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Holland, N.

Publications and source records attributed to Holland, N..

3 recordsLinked to original sources

Trichodesmium Erythraeum produces a higher photocurrent than other cyanobacterial species in bio-photo electrochemical cells.

In recent years, the increase in world energy consumption, and the worries from potential future disasters that may derive from climate change have inspired the motivation to develop renewable energy technologies. One of the promising methods is the utilization of whole bacterial cells to produce photocurrent in a bio-photo electrochemical cell (BPEC). The photocurrent derives from the photosynthesis pathway, while the redox couple NADP+/NADPH perform cyclic electron mediation between photosystem I inside the cells, and the anode. Over the years, various cyanobacterial species were utilized in diverse BPECs setups, while the photocurrent was enhanced by the addition of natural electron mediators such as NAD+, NADP+, Cytochrome C, Vitamin B1, and the artificial mediator potassium ferricyanide. The cyanobacterium Trichodesmium Erythraeum (Te) is a marine species that consist of high content of Phycocyanin and Phycoerythrin pigments that play a major role in photosynthesis enhancement. In this work, we produce for the first-time photocurrent from Te. We apply 2D-fluorescence measurements to detect its NADPH secretion and show that its photocurrent production is enhanced as a function of increasing electrolyte salinity. Finally, we produce photocurrent from additional cyanobacterial species: Synechocystis sp. PCC6803, Synechococcus elongatus PCC 7942, Acaryochloris marina MBIC 11017, and Spirulina, using their cultivation medium as electrolytes in the BPEC. We show that TE produces a photocurrent intensity that is significantly greater than all other species with and without the addition of exogenous electron mediators. The utilization of TE may pave the way toward the establishment of marine clean energy technologies.

microbiology↗

Meta-analysis of epigenome-wide associations between DNA methylation at birth and childhood cognitive skills.

Cognitive skills are a strong predictor of a wide range of later life outcomes. Genetic and epigenetic associations across the genome explain some of the variation in general cognitive abilities in the general population and it is plausible that epigenetic associations might arise from prenatal environmental exposures and/or genetic variation early in life. We investigated the association between cord blood DNA methylation at birth and cognitive skills assessed in children from eight pregnancy cohorts (N=2196-3798) within the Pregnancy And Childhood Epigenetics (PACE) Consortium across overall, verbal and non-verbal cognitive scores. The associations at single CpG sites were weak for all of the cognitive domains investigated. One region near DUSP22 on chromosome 6 was associated with non-verbal cognition in a model adjusted for maternal IQ. We conclude that there is little evidence to support the idea that cord blood DNA methylation at single CpGs can predict cognitive skills and further studies are needed to confirm regional differences.

developmental biology↗

A synergistic core for human brain evolution and cognition

A fundamental question in neuroscience is how brain organisation gives rise to humans unique cognitive abilities. Although complex cognition is widely assumed to rely on frontal and parietal brain regions, the underlying mechanisms remain elusive: current approaches are unable to disentangle different forms of information processing in the brain. Here, we introduce a powerful framework to identify synergistic and redundant contributions to neural information processing and cognition. Leveraging multimodal data including functional MRI, PET, cytoarchitectonics and genetics, we reveal that synergistic interactions are the fundamental drivers of complex human cognition. Whereas redundant information dominates sensorimotor areas, synergistic activity is closely associated with the brains prefrontal-parietal and default networks; furthermore, meta-analytic results demonstrate a close relationship between high-level cognitive tasks and synergistic information. From an evolutionary perspective, the human brain exhibits higher prevalence of synergistic information than non-human primates. At the macroscale, we demonstrate that high-synergy regions underwent the highest degree of evolutionary cortical expansion. At the microscale, human-accelerated genes promote synergistic interactions by enhancing synaptic transmission. These convergent results provide critical insights that synergistic neural interactions underlie the evolution and functioning of humans sophisticated cognitive abilities, and demonstrate the power of our widely applicable information decomposition framework.

neuroscience↗