4,449 research outputs found
Library discovery through augmented reality: a game plan for academics
In order to create innovative pathways to services and resources, the authors propose placing a âgame-layerâ on top of the library, luring new patrons with the potential of playing an Alternate/Augmented Reality Game (ARG). Using both physical and virtual library space a variety of ânodesâ are created, drawing players to various library locales even regular patrons may be unfamiliar with and presenting them with story fragments and puzzles. Each node requires players to use library resources like databases and books, or engage library staff at known service points in order to move forward. Players contribute to the game itself in the form of puzzle solutions. Far more illustrative than a guided tour or required course/class, this library ARG encourages players to discover and utilize resources within the context of the game, generating fluency in library systems, places and platforms. But more importantly, the ARG invites a process of âmeta-level reflectionâ invaluable throughout a patronâs academic career
Alterations in Cortical Sensorimotor Connectivity following Complete Cervical Spinal Cord Injury: A Prospective Resting-State fMRI Study
Functional magnetic resonance imaging (fMRI) studies have demonstrated alterations during task-induced brain activation in spinal cord injury (SCI) patients. The interruption to structural integrity of the spinal cord and the resultant disrupted flow of bidirectional communication between the brain and the spinal cord might contribute to the observed dynamic reorganization (neural plasticity). However, the effect of SCI on brain resting-state connectivity patterns remains unclear. We undertook a prospective resting-state fMRI (rs-fMRI) study to explore changes to cortical activation patterns following SCI. With institutional review board approval, rs-fMRI data was obtained in eleven patients with complete cervical SCI (\u3e2 years post injury) and nine age-matched controls. The data was processed using the Analysis of Functional Neuroimages software. Region of interest (ROI) based analysis was performed to study changes in the sensorimotor network using pre- and post-central gyri as seed regions. Two-sampled t-test was carried out to check for significant differences between the two groups. SCI patients showed decreased functional connectivity in motor and sensory cortical regions when compared to controls. The decrease was noted in ipsilateral, contralateral, and interhemispheric regions for left and right precentral ROIs. Additionally, the left postcentral ROI demonstrated increased connectivity with the thalamus bilaterally in SCI patients. Our results suggest that cortical activation patterns in the sensorimotor network undergo dynamic reorganization following SCI. The presence of these changes in chronic spinal cord injury patients is suggestive of the inherent neural plasticity within the central nervous system
Calcium amido-bisoxazoline complexes in asymmetric hydroamination/cyclisation catalysis
Calcium complexes bearing bis(oxazolinylphenyl)amine (BOPA) ligands have been prepared, and their redistribution chemistry studied. The complexes [Ca(R-BOPA){N(SiMe3)2}(THF)] (R = iPr 1a, Ph 1b and Bn 1c) are active in hydroamination catalysis and give the highest enantioselectivity reported for a calcium complex
Evaluation of Whole-Brain Resting-State Functional Connectivity in Spinal Cord Injury - A Large-Scale Network Analysis Using Network Based Statistic
Large-scale network analysis characterizes the brain as a complex network of nodes and edges to evaluate functional connectivity patterns. The utility of graph-based techniques has been demonstrated in an increasing number of restingstate functional MRI (rs-fMRI) studies in the normal and diseased brain. However, to our knowledge, graph theory has not been used to study the reorganization pattern of resting-state brain networks in patients with traumatic complete spinal cord injury (SCI). In the present analysis, we applied a graph-theoretical approach to explore changes to global brain network architecture as a result of SCI. Fifteen subjects with chronic (\u3e 2 years) complete (American Spinal Injury Association [ASIA] A) cervical SCI and 15 neurologically intact controls were scanned using rs-fMRI. The data were preprocessed followed by parcellation of the brain into 116 regions of interest (ROI) or nodes. The average time series was extracted at each node, and correlation analysis was performed between every pair of nodes. A functional connectivity matrix for each subject was then generated. Subsequently, the matrices were averaged across groups, and network changes were evaluated between groups using the network-based statistic (NBS) method. Our results showed decreased connectivity in a subnetwork of the whole brain in SCI compared with control subjects. Upon further examination, increased connectivity was observed in a subnetwork of the sensorimotor cortex and cerebellum network in SCI. In conclusion, our findings emphasize the applicability of NBS to study functional connectivity architecture in diseased brain states. Further, we show reorganization of large-scale resting-state brain networks in traumatic SCI, with potential prognostic and therapeutic implications
Chromophore-labelled, luminescent platinum complexes: syntheses, structures, and spectroscopic properties
Ligands based upon 4-carboxamide-2-phenylquinoline derivatives have been synthesised with solubilising octyl hydrocarbon chains and tethered aromatic chromophores to give naphthyl (HL2), anthracenyl (HL3) and pyrenyl (HL4) ligand variants, together with a non-chromophoric analogue (HL1) for comparison. 1H NMR spectroscopic studies of the ligands showed that two non-interchangeable isomers exist for HL2 and HL4 while only one isomer exists for HL1 and HL3. Supporting DFT calculations on HL4 suggest that the two isomers may be closely isoenergetic with a relatively high barrier to exchange of ca. 100 kJ molâ1. These new ligands were cyclometalated with Pt(II) to give complexes [Pt(L1â4)(acac)] (acac = acetylacetonate). The spectroscopically characterised complexes were studied using multinuclear NMR spectroscopy including 195Pt{1H} NMR studies which revealed ÎŽPt ca. â2785 ppm for [Pt(L1â4)(acac)]. X-ray crystallographic studies were undertaken on [Pt(L3)(acac)] and [Pt(L4)(acac)], each showing the weakly distorted square planar geometry at Pt(II); the structure of [Pt(L3)(acac)] showed evidence for intermolecular PtâPt interactions. The UV-vis. absorption studies show that the spectral profiles for [Pt(L2â4)(acac)] are a composite of the organic chromophore centred bands and a broad 1MLCT (5d â Ï*) band (ca. 440 nm) associated with the complex. Luminescence studies showed that complexes [Pt(L2â4)(acac)] are dual emissive with fluorescence characteristic of the tethered fluorophore and long-lived phosphorescence attributed to 3MLCT emission. In the case of the pyrenyl derivative, [Pt(L4)(acac)], the close energetic matching of the 3MLCT and 3LCpyr excited states led to an elongation of the 3MLCT emission lifetime (Ï = 42 ÎŒs) under degassed solvent conditions, suggestive of energy transfer processes between the two states
