Quantifying the biologically possible range of steady-state soil and surface climates with climate model simulations

The terrestrial biosphere shapes the exchange fluxes of energy and mass at the land surface. The diversity of plant form and functioning can potentially result in a wide variety of possible climatic conditions at the land surface and in the soil, which in turn feed back to more or less suitable conditions for terrestrial productivity. Here, I use sensitivity simulations to vegetation form and functioning with a global climate model to quantify this possible range of steady-states (“PROSS”) of the surface energy-and mass balances. The surface energy-and water balances over land are associated with substantial sensitivity to vegetation parameters, with precipitation varying by more than a factor of 2, and evapotranspiration by a factor of 5. This range in biologically possible climatic conditions is associated with drastically different levels of vegetation productivity. Optimum conditions for maximum productivity are close to the simulated climate of present-day conditions. These results suggest the conclusions that (a) climate does not determine vegetation form and function, but merely constrains it, and (b) the emergent climatic conditions at the land surface seem to be close to optimal for the functioning of the terrestrial biosphere.     

Influence of different vegetation types on saturated hydraulic conductivity in alluvial topsoils

In the Parí? creek catchment (southwestern part of Slovakia), the influence of different vegetation types on selected soil properties in alluvial topsoils was studied. Specifically, the effect on saturated hydraulic conductivity considered as indicator of water transport process and the effect on soil bulk density considered as indicator of soil structure were analysed. Due to the mutual influence of plant roots on soil properties, the root biomass was also estimated and its relationship to the studied soil properties was explored. Reed and tall-sedge wetlands and alluvial wet meadows represented the studied vegetation types. Adjacent arable lands (former grasslands) with corn were included for comparison. In total, 64 samples were used for comparative analysis. A standard methodology for measurement of the saturated hydraulic conductivity, the so-called falling head technique was used on 250 cm³ soil cores. Undisturbed soil samples were taken from the depth of 5 cm. Analysis of variance, mutual comparison of mean values and correlation matrix were used for statistical analyses. Measurements showed significantly higher values of saturated hydraulic conductivity for topsoils in wetlands (6.2 m day^?1 on average) compared to mown grasslands (1.47 m day^?1) and arable land (0.79 m day^?1). The results indicated a specific significance of wetlands in relation to water transport processes in alluvial topsoils.     

Feedback GAP: pragmatic,cluster-randomized trial of goal setting and action plans to increase the effectiveness of audit and feedback interventions in primary care

Background

Audit and feedback to physicians is a commonly used quality improvement strategy, but its optimal design is unknown. This trial tested the effects of a theory-informed worksheet to facilitate goal setting and action planning, appended to feedback reports on chronic disease management, compared to feedback reports provided without these worksheets.

Methods

A two-arm pragmatic cluster randomized trial was conducted, with allocation at the level of primary care clinics. Participants were family physicians who contributed data from their electronic medical records. The ‘usual feedback’ arm received feedback every six months for two years regarding the proportion of their patients meeting quality targets for diabetes and/or ischemic heart disease. The intervention arm received these same reports plus a worksheet designed to facilitate goal setting and action plan development in response to the feedback reports. Blood pressure (BP) and low-density lipoprotein cholesterol (LDL) values were compared after two years as the primary outcomes. Process outcomes measured the proportion of guideline-recommended actions (e.g., testing and prescribing) conducted within the appropriate timeframe. Intention-to-treat analysis was performed.

Results

Outcomes were similar across groups at baseline. Final analysis included 20 physicians from seven clinics and 1,832 patients in the intervention arm (15% loss to follow up) and 29 physicians from seven clinics and 2,223 patients in the usual feedback arm (10% loss to follow up). Ten of 20 physicians completed the worksheet at least once during the study. Mean BP was 128/72 in the feedback plus worksheet arm and 128/73 in the feedback alone arm, while LDL was 2.1 and 2.0, respectively. Thus, no significant differences were observed across groups in the primary outcomes, but mean haemoglobin A1c was lower in the feedback plus worksheet arm (7.2% versus 7.4%, p<0.001). Improvements in both arms were noted over time for one-half of the process outcomes.

