Feedback with soil biota is an important determinant of terrestrial plant diversity. However, the factors regulating plant-soil feedback, which varies from positive to negative among plant species, ...remain uncertain. In a large-scale study involving 55 species and 550 populations of North American trees, the type of mycorrhizal association explained much of the variation in plant-soil feedbacks. In soil collected beneath conspecifics, arbuscular mycorrhizal trees experienced negative feedback, whereas ectomycorrhizal trees displayed positive feedback. Additionally, arbuscular mycorrhizal trees exhibited strong conspecific inhibition at multiple spatial scales, whereas ectomycorrhizal trees exhibited conspecific facilitation locally and less severe conspecific inhibition regionally. These results suggest that mycorrhizal type, through effects on plant-soil feedbacks, could be an important contributor to population regulation and community structure in temperate forests.
Abstract
This Perspective sketches how recent legislation in the United States may impact the domestic and global energy and climate innovation systems, drawing on systems concepts articulated by ...Arnulf Grubler. It also sets out risks and gaps that could lead to less favorable outcomes.
Background
Coproduction is an approach increasingly recognized across public services internationally. However, awareness of the term and the barriers and facilitators to its implementation in the ...NHS are not widely understood. This study examines clinician and public perceptions of coproduction within the context of the Prudent Healthcare initiative.
Objectives
To provide insights into how coproduction is viewed by clinicians and the public and identify perceived barriers and facilitators to its implementation.
Design
Using qualitative research methods, interviews were conducted with the public (n = 40) and clinicians (n = 40). Five focus groups were also conducted with the public (n = 45) and six focus groups with clinicians (n = 26). The COM‐B model was used to analyse the data; key domains include Capability, Opportunity and Motivation.
Setting
This is an all‐Wales study, involving six Health Boards, an NHS trust and community and patient groups.
Results
Key barriers relating to Capability include lack of awareness of the term coproduction and inadequate communication between clinicians and citizens. Opportunity‐centred barriers include service and time constraints. Conversely, facilitators included utilizing partnerships with community organizations. Motivation‐related barriers included preconceptions about patients’ limitations to coproduce.
Conclusions
There were broadly positive perceptions among participants regarding coproduction, despite initial unfamiliarity with the term. Despite study limitations including underrepresentation of employed public participants and junior doctors, our analysis may assist researchers and policymakers who are designing, implementing and evaluating interventions to promote coproduction.
Using student-level administrative data from North Carolina, we explore whether exposure to samerace teachers affects the rate at which Black students receive exclusionary discipline, such as ...out-of-school suspensions, in-school suspensions, and expulsion. We find consistent evidence that exposure to same-race teachers is associated with reduced rates of exclusionary discipline for Black students. This relationship holds for elementary, middle, and high school grade ranges for male and female students, and for students who do and do not use free and reduced-price lunch. Although we find reductions in referrals for a number of different types of offenses, we find particularly consistent evidence that exposure to same-race teachers lowers office referrals for willful defiance across all grade levels, suggesting that teacher discretion plays a role in driving our results.
Fungal inoculants in the field Hart, Miranda M.; Antunes, Pedro M.; Chaudhary, Veer Bala ...
Functional ecology,
January 2018, Letnik:
32, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Biofertilizers are a large part of the global agricultural economy.
Recently, there has been an increase in the number of companies producing fungal inoculants.
Whether these inoculants are useful is ...not clear; they are difficult to monitor in the field.
The unintended consequences of inoculants in natural systems is not known, but if invasive, they may pose a threat to soil and plant biodiversity and ecosystem functioning.
A plain language summary is available for this article.
