Intact but empty forests? Patterns of hunting-induced mammal defaunation in the tropics

Tropical forests are increasingly degraded by industrial logging, urbanization, agriculture, and infrastructure, with only 20% of the remaining area considered intact. However, this figure does not include other, more cryptic but pervasive forms of degradation, such as overhunting. Here, we quantified and mapped the spatial patterns of mammal defaunation in the tropics using a database of 3,281 mammal abundance declines from local hunting studies. We simultaneously accounted for population abundance declines and the probability of local extirpation of a population as a function of several predictors related to human accessibility to remote areas and species’ vulnerability to hunting. We estimated an average abundance decline of 13% across all tropical mammal species, with medium-sized species being reduced by >27% and large mammals by >40%. Mammal populations are predicted to be partially defaunated (i.e., declines of 10%–100%) in ca. 50% of the pantropical forest area (14 million km2), with large declines (>70%) in West Africa. According to our projections, 52% of the intact forests (IFs) and 62% of the wilderness areas (WAs) are partially devoid of large mammals, and hunting may affect mammal populations in 20% of protected areas (PAs) in the tropics, particularly in West and Central Africa and Southeast Asia. The pervasive effects of overhunting on tropical mammal populations may have profound ramifications for ecosystem functioning and the livelihoods of wild-meat-dependent communities, and underscore that forest coverage alone is not necessarily indicative of ecosystem intactness. We call for a systematic consideration of hunting effects in (large-scale) biodiversity assessments for more representative estimates of human-induced biodiversity loss

Piercing and tatooing in high school students of Veneto region: prevalence and perception of infectious releated risk

Introduction. Body piercing (P) and tattoo (T) is a growing social phenomenon over recent years. Nowadays in Italy little is known about the prevalence, the attitude, the medical and social conse- quences of these activities. The purpose of this study is to examine the prevalence distribution and the attitude towards P and T and the perception of the risk for infections, in a sample of high school students living in the four Provinces of the Veneto Region (Italy). Methods. An anonymous, self administrate multiple-choice questionnaire about piercing and tattoo practices was dis- tributed during the 2009-2010 academic year to a sample of randomly extracted grades to obtain information about socio- demographic characteristics, family educational level, personal attitude, prevalence and perception of the importance of the sanitary, technical and artistic competence of the operator. Results. The correctly compiled questionnaires were 2712 (95.4%). Males and females were respectively 46.2% and 53.8% (mean age 17 ± 1.7 years). The 20.2% and the 6.4% of all the students had already experienced respectively P and T and resulted ?very interested? the 46.7% to P and the 57.4% to T. Esthetical motivations are the main ones referred to use body art. The most part of interviewed subjects (81.6%) think that it is possible to have an infection, but only about 50% of stu- dents reported to know specific information about transmission of HIV, Viral Hepatitis and skin infections. The parents? educa- tional levels do not influence the perception of the risk of infec- tion. The majority of interviewed subjects (88.0%) prefers to undergo body art practices in a qualified center. Only the 30% of students recur to a medical help to solve problem of infection. Discussion. The piercing and tattoo prevalence rate in our study (P: 20.2% and T:6.4%) resulted similar to other Italian ones (range reported: P: 20.3-35.1%, T: 4.8-8.6%), showing an increasing trend with age. Since a high rate of interviewed students referred a substan- tial ignorance about the risk of transmission of body art related infectious diseases, it is suitable to promote as soon as possible among the youth educational interventions and counseling

Bedside calculation of mechanical power during volume- And pressure-controlled mechanical ventilation

Background: Mechanical power (MP) is the energy delivered to the respiratory system over time during mechanical ventilation. Our aim was to compare the currently available methods to calculate MP during volume- and pressure-controlled ventilation, comparing different equations with the geometric reference method, to understand whether the easier to use surrogate formulas were suitable for the everyday clinical practice. This would warrant a more widespread use of mechanical power to promote lung protection. Methods: Forty respiratory failure patients, sedated and paralyzed for clinical reasons, were ventilated in volume-controlled ventilation, at two inspiratory flows (30 and 60 L/min), and pressure-controlled ventilation with a similar tidal volume. Mechanical power was computed both with the geometric method, as the area between the inspiratory limb of the airway pressure and the volume, and with two algebraic methods, a comprehensive and a surrogate formula. Results: The bias between the MP computed by the geometric method and by the comprehensive algebraic method during volume-controlled ventilation was respectively 0.053 (0.77, - 0.81) J/min and - 0.4 (0.70, - 1.50) J/min at low and high flows (r 2 = 0.96 and 0.97, p < 0.01). The MP measured and computed by the two methods were highly correlated (r 2 = 0.95 and 0.94, p < 0.01) with a bias of - 0.0074 (0.91, - 0.93) and - 1.0 (0.45, - 2.52) J/min at high-low flows. During pressure-controlled ventilation, the bias between the MP measured and the one calculated with the comprehensive and simplified methods was correlated (r 2 = 0.81, 0.94, p < 0.01) with mean differences of - 0.001 (2.05, - 2.05) and - 0.81 (2.11, - 0.48) J/min. Conclusions: Both for volume-controlled and pressure-controlled ventilation, the surrogate formulas approximate the reference method well enough to warrant their use in the everyday clinical practice. Given that these formulas require nothing more than the variables already displayed by the intensive care ventilator, a more widespread use of mechanical power should be encouraged to promote lung protection against ventilator-induced lung injury

Mechanistic insights into the role of large carnivores for ecosystem structure and functioning

Large carnivores can exert top–down effects in ecosystems, but the size of these effects are largely unknown. Empirical investigation on the importance of large carnivores for ecosystem structure and functioning presents a number of challenges due to the large spatio-temporal scale and the complexity of such dynamics. Here, we applied a mechanistic global ecosystem model to investigate the influence of large-carnivore removal from undisturbed ecosystems. First, we simulated large-carnivore removal on the global scale to inspect the geographic pattern of top–down control and to disentangle the functional role of large carnivores in top–down control in different environmental contexts. Second, we conducted four small-scale ecosystem simulation experiments to understand direct and indirect changes in food-web structure under different environmental conditions. We found that the removal of top–down control exerted by large carnivores (> 21 kg) can trigger large trophic cascades, leading to an overall decrease in autotroph biomass globally. Furthermore, the loss of large carnivores resulted in an increase of mesopredators. The magnitude of these changes was positively related to primary productivity (NPP), in line with the ‘exploitation ecosystem hypothesis’. In addition, we found that seasonality in NPP dampened the magnitude of change following the removal of large carnivores. Our results reinforce the idea that large carnivores play a fundamental role in shaping ecosystems, and further declines and extinctions can trigger substantial ecosystem responses. Our findings also support previous studies suggesting that natural ecosystem dynamics have been severely modified and are still changing as a result of the widespread decline and extinction of large carnivores