Evolution of Ecological Niche Breadth Sexton, Jason P; Montiel, Jorge; Shay, Jackie E ...
Annual review of ecology, evolution, and systematics,
11/2017, Letnik:
48, Številka:
1
Journal Article
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How ecological niche breadth evolves is central to adaptation and speciation and has been a topic of perennial interest. Niche breadth evolution research has occurred within environmental, ...ecological, evolutionary, and biogeographical contexts, and although some generalities have emerged, critical knowledge gaps exist. Performance breadth trade-offs, although long invoked, may not be common determinants of niche breadth evolution or limits. Niche breadth can expand or contract from specialist or generalist lineages, and so specialization need not be an evolutionary dead end. Whether niche breadth determines diversification and distribution breadth and how niche breadth is partitioned among individuals and populations within a species are important but particularly understudied topics. Molecular genetic and phylogenetic techniques have greatly expanded understanding of niche breadth evolution, but field studies of how niche breadth evolves are essential for providing mechanistic details and allowing the development of comprehensive theory and improved prediction of biological responses under global change.
Consumer-driven sleep-tracking technologies are becoming increasingly popular with patients with sleep disorders and the general population. As the list of sleep-tracking technologies continues to ...grow, clinicians and researchers are faced with new challenges and opportunities to incorporate these technologies into current practice. We review diagnostic tools used in sleep medicine clinical practice, discuss categories of consumer sleep-tracking technologies currently available, and explore the advantages and disadvantages of each. Potential uses of consumer sleep-tracking technologies to enhance sleep medicine patient care and research are also discussed.
Epithelial-mesenchymal transition (EMT) is a developmental program of signaling pathways that determine commitment to epithelial and mesenchymal phenotypes. In the prostate, EMT processes have been ...implicated in benign prostatic hyperplasia and prostate cancer progression. In a model of Pten- and TP53-null prostate adenocarcinoma that progresses via transforming growth factor β-induced EMT, mesenchymal transformation is characterized by plasticity, leading to various mesenchymal lineages and the production of bone. Here we show that SLUG is a major regulator of mesenchymal differentiation. As microRNAs (miRs) are pleiotropic regulators of differentiation and tumorigenesis, we evaluated miR expression associated with tumorigenesis and EMT. Mir-1 and miR-200 were reduced with progression of prostate adenocarcinoma, and we identify Slug as one of the phylogenetically conserved targets of these miRs. We demonstrate that SLUG is a direct repressor of miR-1 and miR-200 transcription. Thus, SLUG and miR-1/miR-200 act in a self-reinforcing regulatory loop, leading to amplification of EMT. Depletion of Slug inhibited EMT during tumorigenesis, whereas forced expression of miR-1 or miR-200 inhibited both EMT and tumorigenesis in human and mouse model systems. Various miR targets were analyzed, and our findings suggest that miR-1 has roles in regulating EMT and mesenchymal differentiation through Slug and functions in tumor-suppressive programs by regulating additional targets.
A key measure of humanity's global impact is by how much it has increased species extinction rates. Familiar statements are that these are 100–1000 times pre‐human or background extinction levels. ...Estimating recent rates is straightforward, but establishing a background rate for comparison is not. Previous researchers chose an approximate benchmark of 1 extinction per million species per year (E/MSY). We explored disparate lines of evidence that suggest a substantially lower estimate. Fossil data yield direct estimates of extinction rates, but they are temporally coarse, mostly limited to marine hard‐bodied taxa, and generally involve genera not species. Based on these data, typical background loss is 0.01 genera per million genera per year. Molecular phylogenies are available for more taxa and ecosystems, but it is debated whether they can be used to estimate separately speciation and extinction rates. We selected data to address known concerns and used them to determine median extinction estimates from statistical distributions of probable values for terrestrial plants and animals. We then created simulations to explore effects of violating model assumptions. Finally, we compiled estimates of diversification—the difference between speciation and extinction rates for different taxa. Median estimates of extinction rates ranged from 0.023 to 0.135 E/MSY. Simulation results suggested over‐ and under‐estimation of extinction from individual phylogenies partially canceled each other out when large sets of phylogenies were analyzed. There was no evidence for recent and widespread pre‐human overall declines in diversity. This implies that average extinction rates are less than average diversification rates. Median diversification rates were 0.05–0.2 new species per million species per year. On the basis of these results, we concluded that typical rates of background extinction may be closer to 0.1 E/MSY. Thus, current extinction rates are 1,000 times higher than natural background rates of extinction and future rates are likely to be 10,000 times higher.
