599 research outputs found
Differences and similarities in inflammatory mechanisms between asthma and chronic obstructive pulmonary disease (COPD)
No full textAsthma and chronic obstructive pulmonary disease (COPD) are the two most common respiratory chronic diseases worldwide, which are increasing in prevalence and have an enormous impact on the lives of patients and their caregivers. Both diseases are characterized by chronic inflammation of the lung, but the nature of the inflammatory response differs between diseases and shows a high degree of heterogeneity within each disease, accounting for a large number of endotypes and phenotypes. During my PhD various lines of research have been explored either by the research group in Padova or in partnerships with both national and international colleagues. We performed two clinical “real life” studies on two large cohorts of adult asthmatics and patients with COPD followed at our Centre, observing the existence of multiple phenotypes and inflammatory endotypes of these two diseases. In adult asthmatics, we differentiated patients with early onset asthma (EOA) from late onset asthma (LOA). In EOA patients, we observed a crucial role of allergic rhinitis and eosinophilic inflammation on disease control and pulmonary function. Conversely, in patients with LOA, rhinitis was not linked to poor asthma control while obesity, associated with a neutrophilic profile, had a major impact. In the cohort of COPD patients we observed that blood lymphopenia was related to a more severe disease with a predominant emphysematous component, while high levels of neutrophils and monocytes were related to chronic bronchitis and bronchiectasis.
My main research field was the investigation of the immunopathology of asthma and its etiology at the beginning of the natural history of the disease. We performed a series of studies on a cohort of wheezing children who underwent bronchoscopy for clinical purposes in whom bronchial biopsies were available for research. We first observed that airway remodeling and inflammatory hallmarks of adult asthma are also present in preschool wheezing and that phenotypes and endotypes of asthma are already recognizable. In particular, we observed that basement membrane thickening, a putative sign of epithelial-mesenchymal activation, is a very early sign that may precede inflammation and predict asthma development. Furthermore, we highlighted the presence of the eosinophilic non-atopic (T2H-nA) endotype where type 2 inflammation is present in absence of atopy. In these patients we described the presence of innate lymphoid cells type 2 (ILC2) as major drivers of type 2 inflammation. Of note, ILC2 infiltration was associated with persistence of asthma in a longitudinal follow-up, while we observed a shift toward the development of atopy with growth. In subsequent analyses we investigated the effects of air pollution and viral infections on the pathological hallmarks of asthma. We observed a direct relationship linking type 2 inflammation to both outdoor air pollution exposure and antiviral innate immune response impairment hypothesizing a possible existence in asthma of a pathogenetic intersection between atopy, air pollution and viral infections. Finally, we also described in a cohort of COPD patients that underwent lung surgery a deranged interferon-response mediated by NK, whose impairment was related to increased disease severity. These observations complement those of a different study, in which we studied the involvement of innate lymphoid cells type 1 (ILC1). Finally, addressing the interaction between COPD and viral infections we investigated the risk factors for the development and severity of COVID-19 in patients with COPD. We reported that cardio-metabolic conditions were the main risk factors for development of COVID-19 in COPD patients. Emphysema and low DLCO, were related to a more severe disease and need for intensive care, remarking a possible relationship between COPD severity and impaired antiviral responses.Asthma and chronic obstructive pulmonary disease (COPD) are the two most common respiratory chronic diseases worldwide, which are increasing in prevalence and have an enormous impact on the lives of patients and their caregivers. Both diseases are characterized by chronic inflammation of the lung, but the nature of the inflammatory response differs between diseases and shows a high degree of heterogeneity within each disease, accounting for a large number of endotypes and phenotypes. During my PhD various lines of research have been explored either by the research group in Padova or in partnerships with both national and international colleagues. We performed two clinical “real life” studies on two large cohorts of adult asthmatics and patients with COPD followed at our Centre, observing the existence of multiple phenotypes and inflammatory endotypes of these two diseases. In adult asthmatics, we differentiated patients with early onset asthma (EOA) from late onset asthma (LOA). In EOA patients, we observed a crucial role of allergic rhinitis and eosinophilic inflammation on disease control and pulmonary function. Conversely, in patients with LOA, rhinitis was not linked to poor asthma control while obesity, associated with a neutrophilic profile, had a major impact. In the cohort of COPD patients we observed that blood lymphopenia was related to a more severe disease with a predominant emphysematous component, while high levels of neutrophils and monocytes were related to chronic bronchitis and bronchiectasis.
