22 research outputs found

    A Simple Stochastic Model with Environmental Transmission Explains Multi-Year Periodicity in Outbreaks of Avian Flu

    Get PDF
    Avian influenza virus reveals persistent and recurrent outbreaks in North American wild waterfowl, and exhibits major outbreaks at 2–8 years intervals in duck populations. The standard susceptible-infected- recovered (SIR) framework, which includes seasonal migration and reproduction, but lacks environmental transmission, is unable to reproduce the multi-periodic patterns of avian influenza epidemics. In this paper, we argue that a fully stochastic theory based on environmental transmission provides a simple, plausible explanation for the phenomenon of multi-year periodic outbreaks of avian flu. Our theory predicts complex fluctuations with a dominant period of 2 to 8 years which essentially depends on the intensity of environmental transmission. A wavelet analysis of the observed data supports this prediction. Furthermore, using master equations and van Kampen system-size expansion techniques, we provide an analytical expression for the spectrum of stochastic fluctuations, revealing how the outbreak period varies with the environmental transmission

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

    Get PDF
    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Compartmentalization of total and virus-specific tissue-resident memory CD8+ T Cells in human lymphoid organs

    Get PDF
    Disruption of T cell memory during severe immune suppression results in reactivation of chronic viral infections, such as Epstein Barr virus (EBV) and Cytomegalovirus (CMV). How different subsets of memory T cells contribute to the protective immunity against these viruses remains poorly defined. In this study we examined the compartmentalization of virus-specific, tissue resident memory CD8+ T cells in human lymphoid organs. This revealed two distinct populations of memory CD8+ T cells, that were CD69+CD103+ and CD69+CD103-, and were retained within the spleen and tonsils in the absence of recent T cell stimulation. These two types of memory cells were distinct not only in their phenotype and transcriptional profile, but also in their anatomical localization within tonsils and spleen. The EBV-specific, but not CMV-specific, CD8+ memory T cells preferentially accumulated in the tonsils and acquired a phenotype that ensured their retention at the epithelial sites where EBV replicates. In vitro studies revealed that the cytokine IL-15 can potentiate the retention of circulating effector memory CD8+ T cells by down-regulating the expression of sphingosine-1-phosphate receptor, required for T cell exit from tissues, and its transcriptional activator, Kruppel-like factor 2 (KLF2). Within the tonsils the expression of IL-15 was detected in regions where CD8+ T cells localized, further supporting a role for this cytokine in T cell retention. Together this study provides evidence for the compartmentalization of distinct types of resident memory T cells that could contribute to the long-term protection against persisting viral infections

    Competing Ways Towards International Antitrust: The WTO versus the ICN

    No full text
    In times of globalization, trade liberalization and deregulation of specific industries, competition authorities face new challenges in order to protect national as well as international competition. With companies operating in various countries, fading market frontiers and increasing crossborder trade, new strategies must be developed in order to overcome threats to domestic markets resulting of anticompetitive behavior abroad. Even though solutions such as the Effects Doctrine or bilateral agreements allow albeit imperfectly countries to protect their domestic market, there are no laws safeguarding the global economy and international competition. Thus, the request arises to establish an international competition policy regime in order to harmonize countries competition laws, to reduce conflicts due to cross-border anti-competitive behavior and to support developing countries in reaching Western standards. Among several approaches, two are of significant interest: On the one hand, the World Trade Organization (WTO) could be enhanced by a board of supervision for international competition issues including a harmonized competition code for all, while on the other hand the International Competition Network (ICN) has been established to take care of global competition concerns through policy coordination [Graham 2003; Janow 2003; Budzinski 2004b]. This paper discusses whether the institutional WTO or the voluntary ICN approach represents the better path to an international competition policy regime to control private anticompetitive activities. The second part will explain the importance of an international competition policy. Subsequently, unilateral, bilateral and multilateral approaches to the prevention and solution of problems in global competition are introduced. Section 3.1 gives a short overview of the WTOs characteristics, its structural organization and its plans to integrate an international competition policy. The organization and the framework of the ICN as well as its attempts to prevent international anticompetitive behavior is explored in section 3.2. Based on the statements made in section 2 and the facts presented in section 3, the fourth section compares the WTO approach with the ICN qualities. The discussion will be divided into the following six criteria: (i) feasibility, (ii) acceptability, (iii) efficiency, (iv) negotiation and implementation of international competition rules, (v) conflict resolution and (vi) adaptability. Conclusions follow in section 5

    Man and Matter: How the Former Gains Ownership of the Latter

    No full text

    Soft tissue tumor imaging in adults : European Society of Musculoskeletal Radiology-Guidelines 2023\u2014overview, and primary local imaging: how and where?

