Collective response to local perturbations: how to evade threats without losing coherence

Living groups move in complex environments and are constantly subject to external stimuli, predatory attacks and disturbances. An efficient response to such perturbations is vital to maintain the group's coherence and cohesion. Perturbations are often local, i.e. they are initially perceived only by few individuals in the group, but can elicit a global response. This is the case of starling flocks, that can turn very quickly to evade predators. In this paper, we investigate the conditions under which a global change of direction can occur upon local perturbations. Using minimal models of self-propelled particles, we show that a collective directional response occurs on timescales that grow with the system size and it is, therefore, a finite-size effect. The larger the group is, the longer it will take to turn. We also show that global coherent turns can only take place if i) the mechanism for information propagation is efficient enough to transmit the local reaction undamped through the whole group; and if ii) motility is not too strong, to avoid that the perturbed individual leaves the group before the turn is complete. No compliance with such conditions results in the group's fragmentation or in a non-efficient response.Comment: 23 pages, 7 figure

Long-Term Impact of the COVID-19 Pandemic on In-Hospital Antibiotic Consumption and Antibiotic Resistance: A Time Series Analysis (2015-2021)

The coronavirus disease 2019 (COVID-19)-pandemic-related overload of health systems has compromised the application of antimicrobial stewardship (AS) models and infection prevention and control (IPC) programs. We aimed to evaluate the impact of COVID-19 on antimicrobial consumption (AC) and antimicrobial resistance (AMR) in the University Hospital of Modena. A time series analysis with an autoregressive integrated moving average model was conducted from January 2015 to October 2021 to evaluate the AC in the whole hospital and the intensive care unit (ICU), the incidence density (ID) of bloodstream infections (BSIs) due to the main multidrug-resistant organisms, and of C. difficile infections (CDIs). After an initial peak during the COVID-19 period, a decrease in the trend of AC was observed, both at the hospital (CT: -1.104, p = 0.025) and ICU levels (CT: -4.47, p = 0.047), with no significant difference in the single classes. Among the Gram-negative isolates, we observed a significant increase only in the level of BSIs due to carbapenem-susceptible Pseudomonas aeruginosa (CL: 1.477, 95% CI 0.130 to 2.824, p = 0.032). Considering Gram-positive bacteria, an increase in the level of BSIs due to methicillin-resistant Staphylococcus aureus and in the trend of CDIs were observed, though they did not reach statistical significance (CL: 0.72, 95% CI -0.039 to 1.48, p = 0.062; CT: 1.43, 95% CI -0.002 to 2.863, p = 0.051; respectively). Our findings demonstrated that the increases in AMR and AC that appeared in the first COVID-19 wave may be later controlled by restoring IPC and AS programs to pre-epidemic levels. A coordinated healthcare effort is necessary to address the longer-term impact of COVID-19 on AC to avoid irreversible consequences on AMR

Subjective Symptoms in Magnetic Resonance Imaging Personnel: A Multi-Center Study in Italy

Introduction: Magnetic Resonance Imaging (MRI) personnel have significant exposure to static and low-frequency time-varying magnetic fields. In these workers an increased prevalence of different subjective symptoms has been observed. The aim of our study was to investigate the prevalence of non-specific subjective symptoms and of “core symptoms” in a group of MRI personnel working in different centers in Italy, and of possible relationships with personal and occupational characteristics.Methods: The occurrence of 11 subjective symptoms was evaluated using a specific questionnaire with 240 subjects working in 6 different Italian hospitals and research centers, 177 MRI health care and research personnel and 63 unexposed subjects employed in the same departments. Exposure was subjectively investigated according to the type of MRI scanner (≤1.5 vs. ≥3 T) and to the number of MRI procedures attended and/or performed by the personnel, even if no information on how frequently the personnel entered the scanner room was collected. The possible associations among symptoms and estimated EMF exposure, the main characteristics of the population, and job stress perception were analyzed.Results: Eighty-six percent of the personnel reported at least one symptom; drowsiness, headache, and sleep disorders were the most frequent. The total number of symptoms did not differ between exposed persons and controls. Considering the total number of annual MRI procedures reported by the personnel, no significant associations were found nor with the total number of symptoms, nor with “core symptoms.” Only subjects complaining of drowsiness also reported a significantly higher mean annual number of MRI procedures with ≤ 1.5 T scanners when compared with exposed subjects without drowsiness. In a multivariate model, subjects with a high level of perceived stress complained of more symptoms (p = 0.0002).Conclusions: Our study did not show any association between the occurrence of reversible subjective symptoms, including the more specific “core symptoms,” and the occupational exposure of MRI personnel to static and low-frequency time-varying magnetic fields. On the other hand, the role played by occupational stress appears to be not negligible. In further research in this field, measurements of EMF exposure should be considered

Breast and Prostate Cancer Risks for Male BRCA1 and BRCA2 Pathogenic Variant Carriers Using Polygenic Risk Scores

