Staphylococcus epidermidis is a safer surrogate of Staphylococcus aureus in testing bacterial filtration efficiency of face masks.

Face masks play a role in reducing the spread of airborne pathogens, providing that they have a good filtration performance, are correctly fitted and maintained. Bacterial Filtration Efficiency (BFE) is a key indicator for evaluating filtration performance according to both European and US standards, requiring the use of Staphylococcus aureus loaded aerosol. However, the generation and handling of a Biohazard group 2 bacterium aerosol require a careful management of the biological risk and pose limitations to the accessibility to this method. To mitigate these drawbacks, we investigated the use of S. epidermidis ATCC 12228, a Biohazard group 1 bacterium, as surrogate in BFE test. To this end, tests with the surrogate strain were performed to tune the method. Then, three face mask models, representative for both surgical and community masks, were tested according to the standard method and then using an aerosolized suspension of S. epidermidis. BFE% values were calculated for each mask model and tested microorganisms. Results showed that BFE test can be performed using the S. epidermidis instead of S. aureus, preserving results validity and turnaround time, but reducing residual risk for laboratory operators.

Exploring the Short-Term Memory of Heart Rate Variability through Model-Free Information Measures.

In this work, we perform a comparative analysis of discrete- and continuous-time estimators of information-theoretic measures quantifying the concept of memory utilization in short-term heart rate variability (HRV). Specifically, considering heartbeat intervals in discrete time we compute the measure of information storage (IS) and decompose it into immediate memory utilization (IMU) and longer memory utilization (MU) terms; considering the timings of heartbeats in continuous time we compute the measure of MU rate (MUR). All measures are computed through model-free approaches based on nearest neighbor entropy estimators applied to the HRV series of a group of 15 healthy subjects measured at rest and during postural stress. We find, moving from rest to stress, statistically significant increases of the IS and the IMU, as well as of the MUR. Our results suggest that both discrete-time and continuous-time approaches can detect the higher predictive capacity of HRV occurring with postural stress, and that such increased memory utilization is due to fast mechanisms likely related to sympathetic activation.

Rhamnolipid 89 Biosurfactant Is Effective against Streptococcus oralis Biofilm and Preserves Osteoblast Behavior: Perspectives in Dental Implantology.

Biofilm-related peri-implant diseases represent the major complication for osteointegrated dental implants, requiring complex treatments or implant removal. Microbial biosurfactants emerged as new antibiofilm coating agents for implantable devices thanks to their high biocompatibility. This study aimed to assess the efficacy of the rhamnolipid 89 biosurfactant (R89BS) in limiting Streptococcus oralis biofilm formation and dislodging sessile cells from medical grade titanium, but preserving adhesion and proliferation of human osteoblasts. The inhibitory activity of a R89BS coating on S. oralis biofilm formation was assayed by quantifying biofilm biomass and microbial cells on titanium discs incubated up to 72 h. R89BS dispersal activity was addressed by measuring residual biomass of pre-formed biofilms after rhamnolipid treatment up to 24 h. Adhesion and proliferation of human primary osteoblasts on R89BS-coated titanium were evaluated by cell count and adenosine-triphosphate quantification, while cell differentiation was studied by measuring alkaline phosphatase activity and observing mineral deposition. Results showed that R89BS coating inhibited S. oralis biofilm formation by 80% at 72 h and dislodged 63-86% of pre-formed biofilms in 24 h according to concentration. No change in the adhesion of human osteoblasts was observed, whereas proliferation was reduced accompanied by an increase in cell differentiation. R89BS effectively counteracts S. oralis biofilm formation on titanium and preserves overall osteoblasts behavior representing a promising preventive strategy against biofilm-related peri-implant diseases.

ETMT: A Tool for Eye-Tracking-Based Trail-Making Test to Detect Cognitive Impairment.

