Aerodynamic roughness parameters in cities: inclusion of vegetation

A widely used morphometric method (Macdonald et al. 1998) to calculate the zero-plane displacement (zd) and aerodynamic roughness length (z0) for momentum is further developed to include vegetation. The adaptation also applies to the Kanda et al. (2013) morphometric method which considers roughness-element height variability. Roughness-element heights (mean, maximum and standard deviation) of both buildings and vegetation are combined with a porosity corrected plan area and drag formulation. The method captures the influence of vegetation (in addition to buildings), with the magnitude of the effect depending upon whether buildings or vegetation are dominant and the porosity of vegetation (e.g. leaf-on or leaf-off state). Application to five urban areas demonstrates that where vegetation is taller and has larger surface cover, its inclusion in the morphometric methods can be more important than the morphometric method used. Implications for modelling the logarithmic wind profile (to 100 m) are demonstrated. Where vegetation is taller and occupies a greater amount of space, wind speeds may be slowed by up to a factor of three

Evaluation of urban local-scale aerodynamic parameters: implications for the vertical profile of wind speed and for source areas

Nine methods to determine local-scale aerodynamic roughness length (z0) and zero-plane displacement (zd) are compared at three sites (within 60 m of each other) in London, UK. Methods include three anemometric (single-level high frequency observations), six morphometric (surface geometry) and one reference-based approach (look-up tables). A footprint model is used with the morphometric methods in an iterative procedure. The results are insensitive to the initial zd and z0 estimates. Across the three sites, zd varies between 5 – 45 m depending upon the method used. Morphometric methods that incorporate roughness-element height variability agree better with anemometric methods, indicating zd is consistently greater than the local mean building height. Depending upon method and wind direction, z0 varies between 0.1 and 5 m with morphometric z0 consistently being 2 – 3 m larger than the anemometric z0. No morphometric method consistently resembles the anemometric methods. Wind-speed profiles observed with Doppler lidar provide additional data with which to assess the methods. Locally determined roughness parameters are used to extrapolate wind-speed profiles to a height roughly 200 m above the canopy. Wind-speed profiles extrapolated based on morphometric methods that account for roughness-element height variability are most similar to observations. The extent of the modelled source area for measurements varies by up to a factor of three, depending upon the morphometric method used to determine zd and z0

A 4-days-on and 3-days-off maintenance treatment strategy for adults with HIV-1 (ANRS 170 QUATUOR): a randomised, open-label, multicentre, parallel, non-inferiority trial

International audienc

Mycoplasma pneumoniae infection in adult inpatients during the 2023–24 outbreak in France (MYCADO): a national, retrospective, observational study

International audienceBackground. An epidemic of Mycoplasma pneumoniae infection has been observed in France since the fall of 2023. We aimed to: i) describe the characteristics of adults hospitalized for M. pneumoniae infection and ii) identify factors associated with severe outcomes of infection (i.e., intensive care unit [ICU)] admission or in-hospital death).Methods. MYCADO is a retrospective observational study including adults hospitalized for ≥24 hours in 76 French hospitals for a M. pneumoniae infection between 1 September 2023 and 29 February 2024. Clinical, laboratory and imaging data were collected from medical records.We identified factors associated with severe outcomes of infection, defined as need for ICU or in-hospital death, using multivariable logistic regression.Findings. Overall, 1309 patients with M. pneumoniae infection were included: 718 (54.9%) males; median age 43 years (IQR 31-63); 288 (22.0%) with chronic respiratory failure; 423 (32.3%) with cardiovascular comorbidities; 95 (7.3%) with immunosuppression. The most common symptoms were: cough (n=1098, 83.9%), fever (n=1023, 78.2%), dyspnoea (n=948, 72.4%), fatigue (n=550, 42.0%), headache (n=211, 16.1%), arthromyalgia (n=253, 19.3%), vomiting (n=132, 10.1%); 156 (11.9%) patients had extra-respiratory manifestations, including 36 (2.8%) erythema multiforme, 19 (1.5%) meningoencephalitis, 44 (3.4%) autoimmune haemolytic anaemia and 17 (1.3%) myocarditis. The median hospital stay duration was 8 days (IQR 6-11); 415 (31.7%) patients were admitted to ICU and 28 (2.1%) died at hospital. Men, patients with hypertension, obesity, respiratory or liver chronic failure, extra-respiratory manifestations, bilateral lung damage or consolidation on computed tomography scan, elevated inflammatory syndrome, lymphopenia, and those who did not receive any active antibiotic against M. pneumoniae prior to admission, were more likely to present with severe outcomes of infection.Interpretation. This national, observational study highlights unexpected, atypical radiologic presentations, a high proportion of transfers to ICU, and an association between severity and delayed administration of effective antibiotics

HCV cure: an appropriate moment to reduce cannabis use in people living with HIV? (ANRS CO13 HEPAVIH data)

Abstract Background Thanks to direct-acting antivirals, hepatitis C virus (HCV) infection can be cured, with similar rates in HCV-infected and HIV–HCV co-infected patients. HCV cure is likely to foster behavioral changes in psychoactive substance use, which is highly prevalent in people living with HIV (PLWH). Cannabis is one substance that is very commonly used by PLWH, sometimes for therapeutic purposes. We aimed to identify correlates of cannabis use reduction following HCV cure in HIV–HCV co-infected cannabis users and to characterize persons who reduced their use. Methods We used data collected on HCV-cured cannabis users in a cross-sectional survey nested in the ANRS CO13 HEPAVIH cohort of HIV–HCV co-infected patients, to perform logistic regression, with post-HCV cure cannabis reduction as the outcome, and socio-behavioral characteristics as potential correlates. We also characterized the study sample by comparing post-cure substance use behaviors between those who reduced their cannabis use and those who did not. Results Among 140 HIV-infected cannabis users, 50 and 5 had reduced and increased their use, respectively, while 85 had not changed their use since HCV cure. Cannabis use reduction was significantly associated with tobacco use reduction, a decrease in fatigue level, paying more attention to one’s dietary habits since HCV cure, and pre-HCV cure alcohol abstinence (p = 0.063 for alcohol use reduction). Conclusions Among PLWH using cannabis, post-HCV cure cannabis reduction was associated with tobacco use reduction, improved well-being, and adoption of healthy behaviors. The management of addictive behaviors should therefore be encouraged during HCV treatment. </jats:sec