Symmetries of Helmholtz forms and globally variational dynamical forms

Invariance properties of classes in the variational sequence suggested to Krupka et al. the idea that there should exist a close correspondence between the notions of variationality of a differential form and invariance of its exterior derivative. It was shown by them that the invariance of a closed Helmholtz form of a dynamical form is equivalent with local variationality of the Lie derivative of the dynamical form, so that the latter is locally the Euler--Lagrange form of a Lagrangian. We show that the corresponding local system of Euler--Lagrange forms is variationally equivalent to a global Euler--Lagrange form.Comment: Presented at QTS7 - Quantum Theory and Symmetries VII, Prague 7-13/08/201

Novel antiviral activity of neuraminidase inhibitors against an avian influenza a virus

<p>Abstract</p> <p>Background</p> <p>Neuraminidase (NA) inhibitors used for influenza therapy are believed to prevent the release of progeny virus from the surface of an infected cell. In this study, we found that NA inhibitors have a novel antiviral function against an avian influenza virus.</p> <p>Results</p> <p>Madin-Darby canine kidney cells, commonly used for the isolation and propagation of the influenza virus, were infected with an avian influenza viral strain A/chicken/German/N/49(H10N7) (H10/chicken) or a human influenza viral strain A/Osaka/981/98(H3N2) (H3/Osaka) virus. Cells were incubated in a medium without or with a NA inhibitor, oseltamivir carboxylate (GS4071), from 1 to 13 h post infection (p.i.). Infected cells were washed 12 h p.i. to remove GS4071, incubated for 1 h without GS4071, and assayed for virus production. Incubation with GS4071 decreased the production of infectious viruses. When H10/chicken virus-infected cells were incubated with GS4071 from 12 to 13 h p.i. (i.e., 1 h before the virus production assay), the inhibitory effect was clearly observed, however, the same was not evident for H3/Osaka virus-infected cells. Furthermore, viral protein synthesis in infected cells was not affected by GS4071. Using a scanning electron microscope, many single spherical buds were observed on the surface of H3/Osaka virus-infected cells incubated without GS4071, whereas many aggregated particles were observed on the surface of cells incubated with GS4071. However, many long tubular virus-like structures, with no aggregated particles, were observed on the surface of H10/chicken virus-infected cells incubated with GS4071. The same results were obtained when another NA inhibitor, zanamivir, was used.</p> <p>Conclusions</p> <p>These results indicate that NA inhibitors interfered with virus particle formation in the H10/chicken virus-infected cells, in which the inhibitor caused the formation of long tubular virus-like structures instead of spherical virus particles.</p

Robots and cyborgs: to be or to have a body?

Starting with service robotics and industrial robotics, this paper aims to suggest philosophical reflections about the relationship between body and machine, between man and technology in our contemporary world. From the massive use of the cell phone to the robots which apparently “feel” and show emotions like humans do. From the wearable exoskeleton to the prototype reproducing the artificial sense of touch, technological progress explodes to the extent of embodying itself in our nakedness. Robotics, indeed, is inspired by biology in order to develop a new kind of technology affecting human life. This is a bio-robotic approach, which is fulfilled in the figure of the cyborg and consequently in the loss of human nature. Today, humans have reached the possibility to modify and create their own body following their personal desires. But what is the limit of this achievement? For this reason, we all must question ourselves whether we have or whether we are a body

Cryotomography of budding influenza a virus reveals filaments with diverse morphologies that mostly do not bear a genome at their distal end

Influenza viruses exhibit striking variations in particle morphology between strains. Clinical isolates of influenza A virus have been shown to produce long filamentous particles while laboratory-adapted strains are predominantly spherical. However, the role of the filamentous phenotype in the influenza virus infectious cycle remains undetermined. We used cryo-electron tomography to conduct the first three-dimensional study of filamentous virus ultrastructure in particles budding from infected cells. Filaments were often longer than 10 microns and sometimes had bulbous heads at their leading ends, some of which contained tubules we attribute to M1 while none had recognisable ribonucleoprotein (RNP) and hence genome segments. Long filaments that did not have bulbs were infrequently seen to bear an ordered complement of RNPs at their distal ends. Imaging of purified virus also revealed diverse filament morphologies; short rods (bacilliform virions) and longer filaments. Bacilliform virions contained an ordered complement of RNPs while longer filamentous particles were narrower and mostly appeared to lack this feature, but often contained fibrillar material along their entire length. The important ultrastructural differences between these diverse classes of particles raise the possibility of distinct morphogenetic pathways and functions during the infectious process

Intensive care nurse managers' experiences during the first wave of the Covid-19 pandemic: Implications for future epidemiological crises

BACKGROUND: Nurse managers play an important role in coordinating the multidisciplinary teamwork, which is specifically important in emergency and crises situations like the COVID-19 pandemic. The aim of this qualitative study is twofold: (1) to explore the experiences of the Intensive care units (ICU) nurse managers regarding their work during the first wave of the COVID-19 pandemic, and (2) to analyse what implications might be provided based on experiences of nurse managers for future possible epidemiological crises. METHODS: In-depth phone interviews were conducted to explore the experiences of ward managers-nurses (n = 15) working in different hospitals across Poland. Interviews were taped and transcribed verbatim, and then qualitatively analysed. RESULTS: Three main categories were identified: (1) Challenge of working with the unknown, (2) Nurse managers' expectations, and (3) Methods of coping and received support. The COVID-19 pandemic strongly affected the work of ICU nurse managers and uncovered the malfunctioning of the healthcare system. CONCLUSION: It is important to improve the knowledge and competence of hospital management personnel through exercises and in-service training on how to handle emergencies in order to improve the management of healthcare facilities, increase the safety of patients and employees, and the quality of healthcare

