61 research outputs found
The âconscious pilotââdendritic synchrony moves through the brain to mediate consciousness
Cognitive brain functions including sensory processing and control of behavior are understood as âneurocomputationâ in axonalâdendritic synaptic networks of âintegrate-and-fireâ neurons. Cognitive neurocomputation with consciousness is accompanied by 30- to 90-Hz gamma synchrony electroencephalography (EEG), and non-conscious neurocomputation is not. Gamma synchrony EEG derives largely from neuronal groups linked by dendriticâdendritic gap junctions, forming transient syncytia (âdendritic websâ) in input/integration layers oriented sideways to axonalâdendritic neurocomputational flow. As gap junctions open and close, a gamma-synchronized dendritic web can rapidly change topology and move through the brain as a spatiotemporal envelope performing collective integration and volitional choices correlating with consciousness. The âconscious pilotâ is a metaphorical description for a mobile gamma-synchronized dendritic web as vehicle for a conscious agent/pilot which experiences and assumes control of otherwise non-conscious auto-pilot neurocomputation
Stable Isotope Biogeochemistry of Seabird Guano Fertilization: Results from Growth Chamber Studies with Maize (Zea Mays)
Stable isotope analysis is being utilized with increasing regularity to examine a wide range of issues (diet, habitat use, migration) in ecology, geology, archaeology, and related disciplines. A crucial component to these studies is a thorough understanding of the range and causes of baseline isotopic variation, which is relatively poorly understood for nitrogen (δ(15)N). Animal excrement is known to impact plant δ(15)N values, but the effects of seabird guano have not been systematically studied from an agricultural or horticultural standpoint.This paper presents isotopic (δ(13)C and δ(15)N) and vital data for maize (Zea mays) fertilized with Peruvian seabird guano under controlled conditions. The level of (15)N enrichment in fertilized plants is very large, with δ(15)N values ranging between 25.5 and 44.7â° depending on the tissue and amount of fertilizer applied; comparatively, control plant δ(15)N values ranged between -0.3 and 5.7â°. Intraplant and temporal variability in δ(15)N values were large, particularly for the guano-fertilized plants, which can be attributed to changes in the availability of guano-derived N over time, and the reliance of stored vs. absorbed N. Plant δ(13)C values were not significantly impacted by guano fertilization. High concentrations of seabird guano inhibited maize germination and maize growth. Moreover, high levels of seabird guano greatly impacted the N metabolism of the plants, resulting in significantly higher tissue N content, particularly in the stalk.The results presented in this study demonstrate the very large impact of seabird guano on maize δ(15)N values. The use of seabird guano as a fertilizer can thus be traced using stable isotope analysis in food chemistry applications (certification of organic inputs). Furthermore, the fertilization of maize with seabird guano creates an isotopic signature very similar to a high-trophic level marine resource, which must be considered when interpreting isotopic data from archaeological material
Cuts from residues: the one-loop case
Using the multivariate residue calculus of Leray, we give a precise
definition of the notion of a cut Feynman integral in dimensional
regularization, as a residue evaluated on the variety where some of the
propagators are put on shell. These are naturally associated to Landau
singularities of the first type. Focusing on the one-loop case, we give an
explicit parametrization to compute such cut integrals, with which we study
some of their properties and list explicit results for maximal and
next-to-maximal cuts. By analyzing homology groups, we show that cut integrals
associated to Landau singularities of the second type are specific combinations
of the usual cut integrals, and we obtain linear relations among different cuts
of the same integral. We also show that all one-loop Feynman integrals and
their cuts belong to the same class of functions, which can be written as
parametric integrals.Comment: v2: fixed minor typos in the normalisation of cut integral
ĐĐžŃОдŃкио воŃŃи. 2017. â 078
Stapp and others have proposed that reality involves a fundamental life process, or creative process. It is shown how this process description may be unified with the description that derives from quantum physics. The methods of the quantum physicist and of the biological sciences are seen to be two alternative approaches to the understanding of nature, involving two distinct modes of description which can usefully supplement each other, and neither on its own contains the full story. The unified view explains the major features of quantum mechanics and suggests that biological systems may function more effectively than would be expected on the basis of quantum mechanics alone
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