Exceptional Points of Degeneracy Induced by Linear Time-Periodic Variation

We present a general theory of exceptional points of degeneracy (EPD) in periodically time-variant systems. We show that even a single resonator with a time-periodic component is able to develop EPDs, contrary to parity-time- (PT) symmetric systems that require two coupled resonators. An EPD is a special point in a system parameter space at which two or more eigenmodes coalesce in both their eigenvalues and eigenvectors into a single degenerate eigenmode. We demonstrate the conditions for EPDs to exist when they are directly induced by time-periodic variation of a system without loss and gain elements. We also show that a single resonator system with zero time-average loss-gain exhibits EPDs with purely real resonance frequencies, yet the resonator energy grows algebraically in time since energy is injected into the system from the time-variation mechanism. Although the introduced concept and formalism are general for any time-periodic system, here, we focus on the occurrence of EPDs in a single LC resonator with time-periodic modulation. These findings have significant importance in various electromagnetic and photonic systems and pave the way for many applications, such as sensors, amplifiers, and modulators. We show a potential application of this time-varying EPD as a highly sensitive sensor

Effects of anabolic steroids on acute phase responses in intra-abdominal sepsis

The acute phase response is an important adaptive response to sepsis and injury. As anabolic steroids increase protein synthesis we postulated that these agents might also increase hepatic acute phase protein synthesis. Male Wistar rats were pretreated with testosterone or danazol for 48 h prior to caecal ligation and puncture (CLP). Thirty-six h following surgery the animals were killed and blood taken for full blood count, total protein, albumin, α, β and γ globulin fractions on serum electrophoresis, complement C3 and transferrin levels. Danazol increased the α1, α2 and β1 globulin serum protein fractions in comparison with no surgery and CLP alone groups. These results indicate that danazol increases plasma acute phase proteins, as measured by electrophoresis, in this model of intra-abdominal sepsis

Munchausen by internet: current research and future directions.

The Internet has revolutionized the health world, enabling self-diagnosis and online support to take place irrespective of time or location. Alongside the positive aspects for an individual's health from making use of the Internet, debate has intensified on how the increasing use of Web technology might have a negative impact on patients, caregivers, and practitioners. One such negative health-related behavior is Munchausen by Internet

The preparation of graphic models for a virtual reality application in Unity

Although Virtual Reality has existed for decades, it is currently experiencing a boom. This is mainly due to the new powerful hardware devices available to many people. Accompanying this greater availability, the fields of use are also currently expanding – medicine, military, business, engineering, education, entertainment, etc. The main purpose of Virtual Reality is to provide the user with a real-looking simulated environment, including interaction. Specialised developer software tools are used in order to create Virtual Reality applications that exploit suitable 3D graphics models. This paper deals with the creation and preparation of such graphical models - including textures, and the problems of the conversion process, to a developer application. Blender is used to create models and UV maps. The export of these models and UV maps from Blender is set up for easy implementation in the Substance Painter software, where the textures are drawn - and later, into the Unity developer engine for Virtual Reality application. © 2020, Springer Nature Switzerland AG

Emergence of responsible sanctions without second order free riders, antisocial punishment or spite

While empirical evidence highlights the importance of punishment for cooperation in collective action, it remains disputed how responsible sanctions targeted predominantly at uncooperative subjects can evolve. Punishment is costly; in order to spread it typically requires local interactions, voluntary participation, or rewards. Moreover, theory and experiments indicate that some subjects abuse sanctioning opportunities by engaging in antisocial punishment (which harms cooperators), spiteful acts (harming everyone) or revenge (as a response to being punished). These arguments have led to the conclusion that punishment is maladaptive. Here, we use evolutionary game theory to show that this conclusion is premature: If interactions are non-anonymous, cooperation and punishment evolve even if initially rare, and sanctions are directed towards non-cooperators only. Thus, our willingness to punish free riders is ultimately a selfish decision rather than an altruistic act; punishment serves as a warning, showing that one is not willing to accept unfair treatments

