Symbiotic N2 fixation by soybean in organic and conventional cropping systems estimated by 15N dilution and 15N natural abundance

Nitrogen (N) is often the most limiting nutrient in organic cropping systems. N2 fixing crops present an important option to improve N supply and to maintain soil fertility. In a field experiment, we investigated whether the lower N fertilization level and higher soil microbial activity in organic than conventional systems affected symbiotic N2 fixation by soybean (Glycine max, var. Maple Arrow) growing in 2004 in plots that were since 1978 under the following systems: bio-dynamic (DYN); bio-organic (ORG); conventional with organic and mineral fertilizers (CON); CON with exclusively mineral fertilizers (MIN); non-fertilized control (NON). We estimated the percentage of legume N derived from the atmosphere (%Ndfa) by the natural abundance (NA) method. For ORG and MIN we additionally applied the enriched 15N isotope dilution method (ID) based on residual mineral and organic 15N labeled fertilizers that were applied in 2003 in microplots installed in ORG and MIN plots. These different enrichment treatments resulted in equal %Ndfa values. The %Ndfa obtained by NA for ORG and MIN was confirmed by the ID method, with similar variation. However, as plant growth was restricted by the microplot frames the NA technique provided more accurate estimates of the quantities of symbiotically fixed N2 (Nfix). At maturity of soybean the %Ndfa ranged from 24 to 54%. It decreased in the order ORG>CON>DYN>NON>MIN, with significantly lowest value for MIN. Corresponding Nfix in above ground plant material ranged from 15 to 26g Nm-2, with a decreasing trend in the order DYN=ORG>CON>MIN>NON. For all treatments, the N withdrawal by harvested grains was greater than Nfix. This shows that at the low to medium %Ndfa, soybeans did not improve the N supply to any system but removed significant amounts of soil N. High-soil N mineralization and/or low-soil P availability may have limited symbiotic N2 fixatio

Nitrogen use efficiency of 15N-labelled sheep manure and mineral fertiliser applied to microplots in long-term organic and conventional cropping systems

Nitrogen (N) utilisation by crops has to be improved to minimize losses to the environment. We investigated N use efficiency of animal manure and mineral fertiliser and fate of fertiliser N not taken up by crops in a conventional (CONMIN) and a bio-organic (BIOORG) cropping system of a long-term field experiment over three vegetation periods (winter wheat-soybean-maize). Microplots planted with wheat received a single application of 15N-labelled slurries (either urine or faeces labelled) or mineral fertiliser. At the end of each vegetation period we tested whether higher microbial activity and larger microbial biomass in BIOORG than CONMIN soils, and lower long-term N input level in BIOORG, affected use efficiency and fate of fertiliser N not taken up by crops. Recovery of 15N in wheat was 37%, 10% and 47% from urine, faeces and mineral fertiliser, respectively, and decreased strongly in the residual years. In total 41%, 15% and 50% of 15N applied as urine, faeces and mineral fertiliser was recovered by the three crops. 15N recovered from originally applied urine, faeces and mineral fertiliser in the topsoil (0-18cm) at the end of the third vegetation period was 19%, 25% and 20%, respectively. Of urine-, faeces- and mineral fertiliser-15N, 40%, 61% and 29%, respectively, was not recovered by the three crops and in topsoil suggesting significant transport of 15N-labelled components to deeper soil layers. CONMIN and BIOORG differed neither in fertiliser N use efficiency by crops nor in 15N recovery in soil indicating insignificant difference in the turnover and utilization of the applied manure nitrogen in the conventional and the bio-organic cropping system

A Concerted Kinase Interplay Identifies PPARγ as a Molecular Target of Ghrelin Signaling in Macrophages

