Influenza Virus Transmission Is Dependent on Relative Humidity and Temperature

Using the guinea pig as a model host, we show that aerosol spread of influenza virus is dependent upon both ambient relative humidity and temperature. Twenty experiments performed at relative humidities from 20% to 80% and 5 °C, 20 °C, or 30 °C indicated that both cold and dry conditions favor transmission. The relationship between transmission via aerosols and relative humidity at 20 °C is similar to that previously reported for the stability of influenza viruses (except at high relative humidity, 80%), implying that the effects of humidity act largely at the level of the virus particle. For infected guinea pigs housed at 5 °C, the duration of peak shedding was approximately 40 h longer than that of animals housed at 20 °C; this increased shedding likely accounts for the enhanced transmission seen at 5 °C. To investigate the mechanism permitting prolonged viral growth, expression levels in the upper respiratory tract of several innate immune mediators were determined. Innate responses proved to be comparable between animals housed at 5 °C and 20 °C, suggesting that cold temperature (5 °C) does not impair the innate immune response in this system. Although the seasonal epidemiology of influenza is well characterized, the underlying reasons for predominant wintertime spread are not clear. We provide direct, experimental evidence to support the role of weather conditions in the dynamics of influenza and thereby address a long-standing question fundamental to the understanding of influenza epidemiology and evolution

The Lie derivative of spinor fields: theory and applications

Starting from the general concept of a Lie derivative of an arbitrary differentiable map, we develop a systematic theory of Lie differentiation in the framework of reductive G-structures P on a principal bundle Q. It is shown that these structures admit a canonical decomposition of the pull-back vector bundle i_P^*(TQ) = P\times_Q TQ over P. For classical G-structures, i.e. reductive G-subbundles of the linear frame bundle, such a decomposition defines an infinitesimal canonical lift. This lift extends to a prolongation Gamma-structure on P. In this general geometric framework the concept of a Lie derivative of spinor fields is reviewed. On specializing to the case of the Kosmann lift, we recover Kosmann's original definition. We also show that in the case of a reductive G-structure one can introduce a "reductive Lie derivative" with respect to a certain class of generalized infinitesimal automorphisms, and, as an interesting by-product, prove a result due to Bourguignon and Gauduchon in a more general manner. Next, we give a new characterization as well as a generalization of the Killing equation, and propose a geometric reinterpretation of Penrose's Lie derivative of "spinor fields". Finally, we present an important application of the theory of the Lie derivative of spinor fields to the calculus of variations.Comment: 28 pages, 1 figur

The experience of individuals placed in quarantine: A systematic review, meta-summary, and meta-synthesis

Objective: To summarize the experience of individuals placed in quarantine during an outbreak. Design: A meta-summary and a meta-synthesis based upon a systematic review of qualitative studies. Sample: The Cumulative Index of Nursing and Allied Health Literature, MEDLINE, and Scopus databases were all searched up to April 2020. Measurements: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed; then, the methodological quality of the studies included was assessed with the Critical Appraisal Screening Programme tool for qualitative studies. Results: Five studies have been included documenting the experience of 125 adult individuals. A total of 16 codes emerged: in the meta-summary, the most and least frequent codes were \u201cThinking about quarantine\u201d (80%) and \u201cEmotional roller coaster,\u201d \u201cBeing alert for any symptom,\u201d \u201cTrusting or not?,\u201d \u201cKnowing who brought the infection,\u201d and \u201cLiving in a surreal world\u201d (20%). The codes which emerged were categorized into three main themes which summarized the whole experience of being placed in quarantine: (a) \u201cBeing swamped with a thousand emotions\u201d; (b) \u201cBeing restrained\u201d; and (c) \u201cNeeding to be considered.\u201d. Conclusions: The experience of quarantine for people is a long journey which can feel chaotic due to uncertainty about the consequences on health, work, and the future. The findings of this study can help nurses in caring for quarantined individuals by enabling them to understand people's need for educational and emotional support. Ensuring the supply of consistent information is also important to increase people's compliance

High mitochondrial DNA copy number is a protective factor from vision loss in heteroplasmic leber’s hereditary optic neuropathy (LHON)

PURPOSE. Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disease that typically causes bilateral blindness in young men. It is characterized by as yet undisclosed genetic and environmental factors affecting the incomplete penetrance. METHODS. We identified 27 LHON subjects who possess heteroplasmic primary LHON mutations. Mitochondrial DNA (mtDNA) copy number was evaluated. RESULTS. The presence of centrocecal scotoma, an edematous, hyperemic optic nerve head, and vascular tortuosity, as well as telangiectasia was recognized in affected subjects. We found higher cellular mtDNA content in peripheral blood cells of unaffected heteroplasmic mutation carriers with respect to the affected. CONCLUSIONS. The increase of cellular mtDNA content prevents complete loss of vision despite the presence of a heteroplasmic state of LHON primary mutation, suggesting that it is a key factor responsible for penetrance of LHON

Inactive Residents Living in Nursing Homes and Associated Predictors: Findings From a Regional-Based, Italian Retrospective Study.

