Cavity-coupled telecom atomic source in silicon

Atomic defects in solid-state materials are promising candidates for quantum interconnect and networking applications. Recently, a series of atomic defects have been identified in the silicon platform, where scalable device integration can be enabled by mature silicon photonics and electronics technologies. In particular, T centers hold great promise due to their telecom band optical transitions and the doublet ground state electronic spin manifold with long coherence times. However, an open challenge for advancing the T center platform is to enhance its weak and slow zero phonon line emission. In this work, we demonstrate the cavity-enhanced fluorescence emission from a single T center. This is realized by integrating single T centers with a low-loss, small mode-volume silicon photonic crystal cavity, which results in an enhancement of the fluorescence decay rate by a factor of $F$ = 6.89. Efficient photon extraction enables the system to achieve an average photon outcoupling rate of 73.3 kHz at the zero phonon line. The dynamics of the coupled system is well modeled by solving the Lindblad master equation. These results represent a significant step towards building efficient T center spin-photon interfaces for quantum information processing and networking applications

Impaired ubiquitin–proteasome system activity in the synapses of Huntington's disease mice

Huntington's disease (HD) is caused by the expansion of a polyglutamine tract in the N-terminal region of huntingtin (htt) and is characterized by selective neurodegeneration. In addition to forming nuclear aggregates, mutant htt accumulates in neuronal processes as well as synapses and affects synaptic function. However, the mechanism for the synaptic toxicity of mutant htt remains to be investigated. We targeted fluorescent reporters for the ubiquitin–proteasome system (UPS) to presynaptic or postsynaptic terminals of neurons. Using these reporters and biochemical assays of isolated synaptosomes, we found that mutant htt decreases synaptic UPS activity in cultured neurons and in HD mouse brains that express N-terminal or full-length mutant htt. Given that the UPS is a key regulator of synaptic plasticity and function, our findings offer insight into the selective neuronal dysfunction seen in HD and also establish a method to measure synaptic UPS activity in other neurological disease models

Is intraprocedural intravenous aspirin safe for patients who require emergent extracranial stenting during mechanical thrombectomy?

Background: Intraoperative antiplatelet therapy is recommended for emergent stenting during mechanical thrombectomy (MT). Most patients undergoing MT are also given thrombolysis. Antiplatelet agents are contraindicated within 24 hours of thrombolysis. We evaluated outcomes and complications of patients stented with and without intravenous aspirin during MT. Methods: All patients who underwent emergent extracranial stenting during MT at the Royal Stoke University Hospital, UK between 2010 and 2020, were included. Patients were thrombolysed before MT, unless contraindicated. Aspirin 500 mg intravenously was given intraoperatively at the discretion of the operator. Symptomatic intracranial haemorrhage (sICH) and the National Institutes for Health Stroke Scale score (NIHSS) were recorded at 7 days, and mortality and functional recovery (modified Rankin Scale: mRS ≤2) at 90 days. Results: Out of 565 patients treated by MT 102 patients (median age 67 IQR 57-72 years, baseline median NIHSS 18 IQR 13-23, 76 (75%) thrombolysed) had a stent placed. Of these 49 (48%) were given aspirin and 53 (52%) were not. Patients treated with aspirin had greater NIHSS improvement (median 8 IQR 1-16 vs median 3 IQR -9-8 points, p=0.003), but there were no significant differences in sICH (2/49 (4%) vs 9/53 (17%)), mRS ≤2 (25/49 (51%) vs 19/53 (36%)) and mortality (10/49 (20%) vs 12/53 (23%)) with and without aspirin. NIHSS improvement (median 12 IQR 4-18 vs median 7 IQR -7-10, p=0.01) was greater, and mortality was lower (4/33 (12%) vs 6/15 (40%), p=0.05) when aspirin was combined with thrombolysis, than for aspirin alone, with no increase in bleeding. Conclusion: Our findings based on registry data derived from routine clinical care suggest that intraprocedural intravenous aspirin in patients undergoing emergent stenting during MT does not increase sICH and is associated with good clinical outcomes, even when combined with intravenous thrombolysis.</p

The Burkholderia contaminans MS14 ocfC Gene Encodes a Xylosyltransferase for Production of the Antifungal Occidiofungin

Burkholderia contaminans strain MS14 produces the antifungal compound occidiofungin, which is responsible for significant antifungal activities against a broad range of plant and animal fungal pathogens. Occidiofungin is a cyclic glycolipopeptide made up of eight amino acids and one xylose. A 56-kb ocf gene cluster was determined to be essential for occidiofungin production. In this study, the ocfC gene, which is located downstream of ocfD and upstream of the ocfB gene in the ocf gene cluster, was examined. Antifungal activity of the ocfC gene mutant MS14KC1 was reduced against the indicator fungus Geotrichum candidum compared with that of the wild-type strain. Furthermore, the analysis of the protein sequence suggests that the ocfC gene encodes a glycosyltransferase. Biochemical analyses using nuclear magnetic resonance (NMR) and mass spectroscopy revealed that the ocfC mutant produced the occidiofungin without the xylose. The purified ocfC mutant MS14KC1 product had a level of bioactivity similar to that of the wild-type product. The revertant MS14KC1-R of the ocfC mutant produced the same antifungal activity level on plate assays and the same antifungal compound based on high-performance liquid chromatography (HPLC) and mass spectroscopy analysis as wild-type strain MS14. Collectively, the study demonstrates that the ocfC gene encodes a glycosyltransferase responsible to add a xylose to the occidiofungin molecule and that the presence of the xylose is not important for antifungal activity against Candida species. The finding provides a novel variant for future studies aimed at evaluating its use for inhibiting clinical and agricultural fungi, and the finding could also simplify the chemical synthesis of occidiofungin variants

