543 research outputs found

    Effectiveness of defatted seed meals from Brassicaceae with or without crude glycerin against black grass ( Alopecurus myosuroides Huds.)

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    Herbicide resistance has become an increasing problem, and at the same time pesticide usage is declining due to stringent EU pesticide legislation which aims to reduce the impact on environment and human health. For these reasons, new alternative integrated weed management approaches are becoming increasingly relevant. Formulations based on Brassica defatted seed meals (DSMs) and glycerin, have previously been shown to be effective in reducing the germination of lettuce seed. In this work five DSMs, formulated with and without crude glycerin, were chosen for in vitro and glasshouse experiments: i) Brassica nigra, ii) Brassica tournefortii, iii) Eruca sativa, iv) Rapistrum rugosum and v) Sinapis alba. Black-grass (Alopecurus myosuroides), a weed demonstrating extensive herbicide resistance, was used as a target, and the germination inhibition caused on this weed by Brassica defatted seed meals was assessed. In both in vitro and in vivo experiments, the most effective DSM for inhibiting germination of both lettuce and black-grass seeds was the sinigrin containing DSM, Brassica nigra. The aim of the manuscript was to suggest a new high value application for Brassicas derived DSM as a co-products from the vegetable oil production chain. The proposed treatments could represent an interesting and 100% novel natural alternative to the conventional herbicides

    A portable diagnostic device for cardiac magnetic field mapping

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    In this paper we present a portable magnetocardiography device. The focus of this development was delivering a rapid assessment of chest pain in an emergency department. The aim was therefore to produce an inexpensive device that could be rapidly deployed in a noisy unshielded ward environment. We found that induction coil magnetometers with a coil design optimized for magnetic field mapping possess sufficient sensitivity (104fT /√ Hz noise floor at 10Hz) and response (813fT /µV at 10Hz) for cycle averaged magnetocardiography and are able to measure depolarisation signals in an unshielded environment. We were unable to observe repolarisation signals to a reasonable fidelity. We present the design of the induction coil sensor array and signal processing routine along with data demonstrating performance in a hospital environment

    Reversible Optogenetic Control of Subcellular Protein Localization in a Live Vertebrate Embryo.

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    We demonstrate the utility of the phytochrome system to rapidly and reversibly recruit proteins to specific subcellular regions within specific cells in a living vertebrate embryo. Light-induced heterodimerization using the phytochrome system has previously been used as a powerful tool to dissect signaling pathways for single cells in culture but has not previously been used to reversibly manipulate the precise subcellular location of proteins in multicellular organisms. Here we report the experimental conditions necessary to use this system to manipulate proteins in vivo. As proof of principle, we demonstrate that we can manipulate the localization of the apical polarity protein Pard3 with high temporal and spatial precision in both the neural tube and the embryo's enveloping layer epithelium. Our optimizations of optogenetic component expression and chromophore purification and delivery should significantly lower the barrier for establishing this powerful optogenetic system in other multicellular organisms

    Sand stirred by chaotic advection

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    We study the spatial structure of a granular material, N particles subject to inelastic mutual collisions, when it is stirred by a bidimensional smooth chaotic flow. A simple dynamical model is introduced where four different time scales are explicitly considered: i) the Stokes time, accounting for the inertia of the particles, ii) the mean collision time among the grains, iii) the typical time scale of the flow, and iv) the inverse of the Lyapunov exponent of the chaotic flow, which gives a typical time for the separation of two initially close parcels of fluid. Depending on the relative values of these different times a complex scenario appears for the long-time steady spatial distribution of particles, where clusters of particles may or not appear.Comment: 4 pages, 3 figure

    Radiocarbon chronology and environmental context of Last Glacial Maximum human occupation in Switzerland

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    Central Europe during the Last Glacial Maximum (LGM) was dominated by polar desert and steppe-tundra biomes. Despite this, a human presence during this time period is evident at several locations across the region, including in Switzerland, less than 50 km from the Alpine ice sheet margin. It has been hypothesised that such human activity may have been restricted to brief periods of climatic warming within the LGM, but chronological information from many of these sites are currently too poorly resolved to corroborate this. Here we present a revised chronology of LGM human occupation in Switzerland. AMS radiocarbon dating of cut-marked reindeer (Rangifer tarandus) bones from the sites of Kastelhöhle-Nord and Y-Höhle indicates human occupation of Switzerland was most likely restricted to between 23,400 and 22,800 cal. BP. This timeframe corresponds to Greenland Interstadial 2, a brief warming phase, supporting the hypothesis that human presence was facilitated by favourable climatic episodes. Carbon, nitrogen and sulphur stable isotope analysis of the fauna provides palaeoenvironmental information for this time period. These findings contribute to our understanding of human activity in ice-marginal environments and have implications for understanding cultural connections across central Europe during the LGM

