An X-ray Survey of Galaxies in Pairs

Results are reported from the first survey of X-ray emission from galaxies in pairs. The sample consists of fifty-two pairs of galaxies from the Catalog of Paired Galaxies Karachentsev (1972) whose coordinates overlap ROSAT Position Sensitive Proportional Counter pointed observations. The mean observed log l_x for early-type pairs is 41.35 +/-0.21 while the mean log l_x predicted using the l_x-l_b relationship for isolated early-type galaxies is 42.10 +/-0.19. With 95% confidence, the galaxies in pairs are underluminous in the X-ray, compared to isolated galaxies, for the same l_b. A significant fraction of the mixed pair sample also appear similarly underluminous. A spatial analysis shows that the X-ray emission from pairs of both types typically has an extent of ~10 - 50 kpc, much smaller than group intergalactic medium and thus likely originates from the galaxies. CPG 564, the most X-ray luminous early-type pair, 4.7x10^42 ergs/sec, is an exception. The extent of it's X-ray emission, >169 kpc, and HWHM, ~80 kpc, is comparable to that expected from an intergalactic medium. The sample shows only a weak correlation, ~81% confidence, between l_x and l_b, presumably due to variations in gas content within the galaxies. No correlation between l_x and the pair velocity difference, separation, or far-infrared luminosity is found though the detection rate is low, 22%.Comment: 40 pages, 6 jpg figures, ApJ (in press

A unified rheological model for cells and cellularised materials.

The mechanical response of single cells and tissues exhibits a broad distribution of time-scales that often gives rise to a distinctive power-law rheology. Such complex behaviour cannot be easily captured by traditional rheological approaches, making material characterisation and predictive modelling very challenging. Here, we present a novel model combining conventional viscoelastic elements with fractional calculus that successfully captures the macroscopic relaxation response of epithelial monolayers. The parameters extracted from the fitting of the relaxation modulus allow prediction of the response of the same material to slow stretch and creep, indicating that the model captured intrinsic material properties. Two characteristic times, derived from the model parameters, delimit different regimes in the materials response. We compared the response of tissues with the behaviour of single cells as well as intra and extra-cellular components, and linked the power-law behaviour of the epithelium to the dynamics of the cell cortex. Such a unified model for the mechanical response of biological materials provides a novel and robust mathematical approach to consistently analyse experimental data and uncover similarities and differences in reported behaviour across experimental methods and research groups. It also sets the foundations for more accurate computational models of tissue mechanics

Stress relaxation in epithelial monolayers is controlled by the actomyosin cortex

Epithelial monolayers are one-cell thick tissue sheets that separate internal and external environments. As part of their function, they have to withstand extrinsic mechanical stresses applied at high strain rates. However, little is known about how monolayers respond to mechanical deformations. Here, by subjecting suspended epithelial monolayers to stretch, we find that they dissipate stresses on a minute time-scale in a process that involves an increase in monolayer length, pointing to active remodelling of cell architecture during relaxation. Strikingly, monolayers consisting of tens of thousands of cells relax stress with similar dynamics to single rounded cells and both respond similarly to perturbations of actomyosin. By contrast, cell-cell junctional complexes and intermediate filaments do not relax tissue stress, but form stable connections between cells, allowing monolayers to behave rheologically as single cells. Taken together our data show that actomyosin dynamics governs the rheological properties of epithelial monolayers, dissipating applied stresses, and enabling changes in monolayer length.Peer ReviewedPostprint (published version

Increased hormonal stress response of Apennine chamois induced by interspecific interactions and anthropogenic disturbance

Responses of animals to environmental changes and their interactions with other species play an important role in conservation. Sharing a common habitat may lead to interspecific competition for resources, but field assessment of these biological events is not always easily accomplished. By using a non-invasive method, we evaluated the physiological stress responses of Apennine chamois (Rupicapra pyrenaica ornata) to the presence of cattle, sheep and goat, red deer (Cervus elaphus), people (hikers), and predators to identify which factors may affect this endangered species. During September 2012, November 2012, and July 2013, a total of 318 faecal samples were collected in representative sites and analysed for faecal cortisol metabolites (FCM). FCM concentration was analysed through linear mixed-effect models. A significant increase in FCM values in Apennine chamois sharing their habitat with domestic animals was recorded during all study periods. On the contrary, stress responses to red deer and people were limited in time and emerged only during summer months, when hikers are more frequent and red deer extend their altitudinal range reaching chamois\u2019 habitat. The observed effects of domestic animals, red deer, and hikers should be considered in future Apennine chamois management plans, which should include the regulation of pastured domestic livestock, anthropogenic disturbances, and possible interferences with other wild species within parks