Aluminium(iii) and zinc(ii) complexes of azobenzene-containing ligands for ring-opening polymerisation of Δ-caprolactone and rac-lactide
The ability to control the outcome of polymerisations using an external stimulus remains a formidable challenge. Herein, we report a series of photoactive Schiff base ligands bearing azobenzene moieties, as well as seven Al(III) and Zn(II) complexes. Transâcis isomerisation of the ligands and complexes occurred by exposure to UV light. Photoisomerisation was investigated using spectroscopic techniques and real-time reaction monitoring was conducted using FlowNMR. The activity of the complexes was tested in ring-opening polymerisation (ROP) of Δ-caprolactone and rac-lactide under ambient and UV light conditions, with the isomers of the Al(III) complexes displaying marked differences in activity in the ROP of Δ-caprolactone
In vivo quantification of peroxisome tethering to chloroplasts in tobacco epidermal cells using optical tweezers
Open access articlePeroxisomes are highly motile organelles that display a range of motions within a short time frame. In static snapshots they can be juxtaposed to chloroplasts which has led to the hypothesis that they are physically interacting. Here, using optical tweezers we have tested the dynamic physical interaction in vivo. Using near-infrared optical tweezers, combined with TIRF microscopy, we were able to trap peroxisomes and approximate the forces involved in chloroplast association in vivo, and observed weaker tethering to additional unknown structures within the cell. We show that chloroplasts and peroxisomes are physically tethered through peroxules, a poorly described structure in plant cells. We suggest peroxules have a novel role in maintaining peroxisome-organelle interactions in the dynamic environment. This could be important for fatty acid mobilisation and photorespiration through interaction with oil bodies and chloroplasts, highlighting a fundamentally important role for organelle interactions for essential biochemistry and physiological processes.Biotechnology and Biological Sciences Research Council (BBSRC)Science and Technology Facilities Council (STFC)Wellcome Trust - Institutional Strategic Support AwardLeverhulme Trus
Latent regulatory potential of human-specific repetitive elements
At least half of the human genome is derived from repetitive elements, which are often lineage specific and silenced by a variety of genetic and epigenetic mechanisms. Using a transchromosomic mouse strain that transmits an almost complete single copy of human chromosome 21 via the female germline, we show that a heterologous regulatory environment can transcriptionally activate transposon-derived human regulatory regions. In the mouse nucleus, hundreds of locations on human chromosome 21 newly associate with activating histone modifications in both somatic and germline tissues, and influence the gene expression of nearby transcripts. These regions are enriched with primate and human lineage-specific transposable elements, and their activation corresponds to changes in DNA methylation at CpG dinucleotides. This study reveals the latent regulatory potential of the repetitive human genome and illustrates the species specificity of mechanisms that control it
Metallocene catalysts for the ring-opening co-polymerisation of epoxides and cyclic anhydrides
The ring-opening co-polymerisation (ROCOP) of epoxides and cyclic anhydrides is a versatile route to new polyesters. The vast number of monomers that are readily available means that an effectively limitless number of unique polymeric materials can be prepared using a common synthetic route, thereby paving the way to polymers that are more recyclable and could be used in applications that currently lie exclusively within the remit of polyolefins. Metallocene complexes [Cp2MCl2] (M = Ti, Zr, Hf, Cp = η5-C5H5) are known to be excellent pre-catalysts for olefin polymerisation and yet have not been reported for ROCOP, despite their supreme pedigree in the polymerisation realm. Herein, we report the first application of [Cp2MCl2] as catalysts for the ROCOP of epoxides and anhydrides and show that they are effective catalysts for this reaction. The catalytic performances are good with standard epoxides such as cyclohexene oxide but are excellent with more challenging sterically demanding limonene oxide, and this therefore represents a highly effective catalyst system for the preparation of bio-derived recyclable polymers
Fully integrated safeguards and security for reprocessing plant monitoring.
Nuclear fuel reprocessing plants contain a wealth of plant monitoring data including material measurements, process monitoring, administrative procedures, and physical protection elements. Future facilities are moving in the direction of highly-integrated plant monitoring systems that make efficient use of the plant data to improve monitoring and reduce costs. The Separations and Safeguards Performance Model (SSPM) is an analysis tool that is used for modeling advanced monitoring systems and to determine system response under diversion scenarios. This report both describes the architecture for such a future monitoring system and present results under various diversion scenarios. Improvements made in the past year include the development of statistical tests for detecting material loss, the integration of material balance alarms to improve physical protection, and the integration of administrative procedures. The SSPM has been used to demonstrate how advanced instrumentation (as developed in the Material Protection, Accounting, and Control Technologies campaign) can benefit the overall safeguards system as well as how all instrumentation is tied into the physical protection system. This concept has the potential to greatly improve the probability of detection for both abrupt and protracted diversion of nuclear material
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