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

A three-group study, internet-based, face-to-face based and standard- management after acute whiplash associated disorders (WAD) – choosing the most efficient and cost-effective treatment: study protocol of a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>The management of Whiplash Associated Disorders is one of the most complicated challenges with high expenses for the health care system and society. There are still no general guidelines or scientific documentation to unequivocally support any single treatment for acute care following whiplash injury.</p> <p>The main purpose of this study is to try a new behavioural medicine intervention strategy at acute phase aimed to reduce the number of patients who have persistent problems after the whiplash injury. The goal is also to identify which of three different interventions that is most cost-effective for patients with Whiplash Associated Disorders. In this study we are controlling for two factors. First, the effect of behavioural medicine approach is compared with standard care. Second, the manner in which the behavioural medicine treatment is administered, Internet or face-to-face, is evaluated in it's effectiveness and cost-effectiveness.</p> <p>Methods/Design</p> <p>The study is a randomized, prospective, experimental three-group study with analyses of cost-effectiveness up to two-years follow-up. <it>Internet – based programme </it>and <it>face-to-face group treatment programme </it>are compared to <it>standard-treatment </it>only. Patient follow-ups take place three, six, twelve and 24 months, that is, short-term as well as long-term effects are evaluated. Patients will be enrolled via the emergency ward during the first week after the accident.</p> <p>Discussion</p> <p>This new self-help management will concentrate to those psychosocial factors that are shown to be predictive in long-term problems in Whiplash Associated Disorders, i.e. the importance of self-efficacy, fear of movement, and the significance of catastrophizing as a coping strategy for restoring and sustaining activities of daily life. Within the framework of this project, we will develop, broaden and evaluate current physical therapy treatment methods for acute Whiplash Associated Disorders. The project will contribute to the creation of a cost-effective behavioural medicine approach to management of acute Whiplash Associated Disorders. The results of this study will answer an important question; on what extent and how should these patients be treated at acute stage and how much does the best management cost.</p> <p>Trial registration number</p> <p>Current Controlled Trials ISRCTN61531337</p

Collaborative International Research in Clinical and Longitudinal Experience Study in NMOSD

OBJECTIVE: To develop a resource of systematically collected, longitudinal clinical data and biospecimens for assisting in the investigation into neuromyelitis optica spectrum disorder (NMOSD) epidemiology, pathogenesis, and treatment. METHODS: To illustrate its research-enabling purpose, epidemiologic patterns and disease phenotypes were assessed among enrolled subjects, including age at disease onset, annualized relapse rate (ARR), and time between the first and second attacks. RESULTS: As of December 2017, the Collaborative International Research in Clinical and Longitudinal Experience Study (CIRCLES) had enrolled more than 1,000 participants, of whom 77.5% of the NMOSD cases and 71.7% of the controls continue in active follow-up. Consanguineous relatives of patients with NMOSD represented 43.6% of the control cohort. Of the 599 active cases with complete data, 84% were female, and 76% were anti-AQP4 seropositive. The majority were white/Caucasian (52.6%), whereas blacks/African Americans accounted for 23.5%, Hispanics/Latinos 12.4%, and Asians accounted for 9.0%. The median age at disease onset was 38.4 years, with a median ARR of 0.5. Seropositive cases were older at disease onset, more likely to be black/African American or Hispanic/Latino, and more likely to be female. CONCLUSION: Collectively, the CIRCLES experience to date demonstrates this study to be a useful and readily accessible resource to facilitate accelerating solutions for patients with NMOSD

Why sustainable, inclusive, and resilient investment makes for efficacious post-COVID medicine

Abstract: The global economy is facing an unprecedented challenge, with the risk of a protracted depression following the response to COVID‐19. In 2014, I argued here that macroeconomic conditions made it a relatively favorable time to kick‐start investments in a resource‐efficient, low carbon economy. Yet the opportunity was, for the most part, squandered. Failure to utilize active fiscal policy contributed to growing private indebtedness, limited productivity and wage growth and widened inequality helping erode trust in institutions. All the while, greenhouse gas emissions continued to rise. This time, there are grounds for optimism that a more coordinated response toward generating an ambitious transition to net zero emissions might contribute to a strong, sustainable, and resilient recovery. This article is categorized under: Climate Economics > Economics of Mitigatio

Treatment of neuromyelitis optica: state-of-the-art and emerging therapies.

Neuromyelitis optica (NMO) is an autoimmune disease of the CNS that is characterized by inflammatory demyelinating lesions in the spinal cord and optic nerve, potentially leading to paralysis and blindness. NMO can usually be distinguished from multiple sclerosis (MS) on the basis of seropositivity for IgG antibodies against the astrocytic water channel aquaporin-4 (AQP4). Differentiation from MS is crucial, because some MS treatments can exacerbate NMO. NMO pathogenesis involves AQP4-IgG antibody binding to astrocytic AQP4, which causes complement-dependent cytotoxicity and secondary inflammation with granulocyte and macrophage infiltration, blood-brain barrier disruption and oligodendrocyte injury. Current NMO treatments include general immunosuppressive agents, B-cell depletion, and plasma exchange. Therapeutic strategies targeting complement proteins, the IL-6 receptor, neutrophils, eosinophils and CD19--all initially developed for other indications--are under clinical evaluation for repurposing for NMO. Therapies in the preclinical phase include AQP4-blocking antibodies and AQP4-IgG enzymatic inactivation. Additional, albeit currently theoretical, treatment options include reduction of AQP4 expression, disruption of AQP4 orthogonal arrays, enhancement of complement inhibitor expression, restoration of the blood-brain barrier, and induction of immune tolerance. Despite the many therapeutic options in NMO, no controlled clinical trials in patients with this condition have been conducted to date