Effects of COVID-19 lockdown on eating disorders and obesity: A systematic review and meta-analysis

Objective: This systematic review and meta-analysis aimed to examine: the pooled prevalence of symptomatic behaviours and mental health deterioration amongst individuals with eating disorders (EDs) and obesity during the COVID-19 confinement. Moreover, we examined changes in EDs and distress before and during the confinement, and the association between psychosocial factors and EDs symptoms. Method: A systematic search was carried out in biomedical databases from January 2020 to January 2021. Both cross-sectional and longitudinal studies that used quantitative measures of ED symptoms and psychological distress during and after the COVID-19 confinement were included. Results: A total of 26 studies met inclusion criteria (n = 3399, 85.7% female). The pooled prevalence of symptomatic deterioration in EDs was 65% (95% CI[48,81], k = 10). The pooled prevalence of increased weight in obesity was 52% (95% CI[25,78], k = 4). More than half of the participants experienced depression and anxiety. Moreover, at least 75% of the individuals with EDs reported shape and eating concerns, and increased thinking about exercising. However, the pooled analyses of longitudinal studies showed no significant differences from pre-pandemic levels to the first lockdown phase in Body Mass Index and ED symptoms, whereas only few studies suggested increased distress, particularly among individuals with anorexia nervosa. Conclusions: The majority of individuals with EDs and obesity reported symptomatic worsening during the lockdown. However, further longitudinal studies are needed to identify vulnerable groups, as well as the long-term consequences of COVID-19

Effects of COVID-19 lockdown on eating disorders and obesity: A systematic review and meta-analysis

OBJECTIVE: This systematic review and meta-analysis aimed to examine: the pooled prevalence of symptomatic behaviours and mental health deterioration amongst individuals with eating disorders (EDs) and obesity during the COVID-19 confinement. Moreover, we examined changes in EDs and distress before and during the confinement, and the association between psychosocial factors and EDs symptoms. METHOD: A systematic search was carried out in biomedical databases from January 2020 to January 2021. Both cross-sectional and longitudinal studies that used quantitative measures of ED symptoms and psychological distress during and after the COVID-19 confinement were included. RESULTS: A total of 26 studies met inclusion criteria (n = 3399, 85.7% female). The pooled prevalence of symptomatic deterioration in EDs was 65% (95% CI[48,81], k = 10). The pooled prevalence of increased weight in obesity was 52% (95% CI[25,78], k = 4). More than half of the participants experienced depression and anxiety. Moreover, at least 75% of the individuals with EDs reported shape and eating concerns, and increased thinking about exercising. However, the pooled analyses of longitudinal studies showed no significant differences from pre-pandemic levels to the first lockdown phase in Body Mass Index and ED symptoms, whereas only few studies suggested increased distress, particularly among individuals with anorexia nervosa. CONCLUSIONS: The majority of individuals with EDs and obesity reported symptomatic worsening during the lockdown. However, further longitudinal studies are needed to identify vulnerable groups, as well as the long-term consequences of COVID-19

The Impact of the First and Second Wave of the COVID-19 Pandemic on Eating Symptoms and Dysfunctional Eating Behaviours in the General Population: A Systematic Review and Meta-Analysis

Background: The aim of this systematic review and meta-analysis was to examine the prevalence of feeding and eating disorder (FED) symptoms or dysfunctional eating behaviours (DEB) in the general population during the COVID-19 outbreak. Method: We searched eligible articles in biomedical databases from 1 January 2020 to 31 March 2022. Prevalence rates of FED or DEB changes between pre-pandemic and pandemic time and correlation with psychological distress were pooled with a meta-analysis using a random-effects model. Heterogeneity was tested using I-squared (I2) statistics. A total of 186 studies with 406,076 participants met the inclusion criteria. Results: The more prevalent FED or DEB during the COVID-19 outbreak were: body image concerns (52%, 95% CI 0.38, 0.66), binge eating (40%, 95% CI 0.25, 0.55), and overeating (40%, 95% CI = 0.32-0.48). Pooled data of longitudinal studies (k = 8) only showed a significant difference in the prevalence of weight gain from pre-pandemic to the pandemic time. Finally, increased levels of psychological distress (k = 35) positively correlated with some ED symptoms. Conclusion: This meta-analysis evidenced a negative impact of the pandemic on eating symptoms and DEB in the general population

TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS

Context. TOI-1055 is a Sun-like star known to host a transiting Neptune-sized planet on a 17.5-day orbit (TOI-1055 b). Radial velocity (RV) analyses carried out by two independent groups using nearly the same set of HARPS spectra have provided measurements of planetary masses that differ by ∼2σ. Aims. Our aim in this work is to solve the inconsistency in the published planetary masses by significantly extending the set of HARPS RV measurements and employing a new analysis tool that is able to account and correct for stellar activity. Our further aim was to improve the precision on measurements of the planetary radius by observing two transits of the planet with the CHEOPS space telescope. Methods. We fit a skew normal function to each cross correlation function extracted from the HARPS spectra to obtain RV measurements and hyperparameters to be used for the detrending. We evaluated the correlation changes of the hyperparameters along the RV time series using the breakpoint technique. We performed a joint photometric and RV analysis using a Markov chain Monte Carlo scheme to simultaneously detrend the light curves and the RV time series. Results. We firmly detected the Keplerian signal of TOI-1055 b, deriving a planetary mass of Mb = 20.4−2.5+2.6 M⊕ (∼12%). This value is in agreement with one of the two estimates in the literature, but it is significantly more precise. Thanks to the TESS transit light curves combined with exquisite CHEOPS photometry, we also derived a planetary radius of Rb = 3.490−0.064+0.070 R⊕ (∼1.9%). Our mass and radius measurements imply a mean density of ρb = 2.65−0.35+0.37 g cm−3 (∼14%). We further inferred the planetary structure and found that TOI-1055 b is very likely to host a substantial gas envelope with a mass of 0.41−0.20+0.34 M⊕ and a thickness of 1.05−0.29+0.30 R⊕. Conclusions. Our RV extraction combined with the breakpoint technique has played a key role in the optimal removal of stellar activity from the HARPS time series, enabling us to solve the tension in the planetary mass values published so far for TOI-1055 b

Lipid profile improvement in virologically suppressed hiv-1-infected patients switched to dolutegravir/ abacavir/lamivudine: Data from the SCOLTA project

open13noIntroduction: Metabolic disorders are common amongst HIV-infected patients. Data from real-life setting on the impact of DTG/ABC/3TC in virologically suppressed HIV-infected patients are scarce. Methods: We investigated the modification of metabolic profile including fasting glucose, lipid profile and markers of insulin resistance (IR) in experienced patients switching from a boosted protease inhibitors (bPI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen to DTG/ABC/3TC in a prospective, observational, multicenter study. Results: We enrolled 131 HIV-infected patients, of whom 91 (69.5%) males, mean age was 50.5±10.6 years. CDC stage was A in 66 (50.4%) patients, of whom 91 (69.5%) had acquired HIV through sexual contacts. The previous regimen was bPI-based in 79 patients (60.3%) and NNRTI-based in 52 (39.7%). Patients switching from NNRTI showed a significant reduction at week 24 in total cholesterol (TC) and low-density lipoprotein cholesterol (LDL). Triglycerides/high-density lipoprotein cholesterol (TG/HDL) ratio, HDL, median TG and TG/HDL ratio did not show significant modification during follow-up times. Among patients switching from a bPI, we observed a significant reduction in TC and LDL at both follow-up times and a slight increase in HDL. Triglycerides/HDL ratio, median TG and TG/HDL ratio showed a decrease over time that became significant at weeks 24 and 48. Blood glucose levels did not significantly vary during the observation period in patients switching from both bPI and NNRTI-based regimens. Conclusion: Our data suggest an improvement in lipid profile and TG/HDL ratio in pretreated HIV-1-infected patients who switched to DTG/ABC/3TC over 48 weeks, especially in those previously receiving a bPI-based regimen.openBagella P.; Squillace N.; Ricci E.; Gulminetti R.; De Socio G.V.; Taramasso L.; Pellicano G.; Menzaghi B.; Celesia B.M.; Dentone C.; Orofino G.; Bonfanti P.; Madeddu G.Bagella, P.; Squillace, N.; Ricci, Elena; Gulminetti, R.; De Socio, G. V.; Taramasso, L.; Pellicano, G.; Menzaghi, B.; Celesia, B. M.; Dentone, C.; Orofino, G.; Bonfanti, P.; Madeddu, G