Systemic inflammation is pivotal in the pathogenesis of cardiovascular disease. As inflammation can directly cause cardiomyocyte injury, we hypothesised that established systemic inflammation, as ...reflected by elevated preoperative neutrophil-lymphocyte ratio (NLR) >4, predisposes patients to perioperative myocardial injury.
We prospectively recruited 1652 patients aged ≥45 yr who underwent non-cardiac surgery in two UK centres. Serum high sensitivity troponin T (hsTnT) concentrations were measured on the first three postoperative days. Clinicians and investigators were blinded to the troponin results. The primary outcome was perioperative myocardial injury, defined as hsTnT≥14 ng L−1 within 3 days after surgery. We assessed whether myocardial injury was associated with preoperative NLR>4, activated reactive oxygen species (ROS) generation in circulating monocytes, or both. Multivariable logistic regression analysis explored associations between age, sex, NLR, Revised Cardiac Risk Index, individual leukocyte subsets, and myocardial injury. Flow cytometric quantification of ROS was done in 21 patients. Data are presented as n (%) or odds ratio (OR) with 95% confidence intervals.
Preoperative NLR>4 was present in 239/1652 (14.5%) patients. Myocardial injury occurred in 405/1652 (24.5%) patients and was more common in patients with preoperative NLR>4 OR: 2.56 (1.92–3.41); P<0.0001. Myocardial injury was independently associated with lower absolute preoperative lymphocyte count OR 1.80 (1.50–2.17); P<0.0001 and higher absolute preoperative monocyte count OR 1.93 (1.12–3.30); P=0.017. Monocyte ROS generation correlated with NLR (r=0.47; P=0.03).
Preoperative NLR>4 is associated with perioperative myocardial injury, independent of conventional risk factors. Systemic inflammation may contribute to the development of perioperative myocardial injury.
NCT01842568.
As many as 20% of patients undergoing cardiac surgery will have acute respiratory distress syndrome during the perioperative period, with a mortality as high as 80%. If patients at risk can be ...identified, preventative measures can be taken and may improve outcomes. Care for patients with acute respiratory distress syndrome is supportive, with low tidal volume ventilation being the mainstay of therapy. Careful fluid management, minimization of blood product transfusion, appropriate nutrition, and early physical rehabilitation may improve outcomes. In cases of refractory hypoxemia, rescue therapies such as recruitment maneuvers, high-frequency oscillatory ventilation, and extracorporeal membrane oxygenation may preserve life.
When interacting with virtual environments, feedback delays between making a movement and seeing the visual consequences of that movement are detrimental for the subjective quality of the VR ...experience. Here we used standard measures of subjective experiences such as ownership, agency and presence to investigate whether prolonged exposure to the delay, and thus the possibility to adapt to it, leads to the recovery of the qualitative experience of VR. Participants performed a target-tracking task in a Virtual Reality environment. We measured the participants' tracking performance in terms of spatial and temporal errors with respect to the target in both No-Delay and Delay conditions. Additionally, participants rated their sense of "ownership" of holding a virtual tool, agency and presence on each trial using sliding scales. These single trial ratings were compared to the results of the more traditional questionnaires for ownership and agency and presence for both No-Delay and Delay conditions. We found that the participants' sliding scales ratings corresponded very well to the scores obtained from the traditional questionnaires. Moreover, not only did participants behaviourally adapt to the delay, their ratings of ownership and agency significantly improved with prolonged exposure to the delay. Together the results suggest a tight link between the ability to perform a behavioural task and the subjective ratings of ownership and agency in virtual reality.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Businesses, governments, and financial institutions are increasingly adopting a policy of no net loss of biodiversity for development activities. The goal of no net loss is intended to help relieve ...tension between conservation and development by enabling economic gains to be achieved without concomitant biodiversity losses, biodiversity offsets represent a necessary component of a much broader mitigation strategy for achieving no net loss following prior application of avoidance, minimization, and remediation measures. However, doubts have been raised about the appropriate use of biodiversity offsets. We examined what no net loss means as a desirable conservation outcome and reviewed the conditions that determine whether, and under what circumstances, biodiversity offsets can help achieve such a goal. We propose a conceptual framework to substitute the often ad hoc approaches evident in many biodiversity offset initiatives. The relevance of biodiversity offsets to no net loss rests on 2 fundamental premises. First, offsets are rarely adequate for achieving no net loss of biodiversity alone. Second, some development effects may be too difficult or risky, or even impossible, to offset. To help to deliver no net