Cardio-Protection Afforded by Β-Blockade Is Maintained During Resistance Exercise

Objectives Whether or not the cardio-protective effect of β-adrenergic blockade is retained during resistance exercise has not been systematically evaluated. Therefore the purpose of this study was to measure selected cardiorespiratory responses to isometric exercise involving hand-gripping, single-leg extension, or double-leg dead-lift, under placebo (control), β1-selective (atenolol), and non-selective (propranolol) adrenergic blockade conditions. Design Eleven young male adults were evaluated in a randomized, double-blinded, repeated measures study design and performed all three exercise modalities at 30% of maximal voluntary contraction under placebo, atenolol and propranolol conditions. Methods Heart rate, systolic and diastolic blood pressure, rate-pressure product, oxygen uptake, cardiac output, stroke volume and total peripheral resistance were directly measured or calculated at rest and during the third minute of each of the three exercise modes. Results Irrespective of drug condition, a graded pressor response was observed going from rest to exercise so that rest \u3c handgrip \u3c leg extension \u3c dead-lift for heart rate, systolic and diastolic blood pressures, rate-pressure product and oxygen uptake (p \u3c 0.05 for all). Cardiac output only increased with the dead-lift mode of exercise (p \u3c 0.01). Importantly β-adrenergic blockade with either atenolol or propranolol similarly attenuated the rise in heart rate, and systolic blood pressure; thus rate-pressure product demonstrated a mode-of-exercise by drug interaction effect (p \u3c 0.001) with the greatest reductions seen with the dead-lift procedure. Conclusions The findings indicate that cardio-protection afforded by selective or non-selective β-blockade at rest is preserved during isometric exercise and even enhanced once heart rate increases above 100 beats min−1

Non-Parametric Estimation of Forecast Distributions in Non-Gaussian, Non-linear State Space Models

The object of this paper is to produce non-parametric maximum likelihood estimates of forecast distributions in a general non-Gaussian, non-linear state space setting. The transition densities that define the evolution of the dynamic state process are represented in parametric form, but the conditional distribution of the non-Gaussian variable is estimated non-parametrically. The filtering and prediction distributions are estimated via a computationally efficient algorithm that exploits the functional relationship between the observed variable, the state variable and a measurement error with an invariant distribution. Simulation experiments are used to document the accuracy of the non-parametric method relative to both correctly and incorrectly specified parametric alternatives. In an empirical illustration, the method is used to produce sequential estimates of the forecast distribution of realized volatility on the S&P500 stock index during the recent financial crisis. A resampling technique for measuring sampling variation in the estimated forecast distributions is also demonstrated.Probabilistic Forecasting; Non-Gaussian Time Series; Grid-based Filtering; Penalized Likelihood; Subsampling; Realized Volatility.

Pulsar Wind Nebulae in EGRET Error Boxes

A remarkable number of pulsar wind nebulae (PWN) are coincident with EGRET gamma-ray sources. X-ray and radio imaging studies of unidentified EGRET sources have resulted in the discovery of at least 6 new pulsar wind nebulae (PWN). Stationary PWN (SPWN) appear to be associated with steady EGRET sources with hard spectra, typical for gamma-ray pulsars. Their toroidal morphologies can help determine the geometry of the pulsar which is useful for constraining models of pulsed gamma-ray emission. Rapidly moving PWN (RPWN) with more cometary morphologies seem to be associated with variable EGRET sources in regions where the ambient medium is dense compared to what is typical for the ISM.Comment: 8 pages, 5 figures, to appear in the proceedings of "The Multiwavelength Approach to Unidentified Sources", ed. G. Romero & K.S. Chen

Youth violence intervention programme for vulnerable young people attending emergency departments in London: a rapid evaluation

BACKGROUND: Youth violence intervention programmes involving the embedding of youth workers in NHS emergency departments to help young people (broadly aged between 11 and 24 years) improve the quality of their lives following their attendance at an emergency department as a result of violent assault or associated trauma are increasing across the NHS. This study evaluates one such initiative run by the charity Redthread in partnership with a NHS trust. OBJECTIVES: To evaluate the implementation and impact of a new youth violence intervention programme at University College London Hospital NHS Trust and delivered by the charity Redthread: (1) literature review of studies of hospital-based violent crime interventions; (2) evaluation of local implementation and of University College London Hospital staff and relevant local stakeholders concerning the intervention and its impact; (3) assessment of the feasibility of using routine secondary care data to evaluate the impact of the Redthread intervention; and (4) cost-effectiveness analysis of the Redthread intervention from the perspective of the NHS. METHODS: The evaluation was designed as a mixed-methods multiphased study, including an in-depth process evaluation case study and quantitative and economic analyses. The project was undertaken in different stages over two years, starting with desk-based research and an exploratory phase suitable for remote working while COVID-19 was affecting NHS services. A total of 22 semistructured interviews were conducted with staff at Redthread and University College London Hospital and others (e.g. a senior stakeholder involved in NHS youth violence prevention policy). We analysed Redthread documents, engaged with experts and conducted observations of staff meetings to gather more in-depth insights about the effectiveness of the intervention, the processes of implementation, staff perceptions and cost. We also undertook quantitative analyses to ascertain suitable measures of impact to inform stakeholders and future evaluations. RESULTS: Redthread's service was viewed as a necessary intervention, which complemented clinical and other statutory services. It was well embedded in the paediatric emergency department and adolescent services but less so in the adult emergency department. The diverse reasons for individual referrals, the various routes by which young people were identified, and the mix of specific support interventions provided, together emphasised the complexity of this intervention, with consequent challenges in implementation and evaluation. Given the relative unit costs of Redthread and University College London Hospital's inpatient services, it is estimated that the service would break even if around one-third of Redthread interventions resulted in at least one avoided emergency inpatient admission. This evaluation was unable to determine a feasible approach to measuring the quantitative impact of Redthread's youth violence intervention programme but has reflected on data describing the service, including costs, and make recommendations to support future evaluation. LIMITATIONS: The COVID-19 pandemic severely hampered the implementation of the Redthread service and the ability to evaluate it. The strongest options for analysis of effects and costs were not possible due to constraints of the consent process, problems in linking Redthread and University College London Hospital patient data and the relatively small numbers of young people having been engaged for longer-term support over the evaluation period. CONCLUSIONS: We have been able to contribute to the qualitative evidence on the implementation of the youth violence intervention programme at University College London Hospital, showing, for example, that NHS staff viewed the service as an important and needed intervention. In the light of problems with routine patient data systems and linkages, we have also been able to reflect on data describing the service, including costs, and made recommendations to support future evaluation. FUTURE WORK: No future work is planned. FUNDING: National Institute for Health and Care Research Health Services and Delivery Research programme (RSET: 16/138/17)