Plain Language Summary
Quantitative modeling is useful for predicting behaviors of a system and for rationally constructing or modifying the system. The predictive power of a model relies on accurate quantification of ...model parameters. Here, we illustrate challenges in parameter quantification and offer means to overcome these challenges, using a case example in which we quantitatively predict the growth rate of a cooperative community. Specifically, the community consists of two Saccharomyces cerevisiae strains, each engineered to release a metabolite required and consumed by its partner. The initial model, employing parameters measured in batch monocultures with zero or excess metabolite, failed to quantitatively predict experimental results. To resolve the model-experiment discrepancy, we chemically identified the correct exchanged metabolites, but this did not improve model performance. We then remeasured strain phenotypes in chemostats mimicking the metabolite-limited community environments, while mitigating or incorporating effects of rapid evolution. Almost all phenotypes we measured, including death rate, metabolite release rate, and the amount of metabolite consumed per cell birth, varied significantly with the metabolite environment. Once we used parameters measured in a range of community-like chemostat environments, prediction quantitatively agreed with experimental results. In summary, using a simplified community, we uncovered and devised means to resolve modeling challenges that are likely general to living systems.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A software package for the calibration and processing of powder X‐ray diffraction and small‐angle X‐ray scattering data is presented. It provides a multitude of data processing and visualization ...tools as well as a command‐line scripting interface for on‐the‐fly processing and the incorporation of complex data treatment tasks. Customizable processing chains permit the execution of many data processing steps to convert a single image or a batch of raw two‐dimensional data into meaningful data and one‐dimensional diffractograms. The processed data files contain the full data provenance of each process applied to the data. The calibration routines can run automatically even for high energies and also for large detector tilt angles. Some of the functionalities are highlighted by specific use cases.
The Powder Calibration and Processing packages implemented in DAWN 2 provide an automated diffraction‐geometry calibration and data processing environment for two‐dimensional diffraction experiments. The customizable processing chains permit the execution of data processing steps to convert raw two‐dimensional data into meaningful data and diffractograms. The provenance of the processed data is maintained, which guarantees reproducibility and transparency of the data treatment.
Foetal bovine serum (FBS), is the most commonly used culture medium additive for in vitro cultures, despite its undefined composition, its potential immunogenicity and possible prion/zoonotic ...transmission. For these reasons, significant efforts have been targeted at finding a substitute, such as serum free-media or human platelet-lysates (hPL). Our aim is to critically appraise the state-of-art for hPL in the published literature, comparing its impact with FBS.
In June 2019 a systematic search of the entire Web of Science, Medline and PubMed database was performed with the following search terms: (mesenchymal stem cells) AND (fetal bovine serum OR fetal bovine calf) AND (human platelet lysate). Excluded from this search were review articles that were published before 2005, manuscripts in which mesenchymal stem cells (MSCs) were not from human sources, and when the FBS controls were missing.
Based on our search algorithm, 56 papers were selected. A review of these papers indicated that hMSCs cultured with hPL showed a spindle-shaped elongated morphology, had higher proliferation indexes, similar cluster of differentiation (CD) markers and no significant variation in differentiation lineage (osteocyte, adipocyte, and chondrocyte) compared to those cultured with FBS. Main sources of primary hMSCs were either fat tissue or bone marrow; in a few studies cells isolated from alternative sources showed no relevant difference in their response.
Despite the difference in medium choice and a lack of standardization of hPL manufacturing, the majority of publications support that hPL was at least as effective as FBS in promoting adhesion, survival and proliferation of hMSCs. We conclude that hPL should be considered a viable alternative to FBS in hMSCs culture-especially with a view for their clinical use.
Although arbuscular mycorrhizal (AM) fungi are obligate symbionts that can influence plant growth, the magnitude and direction of these effects are highly variable within fungal genera and even among ...isolates within species, as well as among plant taxa.
To determine whether variability in AM fungal morphology and growth is correlated with AM fungal effects on plant growth, we established a common garden experiment with 56 AM fungal isolates comprising 17 genera and six families growing with three plant host species.
Arbuscular mycorrhizal fungal morphology and growth was highly conserved among isolates of the same species and among species within a family. By contrast, plant growth response to fungal inoculation was highly variable, with the majority of variation occurring among different isolates of the same AM fungal species.
Our findings show that host performance cannot be predicted from AM fungal morphology and growth traits. Divergent effects on plant growth among isolates within an AM fungal species may be caused by coevolution between co-occurring fungal and plant populations.
Singlet fission is a spin-allowed process in which an excited singlet state evolves into two triplet states. We use femtosecond stimulated Raman spectroscopy, an ultrafast vibrational technique, to ...follow the molecular structural evolution during singlet fission in order to determine the mechanism of this process. In crystalline pentacene, we observe the formation of an intermediate characterized by pairs of excited state peaks that are red- and blue-shifted relative to the ground state features. We hypothesize that these features arise from the formation of cationic and anionic species due to partial transfer of electron density from one pentacene molecule to a neighboring molecule. These observations provide experimental evidence for the role of states with significant charge-transfer character which facilitate the singlet fission process in pentacene. Our work both provides new insight into the singlet fission mechanism in pentacene and demonstrates the utility of structurally-sensitive time-resolved spectroscopic techniques in monitoring ultrafast processes.
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