5G and Net Neutrality

Industry observers have raised the possibility that European network neutrality regulations may obstruct the deployment of 5G. To assess those claims, this Chapter describes the key technologies likely to be incorporated into 5G, including millimeter wave band radios, massive multiple input/multiple output (MIMO), ultra-densification, multiple radio access technologies (multi-RAT), and support for device-to-device (D2D) and machine-to-machine (M2M) connectivity. It then reviews the business models likely to be associated with 5G, including network management through biasing and blanking, an emphasis on business-to-business (B2B) communications, and network function virtualization/network slicing. It then lays out the network neutrality regulations created by the EU in 2015 as well as the nonbinding interpretive guidelines issued by the Body of Body of European Regulators for Electronic Communication (BEREC) in 2016 and assesses how they will be applied to 5G. Network neutrality’s impact on 5G will likely to be determined by the way that the exceptions for reasonable traffic management and specialised services are interpreted. A broad interpretation should accommodate network slicing and other new business models needed to support the deployment of 5G, while a narrow interpretation could restrict innovation and investment

Municipal Fiber in the United States: A Financial Assessment

Despite growing interest in broadband provided by municipally owned and operated fiber-to-the-home networks, the academic literature has yet to undertake a systematic assessment of these projects’ financial performance. To fill this gap, we utilize municipalities’ official reports to offer an empirical evaluation of the financial performance of every municipal fiber project in the U.S. operating in 2010 through 2019. An analysis of the actual performance of the resulting fifteen-project panel dataset reveals that none of the projects generated sufficient nominal cash flow in the short run to maintain solvency without infusions of additional cash from outside sources or debt relief. Similarly, 87% have not actually generated sufficient nominal cash flow to put them on track to achieve long-run solvency. In addition, 73% generated negative nominal cash flow over the past three fiscal years, leaving them poorly positioned to make up their deficits and causing them to fall farther into debt. An assessment based on the net present value of these projects’ operating cash flow indicates that 53% of projects would not be on track to breakeven even assuming the theoretical best-case performance in terms of capital expenditures and debt service. Close analysis of these projects’ performance reveals that revenue generation likely plays a more important role in generating cash flow than efficiency in construction costs or operating efficiency

Suprachoroidal and Subretinal Injections of AAV Using Transscleral Microneedles for Retinal Gene Delivery in Nonhuman Primates.

Retinal gene therapy using adeno-associated viruses (AAVs) is constrained by the mode of viral vector delivery. Intravitreal AAV injections are impeded by the internal limiting membrane barrier, while subretinal injections require invasive surgery and produce a limited region of therapeutic effect. In this study, we introduce a novel mode of ocular gene delivery in rhesus macaques using transscleral microneedles to inject AAV8 into the subretinal or suprachoroidal space, a potential space between the choroid and scleral wall of the eye. Using in vivo imaging, we found that suprachoroidal AAV8 produces diffuse, peripheral expression in retinal pigment epithelial (RPE) cells, but it elicited local infiltration of inflammatory cells. Transscleral subretinal injection of AAV8 using microneedles leads to focal gene expression with transduction of RPE and photoreceptors, and minimal intraocular inflammation. In comparison, intravitreal AAV8 shows minimal transduction of retinal cells, but elicits greater systemic humoral immune responses. Our study introduces a novel mode of transscleral viral delivery that can be performed without vitreoretinal surgery, with focal or diffuse transgene expression patterns suitable for different applications. The decoupling of local and systemic immune responses reveals important insights into the immunological consequences of AAV delivery to different ocular compartments surrounding the blood-retinal barrier

Mechanically Ventilated COVID-19 Patients Admitted to the Intensive Care Unit in the United States With or Without Respiratory Failure Secondary to COVID-19 Pneumonia: A Retrospective Comparison of Characteristics and Outcomes

BACKGROUND: There is increasing heterogeneity in the clinical phenotype of patients admitted to the intensive care unit (ICU) with coronavirus disease 2019 (COVID-19,) and reasons for mechanical ventilation are not limited to COVID pneumonia. We aimed to compare the characteristics and outcomes of intubated patients admitted to the ICU with the primary diagnosis of acute hypoxemic respiratory failure (AHRF) from COVID-19 pneumonia to those patients admitted for an alternative diagnosis. METHODS: Retrospective cohort study of adults with confirmed SARS-CoV-2 infection admitted to nine ICUs between March 18, 2020, and April 30, 2021, at an urban university institution. We compared characteristics between the two groups using appropriate statistics. We performed logistic regression to identify risk factors for death in the mechanically ventilated COVID-19 population. RESULTS: After exclusions, the final sample consisted of 319 patients with respiratory failure secondary to COVID pneumonia and 150 patients intubated for alternative diagnoses. The former group had higher ICU and hospital mortality rates (57.7% vs. 36.7%, P CONCLUSIONS: Mechanically ventilated COVID-19 patients admitted to the ICU with COVID-19-associated respiratory failure are at higher risk of hospital death and have worse ICU utilization outcomes than those whose reason for admission is unrelated to COVID pneumonia

Mechanically ventilated COVID-19 patients admitted to the intensive care unit in the United States with or without respiratory failure secondary to COVID-19 pneumonia: a retrospective comparison of characteristics and outcomes

