The impact of interception losses on the water balance in forested mountains range

International audienceAlthough it is commonly admitted that forest reduces annual runoff, the amount of the reduction may vary considerably as a function of the soil and climatic conditions. Forest enhances evaporation through two main processes: 1) Deeper root systems use the water stored in soil more efficiently during the summer period. As a result, more water is retained in the soil during the following autumn before the resumption of winter discharge, and annual runoff is reduced. 2) Loss by interception is greater in forested areas than for other types of vegetation cover during the winter months, mainly because of more efficient use of advective energy. Studies in small catchments on Mount Lozère (South of France) have shown that during the winter period, "actual" evapotranspiration (calculated by the water balance method) is higher than "potential" evapotranspiration (estimated using a standard equation). These ifferences are due to interception losses. During the study period, one small spruce-forested catchment was cut and replanted, while another grassland/heath catchment was left undisturbed. Interception losses for the two basins were compared. The study period (1982-1995) covered the precut (1982-1987), cutting (1987-1989) and postcut/regrowth (1990-1995) periods. Results show that cutting the forest did reduce interception losses. However, the hydrological behaviour of the cut catchment changed back to its pre-cut behaviour relatively quickly and clearly before the new plants had developed enough to be considered as forest cover

[Evaluation of preoperative non-invasive ventilation in thoracic surgery for lung cancer: the preOVNI study GFPC 12-01].

International audienceBACKGROUND: Surgical resection is the best treatment for stage I and II non-small cell lung cancer. Despite an improvement in the perioperative management of cancer patients and specialization of surgical teams, morbidity and mortality remains significant. Non-invasive ventilation (NIV) is an effective therapeutic option in hypercapnic respiratory failure. It also improves functional and gasometric parameters when undertaken before surgery. The objective of the preOVNI study is to demonstrate that preoperative non-invasive ventilation for 7 days, at home, reduces the postoperative respiratory and cardiovascular complications of lung resection surgery, in a high-risk population. METHODS: A prospective, randomized, controlled open-labelled multicentric French study, under the supervision of the Groupe Français de Pneumocancérologie (GFPC), comparing 7 days of preoperative non-invasive ventilation with standard treatment. Inclusion criteria are: patients suitable for lobectomy or segmentectomy for primary bronchial carcinoma and presenting with obstructive or restrictive lung disease, obesity or chronic cardiac insufficiency. The primary criterion is a composite one, including all respiratory and cardiac complications. The number of patients is 150 in each treatment arm, 300 in total. EXPECTED RESULTS: We think that preoperative NIV will be able to reduce the rate of postoperative complications. If this objective is achieved, the management of these patients could be changed

Assessment of preoperative noninvasive ventilation before lung cancer surgery: The preOVNI randomized controlled study

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Increased risk of severe COVID-19 in hospitalized patients with SARS-CoV-2 Alpha variant infection: a multicentre matched cohort study

International audienceBackground: The impact of the variant of concern (VOC) Alpha on the severity of COVID-19 has been debated. We report our analysis in France.Methods: We conducted an exposed/unexposed cohort study with retrospective data collection, comparing patients infected by VOC Alpha to contemporaneous patients infected by historical lineages. Participants were matched on age (± 2.5 years), sex and region of hospitalization. The primary endpoint was the proportion of hospitalized participants with severe COVID-19, defined as a WHO-scale > 5 or by the need of a non-rebreather mask, occurring up to day 29 after admission. We used a logistic regression model stratified on each matched pair and accounting for factors known to be associated with the severity of the disease.Results: We included 650 pairs of patients hospitalized between Jan 1, 2021, and Feb 28, 2021, in 47 hospitals. Median age was 70 years and 61.3% of participants were male. The proportion of participants with comorbidities was high in both groups (85.0% vs 90%, p = 0.004). Infection by VOC Alpha was associated with a higher odds of severe COVID-19 (41.7% vs 38.5%-aOR = 1.33 95% CI [1.03-1.72]).Conclusion: Infection by the VOC Alpha was associated with a higher odds of severe COVID-19