Myasthenia Gravis and implications for the Certified Registered Nurse Anesthetist

In healthcare and, specifically anesthesia, there are many conditions that require various considerations by the prudent provider. An example of a condition requiring special attention is myasthenia gravis. Myasthenia gravis is an autoimmune disease in which skeletal muscle weakness and rapid fatigue result from destruction of nicotinic acetylcholine receptors [7]. Although the prevalence is not overwhelmingly high with most recent estimates of prevalence around 14 to 20 per 100,000 people in the United States [5] and 20 per 100,000 worldwide [9], inappropriate perioperative management of those with this ailment can result in serious consequences. Understanding the pathophysiology, various treatments (both surgical and medical), and anesthetic implications can result in better outcomes for individuals with myasthenia gravis that require surgery

Plants as river system engineers

I would like to acknowledge three research grants/contracts that are supporting my current research on this theme: Grant F/07 040/AP from the Leverhulme Trust; Grant NE/F014597/1 from the Natural Environment Research Council, UK, and the REFORM collaborative project funded by the European Union Seventh Framework Programme under grant agreement 282656

Data from: An ecosystem services perspective on brush management: research priorities for competing land use objectives

1. The vegetation of semi-arid and arid landscapes is often comprised of mixtures of herbaceous and woody vegetation. Since the early 1900s, shifts from herbaceous to woody plant dominance, termed woody plant encroachment and widely regarded as a state change, have occurred world-wide. This shift presents challenges to the conservation of grassland and savanna ecosystems and to animal production in commercial ranching systems and pastoral societies. 2. Dryland management focused on cattle and sheep grazing has historically attempted to reduce the abundance of encroaching woody vegetation (hereafter, ‘brush management’) with the intent of reversing declines in forage production, stream flow or groundwater recharge. Here, we assess the known and potential consequences of brush management actions, both positive and negative, on a broader suite of ecosystem services, the scientific challenges to quantifying these services and the trade-offs among them. 3. Our synthesis suggests that despite considerable investments accompanying the application of brush management practices, the recovery of key ecosystem services may be short-lived or absent. However, in the absence of such interventions, those and other ecosystem services may be compromised, and the persistence of grassland and savanna ecosystem types and their endemic plants and animals threatened. 4. Addressing the challenges posed by woody plant encroachment will require integrated management systems using diverse theoretical principles to design the type, timing and spatial arrangement of initial management actions and follow-up treatments. These management activities will need to balance cultural traditions and preferences, socio-economic constraints and potentially competing land-use objectives. 5. Synthesis. Our ability to predict ecosystem responses to management aimed at recovering ecosystem services where grasslands and savannas have been invaded by native or exotic woody plants is limited for many attributes (e.g. primary production, land surface–atmosphere interactions, biodiversity conservation) and inconsistent for others (e.g. forage production, herbaceous diversity, water quality/quantity, soil erosion, carbon sequestration). The ecological community is challenged with generating robust information about the response of ecosystem services and their interactions if we are to position land managers and policymakers to make objective, science-based decisions regarding the many trade-offs and competing objectives for the conservation and dynamic management of grasslands and savannas

Biocrusts do not differentially influence emergence and early establishment of native and non-native grasses

Biological soil crusts (biocrusts) cover the soil surface of global drylands and interact with vascular plants. Biocrusts may influence the availability and nature of safe sites for plant recruitment and the susceptibility of an area to invasion by non-native species. Therefore, to investigate the potential role of biocrusts in invasive species management, we sought to determine whether native and non-native grass recruitments in two North American deserts were differentially affected by biocrusts. We conducted a series of coordinated experiments in field, semi-controlled, and controlled environment settings in the Colorado Plateau and Sonoran Desert using contrasting biocrust and grass functional types. Experiments in field environments focused on early establishment of grass seedlings whereas controlled environment experiments focused on seedling emergence. Within each experiment, we compared responses (frequency, magnitude, and timing of emergence/establishment) both across species (biocrust types pooled) and across species and levels of biocrust development. Native grasses varied by experiment and included Aristida purpurea, A. purpurea var. longiseta, Bouteloua gracilis, and Vulpia octoflora. Emergence of non-native Bromus tectorum was similar to that of native grasses on the Colorado Plateau. Differences in emergence of native vs. non-native grasses in the Sonoran Desert were species- and response-specific. Emergence of the non-native Bromus rubens was comparable to that of native grasses whereas emergence frequency and magnitude of the non-native Pennisetum ciliare was lower compared with two of four native species. Within a grass species, emergence was higher and faster on bare soil compared with biocrusts in the Sonoran Desert semi-controlled and greenhouse environment experiments. However, the pattern was not consistent across other experiments. When comparing across Colorado Plateau and Sonoran Desert biocrusts in greenhouse experiments, we found that emergence of native grasses was higher on Colorado Plateau biocrusts. Based on the lack of consistent results across our experiments, grass recruitment on biocrusts appears to be driven more by species-specific traits than species provenance. Our greenhouse experiments suggest that biocrust topographic relief is an important safe site trait influencing plant recruitment. © 2021 The Authors. Ecosphere published by Wiley Periodicals LLC on behalf of The Ecological Society of America.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Figure 2, 3 & 5 data

Data used in Table 1 and Figures 2, 3 and 5 were derived from published papers obtained from Web of Knowledge search strings about brush management. These searches yielded 1350 unique papers published in refereed journals which were distilled to 364 papers that report quantitative responses to brush management. This database was further refined to 59 papers that directly quantified herbaceous production after brush management and these papers contribute the data shown in Figures 2, 3 and 5. Brush management was defined as mechanical, herbicide, fire, or treatments in combination and excluded studies that were confounded by continued sheep or cattle grazing on treatment sites. Of those 59 papers, 18 provided mean changes in herbaceous production with error on both control and treatment sites. Data from these 18 papers were used to generate Figures 2 and 3. Among those in the database of 1350 papers were 46 papers that directly measured changes in herbaceous diversity after brush management. Of those 46 papers, 29 provided mean changes in diversity (richness or Shannon diversity) with error on both control and treatment sites. Data from these papers were used to generate Figure 5. When multiple tables or figures are listed they represent data reported by site or year and were averaged in our dataset. Data originally published in figure format was quantified using Adobe Illustrator CS6 or DataThief III