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Covering the most important topics in trauma anesthesia, this updated edition provides anesthesiology trainees and practitioners with a practical basis for managing trauma patients. Many recent advances in trauma care are identified, including paradigm shifts in the management of bleeding and coagulopathy, new neuromuscular blockade and anticoagulant reversal drugs, and updated clinical practice guidelines. This volume provides a concise, practical review of the essential elements in the care of the severely injured trauma patient, including emergency airway management, fluid and blood resuscitation, monitoring, coagulation therapy, regional and general anesthesia, and perioperative care. Edited by two of the most experienced trauma anesthesiologists in the United States, with chapters written by experts from leading US and Canadian trauma centers with the highest and most varied caseload of critically injured patients, Essentials of Trauma Anesthesia identifies new trends in surgery and anesthesiology practices that impact on the management of trauma patients.
The identification of seed dispersers and predators is essential to understand the effect of anthropogenic disturbances, and the associated defaunation process, on tropical forest dynamics in Central Africa. In this study, the animals involved in seed predation and dispersal of Dacryodes normandii (Burseraceae), an endozoochorously dispersed tree species endemic to Gabonese forests, were identified in a site in south-east Gabon using two complementary methods: direct observation and camera-trap monitoring of fruit piles. The combined sampling effort (172 h of direct observations and 796 d of camera trapping) led to the identification of six disperser and eight predator species of D. normandii seeds. With high frequency of consumption (88% and 57% of their visits, respectively) and long visit duration (83 and 23 min, respectively), the western lowland gorilla and central chimpanzee were identified as the main dispersers of this species. Seeds passed through the gorilla gut exhibited high germination success (68%). Rodents were identified as predators of D. normandii seeds, potentially displaying rare secondary dispersal through scatter-hoarding. The results of this study highlight the importance of great apes in the seed dispersal of this tree species.
Understanding the ecological function of large frugivores in tropical forests is important considering their central position in seed-dispersal networks. This study illustrates the seed-dispersal effectiveness of a western lowland gorilla (Gorilla gorilla gorilla) population in Cameroon by looking at the interaction of seed quantity, species regeneration traits and the environmental characteristics of the deposition sites (sleeping sites vs. feeding trails) in order to discuss the role of gorillas within the ecosystem. The analysis of 1030 faecal samples collected over a 3-y period (September 2009–August 2012) showed that gorillas dispersed a diverse array of species (58 spp. identified), with an average of 289 intact seeds (>5 mm) d−1 per individual. Seed damage during mouth and gut processing occurred for 12 spp., generally accounting for <5% of specific seed load. Germination trials suggested that germination success of passed seeds remained unchanged (N = 6 spp.) or improved (N = 5 spp.) after gut passage compared with hand-cleaned seeds, with one exception. Indicator species identification (IndVal method) and General Discriminant Analysis suggested that sleeping sites (N = 36), as a main type of seed deposition site, correspond to regenerating microhabitats and correspondingly degree of canopy openness is one variable discriminating significantly this type of deposition site with random locations in the forest (N = 36) used as a proxy for non-directed seed deposition on feeding trails. With a mean canopy openness of 19–27%, sleeping sites offer optimal light conditions for the seedling recruitment of non-pioneer light-demanding species, the seeds of which encompass 47.4% of the total seed load dispersed over the 3-y period. From this study, it is hypothesized that the gorilla performed directed-dispersal of some light-demanding plant species at sleeping sites, and hence, by being actively implicated in gap-phase dynamics, fulfils a valuable ecological function within its ecosystem.
Therapeutic misconception (TM)—when clinical research participants fail to adequately grasp the difference between participating in a clinical trial and receiving ordinary clinical care—has long been recognized as a significant problem in consent to clinical trials. We suggest that TM does not primarily reflect inadequate disclosure or participants’ incompetence. Instead, TM arises from divergent primary cognitive frames. The researchers’ frame places the clinical trial in the context of scientific designs for assessing intervention efficacy. In contrast, most participants have a cognitive frame that is personal and focused primarily on their medical problems. To illustrate this, we draw on interview material from both clinical researchers and participants in clinical trials. We suggest that reducing TM requires encouraging subjects to adjust their frame, not just add information to their existing frame. What is necessary is a scientific reframing of participation in a clinical trial.