My main research field was the investigation of the immunopathology of asthma and its etiology at the beginning of the natural history of the disease. We performed a series of studies on a cohort of wheezing children who underwent bronchoscopy for clinical purposes in whom bronchial biopsies were available for research. We first observed that airway remodeling and inflammatory hallmarks of adult asthma are also present in preschool wheezing and that phenotypes and endotypes of asthma are already recognizable. In particular, we observed that basement membrane thickening, a putative sign of epithelial-mesenchymal activation, is a very early sign that may precede inflammation and predict asthma development. Furthermore, we highlighted the presence of the eosinophilic non-atopic (T2H-nA) endotype where type 2 inflammation is present in absence of atopy. In these patients we described the presence of innate lymphoid cells type 2 (ILC2) as major drivers of type 2 inflammation. Of note, ILC2 infiltration was associated with persistence of asthma in a longitudinal follow-up, while we observed a shift toward the development of atopy with growth. In subsequent analyses we investigated the effects of air pollution and viral infections on the pathological hallmarks of asthma. We observed a direct relationship linking type 2 inflammation to both outdoor air pollution exposure and antiviral innate immune response impairment hypothesizing a possible existence in asthma of a pathogenetic intersection between atopy, air pollution and viral infections. Finally, we also described in a cohort of COPD patients that underwent lung surgery a deranged interferon-response mediated by NK, whose impairment was related to increased disease severity. These observations complement those of a different study, in which we studied the involvement of innate lymphoid cells type 1 (ILC1). Finally, addressing the interaction between COPD and viral infections we investigated the risk factors for the development and severity of COVID-19 in patients with COPD. We reported that cardio-metabolic conditions were the main risk factors for development of COVID-19 in COPD patients. Emphysema and low DLCO, were related to a more severe disease and need for intensive care, remarking a possible relationship between COPD severity and impaired antiviral responses
Predictions for imaging and spectroscopic surveys of galaxies and Active Galactic Nuclei in the mid-/far-Infrared
No full textWhile continuum imaging data at far-infrared to sub-millimeter wavelengths have provided tight constraints on the population properties of dusty star-forming galaxies up to high redshifts, future space missions like the Space Infra-Red Telescope for Cosmology and Astrophysics (SPICA) and ground based facilities like the Atacama Large Millimeter/submillimeter Array (ALMA) and the Cerro Chajnantor Atacama Telescope (CCAT) will allow detailed investigations of their physical properties via their mid-/far-infrared line emission.
The goal of this thesis project was to carry out predictions for these spectroscopic surveys using both a phenomenological approach and physically grounded models. These predictions are useful to optimize the planning of the surveys.
In the first part of the work, I present updated predictions for the number counts and the redshift distributions of star-forming galaxies spectroscopically detectable by these future missions. These predictions exploit a recent upgrade of evolutionary models, that includes the effect of strong gravitational lensing, in the light of the most recent Herschel and South Pole Telescope (SPT) data. Moreover the relations between line and continuum infrared luminosity are re-assessed, considering also differences among source populations, with the support of extensive simulations that take into account dust obscuration. My reference model for the redshift dependent IR luminosity functions is the one worked out by Cai et al. (2013) based on a comprehensive hybrid approach combining a physical model for the progenitors of early-type galaxies with a phenomenological one for late-type galaxies. The derived line luminosity functions are found to be highly sensitive to the spread of the line to continuum luminosity ratios. Estimates of the expected numbers of detections per spectral line by the SpicA FAR infrared Instrument (SAFARI) and by CCAT surveys for different integration times per field of view at fixed total observing time are presented. Comparing with the earlier estimates by Spinoglio et al. (2012), I find, in the case of SPICA-SAFARI, differences within a factor of two in most cases, but occasionally much larger. More substantial differences are found for CCAT.
