Summary
Nitrogen‐fixing rhizobacteria can promote plant growth; however, it is controversial whether biological nitrogen fixation (BNF) from associative interaction contributes to growth promotion. ...The roots of Setaria viridis, a model C4 grass, were effectively colonized by bacterial inoculants resulting in a significant enhancement of growth. Nitrogen‐13 tracer studies provided direct evidence for tracer uptake by the host plant and incorporation into protein. Indeed, plants showed robust growth under nitrogen‐limiting conditions when inoculated with an ammonium‐excreting strain of Azospirillum brasilense. 11C‐labeling experiments showed that patterns in central carbon metabolism and resource allocation exhibited by nitrogen‐starved plants were largely reversed by bacterial inoculation, such that they resembled plants grown under nitrogen‐sufficient conditions. Adoption of S. viridis as a model should promote research into the mechanisms of associative nitrogen fixation with the ultimate goal of greater adoption of BNF for sustainable crop production.
Significance Statement
The results indicate that, under the appropriate conditions, the C4 model grass species, Setaria viridis, can obtain 100% of its nitrogen needs from biological nitrogen fixation, as a result of inoculation with plant growth promoting bacteria. The work supports the future use of S. viridis as a model system to explore the mechanistic aspects of associative nitrogen fixation with the goal of transferring this knowledge to important crop species, such as corn.
The primary aim of this study was to extend existing theory on the relationship between chance-level performance and the number of alternatives and trials in closed-set, forced-choice speech ...audiometry and sound localization methods. When calculating chance performance for closed-set, forced-choice experiments with multiple trials, the binomial distribution should be preferred over the simple 1/a probability, as the latter is appropriate only for single trial experiments. The historical use of constant hit rates for determining chance performance has been based upon the assumption that random hits are distributed evenly across multiple trials. For any closed-set, forced-choice task with 2 to 10 alternatives and 2 to 100 trials, we calculated the probability of obtaining any given hit rate due to random guessing alone according to the binomial distribution. Hit rates with probabilities p > 0.05 were interpreted as being likely to occur due to random chance alone, whereas hit rates with probabilities of p ≤ 0.05 were interpreted as being unlikely to occur due to chance alone. For sound localization experiments with speakers at fixed positions, the expected probability of a random hit was also calculated using the binomial distribution. The expected angular root mean square (rms) error in sound localization resulting from the random selection of sound sources was investigated using Monte Carlo simulations. A new aspect in the interpretation of test results was identified for situations in which the observed number of hits is much lower than would be expected due to chance alone. For test methods incorporating a relatively low number of alternatives and a sufficiently high, yet clinically feasible, number of trials, both upper and lower thresholds for chance-level performance could be identified. This lower threshold represents the lowest hit rate which can be expected through random chance alone. Extending interpretation of results to include this lower threshold affords the ability to not only identify performance significantly superior to that of chance, but also that significantly poorer than chance and thereby represents a simple method for the objective detection of malingering.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objectives
To evaluate a communication tool called “Best Case/Worst Case” (BC/WC) based on an established conceptual model of shared decision‐making.
Design
Focus group study.
Setting
Older adults ...(four focus groups) and surgeons (two focus groups) using modified questions from the Decision Aid Acceptability Scale and the Decisional Conflict Scale to evaluate and revise the communication tool.
Participants
Individuals aged 60 and older recruited from senior centers (n = 37) and surgeons from academic and private practices in Wisconsin (n = 17).
Measurements
Qualitative content analysis was used to explore themes and concepts that focus group respondents identified.
Results
Seniors and surgeons praised the tool for the unambiguous illustration of multiple treatment options and the clarity gained from presentation of an array of treatment outcomes. Participants noted that the tool provides an opportunity for in‐the‐moment, preference‐based deliberation about options and a platform for further discussion with other clinicians and loved ones. Older adults worried that the format of the tool was not universally accessible for people with different educational backgrounds, and surgeons had concerns that the tool was vulnerable to physicians’ subjective biases.