The growing number of people with cognitive impairment will significantly increase healthcare demand. Screening tools are crucial for detecting cognitive impairment due to a shortage of mental health experts aiming to improve the quality of life for those living with this condition. Eye tracking is a powerful tool that can provide deeper insights into human behavior and inner cognitive processes. The proposed Eye-Tracking-Based Trail-Making Test, ETMT, is a screening tool for monitoring a person's cognitive function. The proposed system utilizes a fuzzy-inference system as an integral part of its framework to calculate comprehensive scores assessing visual search speed and focused attention. By employing an adaptive neuro-fuzzy-inference system, the tool provides an overall cognitive-impairment score, allowing psychologists to assess and quantify the extent of cognitive decline or impairment in their patients. The ETMT model offers a comprehensive understanding of cognitive abilities and identifies potential deficits in various domains. The results indicate that the ETMT model is a potential tool for evaluating cognitive impairment and can capture significant changes in eye movement behavior associated with cognitive impairment. It provides a convenient and affordable diagnosis, prioritizing healthcare resources for severe conditions while enhancing feedback to practitioners.

Accuracy and Technical Predictability of Computer Guided Bone Harvesting from the Mandible: A Cone-Beam CT Analysis in 22 Consecutive Patients.

This study assesses the accuracy and technical predictability of a computer-guided procedure for harvesting bone from the external oblique ridge using a patient-specific cutting guide. Twenty-two patients needing bone augmentation for implant placement were subjected to mandibular osteotomy employing a case-specific stereolithographic surgical guide generated through computer aided design. Differences between planned and real cut planes were measured comparing pre- and post-operative Cone Beam Computed Tomography images of the donor site according to six validated angular and displacement indexes. Accuracy and technical predictability were assessed for 119 osteotomy planes over the study population. Three different guide fitting approaches were compared. An average root-mean-square discrepancy of 0.52 (0.30-0.97) mm was detected. The accuracy of apical and medial planes was higher than the mesial and distal planes due to occasional antero-posterior guide shift. Fitting the guide with an extra reference point on the closest tooth performed better than using only the bone surface, with two indexes significantly lower and less disperse. The study showed that the surgical plan was actualized with a 1 mm safety margin, allowing effective nerve preservation and reducing technical variability. When possible, surgical guide design should allow fitting on the closest tooth based on both radiological and/or intra-oral scan data.

Implementation of a Night Service of Helicopter Transportation to Reduce the Time to Revascularization in STEMI Patients in a Mountainous Region: Impact on Outcomes.

Background: Treatment delays are the most easily audited index of quality of care in the setting of ST-segment elevation myocardial infarction; among the components of ischemia time, system delay has been demonstrated to be a predictor of outcomes, and in a mountainous region it relies mostly upon helicopter rescue service. Aim: The aim of the study is to analyze the impact of the activation of helicopter rescue service for the nighttime for urgent transportation of patients on the time to revascularization and on the outcomes of STEMI patients. Methods: Data were prospectively collected in a database and retrospectively split into two different cohorts, based on the presentation date in the 18 months before, or after, the first day of implementation of the new organizational model. The patients were also split into two groups based on the place of STEMI diagnosis, either the chief town territory or the rest of the region, and retrospectively evaluated for vital status at 30 days and 2 years after index event. Results: The number of patients included was 751. For patients coming from outside Trento, an improvement in ST-segment resolution was shown (ST-segment elevation reduction >50% in 54.0% of the patients vs. 36.4%, p < 0.01). Moreover, a reduction in diagnosis-to-reperfusion median time has been demonstrated (from 105 to 97 min, p < 0.01), mainly driven by a reduction during the night shift (from 119 to 100 min, p = 0.02). With regard to 30-day and 2-year mortality, no statistically significant differences were achieved. Discussion: The organizational effort has translated into a significant reduction in the treatment delay for patients coming from outside the chief town. However, although a longer diagnosis to reperfusion time has been related to a higher mortality, a significant reduction in mortality was not demonstrated in our study. However, an improvement in ST-segment elevation resolution was shown for patients coming from outside the city of Trento, a result that could have other potential clinical benefits. Conclusions: Implementation of night flight proved to be effective in reducing the time between the diagnosis and the treatment of patients in the setting of STEMI, improving ST-segment elevation resolution, although no impact was shown on short- and long-term mortality.