    Changing environment at the Late Upper Palaeolithic ite of Lynx Cave, North Wales

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    Lynx Cave is one of a handful of locations in North Wales that provide evidence of Late Upper Palaeolithic huntergatherers at the end of the last ice-age. With the region being recolonized at a time of rapid environmental change there is a need to develop on-site palaeoenvironmental records that are directly linked to the archaeology in order to further understanding of the environments and landscapes that these hunter-gatherer groups experienced. Through carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) stable isotope analysis of animal bones we explore the environmental conditions during the human occupation of Lynx Cave. Analysis of the data indicates the faunal isotope results cluster into three distinct groupings, which when considered in light of the species composition, radiocarbon dates, sample layer provenance and known temporal patterns in herbivore isotope data from Northern Europe, are likely to relate to GI-1cba (the Allerød period) around 13,700-13,000 cal BP, GI-1cba/GS-1 (the Late Allerød/ early Younger Dryas period) around 13,100-12,800 cal BP, and the Bronze Age. The isotope data indicates that the Late Upper Palaeolithic or Late Palaeolithic occupations occurred in an open landscape in which soils were undergoing changing hydrological conditions linked to ice sheet melt and permafrost thaw process and subsequent recovery. The evidence of butchery marks on the faunal remains from both Late Glacial isotope clusters, along with the disparate radiocarbon dates and the presence of three hearths, support the idea of very short-term episodic use of the cave over an extended time period

    Robot Assisted Surgical Ward Rounds: Virtually Always There

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    Background:  While an explosion in technological sophistication has revolutionized surgery within the operating theatre, delivery of surgical ward-based care has seen little innovation.  Use of telepresence allowing off-site clinicians communicate with patients has been largely restricted to outpatient settings or use of complex, expensive, static devices.  We designed a prospective study to ascertain feasibility and face validity of a remotely controlled mobile audiovisual drone (LUCY) to access inpatients.  This device is, uniquely, lightweight, freely mobile and emulates ‘human’ interaction by swiveling and adjusting height to patients’ eye-level.   Methods: Robot-assisted ward rounds(RASWR) were conducted over 3 months. A remotely located consultant surgeon communicated with patients/bedside teams via encrypted audiovisual telepresence robot (DoubleRoboticstm, California USA).  Likert-scale satisfaction questionnaires, incorporating free-text sections for mixed-methods data collection, were disseminated to patient and staff volunteers following RASWRs.  The same cohort completed a linked questionnaire following conventional (gold-standard) rounds, acting as control group. Data were paired, and non-parametric analysis performed.  Results: RASWRs are feasible (>90% completed without technical difficulty). The RASWR(n=52 observations) demonstrated face validity with strong correlations (r>0.7; Spearman, p-value <0.05) between robotic and conventional ward rounds among patients and staff on core themes, including dignity/confidentiality/communication/satisfaction with management plan. Patients (96.08%, n=25) agreed RASWR were a satisfactory alternative when consultant physical presence was not possible. There was acceptance of nursing/NCHD cohort (100% (n=11) willing to regularly partake in RASWR).  Conclusion: RASWRs receive high levels of patient and staff acceptance, and offer a valid alternative to conventional ward rounds when a consultant cannot be physically present

    Iso-Wetlands: unlocking wetland ecologies and agriculture in prehistory through sulfur isotopes

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    Iso-Wetlands is a new, NERC-funded collaborative research project involving researchers at UCL Institute of Archaeology, the University of Leeds and the UK Centre for Ecology and Hydrology. The project is developing sulfur isotope analysis of archaeological plants and animals as a new tool for exploring hydrological conditions under which agricultural production was taking place. This development has the potential to improve understanding of water management strategies in the past, particularly in relation to seasonal floodwater agriculture and wetland agriculture (for example, rice paddy systems). The project will open wider possibilities for the use of sulfur isotopes in archaeology and ecology to examine wetland habitat use by both people and animals
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