Thereafter I present new estimates of redshift-dependent luminosity functions of IR lines detectable by SPICA-SAFARI and excited both by star formation and by AGN activity. The new estimates improve over previous work by dealing in a self consistent way with the emission of galaxies as a whole, including both the starburst and the AGN component. While the galaxy-AGN co-evolution was already worked out by Cai et al. (2013) in the case of proto-spheroidal galaxies, the evolution of late-type galaxies was dealt with independently of that of AGNs associated with them. I upgraded the model to enable it to take into account in a coherent way the contributions of both starbursts and AGNs to the IR emission during the cosmic evolution also of late-type galaxies.
New relationships between line and AGN bolometric luminosity have been derived and those between line and IR luminosities of the starburst component have been updated. These ingredients were used to work out predictions for the source counts in 11 mid/far-IR emission lines partially or entirely excited by AGN activity. I find that the statistics of the emission line detection of galaxies as a whole is mainly determined by the star formation rate, because of the rarity of bright AGNs. I also find that the slope of the line integral number counts is flatter than 2 implying that the number of detections at fixed observing time increases more by extending the survey area than by going deeper. I thus propose a spectroscopic survey of 1 hour integration per field-of-view over an area of 5 deg^2 to detect (at 5σ) ~760 AGNs in [OIV]25.89 μm - the brightest AGN mid-infrared line - out to z~2. Pointed observations of strongly lensed or hyper-luminous galaxies previously detected by large area surveys such as those by Herschel and by SPT can provide key information on the galaxy-AGN co-evolution out to higher redshifts.
Finally, as third step of the work, I present predictions for number counts and redshift distributions of galaxies detectable in continuum and in emission lines with the Mid-infrared (MIR) Instrument (SMI) proposed for SPICA. I have considered 24 MIR emission fine-structure lines, four Polycyclic Aromatic Hydrocarbon (PAH) bands (at 6.2, 7.7, 8.6 and 11.3 μm) and two silicate bands (in emission and in absorption) at 9.7 μm and 18.0 μm. Six of these lines are primarily associated with Active Galactic Nuclei (AGNs), the others primarily with star formation. Altogether, they allow us to study the interplay between star formation and super-massive black hole growth. A survey with the SMI spectrometers of 1 hour integration per field-of-view (FoV) over an area of 1 deg^2 will yield 5σ detections of ~140 AGN lines, produced by ~110 AGNs, and of ~5.2x10^4 star-forming galaxies, ~1.6x10^4 of which will be detected in at least two lines. The combination of a shallow (20.0 deg^2, 1.4x10^(-1) h integration per FoV) and a deep survey (6.9x10^(-3) deg^2, 635 h integration time), with the SMI camera, for a total of ~1000 h,
will accurately determine the MIR number counts of galaxies and of AGNs over five orders of magnitude in flux density, reaching values more than one order of magnitude fainter than the Spitzer 24 μm surveys. This will allow us to resolve almost completely the extragalactic background and to determine the cosmic star formation rate (SFR) function down to SFRs more than 100 times fainter than reached by the Herschel Observatory.
These spectroscopic observations will allow us to probe all phases of the interstellar medium (ionized, atomic and molecular). Measurements of these lines will provide redshifts and key insight on physical conditions of dust obscured regions and on the energy sources controlling their temperature and pressure. This information is critically important for investigating the complex physics ruling the dust-enshrouded active star-forming phase of galaxy evolution and the relationship with nuclear activity. Observations of strongly gravitationally lensed galaxies will be of special interest, because strong lensing allows us to measure the gas/dust distribution in galaxies up to high-z and to gain information on sources too faint to be detected with current instrument sensitivities, thus testing models for galaxy formation and dark matter
The Effectiveness of Wearable Devices in Non-Communicable Diseases to Manage Physical Activity and Nutrition: Where We Are?