"Long COVID" results after hospitalization for SARS-CoV-2 infection.

Long-term sequelae of symptomatic infection caused by SARS-CoV-2 are largely undiscovered. We performed a prospective cohort study on consecutively hospitalized Sars-CoV-2 patients (March-May 2020) for evaluating COVID-19 outcomes at 6 and 12 months. After hospital discharge, patients were addressed to two follow-up pathways based on respiratory support needed during hospitalization. Outcomes were assessed by telephone consultation or ambulatory visit. Among 471 patients, 80.9% received no respiratory support during hospitalization; 19.1% received non-invasive ventilation (NIV) or invasive mechanical ventilation (IMV). 58 patients died during hospitalization, therefore 413 were enrolled for follow-up. At 6 months, among 355 patients, the 30.3% had any symptoms, 18.0% dyspnea, 6.2% neurological symptoms. Fifty-two out of 105 had major damages in interstitial computed tomography images. NIV/IMV patients had higher probability to suffer of symptoms (aOR = 4.00, 95%CI:1.99-8.05), dyspnea (aOR = 2.80, 95%CI:1.28-6.16), neurological symptoms (aOR = 9.72, 95%CI:2.78-34.00). At 12 months, among 344, the 25.3% suffered on any symptoms, 12.2% dyspnea, 10.1% neurological symptoms. Severe interstitial lesions were present in 37 out of 47 investigated patients. NIV/IMV patients in respect to no respiratory support, had higher probability of experiencing symptoms (aOR = 3.66, 95%CI:1.73-7.74), neurological symptoms (aOR = 8.96, 95%CI:3.22-24.90). COVID-19 patients showed prolonged sequelae up to 12 months, highlighting the need of follow-up pathways for post-COVID-19 syndrome.

A Simple Method to Quantify Outward Leakage of Medical Face Masks and Barrier Face Coverings: Implication for the Overall Filtration Efficiency.

Face masking proved essential to reduce transmission of COVID-19 and other respiratory infections in indoor environments, but standards and literature do not provide simple quantitative methods for quantifying air leakage at the face seal. This study reports an original method to quantify outward leakage and how wearing style impacts on leaks and filtration efficiency. The amount of air leakage was evaluated on four medical masks and four barrier face coverings, exploiting a theoretical model and an instrumented dummy head in a range of airflows between 30 and 160 L/min. The fraction of air leaking at the face seal of the medical masks and barrier face coverings ranged from 43% to 95% of exhaled air at 30 L/min and reduced to 10-85% at 160 L/min. Filter breathability was the main driver affecting both leak fraction and total filtration efficiency that varied from 5% to 53% and from 15% to 84% at 30 and 160 L/min, respectively. Minor changes were related to wearing style, supporting indications on the correct mask use. The fraction of air leaking from medical masks and barrier face coverings during exhalation is relevant and varies according to design and wearing style. The use of highly breathable filter materials reduces air leaks and improve total filtration efficiency.

Counter-Acting Candida albicans-Staphylococcus aureus Mixed Biofilm on Titanium Implants Using Microbial Biosurfactants.