The peroxisome proliferator-activator receptor PPARγ plays an essential role in vascular biology, modulating macrophage function and atherosclerosis progression. Recently, we have described the beneficial effect of combined activation of the ghrelin/GHS-R1a receptor and the scavenger receptor CD36 to induce macrophage cholesterol release through transcriptional activation of PPARγ. Although the interplay between CD36 and PPARγ in atherogenesis is well recognized, the contribution of the ghrelin receptor to regulate PPARγ remains unknown. Here, we demonstrate that ghrelin triggers PPARγ activation through a concerted signaling cascade involving Erk1/2 and Akt kinases, resulting in enhanced expression of downstream effectors LXRα and ABC sterol transporters in human macrophages. These effects were associated with enhanced PPARγ phosphorylation independently of the inhibitory conserved serine-84. Src tyrosine kinase Fyn was identified as being recruited to GHS-R1a in response to ghrelin, but failure of activated Fyn to enhance PPARγ Ser-84 specific phosphorylation relied on the concomitant recruitment of docking protein Dok-1, which prevented optimal activation of the Erk1/2 pathway. Also, substitution of Ser-84 preserved the ghrelin-induced PPARγ activity and responsiveness to Src inhibition, supporting a mechanism independent of Ser-84 in PPARγ response to ghrelin. Consistent with this, we found that ghrelin promoted the PI3-K/Akt pathway in a Gαq-dependent manner, resulting in Akt recruitment to PPARγ, enhanced PPARγ phosphorylation and activation independently of Ser-84, and increased expression of LXRα and ABCA1/G1. Collectively, these results illustrate a complex interplay involving Fyn/Dok-1/Erk and Gαq/PI3-K/Akt pathways to transduce in a concerted manner responsiveness of PPARγ to ghrelin in macrophages

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Symbiotic N2 fixation by soybean in organic and conventional cropping systems estimated by 15N dilution and 15N natural abundance

Nitrogen (N) is often the most limiting nutrient in organic cropping systems. N2 fixing crops present an important option to improve N supply and to maintain soil fertility. In a field experiment, we investigated whether the lower N fertilization level and higher soil microbial activity in organic than conventional systems affected symbiotic N2 fixation by soybean (Glycine max, var. Maple Arrow) growing in 2004 in plots that were since 1978 under the following systems: bio-dynamic (DYN); bio-organic (ORG); conventional with organic and mineral fertilizers (CON); CON with exclusively mineral fertilizers (MIN); non-fertilized control (NON). We estimated the percentage of legume N derived from the atmosphere (%Ndfa) by the natural abundance (NA) method. For ORG and MIN we additionally applied the enriched 15N isotope dilution method (ID) based on residual mineral and organic 15N labeled fertilizers that were applied in 2003 in microplots installed in ORG and MIN plots. These different enrichment treatments resulted in equal %Ndfa values. The %Ndfa obtained by NA for ORG and MIN was confirmed by the ID method, with similar variation. However, as plant growth was restricted by the microplot frames the NA technique provided more accurate estimates of the quantities of symbiotically fixed N2 (Nfix). At maturity of soybean the %Ndfa ranged from 24 to 54%. It decreased in the order ORG > CON > DYN > NON > MIN, with significantly lowest value for MIN. Corresponding Nfix in above ground plant material ranged from 15 to 26 g N m-2, with a decreasing trend in the order DYN = ORG > CON > MIN > NON. For all treatments, the N withdrawal by harvested grains was greater than Nfix. This shows that at the low to medium %Ndfa, soybeans did not improve the N supply to any system but removed significant amounts of soil N. High-soil N mineralization and/or low-soil P availability may have limited symbiotic N2 fixation

Nitrogen use efficiency of 15N-labelled sheep manure and mineral fertiliser applied to microplots in long-term organic and conventional cropping systems

