Joint Resource Allocation and Link Adaptation for Ultra-Reliable and Low-Latency Services

peer reviewedWith the emergence of ultra-reliable and low latency communication (URLLC) services, link adaptation (LA) plays a pivotal role in improving the robustness and reliability of communication networks via appropriate modulation and coding schemes (MCS). LA-based resource management schemes in both physical and medium access control layers can significantly enhance the system performance in terms of throughput, latency, reliability, and quality of service. Increasing the number of retransmissions will achieve higher reliability and increase transmission latency. In order to balance this trade-off with improved link performance for URLLC services, we study a joint subcarrier and power allocation problem to maximize the achievable sum-rate under an appropriate MCS. The formulated problem is mixed-integer nonconvex programming which is challenging to solve optimally. In addition, a direct application of standard optimization techniques is no longer applicable due to the complication of the effective signal-to-noise ratio (SNR) function. To overcome this challenge, we first relax the binary variables to continuous ones and introduce additional variables to convert the relaxed problem into a more tractable form. By leveraging the successive convex approximation method, we develop a low-complexity iterative algorithm that guarantees to achieve at least a locally optimal solution. Simulation results are provided to show the fast convergence of the proposed iterative algorithm and demonstrate the significant performance improvement in terms of the achievable sum-rate, compared with the conventional LA approach and existing retransmission policy

Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the Global Burden of Disease Study 2021

Background: Future trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050. Methods: Using forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline. Findings: In the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8–63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0–45·0] in 2050) and south Asia (31·7% [29·2–34·1] to 15·5% [13·7–17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4–40·3) to 41·1% (33·9–48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6–25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5–43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5–17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7–11·3) in the high-income super-region to 23·9% (20·7–27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5–6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2–26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [–0·6 to 3·6]). Interpretation: Globally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions

Tree species diversity and utilities in a contracting lowland hillside rainforest fragment in Central Vietnam

Abstract Background Within the highly bio-diverse ‘Northern Vietnam Lowland Rain Forests Ecoregion’ only small, and mostly highly modified forestlands persist within vast exotic-species plantations. The aim of this study was to elucidate vegetation patterns of a secondary hillside rainforest remnant (elevation 120–330 m, 76 ha) as an outcome of natural processes, and anthropogenic processes linked to changing forest values. Methods In the rainforest remnant tree species and various bio-physical parameters (relating to soils and terrain) were surveyed on forty 20 m × 20 m sized plots. The forest's vegetation patterns and tree diversity were analysed using dendrograms, canonical correspondence analysis, and other statistical tools. Results Forest tree species richness was high (172 in the survey, 94 per hectare), including many endemic species (>16%; some recently described). Vegetation patterns and diversity were largely explained by topography, with colline/sub-montane species present mainly along hillside ridges, and lowland/humid-tropical species predominant on lower slopes. Scarcity of high-value timber species reflected past logging, whereas abundance of light-demanding species, and species valued for fruits, provided evidence of human-aided forest restoration and ‘enrichment’ in terms of useful trees. Exhaustion of sought-after forest products, and decreasing appreciation of non-wood products concurred with further encroachment of exotic plantations in between 2010 and 2015. Regeneration of rare tree species was reduced probably due to forest isolation. Conclusions Despite long-term anthropogenic influences, remnant forests in the lowlands of Vietnam can harbor high plant biodiversity, including many endangered species. Various successive future changes (vanishing species, generalist dominance, and associated forest structural-qualitative changes) are, however, expected to occur in small forest fragments. Lowland forest biodiversity can only be maintained if forest fragments maintain a certain size and/or are connected via corridors to larger forest networks. Preservation of the forests may be fostered using new economic incentive schemes

Ten golden rules for optimal antibiotic use in hospital settings: the WARNING call to action

Antibiotics are recognized widely for their benefits when used appropriately. However, they are often used inappropriately despite the importance of responsible use within good clinical practice. Effective antibiotic treatment is an essential component of universal healthcare, and it is a global responsibility to ensure appropriate use. Currently, pharmaceutical companies have little incentive to develop new antibiotics due to scientific, regulatory, and financial barriers, further emphasizing the importance of appropriate antibiotic use. To address this issue, the Global Alliance for Infections in Surgery established an international multidisciplinary task force of 295 experts from 115 countries with different backgrounds. The task force developed a position statement called WARNING (Worldwide Antimicrobial Resistance National/International Network Group) aimed at raising awareness of antimicrobial resistance and improving antibiotic prescribing practices worldwide. The statement outlined is 10 axioms, or “golden rules,” for the appropriate use of antibiotics that all healthcare workers should consistently adhere in clinical practice

Posterior reversible encephalopathy syndrome following septicemia in patient with myasthenia gravis

Posterior reversible encephalopathy syndrome is a clinicoradiologic entity characterized by seizure, headaches, visual symptoms, impaired consciousness, and vasogenic cerebral edema of occipital and parietal lobes of the brain. Magnetic resonance imaging (MRI) is the diagnostic gold standard. The pathophysiology of posterior reversible encephalopathy syndrome is still unknown, but it is thought to be closely related to several medical conditions including hypertension, preeclampsia, eclampsia, immunosuppressive agents, transplantation, and sepsis. We report a rare case of posterior reversible encephalopathy syndrome in patient with myasthenia gravis and sepsis. A 22-year-old male was diagnosed with myasthenia gravis combined with sepsis due to pneumonia. During his recovery, the patient suffered multiple generalized convulsions and subsequent loss of consciousness. On cranial MRI, the abnormalities were observed with hyperintense within the subcortical white matter of the temporal, parietal, and bilateral occipital lobes on T2-weighted and T2 FLAIR. Reversibility of the symptoms and characteristic imaging findings led us to a diagnosis of posterior reversible encephalopathy syndrome. Early recognition and management of posterior reversible encephalopathy syndrome as a cause of encephalopathy in patients with septicemia and myasthenia gravis is necessary to prevent secondary complications in this condition

