An investigation of the relationship between BOLD and perfusion signal changes during epileptic generalised spike wave activity

In pathological conditions interpretation of functional magnetic resonance imaging (fMRI) results can be difficult. This is due to a reliance on the assumed coupling between neuronal activity and changes in cerebral blood flow (CBF) and oxygenation. We wanted to investigate the coupling between blood oxygen level dependant contrast (BOLD) and CBF time courses in epilepsy patients with generalised spike wave activity (GSW) to better understand the underlying mechanisms behind the EEG-fMRI signal changes observed, especially in regions of negative BOLD response (NBR). Four patients with frequent GSW were scanned with simultaneous electroencephalographic (EEG)-fMRI with BOLD and arterial spin labeling (ASL) sequences. We examined the relationship between simultaneous CBF and BOLD measurements by looking at the correlation of the two signals in terms of percentage signal change on a voxel-by-voxel basis. This method is not reliant on coincident activation. BOLD and CBF were positively correlated in patients with epilepsy during background EEG activity and GSW. The subject average value of the ΔCBF/ΔBOLD slope lay between +19 and +36 and also showed spatial variation which could indicate areas with altered vascular response. There was not a significant difference between ΔCBF/ΔBOLD during GSW, suggesting that neurovascular coupling to BOLD signal is generally maintained between states and, in particular, within areas of NBR

Integrated Model and Index for Circular Economy in the Built-Environment in the Indian Context

Sustainable development aims at minimising waste and reducing exploitation of natural resources and energy, so that needs of the future generations are taken care of. Circular Economy (CE) is a new drift towards sustainability that aims at minimising waste and promoting material reuse, thereby creating a regenerative system. The construction industry is responsible for the extraction of raw materials and the generation of waste in large quantities, thereby making it an opportune sector for transition to a circular economy. On account of the complex nature of the built environment comprising various phases and associated actors, a proper framework or indexing for the circular economy is missing at present. This study aims to develop an integrated model of CE in the built environment which considers various construction stages and applicable strategies. An index for measuring the circularity potential in construction materials is also proposed, based on attributes developed from literature review and analysis of questionnaire survey. Simple Additive Weighting Method (SAWM), an elementary multi-criteria decision-making method is used for developing the index. It is anticipated that Circular Economy Potential Index (CEPI) would support decision-making in the initial stage of construction projects and help to compare the circularity of materials

Spoken word recognition without a TRACE

International audienceHow do we map the rapid input of spoken language onto phonological and lexical representations over time? Attempts at psychologically-tractable computational models of spoken word recognition tend either to ignore time or to transform the temporal input into a spatial representation. TRACE, a connectionist model with broad and deep coverage of speech perception and spoken word recognition phenomena, takes the latter approach, using exclusively time-specific units at every level of representation. TRACE reduplicates featural, phonemic, and lexical inputs at every time step in a large memory trace, with rich interconnections (excitatory forward and backward connections between levels and inhibitory links within levels). As the length of the memory trace is increased, or as the phoneme and lexical inventory of the model is increased to a realistic size, this reduplication of time-(temporal position) specific units leads to a dramatic proliferation of units and connections, begging the question of whether a more efficient approach is possible. Our starting point is the observation that models of visual object recognition-including visual word recognition-have grappled with the problem of spatial invariance, and arrived at solutions other than a fully-reduplicative strategy like that of TRACE. This inspires a new model of spoken word recognition that combines time-specific phoneme representations similar to those in TRACE with higher-level representations based on string kernels: temporally independent (time invariant) diphone and lexical units. This reduces the number of necessary units and connections by several orders of magnitude relative to TRACE. Critically, we compare the new model to TRACE on a set of key phenomena, demonstrating that the new model inherits much of the behavior of TRACE and that the drastic computational savings do not come at the cost of explanatory power

Energy decomposition analysis approaches and their evaluation on prototypical protein–drug interaction patterns

The partitioning of the energy in ab initio quantum mechanical calculations into its chemical origins (e.g., electrostatics, exchange-repulsion, polarization, and charge transfer) is a relatively recent development; such concepts of isolating chemically meaningful energy components from the interaction energy have been demonstrated by variational and perturbation based energy decomposition analysis approaches. The variational methods are typically derived from the early energy decomposition analysis of Morokuma [Morokuma, J. Chem. Phys., 1971, 55, 1236], and the perturbation approaches from the popular symmetry-adapted perturbation theory scheme [Jeziorski et al., Methods and Techniques in Computational Chemistry: METECC-94, 1993, ch. 13, p. 79]. Since these early works, many developments have taken place aiming to overcome limitations of the original schemes and provide more chemical significance to the energy components, which are not uniquely defined. In this review, after a brief overview of the origins of these methods we examine the theory behind the currently popular variational and perturbation based methods from the point of view of biochemical applications. We also compare and discuss the chemical relevance of energy components produced by these methods on six test sets that comprise model systems that display interactions typical of biomolecules (such as hydrogen bonding and pi-pi stacking interactions) including various treatments of the dispersion energy