Conclusion
The BC/WC tool is a novel decision support intervention that may help facilitate difficult decision‐making for older adults and their physicians when considering invasive, acute medical treatments such as surgery.
Objectives: To compare the recurrence of non-muscle invasive bladder carcinoma (NMIBC) after transurethral resection employing cystoscopy with hexaminolevulinate-based photodynamic diagnosis (PDD) or ...with standard white light.
Patients and methods: We included patients with newly suspected NMIBC in this retrospective cohort study and compared those undergoing transurethral resection by white light cystoscopy (WLC) (2008–2010) and PDD (2010–2012). All patients were treated following established criteria for good quality resection. The primary outcome was the difference in the recurrence rate after 60 months’ follow-up, but we also stratified recurrence by risk groups, as set by the European Organization for Research and Treatment of Cancer. The mean recurrence-free survival was compared between the cohorts. Odds ratios or hazard ratios are reported with their 95% confidence intervals.
Results: The WLC and PDD cohorts comprised 124 and 91 subjects, respectively. There were no significant differences in recurrence rates between the cohorts at 6 months (recurrence rate 9/123; 7.3%), 12 months (17/118; 14.4%) or 60 months (39/102; 38.2%), with odds ratios of 1.23 (CI 0.48–3.25), 1.32 (CI 0.67–2.62) and 1.12 (CI 0.70–1.79), in favour of WLC, respectively. Further analysis showed no significant effect of PDD on either recurrence by risk group or on mean recurrence-free survival (hazard ratio, 1.12 CI 0.70–1.79).
Conclusion: We found no relevant differences in the recurrence of NMIBC after the introduction of PDD with hexaminolevulinate compared to standard WLC when used for transurethral resection in our single institution.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Introduction and hypothesis
Patients with recurrent urinary tract infection (rUTI) have limited knowledge of preventive strategies to lower the risk of UTI. We aimed to develop and test the ...feasibility of an eHealth system for women with rUTI, named myRUTIcoach, and explored the facilitators and barriers related to its adoption.
Methods
We developed myRUTIcoach in a structured iterative process and tested its feasibility among 25 women with rUTI over 2 months. Subsequent questionnaires covered satisfaction, accessibility, and experiences with myRUTIcoach. A random selection of participants and relevant stakeholders took part in semi-structured interviews to explore adoption. Data were analyzed and elaborated using inductive and deductive approaches using the Non-adoption, Abandonment, Spread, Scale-up, and Sustainability (NASSS) framework.
Results
MyRUTIcoach was not only widely accepted but also facilitated communication with health care professionals (HCPs) and contributed to greater knowledge of rUTI. Women graded the system a mean of 8.0 (±0.6) out of 10, with 89% stating that they would recommend it to others. Patients indicated that self-management skills were the major facilitators and barriers related to adoption, whereas HCPs stated that the disconnect between myRUTIcoach and electronic health care records (EHRs) was the major barrier.
Conclusions
This research describes the development and testing of myRUTIcoach for women with rUTI. Patients and HCPs reported high satisfaction and compliance with myRUTIcoach. However, adoption by the intended users is complex and influenced by all examined domains of the NASSS framework. We have already improved linkage to EHRs, but further optimization to meet patient needs may improve the effectiveness of this self-management tool for rUTI.
The tropical peatlands of southern Brazil are essential for the maintenance of the Atlantic Rain Forest, one of the 25 hotspots of biodiversity in the world. Although diazotrophic micro‐organisms are ...essential for the maintenance of this nitrogen limited ecosystem, so far studies have focused only on micro‐organisms involved in the carbon cycle. In this work, peat samples were collected from three tropical peatland regions during dry and rainy seasons and their chemical and microbial characteristics were evaluated. Our results showed that the structure of the diazotrophic communities in the Brazilian tropical peatlands differs in the evaluated seasons. The abundance of the genus Bradyrhizobium showed to be affected by rainfall and peat pH. Despite the shifts of the nitrogen‐fixing population in the tropical peatland caused by seasonality it showed to be constantly dominated by α‐Proteobacteria followed by Cyanobacteria. In addition, more than 50% of nifH gene sequences have not been classified, indicating the necessity for more studies in tropical peatland, since the reduction of N supply in the peatlands stimulates the recalcitrant organic matter decomposition performed by peatland micro‐organisms, influencing the C stock.
