unique among the SULTs, SULT4A1 localizes with mitochondria of neurons. Recent reports have suggested that this protein is believed play a protective role against oxidative stress. The goal of this project was to generate a SH-SY5Y cell line with a SULT4A1 gene deletion using CRISPR gene-editing technology. These neuroblastoma cells were used because of their ease of culture in the laboratory and their similarity to neurons. CRISPR uses DNA-cutting enzymes to target genes for a variety of mutations and modifications. These enzymes limit the amount of errors made by previous gene modifying techniques in the past, and they also take less time than previous techniques. A circular piece of DNA (plasmid) was designed to include coding for the gene-editing endonuclease, the target sequence for the gene, and puromycin resistance. The plasmid was introduced to the cells via electroporation, a technique in which an electric shock is used to disrupt the cell membranes and allow entry of the plasmid. Plasmid uptake was verified by selection with puromycin for 24 hours. This ensured that all surviving cells had taken up the plasmid and were expressing the puromycin resistance. Future experiments with these mutant cell lines will elucidate not only the function of SULT4A1 but also why it is highly conserved amongst vertebrate species

Phytase activity in lichens

Phytase activity was investigated in 13 lichen species using a novel assay method. The work tested the hypothesis that phytase is a component of the suite of surface-bound lichen enzymes that hydrolyse simple organic forms of phosphorus (P) and nitrogen (N) deposited onto the thallus surface. Hydrolysis of inositol hexaphosphate (InsP6, the substrate for phytase) and appearance of lower-order inositol phosphates (InsP5–InsP1), the hydrolysis products, were measured by ion chromatography. Phytase activity in Evernia prunastri was compared among locations with contrasting rates of N deposition. Phytase activity was readily measurable in epiphytic lichens (e.g. 11.3 lmol InsP6 hydrolysed g-1 h-1 in Bryoria fuscescens) but low in two terricolous species tested (Cladonia portentosa and Peltigera membranacea). Phytase and phosphomonoesterase activities were positively correlated amongst species. In E. prunastri both enzyme activities were promoted by N enrichment and phytase activity was readily released into thallus washings. InsP6 was not detected in tree canopy throughfall but was present in pollen leachate. Capacity to hydrolyse InsP6 appears widespread amongst lichens potentially promoting P capture from atmospheric deposits and plant leachates, and P cycling in forest canopies. The enzyme assay used here might find wider application in studies on plant root–fungal–soil systems

Foraging strategies and diet composition of Hadza children

Among the Hazda hunter-gatherers of Tanzania, children are active foragers and collect various types of wild plant foods and hunt small sized prey animals. The collection effort of Hazda children is reported to have a positive effect on a mother’s foraging yield (Bulurton-Jones et at. 1994, Journal of Anthropological Research 50(3): 217; Hawkes et al. 1995, Current Anthropology 36(4): 688), yet few quantitative data are available on the caloric values of children’s foods and the ways in which children distribute their own foraging yield. Here, we report on foraging return rates, consumption data, and the compositional values for several of the plant foods collected by children. Due to predator pressure, it is not safe for children to wander far from camp without adult supervision, therefore they typically focus on foods that are close to camp and easy to collect and process. We calculated the caloric content for the following foods: baobab fruit (346 kcal/100g dry matter (DM)), berries (320 kcal/100g DM), legumes (311 kcal/100g DM), drupes (325 kcal/100g DM), and figs (365 kcal/100g DM). Legumes, drupes, and figs have not been previously analyzed; our values for baobab and berries agree with previous analyses (Murray et al. 2001, Journal of Food Consumption and Analysis 14: 3). In addition, we calculated foraging return rates and daily consumption values for children. Our results suggest that they collect a significant portion of their daily caloric intake and act as allomothers providing caloric contributions to other children. Support: National Science Foundation, Regents of the University of California San Diego, Friends of the International Center at the University of California San Diego, and Harvard University.AnthropologyHuman Evolutionary Biolog

