On temporal partitioning of a community of ectomycorrhizal fungi

Several mechanisms may contribute to the high species richness often reported in ectomycorrhizal (ECM) fungal communities, including spatial and temporal partitioning. Here, we focus on temporal partitioning. Using molecular methods, we determined the frequencies of occurrence of ECM fungal species detected as hyphae and ECM roots in the forest floor of a Pinus resinosa plantation during a 13-month period. We then used a novel statistical procedure to place the most frequently occurring ECM fungal species into groups distinguished by their patterns of relative frequency over time. Three groups with contrasting temporal patterns were distinguishable for fungal species detected as hyphae. Two groups were distinguishable for species detected as ECM roots. Our results support the hypothesis that temporal partitioning occurs among the species of ECM fungi in this community, but we did not address its causes, which may have involved interactions among species' physiological tolerances, temporal environmental variability, temporal patterns of root production, and variation in fungal genet lifespan. These interactions should be the subjects of future research.     

Promising Role of Moderate Soil Drying and Subsequent Recovery Through Moderate Wetting at Grain-Filling Stage for Rice Yield Enhancement

The study was conducted at the grain-filling stage to elucidate the physiological and molecular mechanisms of the root to enhance yield under alternate wetting and drying (AWD) compared with conventional irrigation. Measurements of root dry weight (RDW), seed setting rate, total kernel weight, and grain yield were determined along with 2D electrophoresis to detect altered protein expression in response to moderate soil drying (MD) and the subsequent recovery phase as moderate wetting (MW) under AWD compared with continuous wetting under CI. We found significant enhancement in RDW as well as 14.30 % increase in inferior spikelets^, seed setting and 10.32 g m⁻² increase in final yield. Among the total 55 differentially expressed proteins, 26 proteins were differentially expressed under both MD treatment and MW treatment, whereas 14 proteins under MD and 15 proteins under MW showed distinct expression. Differentially expressed proteins were involved in redox homeostasis, signaling, defense, energy, photoassimilate remobilization and included 14-3-3 proteins, cysteine-rich receptor-like protein kinase, monodehydroascorbate reductase, ascorbate peroxidase, glutathione S-transferases, translationally controlled tumor protein, remorin C-terminal domain containing protein, protein disulfide isomerase, DnaK family protein, cysteine synthase, aminotransferase, phosphoglycerate mutase, pyruvate phosphate dikinase, ATP synthase, and abscisic acid stress ripening (ASR1). The differential expression ratio of the signaling, redox, and defense group proteins was almost the same under MD and MW. ABA signaling, amino acid synthesis, and N remobilization were upregulated under MD, and the enzymes involved in carbohydrate, energy, and transportation metabolism were upregulated under MW. In conclusion, at the rice grain-filling stage, AWD is a potential technique to trigger signaling and the enzymatic protein network for systematic senescence initiation, root enlargement for maximum nutrient uptake, and maximize photoassimilate remobilization for yield enhancement.

     

Locomotion of an efficient biomechanical sperm through viscoelastic medium

Biomechanics and Modeling in Mechanobiology - Every group of microorganism utilizes a diverse mechanical strategy to propel through complex environments. These swimming problems deal with the...     

Impact of ‘Stretch’ Targets for Cardiovascular Disease Management within a Local Pay-for-Performance Programme

Pay-for-performance programs are often aimed to improve the management of chronic diseases. We evaluate the impact of a local pay for performance programme (QOF+), which rewarded financially more ambitious quality targets (‘stretch targets’) than those used nationally in the Quality and Outcomes Framework (QOF). We focus on targets for intermediate outcomes in patients with cardiovascular disease and diabetes. A difference-in-difference approach is used to compare practice level achievements before and after the introduction of the local pay for performance program. In addition, we analysed patient-level data on exception reporting and intermediate outcomes utilizing an interrupted time series analysis. The local pay for performance program led to significantly higher target achievements (hypertension: p-value <0.001, coronary heart disease: p-values <0.001, diabetes: p-values <0.061, stroke: p-values <0.003). However, the increase was driven by higher rates of exception reporting (hypertension: p-value <0.001, coronary heart disease: p-values <0.03, diabetes: p-values <0.05) in patients with all conditions except for stroke. Exception reporting allows practitioners to exclude patients from target calculations if certain criteria are met, e.g. informed dissent of the patient for treatment. There were no statistically significant improvements in mean blood pressure, cholesterol or HbA1c levels. Thus, achievement of higher payment thresholds in the local pay for performance scheme was mainly attributed to increased exception reporting by practices with no discernable improvements in overall clinical quality. Hence, active monitoring of exception reporting should be considered when setting more ambitious quality targets. More generally, the study suggests a trade-off between additional incentive for better care and monitoring costs.     