Background There is increasing heterogeneity in the clinical phenotype of patients admitted to the intensive care unit (ICU) with coronavirus disease 2019 (COVID-19,) and reasons for mechanical ventilation are not limited to COVID pneumonia. We aimed to compare the characteristics and outcomes of intubated patients admitted to the ICU with the primary diagnosis of acute hypoxemic respiratory failure (AHRF) from COVID-19 pneumonia to those patients admitted for an alternative diagnosis. Methods Retrospective cohort study of adults with confirmed SARS-CoV-2 infection admitted to nine ICUs between March 18, 2020, and April 30, 2021, at an urban university institution. We compared characteristics between the two groups using appropriate statistics. We performed logistic regression to identify risk factors for death in the mechanically ventilated COVID-19 population. Results After exclusions, the final sample consisted of 319 patients with respiratory failure secondary to COVID pneumonia and 150 patients intubated for alternative diagnoses. The former group had higher ICU and hospital mortality rates (57.7% vs. 36.7%, P<0.001 and 58.9% vs. 39.3%, P<0.001, respectively). Patients with AHRF secondary to COVID-19 pneumonia also had longer ICU and hospital lengths-of-stay (12 vs. 6 days, P<0.001 and 20 vs. 13.5 days, P=0.001). After risk-adjustment, these patients had 2.25 times higher odds of death (95% confidence interval, 1.42–3.56; P=0.001). Conclusions Mechanically ventilated COVID-19 patients admitted to the ICU with COVID-19-associated respiratory failure are at higher risk of hospital death and have worse ICU utilization outcomes than those whose reason for admission is unrelated to COVID pneumonia

Utilization of Vertebroplasty/Kyphoplasty in the Management of Compression Fractures: National Trends and Predictors of Vertebroplasty/Kyphoplasty

Objective The purpose of this study is to examine the utilization of kyphoplasty/vertebroplasty procedures in the management of compression fractures. With the growing elderly population and the associated increase in rates of osteoporosis, vertebral compression fractures have become a daily encounter for spine surgeons. However, there remains a lack of consensus on the optimal management of this patient population. Methods A retrospective analysis of 91 million longitudinally followed patients from 2016 to 2019 was performed using the PearlDiver Patient Claims Database. Patients with compression fractures were identified using International Classification of Disease, 10th Revision codes, and a subset of patients who received kyphoplasty/vertebroplasty were identified using Common Procedural Terminology codes. Baseline demographic and clinical data between groups were acquired. Multivariable regression analysis was performed to determine predictors of receiving kyphoplasty/vertebroplasty. Results A total of 348,457 patients with compression fractures were identified with 9.2% of patients receiving kyphoplasty/vertebroplasty as their initial treatment. Of these patients, 43.5% underwent additional kyphoplasty/vertebroplasty 30 days after initial intervention. Patients receiving kyphoplasty/vertebroplasty were significantly older (72.2 vs. 67.9, p < 0.05), female, obese, had active smoking status and had higher Elixhauser Comorbidity Index scores. Multivariable analysis demonstrated that female sex, smoking status, and obesity were the 3 strongest predictors of receiving kyphoplasty/vertebroplasty (odds ratio, 1.27, 1.24, and 1.14, respectively). The annual rate of kyphoplasty/vertebroplasty did not change significantly (range, 8%–11%). Conclusion The majority of vertebral compression fractures are managed nonoperatively. However, certain patient factors such as smoking status, obesity, female sex, older age, osteoporosis, and greater comorbidities are predictors of undergoing kyphoplasty/vertebroplasty

Brain ageing in schizophrenia: evidence from 26 international cohorts via the ENIGMA Schizophrenia consortium

Schizophrenia (SZ) is associated with an increased risk of life-long cognitive impairments, age-related chronic disease, and premature mortality. We investigated evidence for advanced brain ageing in adult SZ patients, and whether this was associated with clinical characteristics in a prospective meta-analytic study conducted by the ENIGMA Schizophrenia Working Group. The study included data from 26 cohorts worldwide, with a total of 2803 SZ patients (mean age 34.2 years; range 18-72 years; 67% male) and 2598 healthy controls (mean age 33.8 years, range 18-73 years, 55% male). Brain-predicted age was individually estimated using a model trained on independent data based on 68 measures of cortical thickness and surface area, 7 subcortical volumes, lateral ventricular volumes and total intracranial volume, all derived from T1-weighted brain magnetic resonance imaging (MRI) scans. Deviations from a healthy brain ageing trajectory were assessed by the difference between brain-predicted age and chronological age (brain-predicted age difference [brain-PAD]). On average, SZ patients showed a higher brain-PAD of +3.55 years (95% CI: 2.91, 4.19; I2 = 57.53%) compared to controls, after adjusting for age, sex and site (Cohen's d = 0.48). Among SZ patients, brain-PAD was not associated with specific clinical characteristics (age of onset, duration of illness, symptom severity, or antipsychotic use and dose). This large-scale collaborative study suggests advanced structural brain ageing in SZ. Longitudinal studies of SZ and a range of mental and somatic health outcomes will help to further evaluate the clinical implications of increased brain-PAD and its ability to be influenced by interventions

Dynamics of magnetization at infinite temperature in a Heisenberg spin chain

Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the 1D Heisenberg model were conjectured to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we study the probability distribution, $P(\mathcal{M})$, of the magnetization transferred across the chain's center. The first two moments of $P(\mathcal{M})$ show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments rule out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide key insights into universal behavior in quantum systems