Discussion

Appending a theory-informed goal setting and action planning worksheet to an externally produced audit and feedback intervention did not lead to improvements in patient outcomes. The results may be explained in part by passive dissemination of the worksheet leading to inadequate engagement with the intervention.

Trial registration

ClinicalTrials.gov NCT00996645

     

Predicting beta-turns in proteins using support vector machines with fractional polynomials

Background

β-turns are secondary structure type that have essential role in molecular recognition, protein folding, and stability. They are found to be the most common type of non-repetitive structures since 25% of amino acids in protein structures are situated on them. Their prediction is considered to be one of the crucial problems in bioinformatics and molecular biology, which can provide valuable insights and inputs for the fold recognition and drug design.

Results

We propose an approach that combines support vector machines (SVMs) and logistic regression (LR) in a hybrid prediction method, which we call (H-SVM-LR) to predict β-turns in proteins. Fractional polynomials are used for LR modeling. We utilize position specific scoring matrices (PSSMs) and predicted secondary structure (PSS) as features. Our simulation studies show that H-SVM-LR achieves Qtotal of 82.87%, 82.84%, and 82.32% on the BT426, BT547, and BT823 datasets respectively. These values are the highest among other β-turns prediction methods that are based on PSSMs and secondary structure information. H-SVM-LR also achieves favorable performance in predicting β-turns as measured by the Matthew's correlation coefficient (MCC) on these datasets. Furthermore, H-SVM-LR shows good performance when considering shape strings as additional features.

Conclusions

In this paper, we present a comprehensive approach for β-turns prediction. Experiments show that our proposed approach achieves better performance compared to other competing prediction methods.

     

The use of H2 antagonists in treating and preventing NSAID-induced mucosal damage

Pain affects the quality of life for millions of individuals and is a major reason for healthcare utilization. As populations age, medical personnel will need to manage more and more patients suffering from pain associated with degenerative and inflammatory musculoskeletal disorders. Nonsteroidal anti-inflammatory drugs (NSAIDs) are an effective treatment for both acute and chronic musculoskeletal pain; however, their use is associated with potentially significant gastrointestinal (GI) toxicity. Guidelines suggest various strategies to prevent problems in those at risk for NSAID-associated GI complications. In this article, we review the data supporting one such strategy - the use of histamine type-2 receptor antagonists (H2RAs) - for the prevention of GI adverse events in NSAID users. Older studies suggest that high-dose H2RAs are effective in preventing upper GI ulcers and dyspepsia. This suggestion was recently confirmed during clinical trials with a new ibuprofen/famotidine combination that reduced the risk of ulcers by 50% compared with ibuprofen alone.     

Bacillus methylotrophicus M4-96 Stimulates the Growth of Strawberry (Fragaria × ananassa ‘Aromas’) Plants In Vitro and Slows Botrytis cinerea Infection by Two Different Methods of Interaction

Bacillus methylotrophicus M4-96 is a beneficial rhizobacterium that has been isolated from the rhizosphere of maize (Zea mays). In this study, we investigated its efficacy as a plant growth promoter for strawberry in vitro, as well as its ability to induce callose deposition in leaves to reduce the severity of Botrytis cinerea infection. Two methods of plant-bacterial interaction were used: inoculation near the root and emission of volatile compounds with no physical contact. Plant biomass increased under both treatments, but with developmental parameters of the plants differentially stimulated by each method. Root inoculation increased petiole number and root length, whereas bacterial volatiles increased petiole length and root number. A chemical analysis of the bacterial culture revealed the presence of indole acetic acid (0.21 μg L⁻¹) and gibberellic acid (6.16 μg L⁻¹). Acetoin was previously identified as the major volatile produced by the bacteria, and its application to strawberry explants increased their growth and development. Furthermore, when acetoin and both phytoregulators were added to the culture media, these positive effects were enhanced. The inoculation method also affected the size and quantity of callose deposits in the leaves. Treatment with volatiles increased callose deposition in the leaves by up to five-fold, which promoted a rapid defense reaction that inhibited the incidence of gray mold by reinforcing cell wall. Taken together, our results show that B. methylotrophicus M4-96 promotes growth and induces systemic resistance in strawberry plants.