Nitrogen (N) utilisation by crops has to be improved to minimize losses to the environment. We investigated N use efficiency of animal manure and mineral fertiliser and fate of fertiliser N not taken up by crops in a conventional (CONMIN) and a bioorganic (BIOORG) cropping system of a long-term field experiment over three vegetation periods (winter wheat–soybean–maize). Microplots planted with wheat received a single application of 15N-labelled slurries (either urine or faeces labelled) or mineral fertiliser. At the end of each vegetation period we tested whether higher microbial activity and larger microbial biomass in BIOORG than CONMIN soils, and lower long-term N input level in BIOORG, affected use efficiency and fate of fertiliser N not taken up by crops. Recovery of 15N in wheat was 37%, 10% and 47% from urine, faeces and mineral fertiliser, respectively, and decreased strongly in the residual years. In total 41%, 15% and 50% of 15N applied as urine, faeces and mineral fertiliser was recovered by the three crops. 15N recovered from originally applied urine, faeces and mineral fertiliser in the topsoil (0–18 cm) at the end of the third vegetation period was 19%, 25% and 20%, respectively. Of urine-, faeces- and mineral fertiliser-15N, 40%, 61% and 29%, respectively, was not recovered by the three crops and in topsoil suggesting significant transport of 15N-labelled components to deeper soil layers. CONMIN and BIOORG differed neither in fertiliser N use efficiency by crops nor in 15N recovery in soil indicating insignificant difference in the turnover and utilization of the applied manure nitrogen in the conventional and the bio-organic cropping systems

Novel molecular aspects of pituitary adenomas.

Ghrelin stimulates while somatostatin inhibits GH release and they thus serve as functional antagonists. We have compared their effects on cell proliferation. Ghrelin stimulates while somatostatin inhibits cell proliferation in most tissues and cell lines. Here we show that ghrelin and desoctanoyl ghrelin stimulate cell proliferation in rat pituitary cell line (GH3), and these effects could be inhibited with mitogen-activated protein kinase (MAPK), tyrosine kinase and protein kinase C inhibitors. Somatostatin and its analogs negatively regulate the growth of pituitary cells, and we now show that they inhibit MAPK activation. We hypothesised that one of the mechanisms involved in the somatostatin effect is a stimulation of cell cycle inhibitor p27, as pituitary adenomas have decreased p27 peptide content. Both octreotide and a new somatostatin analog SOM230 treatment resulted in an upregulation of p27 protein levels in human somatotrophinoma cells. In summary, we suggest that ghrelin and somatostatin have opposite effects on somatotroph cells not just at the level of GH release but also in terms of cell proliferation. Ghrelin may play a role in pituitary tumorigenesis via an autocrine/paracrine pathway. Our results also suggest that the antiproliferative effect of somatostatin analogs octreotide and SOM230 involve the up-regulation of p27 and down-regulation of the MAPK pathway in human somatotrophinomas

Nitrogen use efficiency of 15N-labelled sheep manure and mineral fertiliser applied to microplots in long-term organic and conventional cropping systems

ISSN:1385-1314ISSN:1573-086

Моделирование агрегации с учетом кулоновского взаимодеиствия частиц

Background and aims: The current paradigm for phosphorus (P) fertilizers applied to calcareous soil is that almost entirely water soluble P fertilizers are efficient and sparingly soluble P fertilizers are not efficient P sources for crops. We hypothesize that this paradigm does not apply to recycled P fertilizers and that other P pools can explain the plant use of recycled P fertilizers on calcareous soil. Methods: We applied P isotopic dilution method to evaluate recycled P fertilizers based on plant P uptake from fertilizer relative to plant uptake from a water soluble P reference fertilizer. The predictability of fertilizer effectiveness based on sequentially extracted P forms and X-ray diffraction pattern of recycled fertilizers derived from sewage sludge, human urine and organic waste was evaluated. Results: The plant experiments showed that tested recycled P fertilizers including compost were more effective than rock phosphate. The water insoluble P contained in urine based products was almost as effective as a fully water soluble P fertilizer. The tested recycled P fertilizers are characterized by complex P compounds differing in solubility which were so far not considered in the water and citric acid extraction methods. The fraction of resin- and NaHCO extractable fertilizer P explained effectiveness of P fertilizer applied to the calcareous and to an acidic soil. Conclusion: We concluded that water solubility is not required when P forms in recycled products are comparable to reactions products of rock phosphate based fertilizers in soil. Alternatives to fully water soluble P fertilizers are available to supply P to crops grown on calcareous soil efficiently