Functional representativeness and distinctiveness of reintroduced birds and mammals in Europe.

Reintroduction, the human-mediated movement of organisms to re-establish locally extinct populations, has become a popular conservation tool. However, because reintroductions often focus on local or national conservation issues, their contribution to the conservation of biodiversity at large scale remains unclear. While taxonomic biases have already been identified in reintroduction programs at regional scales, studies have stressed the need to account for other facets of biodiversity when assessing the relevance of the allocation of conservation efforts. In particular, it may be very fruitful to discriminate if and how such taxonomic biases may influence the functional complementarity of reintroduction targets, and to which extent reintroduction practitioners may have focused on species performing more singular functions than others. Here, we investigate the diversity of functional traits supported by reintroduced species of terrestrial birds and mammals in Europe. For each taxonomic group, we explored the functional representativeness of reintroduction targets at the European scale, i.e., whether species involved in reintroduction programs collectively represent the range of functional trait variation observed in the regional assemblage. Because additional conservation value could have been given by practitioners to species performing singular functions, we also measured the functional distinctiveness of reintroduced species. We found that reintroductions of birds did not focus on functionally distinct species, and that the subset of reintroduced birds is representative of the functional diversity at a continental scale. However, reintroductions of mammals involved more functionally distinct species than expected, even though reintroduced mammals are not collectively representative of the functional diversity of the continental assemblage.

Setting up home noninvasive ventilation.

Home noninvasive ventilation (NIV) is widely used to correct nocturnal alveolar hypoventilation in patients with chronic respiratory failure of various etiologies. The most commonly used ventilation mode is pressure support with a backup respiratory rate. This mode requires six main settings, as well as some additional settings that should be adjusted according to the individual patient. This review details the effect of each setting, how the settings should be adjusted according to each patient, and the risks if they are not adjusted correctly. The examples described here are based on real patient cases and bench simulations. Optimizing the settings for home NIV may improve the quality and tolerance of the treatment.

Impact of leaks and ventilation parameters on the efficacy of humidifiers during home ventilation for tracheostomized patients: a bench study.

BACKGROUND: During invasive ventilation, the upper airway is bypassed and no longer participates in humidification of inspired gases, which is essential to avoid harmful consequences such as endotracheal tube occlusion. In the case of increased air flow, especially in the presence of leaks (intentional or unintentional), the humidification provided by humidifiers may become ineffective. The objective of this bench study was to evaluate the quality of humidification provided by heated humidifiers under various home ventilation conditions. METHODS: Five heated humidifiers were tested in eight configurations combining circuit (expiratory valve or vented circuit), tidal volume (600 or 1000 mL) and presence of unintentional leak. Absolute humidity (AH) was measured at the upstream of the test lungs, which were placed in a 34 °C environmental chamber in order to simulate body temperature. RESULTS: The AH measured in the valve circuit ranged between 30 mg/L and 40 mg/L and three out of the five humidifiers achieved an AH higher than the recommended level (33 mg/L). With the vented circuit without unintentional leak, when tidal volume was set at 600 mL, all humidifiers reached an AH higher than 33 mg/L except one device; when the tidal volume was set at 1000 mL and unintentional leak was present, four out of the five humidifiers provided an AH lower than 33 mg/L. CONCLUSION: This study shows that, except under certain home ventilation conditions, such as high tidal volumes with unintentional leak in vented circuit, most heated humidifiers ensure sufficient humidification to avoid the risk of side effect in patients.

Reintroductions of birds and mammals involve evolutionarily distinct species at the regional scale.

Reintroductions offer a powerful tool for reversing the effects of species extirpation and have been increasingly used over recent decades. However, this species-centered conservation approach has been criticized for its strong biases toward charismatic birds and mammals. Here, we investigated whether reintroduced species can be representative of the phylogenetic diversity within these two groups at a continental scale (i.e., Europe, North and Central America). Using null models, we found that reintroduced birds and mammals of the two subcontinents tend to be more evolutionarily distinct than expected by chance, despite strong taxonomic biases leading to low values of phylogenetic diversity. While evolutionary considerations are unlikely to have explicitly driven the allocation of reintroduction efforts, our results illustrate an interest of reintroduction practitioners toward species with fewer close relatives. We discuss how this phylogenetic framework allows us to investigate the contribution of reintroductions to the conservation of biodiversity at multiple geographic scales. We argue that because reintroductions rely on a parochial approach of conservation, it is important to first understand how the motivations and constraints at stake at a local context can induce phylogenetic biases before trying to assess the relevance of the allocation of reintroduction efforts at larger scales.

An in silico analysis of oxygen uptake of a mild COPD patient during rest and exercise using a portable oxygen concentrator.

Oxygen treatment based on intermittent-flow devices with pulse delivery modes available from portable oxygen concentrators (POCs) depends on the characteristics of the delivered pulse such as volume, pulse width (the time of the pulse to be delivered), and pulse delay (the time for the pulse to be initiated from the start of inhalation) as well as a patient's breathing characteristics, disease state, and respiratory morphology. This article presents a physiological-based analysis of the performance, in terms of blood oxygenation, of a commercial POC at different settings using an in silico model of a COPD patient at rest and during exercise. The analysis encompasses experimental measurements of pulse volume, width, and time delay of the POC at three different settings and two breathing rates related to rest and exercise. These experimental data of device performance are inputs to a physiological-based model of oxygen uptake that takes into account the real dynamic nature of gas exchange to illustrate how device- and patient-specific factors can affect patient oxygenation. This type of physiological analysis that considers the true effectiveness of oxygen transfer to the blood, as opposed to delivery to the nose (or mouth), can be instructive in applying therapies and designing new devices.