Antibody response and risk of reinfection over 2 years among the patients with first wave of COVID-19

Objectives: To describe the dynamics and factors related to natural and hybrid humoral response against the SARS-CoV-2 and risk of reinfection among first-wave patients. Methods: A prospective longitudinal study with periodic serological follow-up after acute onset of all recovered patients with SARS-CoV-2 infection cared in Udine Hospital (March–May 2020). Nucleocapsid (N) protein and spike receptor-binding domain (S-RBD) antibody tests were used to distinguish natural and vaccine-induced response. Results: Overall, 153 patients (66 men, mean age 56 years) were followed for a median of 27.3 (interquartile range 26.9–27.8) months. Seroreversion was 98.5% (95% CI: 96.8–99.4) for SARS-CoV-2-N IgM at 1 year and 57.4% (95% CI: 51.5–63.5) for SARS-CoV-2-N IgG at 2 years. Initial serological response (hazard ratio [HR]: 0.99, 95% CI: 0.99–0.99, p 0.002 for IgM and HR: 0.97, 95% CI: 0.97–0.98, p < 0.001 for IgG) and severity of acute infection (HR: 0.62, 95% CI: 0.39–0.96, p 0.033 for IgM and HR: 0.60, 95% CI: 0.37–0.99, p < 0.001 for IgG) were independently associated with persistent SARS-CoV-2-N IgM/IgG response. Older age and smoker status were associated with long-term SARS-CoV-2-N IgM and SARS-CoV-2-N IgG, respectively (HR: 0.75, 95% CI: 0.57–0.98, p 0.038; HR: 1.77, 95% CI: 1.19–2.61, p 0.004 respectively). All patients maintained SARS-CoV-2-S-RBD IgG response at 24-month follow-up. Reinfections occurred in 25 of 153 (16.3%) patients, mostly during the omicron circulation. Reinfection rates did not differ significantly between SARS-CoV-2-N IgG seronegative and seropositive patients (14/89, 15.7% vs. 10/62, 16.1%, p 0.947). Unvaccinated patients had higher risk of reinfection (4/7, 57.1% vs. vaccinated 21/146, 14.4%, p 0.014). Discussion: First-wave patients had durable natural humoral immunity in 40% and anti-S-RBD response in 100% up to 2 years after infection. Natural humoral response alone was not protective against reinfections with omicron SARS-CoV-2 variants, whereas vaccination was effective to reduce the risk of a new infection

Clinical Learning Environment and Supervision plus nurse Teacher (CLES+T) scale: testing the psychometric characteristics of the Italian version.

A clinical learning environment is an \u201cinteractive network of forces within the clinical setting that influence the students\u2019 learning outcomes\u201d. International research indicates the Clinical Learning Environment, Supervision and Nurse Teacher scale (CLES+T) as the gold standard tool to assess the forces involved in defining a good clinical learning environment. This study aimed to evaluate the psychometric proprieties of CLES+T Italian version. 875 Bachelor in Nursing students in 3 Universities in Italy partecipated in the study. Cronbach\u2019s alpha, item to total correlations, shape indexes were calculated and factor analysis was performed using Principal Axis Factoring and an oblique rotation method. Results showed an internal reliability for the total scale of 0.95, with subscales ranging from 0.80 to 0.96 among factors; all items add value to the scale and the distribution of answers have good shape indexes. Factor analysis showed a 7-factors model as explaining more than 67% of the variance, the higher variance was found in the \u201cpedagogical atmosphere\u201d factor (37.61%). The nurse teacher factor in the Italian model is split into 3 sub-factors: theory-practice integration, cooperation with ward staff and relationship with mentor and student. These results enable an international debate concerning the theoretical structure of CLES+T and enable a wider comparison on supervisory models in guiding students\u2019 clinical learning

An international consensus definition for contextual factors: findings from a nominal group technique

Objective: Emerging literature suggests contextual factors are important components of therapeutic encounters and may substantially influence clinical outcomes of a treatment intervention. At present, a single consensus definition of contextual factors, which is universal across all health-related conditions is lacking. The objective of this study was to create a consensus definition of contextual factors to better refine this concept for clinicians and researchers. Design: The study used a multi-stage virtual Nominal Group Technique (vNGT) to create and rank contextual factor definitions. Nominal group techniques are a form of consensus-based research, and are beneficial for identifying problems, exploring solutions and establishing priorities. Setting: International. Main outcome measures: The initial stages of the vNGT resulted in the creation of 14 independent contextual factor definitions. After a prolonged discussion period, the initial definitions were heavily modified, and 12 final definitions were rank ordered by the vNGT participants from first to last. Participants: The 10 international vNGT participants had a variety of clinical backgrounds and research specializations and were all specialists in contextual factors research. Results: A sixth round was used to identify a final consensus, which reflected the complexity of contextual factors and included three primary domains: (1) an overall definition; (2) qualifiers that serve as examples of the key areas of the definition; and (3) how contextual factors may influence clinical outcomes. Conclusion: Our consensus definition of contextual factors seeks to improve the understanding and communication between clinicians and researchers. These are especially important in recognizing their potential role in moderating and/or mediating clinical outcomes