30 research outputs found
Multi-Constellation Signal Design Aided Affine Frequency Division Multiplexing for 6G Communication Systems
As one of the novel waveforms recently proposed for future 6G communications, affine frequency division multiplexing (AFDM) is capable of combating the effects of the high Doppler and achieving full diversity over high mobility wireless channels. In this paper, hybrid multi-constellations for AFDM systems are proposed. A hybrid multi-constellation is obtained by eliminating points with the largest energy and by geometric interpolation among the signal points of the traditional single constellation. Two types of hybrid multi-constellation schemes, namely multiconstellation aided AFDM-Type 1 (MC-AFDM-T1) and multiconstellation aided AFDM-Type 2 (MC-AFDM-T2), are designed to improve AFDM system reliability. Monte Carlo simulations demonstrate that the proposed MC-AFDM-T1 and MC-AFDMT2 schemes are capable of achieving better symbol error rate (SER) compared to that of the original-AFDM (Ori-AFDM)
Impact of Sauropod Dinosaurs on Lagoonal Substrates in the Broome Sandstone (Lower Cretaceous), Western Australia
Existing knowledge of the tracks left by sauropod dinosaurs (loosely ‘brontosaurs’) is essentially two-dimensional, derived mainly from footprints exposed on bedding planes, but examples in the Broome Sandstone (Early Cretaceous) of Western Australia provide a complementary three-dimensional picture showing the extent to which walking sauropods could deform the ground beneath their feet. The patterns of deformation created by sauropods traversing thinly-stratified lagoonal deposits of the Broome Sandstone are unprecedented in their extent and structural complexity. The stacks of transmitted reliefs (underprints or ghost prints) beneath individual footfalls are nested into a hierarchy of deeper and more inclusive basins and troughs which eventually attain the size of minor tectonic features. Ultimately the sauropod track-makers deformed the substrate to such an extent that they remodelled the topography of the landscape they inhabited. Such patterns of substrate deformation are revealed by investigating fragmentary and eroded footprints, not by the conventional search for pristine footprints on intact bedding planes. For that reason it is not known whether similar patterns of substrate deformation might occur at sauropod track-sites elsewhere in the world
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
The role of localizable concurrence in quantum teleportation protocols
Teleporting an unknown qubit state is a paradigmatic quantum information processing task revealing the advantage of quantum communication protocols over their classical counterpart. For a teleportation protocol using a Bell state as quantum channel, the resource has been identified to be the concurrence. However, for mixed multipartite states the lack of computable entanglement measures has made the identification of the quantum resource responsible for this advantage more challenging. Here, by building on previous results showing that localizable concurrence is the necessary resource for controlled quantum teleportation, we show that any teleportation protocol using an arbitrary multipartite state, that includes a Bell measurement, requires a nonvanishing localizable concurrence between two of its parties to perform better than the classical protocol. By first analyzing Greenberger–Horne–Zeilinger (GHZ) channel and GHZ measurement teleportation protocol, in the presence of GHZ-symmetric-preserving noise, we compare different multipartite entanglement measures with the fidelity of teleportation, and we find that the protocol performs better than the classical protocol when all multipartite entanglement measures vanish, except for the localizable concurrence. Finally, we extend our proof to an arbitrary teleportation protocol with an arbitrary multipartite entangled channel. </jats:p
013 Validation of an algorithm identifying epilepsy related hospital admissions from routinely collected administrative data
Routinely collected administrative datasets can be used to identify healthcare resource use and inform strategic planning and policy development. We evaluate a new comprehensive epilepsy admission algorithm using ICD-10 coding data from these administrative datasets against a gold standard and existing admission identification algorithms.All consecutive admissions to a large UK general hospital meeting predefined criteria were identified over a one-month period. Case note review was performed by independent clinicians and admission classi- fied as epilepsy or not epilepsy related. The Liverpool algorithm and a widely used comparator algorithm were applied to the ICD-10 administrative data and compared to clinician classification.In total 205 admissions were identified. Case-note review (gold standard) identified that 35 cases were epilepsy related admissions, and 156 were not epilepsy related. It was not possible to classify 14 admis- sions due to missing or insufficient data. The Liverpool algorithm incorrectly classified only 17 out of 191 admissions compared to 30 incorrectly classified admissions from a comparator algorithm. The Liverpool algorithm demonstrates sensitivity of 85.7% and specificity of 92.3%.Whilst no perfect algorithm is likely to exist, the Liverpool algorithm identifies hospital admissions due to epileptic seizures using administrative data with improved sensitivity and specificity compared to previous [email protected]</jats:sec
An outbreak of norovirus genogroup II associated with New South Wales oysters
Introduction: Currently available antigen tests for norovirus (NoV) have excellent specificity but negative results do not always rule out infection. Real-time reverse transcription polymerase chain reaction (RT-PCR) is a useful method for detecting and genotyping NoV in humans and oysters. An outbreak of NoV associated with oyster consumption in northern New South Wales confirmed the value of real-time RT-PCR where immunochromatography (ICT) tests were negative. Methods: Eight cases of gastrointestinal illness in northern NSW, clinically suggestive of NoV infection, were associated with consumption of oysters. A joint environmental investigation was conducted by the New South Wales Food Authority and local council. One human sample was collected and tested for NoV using ICT and real-time RT-PCR. Oyster samples were tested for NoV utilising real-time RT-PCR. Results: The patient with a stool sample had NoV genogroup II (GII) confirmed by real-time RT-PCR after testing negative by ICT. Illness in all cases was consistent with NoV with median incubation and duration of 36 and 50.5 hours respectively. All cases consumed oysters that were harvested from the same area. Three oyster samples from the harvest area were also positive for NoV GII. A nearby leaking sewer line was identified as the likely source of the contamination with hydrological studies confirming its potential to contaminate implicated oyster leases. Conclusion: This investigation confirmed the value of real-time RT-PCR testing of human specimens where ICT tests are negative and clinical illness is suggestive of NoV infection. NoV real-time RT-PCR and epidemiological evidence effectively linked human infection with oyster contamination to motivate a thorough environmental investigation and appropriate action to mitigate further public health risk
Land-Use Modelling in New Zealand: Current Practice and Future Needs
New Zealand faces the challenge of using our land in ways that are not only resilient to future pressures and sustain our rural communities but also enhance our natural environment. For the public and private sectors to make robust land-use decisions under uncertainty, high-quality modelling tools and data are essential. The drivers of land-use decisions are complex and models provide a structured methodology for investigating these. While New Zealand is fortunate to have a range of different modelling tools, these have historically been used in a sporadic and ad hoc way, and underlying datasets are deficient in some areas. As the foundation for more strategic development of New Zealand’s modelling capability, this paper profiles the main land-sector and farm- and production-related models and datasets currently applied in New Zealand. It also explores priority policy areas where modelling is needed, such as achieving emission reduction targets; managing freshwater, biodiversity and soil quality; and understanding the distributional impacts of policy options as well as climate change. New Zealand’s modelling capability could be strengthened by collecting and sharing land-use data more effectively; building understanding of underlying relationships informed by primary research; creating more collaborative and transparent processes for applying common datasets, scenarios and assumptions, and conducting peer review; and conducting more integrated modelling across environmental issues. These improvements will require strategic policies and processes for refining model development, providing increased, predictable and sustained funding for modelling activity and underlying data collection and primary research, and strengthening networks across modellers inside and outside of government