    No full text
    Abstract: ObjectivesEarly, accurate diagnosis is crucial for the prognosis of patients with soft tissue sarcomas. To this end, standardization of imaging algorithms, technical requirements, and reporting is therefore a prerequisite. Since the first European Society of Musculoskeletal Radiology (ESSR) consensus in 2015, technical achievements, further insights into specific entities, and the revised WHO-classification (2020) and AJCC staging system (2017) made an update necessary. The guidelines are intended to support radiologists in their decision-making and contribute to interdisciplinary tumor board discussions.Materials and methodsA validated Delphi method based on peer-reviewed literature was used to derive consensus among a panel of 46 specialized musculoskeletal radiologists from 12 European countries. Statements were scored online by level of agreement (0 to 10) during two iterative rounds. Either "group consensus," "group agreement," or "lack of agreement" was achieved.ResultsEight sections were defined that finally contained 145 statements with comments. Overall, group consensus was reached in 95.9%, and group agreement in 4.1%. This communication contains the first part consisting of the imaging algorithm for suspected soft tissue tumors, methods for local imaging, and the role of tumor centers.ConclusionUltrasound represents the initial triage imaging modality for accessible and small tumors. MRI is the modality of choice for the characterization and local staging of most soft tissue tumors. CT is indicated in special situations. In suspicious or likely malignant tumors, a specialist tumor center should be contacted for referral or teleradiologic second opinion. This should be done before performing a biopsy, without exception.Clinical relevanceThe updated ESSR soft tissue tumor imaging guidelines aim to provide best practice expert consensus for standardized imaging, to support radiologists in their decision-making, and to improve examination comparability both in individual patients and in future studies on individualized strategies.Key Points center dot Ultrasound remains the best initial triage imaging modality for accessible and small suspected soft tissue tumors.center dot MRI is the modality of choice for the characterization and local staging of soft tissue tumors in most cases; CT is indicated in special situations. Suspicious or likely malignant tumors should undergo biopsy.center dot In patients with large, indeterminate or suspicious tumors, a tumor reference center should be contacted for referral or teleradiologic second opinion; this must be done before a biopsy.Key Points center dot Ultrasound remains the best initial triage imaging modality for accessible and small suspected soft tissue tumors.center dot MRI is the modality of choice for the characterization and local staging of soft tissue tumors in most cases; CT is indicated in special situations. Suspicious or likely malignant tumors should undergo biopsy.center dot In patients with large, indeterminate or suspicious tumors, a tumor reference center should be contacted for referral or teleradiologic second opinion; this must be done before a biopsy.Key Points center dot Ultrasound remains the best initial triage imaging modality for accessible and small suspected soft tissue tumors.center dot MRI is the modality of choice for the characterization and local staging of soft tissue tumors in most cases; CT is indicated in special situations. Suspicious or likely malignant tumors should undergo biopsy. center dot In patients with large, indeterminate or suspicious tumors, a tumor reference center should be contacted for referral or teleradiologic second opinion; this must be done before a biopsy

    Customary International Law and Public Goods

    No full text
    The paper examines the potential of customary international law to protect global public goods. In particular, it focuses on the question whether customary law can contribute to the mitigation of climate change. The analysis proceeds in the three steps. First, it will have a closer look at the concept of public goods and common pool resources in economic theory and experimental economics. On this basis, the second section examines the formation of customary international law. The analysis shows that sustaining cooperation in multilateral settings through customary law is difficult. With regard to the mitigation of climate change, it is unlikely that states will coordinate on an equilibrium that will lead to a reduction of greenhouse gas emissions. The section then examines two further ways of identifying customary international law through moral interpretation and judicial lawmaking. However, the potential of these two avenues to protect global public goods effectively is rather limited. The final section analyzes the protection of global public goods through the initially unilateral extension of authority. One problem of global public goods is that states have shared authority over them. A solution might be to divide authority by extending the jurisdiction of the nation states. I will draw from an example concerning the protection of common pool resources, the protection of fish stocks, and analyze whether this example contains any lessons for the mitigation of climate change
    corecore