Ferrets exclusively synthesize Neu5Ac and express naturally humanized influenza A virus receptors

Mammals express the sialic acids ​N-acetylneuraminic acid (​Neu5Ac) and ​N-glycolylneuraminic acid (​Neu5Gc) on cell surfaces, where they act as receptors for pathogens, including influenza A virus (IAV). ​Neu5Gc is synthesized from ​Neu5Ac by the enzyme cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH). In humans, this enzyme is inactive and only ​Neu5Ac is produced. Ferrets are susceptible to human-adapted IAV strains and have been the dominant animal model for IAV studies. Here we show that ferrets, like humans, do not synthesize ​Neu5Gc. Genomic analysis reveals an ancient, nine-exon deletion in the ferret CMAH gene that is shared by the Pinnipedia and Musteloidia members of the Carnivora. Interactions between two human strains of IAV with the sialyllactose receptor (sialic acid—α2,6Gal) confirm that the type of terminal sialic acid contributes significantly to IAV receptor specificity. Our results indicate that exclusive expression of ​Neu5Ac contributes to the susceptibility of ferrets to human-adapted IAV strains

Spectral and morphological analysis of the remnant of Supernova 1987A with ALMA & ATCA

We present a comprehensive spectral and morphological analysis of the remnant of Supernova (SN) 1987A with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The non-thermal and thermal components of the radio emission are investigated in images from 94 to 672 GHz ($\lambda$ 3.2 mm to 450 $\mu$m), with the assistance of a high-resolution 44 GHz synchrotron template from the ATCA, and a dust template from ALMA observations at 672 GHz. An analysis of the emission distribution over the equatorial ring in images from 44 to 345 GHz highlights a gradual decrease of the east-to-west asymmetry ratio with frequency. We attribute this to the shorter synchrotron lifetime at high frequencies. Across the transition from radio to far infrared, both the synchrotron/dust-subtracted images and the spectral energy distribution (SED) suggest additional emission beside the main synchrotron component ($S_{\nu}\propto\nu^{-0.73}$) and the thermal component originating from dust grains at $T\sim22$ K. This excess could be due to free-free flux or emission from grains of colder dust. However, a second flat-spectrum synchrotron component appears to better fit the SED, implying that the emission could be attributed to a pulsar wind nebula (PWN). The residual emission is mainly localised west of the SN site, as the spectral analysis yields $-0.4\lesssim\alpha\lesssim-0.1$ across the western regions, with $\alpha\sim0$ around the central region. If there is a PWN in the remnant interior, these data suggest that the pulsar may be offset westward from the SN position.Comment: ApJ accepted. 21 pages, emulateapj. References update

Novel cement curing technique by using controlled release of carbon dioxide coupled with nanosilica

Nanotechnology has attracted a lot of interest in the modification of building materials involving nanoparticles. Among the nanoparticles available, the incorporation of nano-silica draws intense attention due to the similarity of its chemical composition with cement and its pozzolanic properties. In this work, the potential capability to utilise CO2 in improving cement composites properties through carbonation acceleration mechanism was explored. In this study, various type of nano silica was used as a CO2 carrier and incorporated into cement mortar design with different amount of carbonated silica loading, ranging from 0.55 wt% to 2.42 wt% and cured in water and ambient air condition. The aim of this study is to examine the effects on the compressive strength of nano-silica impregnated with CO2 and incorporated into cement mortar. From the results, it was found that at 1.89% silica loading, the hydrophilic silica mortar (HSAM) samples can achieve the highest compressive strength of 34.1 MPa at 7 days and 40.7 MPa at 28 days, with a percentage gain of +38.06% and +17.29% respectively as compared to blank samples. However, the incorporation of silica for more than 1.89 wt% resulted in a negative effect on the compressive strength gain of HSAM samples. By the incorporation of 2.42 wt%, the samples showed a significant drop in compressive strength of −21.46% at 7 days and −17.29% at 28 days. The results proved that nano-silica coupled with CO2 can accelerate curing of cement mortar by means of carbonation