Objectives: It has been amply reported that nursing home (NH) residents are largely inactive, a condition that may further increase functional decline, behavioral disorders, and risk of death. To date, studies have mainly focused on individual characteristics that may decrease residents' involvement in activities. Therefore, the aim of this study is to describe the prevalence of inactive NH residents in an Italian context, identifying predictors of inactivity at the individual and NH levels. Design: Retrospective regional-based study performed in 2014. Setting: All NHs (n = 105) located in the Friuli Venezia Giulia Region, northeastern region of Italy. Participants: A total of 8875 residents with at least 1 nursing assessment and living in an NH for at least 1 year. Measurements: The dependent variable was inactivity in the last week, defined as the resident not being involved in any socially or individually based, or meaningful recreational (eg, gardening) activities. The independent variables were set at individual and NH levels. Aiming at identifying predictors of inactivity, a hierarchical generalized linear (mixed-effects) model incorporating both fixed-effect parameters and random effects, was performed. Results: A total of 4042 (45.6%) residents were inactive during the week before the evaluation. At the resident level, those with severe cognitive impairment [odds (OR) 4.462, 95% confidence interval (CI) 3.880-5.132], unsociable behavior (OR 2.961, 95% CI 2.522-3.473), night restlessness (OR 1.605, 95% CI 1.395-1.853), lack of cooperation in daily care (OR 1.408, 95% CI 1.199-1.643), pressure sores (OR 1.314, 95% CI 1.065-1.622), depressive disorders (OR 1.242, 95% CI 1.089-1.416), and clinical instability (OR 1.110, 95% CI 1.037-1.188) reported an increased risk of being inactive. At the NH level, for each additional hour of care offered by professional educators, there was 1% less likelihood of inactive residents (OR .964, 95% .933-.996). Conclusions: Approximately one-half of the residents in this study living in Italian NHs are inactive. Inactivity is significantly associated with the presence of severe cognitive impairment, behavioral disorders (eg, unsociability, night restlessness, and lack of cooperation in daily care), pressure sores, depressive symptoms, and clinical instability. Moreover, receiving care from professional educators whose aim in their training program and professional mission is to improve individual and social engagement, decreased the likelihood of resident inactivity. \ua9 2016 AMDA - The Society for Post-Acute and Long-Term Care Medicine

Perceptions and Experiences of Individuals With Neck Pain: A Systematic Critical Review of Qualitative Studies With Meta-Summary and Meta-Synthesis

This study aimed at exploring the perspectives and experiences of individuals with neck pain by synthesizing all available qualitative studies

UniPR1331: small Eph/ephrin antagonist beneficial in intestinal inflammation by interfering with type-B signaling

Eph receptors, comprising A and B classes, interact with cell-bound ephrins generating bidirectional signaling. Although mainly related to carcinogenesis and organogenesis, the role of Eph/ephrin system in inflammation is growingly acknowledged. Recently, we showed that EphA/ephrin-A proteins can modulate the acute inflammatory responses induced by mesenteric ischemia/reperfusion, while beneficial effects were granted by EphB4, acting as EphB/ephrin-B antagonist, in a murine model of Crohn’s disease (CD). Accordingly, we now aim to evaluate the effects of UniPR1331, a pan-Eph/ephrin antagonist, in TNBS-induced colitis and to ascertain whether UniPR1331 effects can be attributed to A- or B-type signaling interference. The potential anti-inflammatory action of UniPR1331 was compared to those of the recombinant proteins EphA2, a purported EphA/ephrin-A antagonist, and of ephrin-A1-Fc and EphA2-Fc, supposedly activating forward and reverse EphA/ephrin-A signaling, in murine TNBS-induced colitis and in stimulated cultured mononuclear splenocytes. UniPR1331 antagonized the inflammatory responses both in vivo, mimicking EphB4 protection, and in vitro; EphA/ephrin-A proteins were inactive or only weakly effective. Our findings represent a further proof-of-concept that blockade of EphB/ephrin-B signaling is a promising pharmacological strategy for CD management and highlight UniPR1331 as a novel drug candidate, seemingly working through the modulation of immune responses

Chemical, biochemical and microbiological properties of soils from abandoned and extensively cultivated olive orchards

The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical and microbiological properties in a soil of a Southern olive grove abandoned since 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization). Soil organic matter, total nitrogen and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, inter alia, increased the number of cellulolytic bacteria and stimulated the activity of β-glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means of the Biolog® method, as a result of a sort of specialization trend towards low quality organic substrates. From this point of view, the extensive cultivation management seemed to not induce a disturbance to microbiological communities

Vaccination with recombinant neuraminidase protects against influenza virus infection in mice

While the efficacy of most influenza virus vaccines is measured by the ability to induce antibodies against the hemagglutinin (HA), antibodies against the viral neuraminidase (NA) are also correlated with less severe disease in humans and animal models. Yet, neither the amount nor the enzymatic activity of NA is standardized in current seasonal vaccines, and the breadth of NA-based protection is unknown. In the present study, different subtypes of recombinant NA were expressed in a baculovirus system and used to vaccinate mice prior to homologous, heterologous, or heterosubtypic virus challenge. Additionally, pre- and post-vaccination human serum samples from vaccinees that received TIV were studied to compare induction of antibodies against the HA and NA. Finally, the amounts of NA in 4 different vaccine formulations from 2013-2014 were quantified using ELISA. Mice immunized with N2 were 100% protected from morbidity and mortality in a homologous challenge and displayed significantly reduced viral lung titers. Heterologous challenge with a drifted strain resulted in morbidity but no mortality. Mice immunized with B/Yamagata/16/88 NA were 100% protected from morbidity and mortality when lethally challenged with a recent Victoria lineage strain. In our human cohorts, the increase in endpoint titers against N1 NA post-vaccination was less robust than that against HA and, as our quantification data suggests, the N1 NA amounts in seasonal vaccine formulations is quite variable. To confirm the broad protective effects of anti-influenza B NA antibodies on a monoclonal level, a panel of mouse monoclonal antibodies was generated against influenza B virus NA; several of these displayed broad reactivity in ELISA to whole virus and recombinant NA and protected against lethal influenza B virus challenge in mice when delivered at a dose of 5 mg/kg prophylactically, or therapeutically, 48 hours post-infection. Analysis of the protective epitopes is currently in progress. The demonstrated protective capacity of anti-NA antibodies suggests that targeting the NA through vaccination may offer increased protection against influenza virus infection