Background: Recent population-based female breast cancer and prostate cancer polygenic risk scores (PRS) have been developed. We assessed the associations of these PRS with breast and prostate cancer risks for male BRCA1 and BRCA2 pathogenic variant carriers. Methods: 483 BRCA1 and 1318 BRCA2 European ancestry male carriers were available from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). A 147-single nucleotide polymorphism (SNP) prostate cancer PRS (PRSPC) and a 313-SNP breast cancer PRS were evaluated. There were 3 versions of the breast cancer PRS, optimized to predict overall (PRSBC), estrogen receptor (ER)-negative (PRSER-), or ER-positive (PRSER+) breast cancer risk. Results: PRSER+ yielded the strongest association with breast cancer risk. The odds ratios (ORs) per PRSER+ standard deviation estimates were 1.40 (95% confidence interval [CI] =1.07 to 1.83) for BRCA1 and 1.33 (95% CI = 1.16 to 1.52) for BRCA2 carriers. PRSPC was associated with prostate cancer risk for BRCA1 (OR = 1.73, 95% CI = 1.28 to 2.33) and BRCA2 (OR = 1.60, 95% CI = 1.34 to 1.91) carriers. The estimated breast cancer odds ratios were larger after adjusting for female relative breast cancer family history. By age 85 years, for BRCA2 carriers, the breast cancer risk varied from 7.7% to 18.4% and prostate cancer risk from 34.1% to 87.6% between the 5th and 95th percentiles of the PRS distributions. Conclusions: Population-based prostate and female breast cancer PRS are associated with a wide range of absolute breast and prostate cancer risks for male BRCA1 and BRCA2 carriers. These findings warrant further investigation aimed at providing personalized cancer risks for male carriers and informing clinical management.Peer reviewe

SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

Novel Options to Counteract Oral Biofilm Formation: In Vitro Evidence

Biofilm production on biotic and abiotic surfaces is crucial in the pathogenesis of most infections, particularly those occurring in the oral cavity. Its prevention and/or control may greatly facilitate the management of patients with oral diseases. Here, the antibiofilm activity of a biomimetic hydroxyapatite and a natural compound, MicroRepair (MicroR) and pomegranate (PomeGr), respectively, was assessed. By luminescence/fluorescence-based assays, Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans) were tested for biofilm production in the presence of MicroR and/or PomeGr. We found that both MicroR and PomeGr could affected biofilm production; however, the efficacy of the two, given alone or in combination, varied according to the microbial agent considered. These data open to clinical studies aimed at defining the most efficacious protocols to counteract oral biofilm-associated infections

Abgründe und Spiegelungen. Noten zu einem Versuch über die Heimat

Il concetto di Heimat viene analizzato attraverso gli abissi e i rispecchiamenti che suscita. La particolarità di questo concetto di essere legato a una terra e a una cultura viene sottoposta a critica per elaborare una delle tesi di fondo e cioè che Heimat non è un concetto legato a cose materiali, bensì una esperienza che vive e si rinnova continuamente all'interno di una costellazione di rapporti

Role of selective digestive decontamination in the prevention of VAP in COVID-19 patients: a pre-post observational study.

The aim of our study was to evaluate whether the introduction of SDD in a structured protocol for VAP prevention was effective in reducing the occurrence of ventilator associated pneumonia (VAP) in COVID19 patients without changes in the microbiological pattern of antibiotic resistances. This observational pre-post study including adult patients requiring invasive mechanical ventilation (IMV) for severe respiratory failure related to SARS-CoV-2 admitted in three COVID19 intensive care units (ICUs) in an Italian hospital from February 22, 2020, to March 8, 2022. Selective digestive decontamination (SDD) was introduced from the end of April 2021 in the structured protocol for VAP prevention. The SDD consisted of a tobramycin sulphate, colistin sulphate and amphotericin B suspension applied in the patient oropharynx and the stomach via nasogastric tube. Three-hundred forty-eight patients were included in the study. In the 86 patients (32,9%) who received SDD the occurrence of VAP decreased by 7,7% (p = 0,192) compared to patients who did not receive SDD. Onset time of VAP, the occurrence of multidrug-resistant microorganisms AP, the length of invasive mechanical ventilation and hospital mortality were similar in patients who received and who did not receive SDD. The multivariate analysis adjusted for confounders showed that the use of SDD reduces the occurrence of VAP (HR 0,536, CI 0,338-0,851; p = 0,017) Our pre-post observational study indicates that the use of SDD in a structured protocol for VAP prevention seems to reduce the occurrence of VAP without changes in the incidence of multidrug-resistant bacteria in COVID19 patients

Role of Selective Digestive Decontamination in the Prevention of Ventilator-Associated Pneumonia in COVID-19 Patients: A Pre-Post Observational Study

The aim of our study was to evaluate whether the introduction of SDD in a structured protocol for VAP prevention was effective in reducing the occurrence of ventilator-associated pneumonia (VAP) in COVID-19 patients without changes in the microbiological pattern of antibiotic resistance. This observational pre-post study included adult patients requiring invasive mechanical ventilation (IMV) for severe respiratory failure related to SARS-CoV-2 admitted in three COVID-19 intensive care units (ICUs) in an Italian hospital from 22 February 2020 to 8 March 2022. Selective digestive decontamination (SDD) was introduced from the end of April 2021 in the structured protocol for VAP prevention. The SDD consisted of a tobramycin sulfate, colistin sulfate, and amphotericin B suspension applied in the patient’s oropharynx and the stomach via a nasogastric tube. Three-hundred-and-forty-eight patients were included in the study. In the 86 patients (32.9%) who received SDD, the occurrence of VAP decreased by 7.7% (p = 0.192) compared to the patients who did not receive SDD. The onset time of VAP, the occurrence of multidrug-resistant microorganisms AP, the length of invasive mechanical ventilation, and hospital mortality were similar in the patients who received and who did not receive SDD. The multivariate analysis adjusted for confounders showed that the use of SDD reduces the occurrence of VAP (HR 0.536, CI 0.338–0.851; p = 0.017). Our pre-post observational study indicates that the use of SDD in a structured protocol for VAP prevention seems to reduce the occurrence of VAP without changes in the incidence of multidrug-resistant bacteria in COVID-19 patients