This study aimed to grow a fungal-bacterial mixed biofilm on medical-grade titanium and assess the ability of the biosurfactant R89 (R89BS) coating to inhibit biofilm formation. Coated titanium discs (TDs) were obtained by physical absorption of R89BS. Candida albicans-Staphylococcus aureus biofilm on TDs was grown in Yeast Nitrogen Base, supplemented with dextrose and fetal bovine serum, renewing growth medium every 24 h and incubating at 37 °C under agitation. The anti-biofilm activity was evaluated by quantifying total biomass, microbial metabolic activity and microbial viability at 24, 48, and 72 h on coated and uncoated TDs. Scanning electron microscopy was used to evaluate biofilm architecture. R89BS cytotoxicity on human primary osteoblasts was assayed on solutions at concentrations from 0 to 200 µg/mL and using eluates from coated TDs. Mixed biofilm was significantly inhibited by R89BS coating, with similar effects on biofilm biomass, cell metabolic activity and cell viability. A biofilm inhibition >90% was observed at 24 h. A lower but significant inhibition was still present at 48 h of incubation. Viability tests on primary osteoblasts showed no cytotoxicity of coated TDs. R89BS coating was effective in reducing C. albicans-S. aureus mixed biofilm on titanium surfaces and is a promising strategy to prevent dental implants microbial colonization.

The negative effects of COVID-19 and national lockdown on emergency surgery morbidity due to delayed access.

BACKGROUND: The aim of this retrospective comparative study was to assess the impact of COVID-19 and delayed emergency department access on emergency surgery outcomes, by comparing the main clinical outcomes in the period March-May 2019 (group 1) with the same period during the national COVID-19 lockdown in Italy (March-May 2020, group 2). METHODS: A comparison (groups 1 versus 2) and subgroup analysis were performed between patients' demographic, medical history, surgical, clinical and management characteristics. RESULTS: Two-hundred forty-six patients were included, 137 in group 1 and 109 in group 2 (p = 0.03). No significant differences were observed in the peri-operative characteristics of the two groups. A declared delay in access to hospital and preoperative SARS-CoV-2 infection rates were 15.5% and 5.8%, respectively in group 2. The overall morbidity (OR = 2.22, 95% CI 1.08-4.55, p = 0.03) and 30-day mortality (OR = 1.34, 95% CI 0.33-5.50, =0.68) were significantly higher in group 2. The delayed access cohort showed a close correlation with increased morbidity (OR = 3.19, 95% CI 0.89-11.44, p = 0.07), blood transfusion (OR = 5.13, 95% CI 1.05-25.15, p = 0.04) and 30-day mortality risk (OR = 8.00, 95% CI 1.01-63.23, p = 0.05). SARS-CoV-2-positive patients had higher risk of blood transfusion (20% vs 7.8%, p = 0.37) and ICU admissions (20% vs 2.6%, p = 0.17) and a longer median LOS (9 days vs 4 days, p = 0.11). CONCLUSIONS: This article provides enhanced understanding of the effects of the COVID-19 pandemic on patient access to emergency surgical care. Our findings suggest that COVID-19 changed the quality of surgical care with poorer prognosis and higher morbidity rates. Delayed emergency department access and a "filter effect" induced by a fear of COVID-19 infection in the population resulted in only the most severe cases reaching the emergency department in time.

Estimation of Granger causality through Artificial Neural Networks: applications to physiological systems and chaotic electronic oscillators.

