Split buildings of type F₄ in buildings of type E₆

A symplectic polarity of a building of type is a polarity whose fixed point structure is a building of type containing residues isomorphic to symplectic polar spaces (i.e., so-called split buildings of type ). In this paper, we show in a geometric way that every building of type contains, up to conjugacy, a unique class of symplectic polarities. We also show that the natural point-line geometry of each split building of type fully embedded in the natural point-line geometry of arises from a symplectic polarity

A deep gold mine metagenome as a source of novel esterases

New sources of enzymes for biotechnological applications are continually being sought for. While diverse microbial ecosysyems have been demonstrated in the deep subsurfaces, deep mines provide easy access to these specialist communities. Therefore, the aim of this study was to assess a deep mine biofilm as a source of novel esterase enzymes. Biofilm was collected from the Beatrix Mine in South Africa, at a depth of 808 m. Assessment of the diversity revealed a group of previously uncultured bacteria and archaea. A metagenome library was screened for esterolytic activity, producing two esterolytic clones: a phospholipase patatin protein and an isochorismatase family protein. The isochorismatase family protein contained the catalytic Asp and Cys but not the Arg, which is considered as important for catalysis. The patatin showed 55% similarity to its closest relative; the patatin family protein from Plesiocystis pacifica. The expressed patatin displayed a preference for the C6 ester and was maximally active at pH 8 and 30°C. This study reported that screening of a relatively small metagenome library from the deep mine biofilm provided two esterolytic clones, which differed from their known counterparts. This indicates that the deep mine ecosystems contain an untapped resource of novel and potentially useful enzymes which may have applications in chemical syntheses.Key words: Metagenome library, functional screening, lipolytic activity, patatin, isochorismatas

Pitfalls using tributyrin agar screening to detect lipolytic activity in metagenomic studies

The metagenomics approach is an efficient method for obtaining novel biocatalysts and useful genes from uncultured microorganisms within diverse environments. In this study, we constructed a metagenomic library using a South African deep mine biofilm sample. The library was screened forlipolytic activity using LB Tributyrin (TLB). Although we were able to identify 3 diverse esterase enzymes, we found that 70% of the obtained sequence data revealed the presence of enzymes and genes completely unrelated to that of lipolytic enzymes thereby highlighting the limitation of screening with TLB

What is trained during food go/no-go training? A review focusing on mechanisms and a research agenda

This is the final version of the article. Available from the publisher via the DOI in this record.Purpose of Review: During food go/no-go training, people consistently withhold responses toward no-go food items. We discuss how food go/no-go training may change people’s behavior toward no-go food items by comparing three accounts: (a) the training strengthens ‘top-down’ inhibitory control over food-related responses, (b) the training creates automatic ‘bottom-up’ associations between no-go food items and stopping responses, and (c) the training leads to devaluation of no-go food items. Recent Findings: Go/no-go training can reduce intake of food and choices for food and facilitate short-term weight loss. It appears unlikely that food go/no-go training strengthens top-down inhibitory control. There is some evidence suggesting the training could create automatic stop associations. There is strong evidence suggesting go/no-go training reduces evaluations of no-go food items. Summary: Food go/no-go training can change behavior toward food and evaluation of food items. To advance knowledge, more research is needed on the underlying mechanisms of the training, the role of attention during go/no-go training, and on when effects generalize to untrained food items.© The Author(s) 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. About this articl

Movement-related beta oscillations show high intra-individual reliability

Oscillatory activity in the beta frequency range (15-30Hz) recorded from human sensorimotor cortex is of increasing interest as a putative biomarker of motor system function and dysfunction. Despite its increasing use in basic and clinical research, surprisingly little is known about the test-retest reliability of spectral power and peak frequency measures of beta oscillatory signals from sensorimotor cortex. Establishing that these beta measures are stable over time in healthy populations is a necessary precursor to their use in the clinic. Here, we used scalp electroencephalography (EEG) to evaluate intra-individual reliability of beta-band oscillations over six sessions, focusing on changes in beta activity during movement (Movement-Related Beta Desynchronization, MRBD) and after movement termination (Post-Movement Beta Rebound, PMBR). Subjects performed visually-cued unimanual wrist flexion and extension. We assessed Intraclass Correlation Coefficients (ICC) and between-session correlations for spectral power and peak frequency measures of movement-related and resting beta activity. Movement-related and resting beta power from both sensorimotor cortices was highly reliable across sessions. Resting beta power yielded highest reliability (average ICC=0.903), followed by MRBD (average ICC=0.886) and PMBR (average ICC=0.663). Notably, peak frequency measures yielded lower ICC values compared to the assessment of spectral power, particularly for movement-related beta activity (ICC=0.386-0.402). Our data highlight that power measures of movement-related beta oscillations are highly reliable, while corresponding peak frequency measures show greater intra-individual variability across sessions. Importantly, our finding that beta power estimates show high intra-individual reliability over time serves to validate the notion that these measures reflect meaningful individual differences that can be utilised in basic research and clinical studies