loss through biodiversity offsets, biodiversity gains must be comparable to losses, be in addition to conservation gains that may have occurred in absence of the offset, and be lasting and protected from risk of failure. Adherence to these conditions requires consideration of the wider landscape context of development and offset activities, timing of offset delivery, measurement of biodiversity, accounting procedures and rule sets used to calculate biodiversity losses and gains and guide offset design, and approaches to managing risk. Adoption of this framework will strengthen the potential for offsets to provide an ecologically defensible mechanism that can help reconcile conservation and development. Los negocios, gobiernos e instituciones financieras adoptan cada vez más una política de no pérdida neta de biodiversidad para el desarrollo de actividades. La meta de la no pérdida neta está enfocada en ayudar a aliviar la tensión entre la conservación y el desarrollo al permitir que se obtengan ganancias económicas sin pérdidas de biodiversidad acompañantes. Los balances de biodiversidad representan un componente necesario de una estrategia de mitigación mucho más amplia para obtener una no pérdida neta siguiendo la aplicación previa de evitación, minimización y medidas de remediación. Sin embargo, han surgido dudas sobre el uso apropiado de los balances de biodiversidad. Examinamos lo que implica una no pérdida neta como un resultado de conservación deseable y revisamos las condiciones que determinan si, y bajo cuales circunstancias, los balances de biodiversidad pueden ayudar a obtener dicha meta. Propusimos un marco de trabajo conceptual para sustituir las aproximaciones seguidas y ad hoc en muchas iniciativas de balances de biodiversidad. La relevancia de los balances de biodiversidad hacia la no pérdida neta yace sobre dos premisas fundamentales. Primero, los balances rara vez son adecuados para obtener la no pérdida neta por sí sola. Segundo, algunos efectos de desarrollo pueden ser muy difíciles o riesgosos, o incluso imposibles, para el balance. Para ayudar a obtener no pérdida neta a través de los balances de biodiversidad, las ganancias de biodiversidad deben ser comparables con las pérdidas, estar sumadas a las ganancias de conservación que pueden haber ocurrido en la ausencia de los balances y ser duraderas y estar protegidas del riesgo de fracaso. La adhesión a estas condiciones requiere una consideración del contexto de paisaje más amplio de desarrollo y de las actividades del balance, la sincronización de la obtención del balance, medida de la biodiversidad, procedimientos de aseguramiento y juegos de reglas usados para calcular las pérdidas y ganancias de biodiversidad y guías en el diseño de balances, y aproximaciones al manejo de riesgo. La adopción de este marco de trabajo hará más fuerte el potencial para que los balances proporcionen un mecanismo defendible ecológicamente que pueda ayudar a reconciliar a la conservación con el desarrollo.
Obesity is a result of a long-term energy imbalance due to decisions associated with energy intake and expenditure. Those decisions fit the definition of heuristics: cognitive processes with a rapid ...and effortless implementation which can be very effective in dealing with scenarios that threaten an organism's viability. We study the implementation and evaluation of heuristics, and their associated actions, using agent-based simulations in environments where the distribution and degree of richness of energetic resources is varied in space and time. Artificial agents utilize foraging strategies, combining movement, active perception, and consumption, while also actively modifying their capacity to store energy-a "thrifty gene" effect-based on three different heuristics. We show that the selective advantage associated with higher energy storage capacity depends on both the agent's foraging strategy and heuristic, as well as being sensitive to the distribution of resources, with the existence and duration of periods of food abundance and scarcity being crucial. We conclude that a "thrifty genotype" is only beneficial in the presence of behavioral adaptations that encourage overconsumption and sedentariness, as well as seasonality and uncertainty in the food distribution.
OBJECTIVES:Cardiac surgery, including coronary artery bypass, cardiac valve, and aortic procedures, is among the most common surgical procedures performed in the United States. Successful outcomes ...after cardiac surgery depend on optimum postoperative critical care. The cardiac intensivist must have a comprehensive understanding of cardiopulmonary physiology and the sequelae of cardiopulmonary bypass. In this concise review, targeted at intensivists and surgeons, we discuss the routine management of the postoperative cardiac surgical patient.
DATA SOURCE AND SYNTHESIS:Narrative review of relevant English-language peer-reviewed medical literature.
CONCLUSIONS:Critical care of the cardiac surgical patient is a complex and dynamic endeavor. Adequate fluid resuscitation, appropriate inotropic support, attention to rewarming, and ventilator management are key components. Patient safety is enhanced by experienced personnel, a structured handover between the operating room and ICU teams, and appropriate transfusion strategies.
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