One of the most challenging problems in the study of complex dynamical systems is to find the statistical interdependencies among the system components. Granger causality (GC) represents one of the most employed approaches, based on modeling the system dynamics with a linear vector autoregressive (VAR) model and on evaluating the information flow between two processes in terms of prediction error variances. In its most advanced setting, GC analysis is performed through a state-space (SS) representation of the VAR model that allows to compute both conditional and unconditional forms of GC by solving only one regression problem. While this problem is typically solved through Ordinary Least Square (OLS) estimation, a viable alternative is to use Artificial Neural Networks (ANNs) implemented in a simple structure with one input and one output layer and trained in a way such that the weights matrix corresponds to the matrix of VAR parameters. In this work, we introduce an ANN combined with SS models for the computation of GC. The ANN is trained through the Stochastic Gradient Descent L1 (SGD-L1) algorithm, and a cumulative penalty inspired from penalized regression is applied to the network weights to encourage sparsity. Simulating networks of coupled Gaussian systems, we show how the combination of ANNs and SGD-L1 allows to mitigate the strong reduction in accuracy of OLS identification in settings of low ratio between number of time series points and of VAR parameters. We also report how the performances in GC estimation are influenced by the number of iterations of gradient descent and by the learning rate used for training the ANN. We recommend using some specific combinations for these parameters to optimize the performance of GC estimation. Then, the performances of ANN and OLS are compared in terms of GC magnitude and statistical significance to highlight the potential of the new approach to reconstruct causal coupling strength and network topology even in challenging conditions of data paucity. The results highlight the importance of of a proper selection of regularization parameter which determines the degree of sparsity in the estimated network. Furthermore, we apply the two approaches to real data scenarios, to study the physiological network of brain and peripheral interactions in humans under different conditions of rest and mental stress, and the effects of the newly emerged concept of remote synchronization on the information exchanged in a ring of electronic oscillators. The results highlight how ANNs provide a mesoscopic description of the information exchanged in networks of multiple interacting physiological systems, preserving the most active causal interactions between cardiovascular, respiratory and brain systems. Moreover, ANNs can reconstruct the flow of directed information in a ring of oscillators whose statistical properties can be related to those of physiological networks.

Quantitative MRI T2 Mapping is Able to Assess Tissue Quality After Reparative and Regenerative Treatments of Osteochondral Lesions of the Talus.

BACKGROUND: Quantitative MRI has potential for tissue characterization after reparative and regenerative surgical treatment of osteochondral lesions of the talus (OCLTs). However available data is inconclusive and quantitative sequences can be difficult to implement in real-time clinical application. PURPOSE: To assess the potential of T2 mapping in discriminating articular tissue characteristics after reparative and regenerative surgery of OCLTs in real-world clinical settings. STUDY TYPE: Observational and prospective cohort study. POPULATION: 15 OCLT patients who had received either reparative treatment with arthroscopic microfracture surgery (MFS) for a grade I lesion or regenerative treatment with bone marrow derived cell transplantation (BMDCT) for a grade II lesion. FIELD STRENGTH/SEQUENCE: 1.5 T, proton density weighted TSE, T2-weighted true fast imaging with steady-state-free precession and multi-echo T2 mapping sequences. ASSESSMENT: Patients were evaluated at a minimum postoperative follow-up of 24 months. T2 maps of the ankle were generated and the distribution of T2 values was analyzed in manually identified volumes of interest (VOIs) for both treated lesions (TX) and healthy cartilage (CTRL). The amount of fibrocartilage, hyaline-like and remodeling tissue in TX VOIs was obtained, based on T2 thresholds from CTRL VOIs. STATISTICAL TESTS: Fisher's exact test for categorical data, nonparametric Mann-Whitney U test for continuous data. The statistical significance level was P < 0.05. RESULTS: From CTRL VOI analysis, T2 < 25 msec, 25 msec ≤ T2 ≤ 45 msec, and T2 > 45 msec were considered as representative for fibrocartilage, hyaline-like and remodeling tissue, respectively. Tissue composition of the two treatment groups was different, with significantly more fibrocartilage (+28%) and less hyaline-like tissue (-15%) in MFS than in BMDCT treated lesions. No difference in healthy tissue composition was found between the two groups (P = 0.75). DATA CONCLUSIONS: T2 mapping of surgically treated OCLTs can provide quantitative information about the type and amount of newly formed tissue at the lesion site, thereby facilitating surgical follow-up in a real-word clinical setting. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 3.

A Propensity Score-Matched Analysis to Assess the Outcomes in Pre- and Post-Fast-Track Hip and Knee Elective Prosthesis Patients.