Transvection-based gene regulation in Drosophila is a complex and plastic trait

Transvection, a chromosome pairing-dependent form of trans-based gene regulation, is potentially widespread in the Drosophila melanogaster genome and varies across cell types and within tissues in D. melanogaster, characteristics of a complex trait. Here, we demonstrate that the trans-interactions at the Malic enzyme (Men) locus are, in fact, transvection as classically defined and are plastic with respect to both genetic background and environment. Using chromosomal inversions, we show that trans-interactions at the Men locus are eliminated by changes in chromosomal architecture that presumably disrupt somatic pairing. We further show that the magnitude of transvection at the Men locus is modified by both genetic background and environment (temperature), demonstrating that transvection is a plastic phenotype. Our results suggest that transvection effects in D. melanogaster are shaped by a dynamic interplay between environment and genetic background. Interestingly, we find that cis-based regulation of the Men gene is more robust to genetic background and environment than trans-based. Finally, we begin to uncover the nonlocal factors that may contribute to variation in transvection overall, implicating Abd-B in the regulation of Men in cis and in trans in an allele-specific and tissue-specific manner, driven by differences in expression of the two genes across genetic backgrounds and environmental conditions

Photovoltaic characterisation of GaAsBi/GaAs multiple quantum well devices

A series of strained GaAsBi/GaAs multiple quantum well diodes are characterised to assess the potential of GaAsBi for photovoltaic applications. The devices are compared with strained and strain-balanced InGaAs based devices. The dark currents of the GaAsBi based devices are around 20 times higher than those of the InGaAs based devices. The GaAsBi devices that have undergone significant strain relaxation have dark currents that are a further 10–20 times higher. Quantum efficiency measurements show the GaAsBi devices have a lower energy absorption edge and stronger absorption than the strained InGaAs devices. These measurements also indicate incomplete carrier extraction from the GaAsBi based devices at short circuit, despite the devices having a relatively low background doping. This is attributed to hole trapping within the quantum wells, due to the large valence band offset of GaAsBi

Invitation to the Table Conversation: A Few Diverse Perspectives on Integration

This article represents an invitation to the integration table to several previously underrepresented perspectives within Christian psychology. The Judeo-Christian tradition and current views on scholarship and Christian faith compel us to extend hospitality to minority voices within integration, thereby enriching and challenging existing paradigms in the field. Contributors to this article, spanning areas of cultural, disciplinary, and theological diversity, provide suggestions for how their distinct voices can enhance future integrative efforts

Morphology, phenology and agronomic traits of two wild Mexican common bean (Phaseolus vulgaris L.) populations under cultivation

The objective of this research was to characterise two populations of wild bean grown simultaneously in an experimental field site in Chapingo, Mexico. For comparative purposes, two cultivars of common bean were included. Only seven of 24 phenological and morphological traits (e.g. number of days to emergence, expansion of primary leaves and third trifoliolate leaf, number of branches per plant, diameter of stem, number of flower buds per plant and nodes per branch) investigated were statistically similar between and within wild samples due largely to differences in growth habit. The number of inflorescences, leaves, pods and seeds per wild plant fluctuated between 72 and 145, 109 and 206, 68 and 284 and 180 and 513, respectively. In contrast, each cultivar was highly homogeneous. Principal component analyses supported the conclusion that these morphological and agronomic characteristics of wild common bean populations primarily depend on the predominant growth habit type and that under different environments, the expression of these traits may change

Bohm's interpretation and maximally entangled states

Several no-go theorems showed the incompatibility between the locality assumption and quantum correlations obtained from maximally entangled spin states. We analyze these no-go theorems in the framework of Bohm's interpretation. The mechanism by which non-local correlations appear during the results of measurements performed on distant parts of entangled systems is explicitly put into evidence in terms of Bohmian trajectories. It is shown that a GHZ like contradiction of the type+1=-1 occurs for well-chosen initial positions of the Bohmian trajectories and that it is this essential non-classical feature that makes it possible to violate the locality condition.Comment: 18 page