Selective cytotoxicity of Pancratistatin-related natural <Emphasis Type="Italic">Amaryllidaceae</Emphasis> alkaloids: evaluation of the activity of two new compounds

Background  

Pancratistatin (PST), a compound extracted from an Amaryllidaceae (AMD) family plant, has been shown to specifically induce apoptosis in cancer cells with no/minimal toxic effect on normal cells. A systematic synthetic approach has indicated that the minimum cytotoxic pharmacophore comprises the trans-fused b/c-ring system containing the 2, 3, 4-triol unit in the C-ring. To further explore the structure-activity relationship of this group of compounds we have investigated the anti-cancer efficacy and specificity of two PST-related natural compounds, AMD4 and AMD5. Both of these compounds lack the polyhydroxylated lycorane element of PST instead having a methoxy-substuituted crinane skeleton.     

Role of post translational modifications and novel crosstalk between phosphorylation and O-beta-GlcNAc modifications in human claudin-1, -3 and -4

The precise characterization of post translational modifications (PTMs) is important for the understanding of protein regulatory mechanisms and their role in disease. However, experimental studies on PTMs, especially with multifunctional proteins are difficult to follow and investigate. Bioinformatic tools are therefore helpful in predicting key protein modifications. To study the role of PTMs in claudin proteins, specifically claudin-1, -3 and -4 in the onset or progression of human cancers, we performed an in silico study of various PTMs and investigated their interplay. Given that the activity of claudins is known to be influenced by two types of PTMs, specifically palmitoylation and kinase- dependent phosphorylation, we predicted two conserved regions in the topological domains of claudin-1, -3 and -4 as potential palmitoylation sites. Furthermore, conserved phosphorylation residues, which may be targets for kinases and can alter claudin’s ability to maintain the integrity of tight junctions, were identified. To our knowledge, this is the first report to suggest O-glycosylation of claudin proteins, as well as a potential novel interplay between phosphorylation and O-glycosylation at Yin Yang sites. Thus, our findings may facilitate the production of anti-cancer drugs, and suggest that novel therapeutic strategies should target post translational events.     

Short-Term Consequences of Angiographically-Confirmed Coronary Stent Thrombosis

Objectives

To conduct a meta-analysis to quantify the real-world incidence of in-hospital or 30-day death or myocardial infarction (MI), and angiographically-confirmed ST-related treatment costs.

Background

The short-term clinical and economic consequences of coronary stent thrombosis (ST) are thought to be significant.

Methods

We searched MEDLINE, Embase and Scopus from January 2000-July 2012 to identify observational/registry studies that evaluated a cohort of ≥25 patients experiencing angiographically-confirmed thrombosis of a drug-eluting or bare-metal stent, required the use of dual-antiplatelet therapy for guideline-recommended durations, and reported incidences of in-hospital or 30-day death or MI and/or ST-related treatment costs. Incidences and costs from each study were pooled using random-effects meta-analysis.

Results

Twenty-three studies were included. Of the 13 studies reporting in-hospital outcomes, 12 (N=8,832 STs) reported mortality data, with the pooled incidence rate estimated to be 7.9%, 95%CI=5.4%-11.3%, I²=86%. Ten studies (N=1,294 STs) reported 30-day death, with a pooled incidence of 11.6%, 95%CI=8.8%-15.1%, I²=55%. Patients experiencing early ST (within 30-days of implant) had higher in-hospital and 30-day mortality than those experiencing very-late ST (interaction p<0.04 for both). Stent type had no significant effect on in-hospital or 30-day mortality. In the 5 studies (N=542 STs) and 3 studies (N=180 STs) reporting in-hospital and 30-day MI, respectively, the pooled incidence rates were 6.1%, 95%CI=2.1%-16.2%, I²=88% and 9.5%, 95%CI=3.8%-22.0%, I²=65%. One study reported costs associated with ST, estimating the median/patient cost of hospitalization to treat early ST at $11,134 (in 2000US$).

Conclusions

Regardless of stent type used, the short-term consequences of coronary ST appear significant.     

Symbiotic interactions between arbuscular mycorrhizal (AM) fungi and male papaya plants: Its status,role and implications

Experiments were conducted to study the arbuscular mycorrhizal (AM) status and its role in P-uptake through assay of root phosphatases activities in four varieties of male Carica papaya L. viz. CO-1, CO-2, Honey Dew and Washington during flowering stages. In the present study, mean total root colonization of AM fungi recorded peak increase in flowering stage-II while mean root phosphatase (acid and alkaline) activities recorded peak increase in flowering stage-I. Unlike root colonization and root phosphatase activities, spore density did not exhibit any definite patterns and recorded a narrow range of fluctuation during different flowering stages of male C. papaya. The study brought out the fact that root colonization and spore density of AM fungi along with root phosphatase activities varied significantly within the four varieties of male C. papaya plants during each flowering stage. The study also recorded consistently higher acid root phosphatase activity than alkaline root phosphatase activity under P-deficient, acidic soil conditions during all flowering stages of male C. papaya plants. Studies revealed that the root colonization of AM fungi influenced root phosphatase activities (acid and alkaline) positively and significantly during all flowering stages of male C. papaya plants. A total of twelve species of AM fungi belonging to five genera viz. Acaulospora, Dentiscutata, Gigaspora, Glomus, and Racocetra were recovered from the rhizosphere of male C. papaya plants.