Fast-track surgery is a multimodal evidence-based approach to perioperative care aimed at reducing complications and recovery time. We compared a fast-track protocol to standard care in the setting of a small Italian general hospital. Propensity score estimation before and after the study was performed to compare pre-fast-track (pre-FT; January 2013-March 2014) and fast-track (FT; January 2016-December 2016) patients undergoing elective hip and knee replacement surgery with a three-year follow-up (up to January 2020). The primary endpoints were the mean hemoglobin drop, mean predischarge hemoglobin, transfusion and reinfusion rates, pain, ambulation day, hospital length of stay (LOS), and discharge to home/outpatient care or rehabilitation hospital center. The secondary endpoints were the adherence measures to the FT protocol, namely, tourniquet and surgical times, use of drains and catheters, type of anesthesia administered, and complications within three years. The risk difference (RD) and the adjusted odds ratio (aOR) were calculated for each outcome. After the propensity score estimation, we analyzed 59 patients in the pre-FT and 122 in the FT categories. The FT patients, with respect to the pre-FT patients, ameliorated their mean hemoglobin drop from 3.7 to 3.1 g/dl (p < 0.01) and improved their predischarge mean hemoglobin (10.5 g/dL versus 11.0 g/dL; p = 0.01). Furthermore, the aOR of being transfused was reduced by 81% (p < 0,01); the RD of being reinfused was reduced by 63% (p < 0.01); the aOR of having low pain on the first day was increased by more than six times (p < 0.01); the RD of ambulating the first day increased by 91% (p < 0.01); the aOR of admission to a rehabilitation hospital center was reduced by 98% (p < 0.01); the aOR of home discharge increased by 42 times (p < 0.01); the median LOS, tourniquet and surgical times, and use of catheters and drains significantly decreased. Patients with complications at 1 month were 43.1% and 38.2%, respectively, of pre-FT and FT patients (p = 0.63). Complications at 6, 12, 24, and 36 months were significantly lower for the FT patients. This study showed that the uptake of enhanced recovery practices was successful and resulted in the improvement of clinical and organizational outcomes. The fast-track concept and related programs may optimize perioperative care and streamline surgical and rehabilitation care paths.

The Conundrum of Giglio Island: Unraveling the dynamics of an apparent resistance to COVID-19 - A descriptive study.

OBJECTIVES: Despite an extensive risk of exposure to COVID-19, the residents of Giglio Island, Italy, did not develop any symptom of SARS-CoV-2. The present study aims to characterize the nature of exposure and to describe the local population dynamics underlying its apparent resistance to COVID-19. METHODS: Descriptive study of an islander partially-segregated population cohort based on a seroprevalence screening conducted from Aprile 29 to May 3, 2020 and including SARS-CoV-2 seroprevalence and viral prevalence in samples of saliva assessed through RT-qPCR. Serologic testing was performed using a COVID-19 IgG/IgM rapid test while molecular analyses were carried out by Allplex 2019-nCoV Assay (Seegene). RESULTS: A total of 634 residents out of 748 (84.8%) present at the time, and 89 non-residents underwent serological testing. 364 males and 359 females with a median age of 58.5 years. The serological screening identified one positive, asymptomatic subject. The Nucleic Acid Amplification Tests (NAAT) did not yield any positive result. CONCLUSION: Despite extensive exposure to SARS-CoV-2, possibly only one new asymptomatic infection occurred in this population, as documented by IgM positivity not confirmed by RT-qPCR. This may be due to unknown protective factors or chance. On the basis of this baseline study, using its population as a reference model, further investigations will be conducted to test the advanced hypotheses, focusing on the evaluation of a possible cross-reactivity to SARS-CoV-2 from exposure to endemic viruses.

Rhamnolipid coating reduces microbial biofilm formation on titanium implants: an in vitro study.