For endozoochorous seed dispersal systems, the extant dung beetle assemblage at seed deposition sites may influence site suitability as burial activity may change the probability that seeds germinate and seedlings establish. This study tested if the different conditions of the two main seed-deposition habitats of a western lowland gorilla population of south-east Cameroon (sleeping sites and old secondary forest) influenced dung beetle assemblages and consequently the seed relocation patterns. In March 2012, in both habitats, burial patterns (proportion and depth) were described in eight stations based on two 300-g experimental faeces with known number of Uapaca spp. seeds (N = 75) left for 48 h, and beetle assemblages were described based on one 48h-dung-baited pitfall trapping session in five of these stations. To assess the impact of burial pattern on seedling emergence, Uapaca seedling emergence trials were performed in a nursery (75 seeds per depth treatment). Assemblage at sleeping sites had a higher species richness (non-significant) and was significantly more abundant than in old secondary forests. Conversely, significantly more seeds were buried in old secondary forests than sleeping sites and at significantly greater depths (mean: 14.9 cm vs. 8.7 cm). As trials suggested that burial depth ≥7 cm prevented Uapaca seedling emergence, dung beetles are assumed to induce seed loss more strongly in old secondary forests than sleeping sites (20.5% vs. 6.7% of initial seed crop). The demonstration that dung beetles may exert a negative influence on seed fate overall, and that the degree to which this occurs may vary depending on habitat, highlights the complexity in determining the suitability of deposition sites for recruitment.
Abstract A great deal of academic and theoretical work has been dedicated to optimal liquidation of large orders these last twenty years. The optimal split of an order through time (‘optimal trade scheduling’) and space (‘smart order routing’) is of high interest to practitioners because of the increasing complexity of the market micro structure because of the evolution recently of regulations and liquidity worldwide. This chapter translates into quantitative terms these regulatory issues and, more broadly, current market design.
It relates the recent advances in optimal trading, order-book simulation and optimal liquidity to the reality of trading in an emerging global network of liquidity.
Market microstructure modeling and payoff understanding are key elements of quantitative trading
As is well known, optimal (or quantitative) trading is about finding the proper balance between providing liquidity in order to minimize the impact of the trades, and consuming liquidity in order to minimize the market risk exposure, while taking profit through potentially instantaneous trading signals, supposed to be triggered by liquidity inefficiencies.
The mathematical framework required to solve this kind of optimization problem needs:
a model of the consequences of the different ways of interacting with liquidity (such as the market impact model (Almgren et al., 2005; Wyart et al., 2008; Gatheral, 2010));
a proxy for the ‘market risk’ (the most natural of them being the high frequency volatility (Aït-Sahalia and Jacod, 2007; Zhang et al., 2005; Robert and Rosenbaum, 2011));
and a model for quantifying the likelihood of the liquidity state of the market (Bacry et al., 2009; Cont et al., 2010).
Late-life depression may increase the risk of incident dementia, in
particular of Alzheimer's disease and vascular dementia.
To conduct a systematic review and meta-analysis to evaluate the risk of
incident all-cause dementia, Alzheimer's disease and vascular dementia in
individuals with late-life depression in population-based prospective
A total of 23 studies were included in the meta-analysis. We used the
generic inverse variance method with a random-effects model to calculate
the pooled risk of dementia, Alzheimer's disease and vascular dementia in
older adults with late-life depression.
Late-life depression was associated with a significant risk of all-cause
dementia (1.85, 95% CI 1.67-2.04, P< 0.001), Alzheimer's disease
(1.65, 95% CI 1.42-1.92, P<0.001) and vascular dementia (2.52, 95% CI
1.77-3.59, P<0.001). Subgroup analysis, based on five studies, showed
that the risk of vascular dementia was significantly higher than for
Alzheimer's disease (P=0.03).
Late-life depression is associated with an increased risk for all-cause
dementia, vascular dementia and Alzheimer's disease. The present results
suggest that it will be valuable to design clinical trials to investigate
the effect of late-life depression prevention on risk of dementia, in
particular vascular dementia and Alzheimer's disease.