A rare case of fusiform basilar trunk aneurysm

Aneurysms in the posterior circulation and distal sites are more common among the pediatric population than among adults, with a male predominance. Symptoms of an aneurysm in the posterior circulation can include a stiff neck or severe headache due to a ruptured aneurysm, whereas an unruptured aneurysm can cause mass effects or neurological deficits. However, in children, the complete occlusion of the aneurysm while preserving the flow of the main artery can be difficult to achieve when attempting a stent-assisted coil embolization technique. A 25-month-old girl presented with left hemiparesis and was diagnosed with a basilar artery aneurysm 10 months prior, but she did not receive any specific treatment. No history of trauma and no significant familial history were recorded. Angiography showed a fusiform aneurysm on the basilar artery trunk, which was successfully occluded using stent-assisted coiling following dual antiplatelet therapy with clopidogrel and aspirin. She was discharged with the complete restoration of motor deficits

Reference Value Fibrin Monomer in Healthy Children: A Cross-Sectional Study

The objective of this study is to determine the fibrin monomer reference intervals in healthy children. This cross-sectional study was conducted in the Hematology Department at Vietnam National Children's Hospital (April 2023 to March 2024). Children without prior history of clotting disorders or anticoagulants use hospitalized in preparation for orthopedic surgery or inguinal hernia surgery were enrolled in the study. The fibrin monomer test method was the quantitative fibrin monomer test on the STA-R system (Diagnostica Stago™, France). Eighty-six children (58 males and 28 females) were enrolled in the study. The median (interquartile range, 2.5th-97.5th) fibrin monomer value of the study subjects was 2.56 (0.11-5.93) µg/mL, with no statistically significant difference in fibrin monomer values among the age groups of 1 month to 3 years, 3 years to 13 years, and 13 years to 18 years. This is the first study conducted in Vietnam to determine reference values of fibrin monomer in children. This information can help in the diagnosis and treatment of early hypercoagulation stage and disseminated intravascular coagulation in children

Spontaneous thrombosis of a large unruptured intracranial aneurysm causing ischemic stroke due to occlusion of the parent artery: A case report and literature review

Spontaneous thrombosis of an unruptured large or giant saccular intracranial aneurysm is a well-known phenomenon and can cause ischemic stroke (IS), which is a rare event. The possible pathogenic mechanisms of IS include distal embolic occlusion secondary to migration of the intra-aneurysmal thrombus, occlusion of the parent artery lumen caused by the retrograde extension of the aneurysmal thrombosis, external compression of the parent artery due to the increased aneurysmal mass effect. Among these, IS due to simultaneous thromboses of the aneurysm and its parent artery is extremely rare, with only a few cases reported in the literature. Herein, we present a case of a 18-year-old woman who suffered an acute IS, attribute to spontaneous complete thrombosis of an unruptured large saccular aneurysm of the right middle cerebral artery with occlusion of the parent artery, and we review the literature simultaneously

Rescue intracranial stenting in acute ischemic stroke (study).

BACKGROUND AND PURPOSE: In cases of acute ischemic stroke that are caused by intracranial large vessel occlusion, rescue intracranial stenting has recently become a treatment option to achieve recanalization in patients when mechanical thrombectomy fails. However, there have been few studies to date that support this beneficial treatment. Our goal is to analyze whether the use of rescue intracranial stenting would improve non-poor prognosis in patients 3 months posttreatment. METHODS: This was a retrospective analysis of a prospective cohort of patients with acute ischemic stroke who were treated with rescue stenting at our hospital. Inclusion criteria for the study consisted of evidence of intracranial large vessel occlusion, absence of intracranial hemorrhage, and severe stenosis or reocclusion after mechanical thrombectomy. Tandem occlusions, failure to follow up after discharge, and a severe combined illness concomitant with acute ischemic stroke were excluded. The primary outcome was the non-poor outcome rate at 3 months and postprocedural symptomatic intracerebral hemorrhage. RESULTS: The posttreatment outcomes of 85 eligible patients who received rescue intracranial stenting between August 2019 and May 2021 are reported. In total, 82 of these patients (96.5%) had successful recanalization and 4 (4.7%) experienced symptomatic intracerebral hemorrhage. In total, 47 (55.3%) patients had non-poor and 35 (41.2%) good outcomes at 3 months after treatment with rescue intracranial stenting. The use of dual antiplatelet therapy was associated with new infarcts (relative risk = 0.1; 95% confidence interval 0.01-0.7) and symptomatic intracerebral hemorrhage (relative risk = 0.1; 95% confidence interval 0.01-0.9). CONCLUSION: Our study suggests that despite the occurrence of postprocedural symptomatic intracerebral hemorrhage in a low proportion of cases, rescue intracranial stenting could be an important alternative treatment after mechanical thrombectomy failure