Embedding knowledge and value of a brand into sustainability for differentiation

This is the post-print version of the final paper published in the Journal of World Business (under the provisional title "Embedding sustainability into brand knowledge and brand value for brand differentiation"). The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2012 Elsevier B.V.Organisations offer products to consumers, buyers often question if the product or its production process are linked to the environmental, social or economic challenges being faced by mankind. Inquisitiveness of customers in this direction points towards an opportunity for marketers to create differentiation based on the concerns of brand towards overall issue of sustainability. The authors have synthesized knowledge from various domains with a positivistic approach to understand sustainability from the perspective of branding. Using empirical knowledge this study recommends embedding sustainability into brand knowledge and brand value for creating a differentiation for the brand in a competitive market

Lichen response to ammonia deposition defines the footprint of a penguin rookery

Ammonia volatilized from penguin rookeries is a major nitrogen source in Antarctic coastal terrestrial ecosystems. However, the spatial extent of ammonia dispersion from rookeries and its impacts have not been quantified previously. We measured ammonia concentration in air and lichen ecophysiological response variables proximate to an Adèlie penguin rookery at Cape Hallett, northern Victoria Land. Ammonia emitted from the rookery was 15N-enriched (δ15N value +6.9) and concentrations in air ranged from 36–75 µg m−3 at the rookery centre to 0.05 µg m−3 at a distance of 15.3 km. δ15N values and rates of phosphomonoesterase (PME) activity in the lichens Usnea sphacelata and Umbilicaria decussata were strongly negatively related to distance from the rookery and PME activity was positively related to thallus N:P mass ratio. In contrast, the lichen Xanthomendoza borealis, which is largely restricted to within an area 0.5 km from the rookery perimeter, had high N, P and 15N concentrations but low PME activity suggesting that nutrient scavenging capacity is suppressed in highly eutrophicated sites. An ammonia dispersion model indicates that ammonia concentrations sufficient to significantly elevate PME activity and δ15N values (≥0.1 µg NH3 m−3) occurred over c. 40–300 km2 surrounding the rookery suggesting that penguin rookeries potentially can generate large spatial impact zones. In a general linear model NH3 concentration and lichen species identity were found to account for 72 % of variation in the putative proportion of lichen thallus N originating from penguin derived NH3. The results provide evidence of large scale impact of N transfer from a marine to an N-limited terrestrial ecosystem

The role of prediction and outcomes in adaptive cognitive control

Humans adaptively perform actions to achieve their goals. This flexible behaviour requires two core abilities: the ability to anticipate the outcomes of candidate actions and the ability to select and implement actions in a goal-directed manner. The ability to predict outcomes has been extensively researched in reinforcement learning paradigms, but this work has often focused on simple actions that are not embedded in hierarchical and sequential structures that are characteristic of goal-directed human behaviour. On the other hand, the ability to select actions in accordance with high-level task goals, particularly in the presence of alternative responses and salient distractors, has been widely researched in cognitive control paradigms. Cognitive control research, however, has often paid less attention to the role of action outcomes. The present review attempts to bridge these accounts by proposing an outcome-guided mechanism for selection of extended actions. Our proposal builds on constructs from the hierarchical reinforcement learning literature, which emphasises the concept of reaching and evaluating informative states, i.e., states that constitute subgoals in complex actions. We develop an account of the neural mechanisms that allow outcome-guided action selection to be achieved in a network that relies on projections from cortical areas to the basal ganglia and back-projections from the basal ganglia to the cortex. These cortico-basal ganglia-thalamo-cortical ‘loops’ allow convergence – and thus integration – of information from non-adjacent cortical areas (for example between sensory and motor representations). This integration is essential in action sequences, for which achieving an anticipated sensory state signals the successful completion of an action. We further describe how projection pathways within the basal ganglia allow selection between representations, which may pertain to movements, actions, or extended action plans. The model lastly envisages a role for hierarchical projections from the striatum to dopaminergic midbrain areas that enable more rostral frontal areas to bias the selection of inputs from more posterior frontal areas via their respective representations in the basal ganglia.This work is supported by the Biotechnology and Biological Sciences Research Council (BBSRC) Grant BB/I019847/1, awarded to NY and FW

Old stones' song: Use-wear experiments and analysis of the Oldowan quartz and quartzite assemblage from Kanjera South (Kenya)