Significance and Impact of the Study: This manuscript reports the first ecological study of tropical peatlands diazotrophic communities from the Brazilian Atlantic Rain Forest, one of the world's largest biodiversity hotspots. Based on culturing and culture‐independent approaches, our results showed alterations in the structure of the diazotrophic communities in different seasons. The genus Bradyrhizobium abundance was affected by rainfall and peat pH. In addition, the great number of unclassified nitrogen‐fixing bacteria indicated the need for additional studies to guide future mitigation actions, since the reduction of N supply in the peatlands stimulates the recalcitrant organic matter decomposition performed by peatland micro‐organisms, influencing the C stock.
Abstract Context Older adults often have surgery in the months preceding death, which can initiate postoperative treatments inconsistent with end-of-life values. “Best Case/Worst Case” (BC/WC) is a ...communication tool designed to promote goal-concordant care during discussions about high-risk surgery. Objective The objective of this study was to evaluate a structured training program designed to teach surgeons how to use BC/WC. Methods Twenty-five surgeons from one tertiary care hospital completed a two-hour training session followed by individual coaching. We audio-recorded surgeons using BC/WC with standardized patients and 20 hospitalized patients. Hospitalized patients and their families participated in an open-ended interview 30 to 120 days after enrollment. We used a checklist of 11 BC/WC elements to measure tool fidelity and surgeons completed the Practitioner Opinion Survey to measure acceptability of the tool. We used qualitative analysis to evaluate variability in tool content and to characterize patient and family perceptions of the tool. Results Surgeons completed a median of 10 of 11 BC/WC elements with both standardized and hospitalized patients (range 5–11). We found moderate variability in presentation of treatment options and description of outcomes. Three months after training, 79% of surgeons reported BC/WC is better than their usual approach and 71% endorsed active use of BC/WC in clinical practice. Patients and families found that BC/WC established expectations, provided clarity, and facilitated deliberation. Conclusions Surgeons can learn to use BC/WC with older patients considering acute high-risk surgical interventions. Surgeons, patients, and family members endorse BC/WC as a strategy to support complex decision making.
Background
Enrollment in therapeutic cancer trials remains low, and is especially challenging for patients with low health literacy. The authors tested an interactive technology designed for patients ...with diverse health literacy skills with the aim of improving patient receptiveness, willingness, knowledge, self‐efficacy, and positive attitudes regarding clinical trials.
Methods
Patients presenting for their first oncology appointment were eligible. Patients viewed an interactive teaching video concerning clinical trials that was adapted from the National Institutes of Health. Validated surveys assessing receptiveness, willingness, knowledge, self‐efficacy, and positive attitudes regarding clinical trials were administered before and after the test.
Results
A total of 120 patients with cancer were enrolled. Approximately 80% were non‐Hispanic white, 33% were female, 69% had >high school education, and 8% reported an income <$20,000. Approximately 33% scored within the low health literacy range. Changes between pretest and posttest demonstrated increases in knowledge (P < .001), self‐efficacy (P < .001), and positive beliefs (P = .004); a slight decrease in willingness (P = .009); and no difference in patient receptivity (P = .31). Higher health literacy was associated with improved willingness (P = .049) and non‐Hispanic white race was associated with improved receptivity (P = .034).
Conclusions
Interactive technology that was designed for patients with diverse health literacy skills demonstrated the ability to improve knowledge, self‐efficacy, and positive beliefs regarding cancer clinical trials. Contrary to the hypothesis of the current study, patients with lower health literacy did not appear to derive a greater advantage from this technology. There was no improvement noted with regard to patient willingness or receptivity, and clinical trial enrollment remained at historical institutional levels. Talking touchscreen technology has a potential role as an important element in informed decision making for patients, but likely needs to be coupled with more robust and multitargeted interventions.