No full textWearable devices are increasingly popular in clinical and non-clinical populations as a tool for exercise prescription, monitoring of daily physical activity and nutrition, and health-related parameters management. In this regard, smart devices not only assist people in pursuing a healthier lifestyle, but also provide a constant stream of physiological and metabolic data for management of non-communicable diseases (NCDs). Although the benefits of lifestyle-based interventions (exercise and nutrition) for NCDs are well known, the potential of wearable devices to promote healthy behaviors in clinical populations is still controversial. In this narrative review, we aimed to discuss the current application of wearable devices in NCDs, highlighting their role in prescribing and monitoring daily physical activity and dietary habits in the population living with chronic diseases. None of the studies considered specifically addressed the efficacy of the use of wearable devices, and limited are those that incorporate monitoring of both physical activity and nutrition for NCDs. However, there is evidence that such devices have helped improve physical activity levels, physical fitness, body composition, and metabolic and psychological parameters. Therefore, the authors believe that the benefits obtained from the use of wearable devices are likely to translate to public health and represent one of the important tools for the development of prevention plans in everyday life and clinical practice for optimal patient management
Editorial: Wellbeing and adherence to physical activity: What are the factors of the wellbeing concept leading to exercise adherence?
No full textRisk spillovers in international equity portfolios
No full textWe define risk spillover as the dependence of a given asset variance on the past covariances and variances of other assets. Building on this idea, we propose the use of a highly flexible and
tractable model to forecast the volatility of an international equity portfolio. According to the risk management strategy proposed, portfolio risk is seen as a specific combination of daily
realized variances and covariances extracted from a high frequency dataset, which includes equities and currencies. In this framework, we focus on the risk spillovers across equities
within the same sector (sector spillover), and from currencies to international equities (currency spillover).We compare these specific risk spillovers to a more general framework (full spillover)
whereby we allow for lagged dependence across all variances and covariances. The forecasting analysis shows that considering only sector- and currency-risk spillovers, rather than full spillovers, improves performance, both in economic and statistical terms
Pupil dilation reveals top-down attentional load during spatial monitoring
No full textIt has long been known that the diameter of human pupil enlarges with increasing effort during the execution of a task. This has been observed not only for purely mechanical effort but also for mental effort, as for example the computation of arithmetic problems with different levels of difficulty. Here we show that pupil dilation reflects changes in visuospatial awareness induced by attentional load during multi-tasking. In the single-task condition, participants had to report the position of lateralized, briefly presented, masked visual targets ("right", "left", or "both" sides). In the multitasking conditions, participants also performed additional tasks, either visual or auditory, to increase the attentional load. Sensory stimulation was kept constant across all conditions to rule out the influence of low-level factors. Results show that event-related pupil dilation strikingly increased with task demands, mirroring a concurrent decrease in visuospatial awareness. Importantly, pupil dilation significantly differed between two dual-task conditions that required to process the same number of stimuli but yielded differed levels of accuracy (difficulty). In contrast, pupil dilation did not differ between two conditions which were equally challenging but differed both in the modality of the dual task (auditory vs. visual) and in the number of stimuli to be attended. We conclude that pupil dilation genuinely reflects the top-down allocation of supramodal attentional resources
High-Intensity interval vs moderate-intensity continuous training in endurance runners: A systematic review of physiological, biochemical, physical, and biomechanical adaptations
No full text
The Effectiveness of Wearable Devices in Non-Communicable Diseases to Manage Physical Activity and Nutrition: Where We Are?
No full textCue-target contingencies modulate voluntary orienting of spatial attention : dissociable effects for speed and accuracy
No full textVoluntary orienting of spatial attention is typically investigated by visually presented directional cues, which are called predictive when they indicate where the target is more likely to appear. In this study we investigated the nature of the potential link between cue predictivity (the proportion of valid trials) and the strength of the resulting, covert, orienting of attention. Participants judged the orientation of a unilateral Gabor grating preceded by a centrally-presented, non-directional, colour cue, arbitrarily prompting a leftwards or rightwards shift of attention. Unknown to them, cue predictivity was manipulated across blocks, whereby the cue was only predictive for either the first or the second half of the experiment. Our results show that the cueing effects were strongly influenced by the change in predictivity. This influence differently emerged in response speed and accuracy. The speed difference between valid and invalid trials was significantly larger when cues were predictive, and the amplitude of this effect was modulated at the single trial level by the recent trial history. Complementary to these findings, accuracy revealed a robust effect of block history and also a different time-course compared to speed, as if it mainly mirrored voluntary processes. These findings, obtained with a new manipulation and by using arbitrary non-directional cueing, demonstrate that cue-target contingencies strongly modulate the way attention deploys in space
- …