Evidence of Oldowan tools by w2.6 million years ago (Ma) may signal a major adaptive shift in hominin evolution. While tool-dependent butchery of large mammals was important by at least 2.0 Ma, the use of artifacts for tasks other than faunal processing has been difficult to diagnose. Here we report on use-wear analysis ofw2.0 Ma quartz and quartzite artifacts from Kanjera South, Kenya. A use-wear framework that links processing of specific materials and tool motions to their resultant use-wear patterns was developed. A blind test was then carried out to assess and improve the efficacy of this experimental use-wear framework, which was then applied to the analysis of 62 Oldowan artifacts from Kanjera South. Usewear on a total of 23 artifact edges was attributed to the processing of specific materials. Use-wear on seven edges (30%) was attributed to animal tissue processing,corroborating zooarchaeological evidence for butchery at the site. Use-wear on 16 edges (70%)was attributed to the processing of plant tissues, including wood, grit-covered plant tissues that we interpret asunderground storage organs (USOs), and stems of grass or sedges. These results expand our knowledge of the suite of behaviours carried out in the vicinity of Kanjera South to include the processing of materials that would be ‘invisible’ using standard archaeological methods. Wood cutting and scraping may represent the production and/or maintenance of wooden tools. Use-wear related to USO processing extends the archaeological evidence for hominin acquisition and consumption of this resource by over 1.5 Ma. Cutting of grasses, sedges or reeds may be related to a subsistence task (e.g., grass seed harvesting, cutting out papyrus culm for consumption) and/or a non-subsistence related task (e.g., production of ‘twine,’ simple carrying devices, or bedding). These results highlight the adaptive significance of lithic technology for hominins at Kanjera

Hierarchical prediction errors in midbrain and septum during social learning

Social learning is fundamental to human interactions, yet its computational and physiological mechanisms are not well understood. One prominent open question concerns the role of neuromodulatory transmitters. We combined fMRI, computational modelling, and genetics to address this question in two separate samples (N=35, N=47). Participants played a game requiring inference on an advisor's intentions whose motivation to help or mislead changed over time. Our analyses suggest that hierarchically structured belief updates about current advice validity and the adviser's trustworthiness, respectively, depend on different neuromodulatory systems. Low-level prediction errors (PEs) about advice accuracy not only activated regions known to support "theory of mind", but also the dopaminergic midbrain. Furthermore, PE responses in ventral striatum were influenced by the Met/Val polymorphism of the Catechol-O-Methyltransferase (COMT) gene. By contrast, high-level PEs ("expected uncertainty") about the adviser's fidelity activated the cholinergic septum. These findings, replicated in both samples, have important implications: They suggest that social learning rests on hierarchically related PEs encoded by midbrain and septum activity, respectively, in the same manner as other forms of learning under volatility. Furthermore, these hierarchical PEs may be broadcast by dopaminergic and cholinergic projections to induce plasticity specifically in cortical areas known to represent beliefs about others. Copyright The Authors (2017). Published by Oxford University Press

Dopamine, affordance and active inference.

The role of dopamine in behaviour and decision-making is often cast in terms of reinforcement learning and optimal decision theory. Here, we present an alternative view that frames the physiology of dopamine in terms of Bayes-optimal behaviour. In this account, dopamine controls the precision or salience of (external or internal) cues that engender action. In other words, dopamine balances bottom-up sensory information and top-down prior beliefs when making hierarchical inferences (predictions) about cues that have affordance. In this paper, we focus on the consequences of changing tonic levels of dopamine firing using simulations of cued sequential movements. Crucially, the predictions driving movements are based upon a hierarchical generative model that infers the context in which movements are made. This means that we can confuse agents by changing the context (order) in which cues are presented. These simulations provide a (Bayes-optimal) model of contextual uncertainty and set switching that can be quantified in terms of behavioural and electrophysiological responses. Furthermore, one can simulate dopaminergic lesions (by changing the precision of prediction errors) to produce pathological behaviours that are reminiscent of those seen in neurological disorders such as Parkinson's disease. We use these simulations to demonstrate how a single functional role for dopamine at the synaptic level can manifest in different ways at the behavioural level