Interactive technology designed for patients with diverse health literacy skills appears to improve knowledge, self‐efficacy, and positive beliefs regarding cancer clinical trials, although, contrary to the authors‘ hypothesis, patients with lower health literacy are not noted to derive greater benefit from this technology. Further research is needed to address provider barriers, including improving physician communication regarding clinical trials, addressing attitudes concerning how best to discuss and enroll in clinical trials, and establishing new standards of empowered shared decision making between health care providers and patients.
Increasing grazing pressure and climate change affect nitrogen (N) dynamics of grassland ecosystems in the Eurasian steppe belt with unclear consequences for future delivery of essential services ...such as forage production, C sequestration, and diversity conservation. The identification of key processes responsive to grazing is crucial to optimize grassland management. In this comprehensive case study of a Chinese typical steppe, we present an in-depth analysis of grazing effects on N dynamics, including the balance of N gains and losses, and N cycling. N pools and fluxes were simultaneously quantified on three grassland sites of different long-term grazing intensities.
Dust deposition, wind erosion, and wet deposition were the predominant but most variable processes contributing to N losses and gains. Heavy grazing increased the risk of N losses by wind erosion. Hay-making and sheep excrement export to folds during nighttime keeping were important pathways of N losses from grassland sites. Compared to these fluxes, gaseous N losses (N
2
O, NO, N
2
, and NH
3
) and N losses via export of sheep live mass and wool were of minor relevance. Our N balance calculation indicated mean annual net N losses of 0.9 ± 0.8 g N/m
2
(mean ± SD) at the heavily grazed site, whereas the long-term ungrazed site was an N sink receiving mean annual inputs of 1.8 ± 1.1 g N/m
2
, mainly due to dust deposition. Heavy grazing reduced pool sizes of topsoil organic N, above- and belowground biomass, and N fluxes with regard to plant N uptake, decomposition, gross microbial N turnover, and immobilization. Most N-related processes were more intensive in seasons of higher water availability, indicating complex interactions between land use intensity and climate variability. The projected increase of atmospheric N depositions and changes in rainfall pattern imposed by land use change will likely affect N sink-source pathways and N flux dynamics, indicating high potential impact on grassland ecosystem functions. Land use practices will be increasingly important for the management of N dynamics in Chinese typical steppe and, therefore, must be considered as key component to maintain, restore or optimize ecosystem services.
Spatial inaccessibility of soil organic carbon (SOC) for microbial decay within soil aggregates is an important stabilization mechanism. However, little is known about the stability of aggregates in ...semiarid grasslands and their sensitivity to intensive grazing. In this study, a combined approach using soil chemical and physical analytical methods was applied to investigate the effect of grazing and grazing exclusion on the amount and stability of soil aggregates and the associated physical protection of SOC. Topsoils from continuously grazed (CG) and ungrazed sites where grazing was excluded from 1979 onwards (UG79) were sampled for two steppe types in Inner Mongolia, northern China. All samples were analysed for basic soil properties and separated into free and aggregate‐occluded light fractions (fLF, oLF) and mineral‐associated fractions. Tensile strength of soil aggregates was measured by crushing tests. Undisturbed as well as artificially compacted samples, where aggregates were destroyed mechanically by compression, were incubated and the mineralization of SOC was measured. For undisturbed samples, the cumulative release of CO2‐C was greater for CG compared with UG79 for both steppe types. A considerably greater amount of oLF was found in UG79 than in CG soils, but the stabilities of 10–20‐mm aggregates were less for ungrazed sites. Compacted samples showed only a slightly larger carbon release with CG but a considerably enhanced mineralization with UG79. We assume that the continuous trampling of grazing animals together with a smaller input of organic matter leads to the formation of mechanically compacted stable ‘clods’, which do not provide an effective physical protection for SOC in the grazed plots. In UG79 sites, a greater input of organic matter acting as binding agents in combination with an exclusion of animal trampling enhances the formation of soil aggregates. Thus, grazing exclusion promotes the physical protection of SOC by increasing soil aggregation and is hence a management option to enhance the C sequestration potential of degraded steppe soils.
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