BACKGROUND: Peri-implant mucositis and peri-implantitis are biofilm-related diseases causing major concern in oral implantology, requiring complex anti-infective procedures or implant removal. Microbial biosurfactants emerged as new anti-biofilm agents for coating implantable devices preserving biocompatibility. This study aimed to assess the efficacy of rhamnolipid biosurfactant R89 (R89BS) to reduce Staphylococcus aureus and Staphylococcus epidermidis biofilm formation on titanium. METHODS: R89BS was physically adsorbed on titanium discs (TDs). Cytotoxicity of coated TDs was evaluated on normal lung fibroblasts (MRC5) using a lactate dehydrogenase assay. The ability of coated TDs to inhibit biofilm formation was evaluated by quantifying biofilm biomass and cell metabolic activity, at different time-points, with respect to uncoated controls. A qualitative analysis of sessile bacteria was also performed by scanning electron microscopy. RESULTS: R89BS-coated discs showed no cytotoxic effects. TDs coated with 4 mg/mL R89BS inhibited the biofilm biomass of S. aureus by 99%, 47% and 7% and of S. epidermidis by 54%, 29%, and 10% at 24, 48 and 72 h respectively. A significant reduction of the biofilm metabolic activity was also documented. The same coating applied on three commercial implant surfaces resulted in a biomass inhibition higher than 90% for S. aureus, and up to 78% for S. epidermidis at 24 h. CONCLUSIONS: R89BS-coating was effective in reducing Staphylococcus biofilm formation at the titanium implant surface. The anti-biofilm action can be obtained on several different commercially available implant surfaces, independently of their surface morphology.

Testing Surgical Face Masks in an Emergency Context: The Experience of Italian Laboratories during the COVID-19 Pandemic Crisis.

The first wave of the COVID-19 pandemic brought about a broader use of masks by both professionals and the general population. This resulted in a severe worldwide shortage of devices and the need to increase import and activate production of safe and effective surgical masks at the national level. In order to support the demand for testing surgical masks in the Italian context, Universities provided their contribution by setting up laboratories for testing mask performance before releasing products into the national market. This paper reports the effort of seven Italian university laboratories who set up facilities for testing face masks during the emergency period of the COVID-19 pandemic. Measurement set-ups were built, adapting the methods specified in the EN 14683:2019+AC. Data on differential pressure (DP) and bacterial filtration efficiency (BFE) of 120 masks, including different materials and designs, were collected over three months. More than 60% of the masks satisfied requirements for DP and BFE set by the standard. Masks made of nonwoven polypropylene with at least three layers (spunbonded-meltblown-spunbonded) showed the best results, ensuring both good breathability and high filtration efficiency. The majority of the masks created with alternative materials and designs did not comply with both standard requirements, resulting in suitability only as community masks. The effective partnering between universities and industries to meet a public need in an emergency context represented a fruitful example of the so-called university "third-mission".

Information Transfer in Linear Multivariate Processes Assessed through Penalized Regression Techniques: Validation and Application to Physiological Networks.

The framework of information dynamics allows the dissection of the information processed in a network of multiple interacting dynamical systems into meaningful elements of computation that quantify the information generated in a target system, stored in it, transferred to it from one or more source systems, and modified in a synergistic or redundant way. The concepts of information transfer and modification have been recently formulated in the context of linear parametric modeling of vector stochastic processes, linking them to the notion of Granger causality and providing efficient tools for their computation based on the state-space (SS) representation of vector autoregressive (VAR) models. Despite their high computational reliability these tools still suffer from estimation problems which emerge, in the case of low ratio between data points available and the number of time series, when VAR identification is performed via the standard ordinary least squares (OLS). In this work we propose to replace the OLS with penalized regression performed through the Least Absolute Shrinkage and Selection Operator (LASSO), prior to computation of the measures of information transfer and information modification. First, simulating networks of several coupled Gaussian systems with complex interactions, we show that the LASSO regression allows, also in conditions of data paucity, to accurately reconstruct both the underlying network topology and the expected patterns of information transfer. Then we apply the proposed VAR-SS-LASSO approach to a challenging application context, i.e., the study of the physiological network of brain and peripheral interactions probed in humans under different conditions of rest and mental stress. Our results, which document the possibility to extract physiologically plausible patterns of interaction between the cardiovascular, respiratory and brain wave amplitudes, open the way to the use of our new analysis tools to explore the emerging field of Network Physiology in several practical applications.