Lyapunov exponent of the random frequency oscillator: cumulant expansion approach

We consider a one-dimensional harmonic oscillator with a random frequency, focusing on both the standard and the generalized Lyapunov exponents, $\lambda$ and $\lambda^\star$ respectively. We discuss the numerical difficulties that arise in the numerical calculation of $\lambda^\star$ in the case of strong intermittency. When the frequency corresponds to a Ornstein-Uhlenbeck process, we compute analytically $\lambda^\star$ by using a cumulant expansion including up to the fourth order. Connections with the problem of finding an analytical estimate for the largest Lyapunov exponent of a many-body system with smooth interactions are discussed.Comment: 6 pages, 4 figures, to appear in J. Phys. Conf. Series - LAWNP0

Reconstructions of deltaic environments from Holocene palynological records in the Volga delta, northern Caspian Sea

This article was made available through open access by the Brunel Open Access Publishing Fund.New palynological and ostracod data are presented from the Holocene Volga delta, obtained from short cores and surface samples collected in the Damchik region, near Astrakhan, Russian Federation in the northern Caspian Sea. Four phases of delta deposition are recognized and constrained by accelerated mass spectrometry (AMS) radiocarbon ages. Palynological records show that erosive channels, dunes (Baer hills) and inter-dune lakes were present during the period 11,500–8900 cal. BP at the time of the Mangyshlak Caspian lowstand. The period 8900–3770 cal. BP was characterized regionally by extensive steppe vegetation, with forest present at times with warmer, more humid climates, and with halophytic and xerophytic vegetation present at times of drought. The period 3770–2080 cal. BP was a time of active delta deposition, with forest or woodland close to the delta, indicating relatively warm and humid climates and variable Caspian Sea levels. From 2080 cal. BP to the present-day, aquatic pollen is frequent in highstand intervals and herbaceous pollen and fungal hyphae frequent in lowstand intervals. Soils and incised valley sediments are associated with the regional Derbent regression and may be time-equivalent with the ‘Medieval Warm Period’. Fungal spores are an indicator of erosional or aeolian processes, whereas fungal hyphae are associated with soil formation. Freshwater algae, ostracods and dinocysts indicate mainly freshwater conditions during the Holocene with minor brackish influences. Dinocysts present include Spiniferites cruciformis, Caspidinium rugosum, Impagidinium caspienense and Pterocysta cruciformis, the latter a new record for the Caspian Sea. The Holocene Volga delta is a partial analogue for the much larger oil and gas bearing Mio-Pliocene palaeo-Volga delta.Funding for the data collection and field work was provided from the following sources: 1 – IGCP-UNESCO 2003–2008 (Project 481 CASPAGE, Dating Caspian Sea Level Change); 2 – NWO, Netherlands Science Foundation and RFFI, Russian Science Foundation 2005–2008 (Programme: ‘VHR Seismic Stratigraphy and Paleoecology of the Holocene Volga Delta’); and 3 – BP Exploration (Caspian Sea) Sea Ltd. (Azeri-Chirag-Gunashli) 2005–2008 (‘Unravelling the Small-Scale Stratigraphy and Sediment Dynamics of the Modern Volga Delta Using VHR Marine Geophysics’). The palynological work was funded jointly by BP Exploration (Caspian Sea) Ltd., Delft University of Technology and KrA Stratigraphic Ltd. Ostracod analyses were funded by StrataData Ltd. and funding for two additional radiocarbon dates provided by Deltares