The charcoal trap: Miombo forests and the energy needs of people

<p>Abstract</p> <p>Background</p> <p>This study evaluates the carbon dioxide and other greenhouse gas fluxes to the atmosphere resulting from charcoal production in Zambia. It combines new biomass and flux data from a study, that was conducted in a <it>miombo </it>woodland within the Kataba Forest Reserve in the Western Province of Zambia, with data from other studies.</p> <p>Results</p> <p>The measurements at Kataba compared protected area (3 plots) with a highly disturbed plot outside the forest reserve and showed considerably reduced biomass after logging for charcoal production. The average aboveground biomass content of the reserve (Plots 2-4) was around 150 t ha^-1, while the disturbed plot only contained 24 t ha^-1. Soil carbon was not reduced significantly in the disturbed plot. Two years of eddy covariance measurements resulted in net ecosystem exchange values of -17 ± 31 g C m^-2y^-1, in the first and 90 ± 16 g C m^-2in the second year. Thus, on the basis of these two years of measurement, there is no evidence that the <it>miombo </it>woodland at Kataba represents a present-day carbon sink. At the country level, it is likely that deforestation for charcoal production currently leads to a per capita emission rate of 2 - 3 t CO₂y^-1. This is due to poor forest regeneration, although the resilience of <it>miombo </it>woodlands is high. Better post-harvest management could change this situation.</p> <p>Conclusions</p> <p>We argue that protection of <it>miombo </it>woodlands has to account for the energy demands of the population. The production at national scale that we estimated converts into 10,000 - 15,000 GWh y^-1of energy in the charcoal. The term "Charcoal Trap" we introduce, describes the fact that this energy supply has to be substituted when woodlands are protected. One possible solution, a shift in energy supply from charcoal to electricity, would reduce the pressure of forests but requires high investments into grid and power generation. Since Zambia currently cannot generate this money by itself, the country will remain locked in the charcoal trap such as many other of its African neighbours. The question arises whether and how money and technology transfer to increase regenerative electrical power generation should become part of a post-Kyoto process. Furthermore, better inventory data are urgently required to improve knowledge about the current state of the woodland usage and recovery. Net greenhouse gas emissions could be reduced substantially by improving the post-harvest management, charcoal production technology and/or providing alternative energy supply.</p

Cardiovascular Fitness and Executive Functioning in Primary School-aged Children

Previous research in children has shown that higher cardiovascular fitness is related to better executive functioning. However, the available literature is hampered by methodological limitations. The present study investigates the relationship between cardiovascular fitness and executive functioning in a large sample of healthy children (N = 814). Cardiovascular fitness was assessed with estimated VO2Max from 20 m Shuttle Run Test performance. Executive functioning was assessed using a set of computerized neurocognitive tasks aimed at executive functions (working memory, motor inhibition, interference control) and lower-level neurocognitive functions (information processing and attention). Dependent measures derived from the neurocognitive tests were subjected to principal component analysis. Mixed model analyses tested the relation between cardiovascular fitness and neurocognitive functioning components. Results showed that children with higher cardiovascular fitness performed better on the neurocognitive function components Information Processing and Control, Visuospatial Working Memory and Attention Efficiency. The following measures contained in these components contributed to the observed relations: information processing measures, visuospatial working memory, and speed of alerting attention. No relationship was found between cardiovascular fitness and the other components: Verbal Working Memory, Attention Accuracy, and Interference Control. The present study suggests that there is a relationship between cardiovascular fitness and a specific set of executive functions and lower level neurocognitive functions. These findings highlight the importance of cardiovascular fitness for the overall health of school-aged children

Search for supersymmetric particles in scenarios with a gravitino LSP and stau NLSP

Sleptons, neutralinos and charginos were searched for in the context of scenarios where the lightest supersymmetric particle is the gravitino. It was assumed that the stau is the next-to-lightest supersymmetric particle. Data collected with the DELPHI detector at a centre-of-mass energy near 189 GeV were analysed combining the methods developed in previous searches at lower energies. No evidence for the production of these supersymmetric particles was found. Hence, limits were derived at 95% confidence level.Comment: 31 pages, 14 figure

Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}$and correspond to an integrated luminosity of$4.6\;{\rm f}{{{\rm b}}^{-1}}$. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum${{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}$and pseudorapidity$|\eta |\lt 1.9$, is measured to be${{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques