Seed priming with co-flocs of Azospirillum and Pseudomonas for effective management of rice blast

A modified approach was adopted to develop co-flocs consisting of Azospirillum brasilense MTCC-125 and Pseudomonas fluorescens MTCC-4828. The results of our study revealed that both Azospirillum and Pseudomonas strains exhibited a higher survivability when embedded in the flocs. The survivability of the strains in co-floc was found to be higher when compared to the log phase vegetative cells in different inoculant carriers, spermosphere rhizoplane and rhizosphere. The co-floc treatment has also significantly increased the germination percentage and vigour index of rice. In the present study flocculation was found to play a major role in enhancing adhesion of both the strains to rice roots. The co-flocs were studied for their efficiency to induce resistance in rice crop against rice blast. The relative role of Azospirillum and Pseudomonas co-flocs in the induction of resistance against the phytopathogen was evaluated. It was found that when the activities of polyphenol oxidase, peroxidase and phenol were high and when the relative amounts of the sugars were low, the disease infestation was less and vice versa. The association of these compounds strongly implies their role as casual agents of induced resistance against Pyricularia oryzae.     

Novel Simulation Tools for Materials Engineering Education

Abstract

A novel simulation interface is being developed as an educational tool to help students better understand fundamentals of materials science. This interface makes use of virtual reality (VR) technology consisting of PC-based graphics and a force-feedback haptic device. Visualization of atomistic processes with simultaneous tactile sensation via the haptic provides a powerful method for understanding complex phenomena that are otherwise difficult to comprehend. Modules are described that allow students to interactively explore interatomic bonding and single-atom diffusion through materials.     

Control of Adipogenesis by the Autocrine Interplays between Angiotensin 1–7/Mas Receptor and Angiotensin II/AT1 Receptor Signaling Pathways

Angiotensin II (AngII), a peptide hormone released by adipocytes, can be catabolized by adipose angiotensin-converting enzyme 2 (ACE2) to form Ang(1–7). Co-expression of AngII receptors (AT₁ and AT₂) and Ang(1–7) receptors (Mas) in adipocytes implies the autocrine regulation of the local angiotensin system upon adipocyte functions, through yet unknown interactive mechanisms. In the present study, we reveal the adipogenic effects of Ang(1–7) through activation of Mas receptor and its subtle interplays with the antiadipogenic AngII-AT1 signaling pathways. Specifically, in human and 3T3-L1 preadipocytes, Ang(1–7)-Mas signaling promotes adipogenesis via activation of PI3K/Akt and inhibition of MAPK kinase/ERK pathways, and Ang(1–7)-Mas antagonizes the antiadipogenic effect of AngII-AT₁ by inhibiting the AngII-AT₁-triggered MAPK kinase/ERK pathway. The autocrine regulation of the AngII/AT₁-ACE2-Ang(1–7)/Mas axis upon adipogenesis has also been revealed. This study suggests the importance of the local regulation of the delicately balanced angiotensin system upon adipogenesis and its potential as a novel therapeutic target for obesity and related metabolic disorders.     

Pharmacological properties and predicted binding mode of arylmethylene quinuclidine-like derivatives at the α3β4 nicotinic acetylcholine receptor (nAChR)

We have carried out a pharmacological evaluation of arylmethylene quinuclidine derivatives interactions with human α3β4 nAChRs subtype, using cell-based receptor binding, calcium-influx, electrophysiological patch-clamp assays and molecular modeling techniques. We have found that the compounds bind competitively to the α3β4 receptor with micromolar affinities and some of the compounds behave as non-competitive antagonists (compounds 1, 2 and 3), displaying submicromolar IC₅₀ values. These evidences suggest a mixed mode of action for these compounds, having interactions at the orthosteric site and more pronounced interactions at an allosteric site to block agonist effects. One of the compounds, 1-benzyl-3-(diphenylmethylene)-1-azoniabicyclo[2.2.2]octane chloride (compound 3), exhibited poorly reversible use-dependent block of α3β4 channels. We also found that removal of a phenyl group from compound 1 confers a partial agonism to the derived analog (compound 6). Introducing a hydrogen-bond acceptor into the 3-benzylidene quinuclidine derivative (compound 7) increases agonism potency at the α3β4 receptor subtype. Docking into the orthosteric binding site of a α3β4 protein structure derived by comparative modeling accurately predicted the experimentally-observed trend in binding affinity. Results supported the notion that binding requires a hydrogen bond formation between the ligand basic nitrogen and the backbone carbonyl oxygen atom of the conserved Trp-149.     

Maternal sociodemographic characteristics and the use of the Iowa Infant Attitude Feeding Scale to describe breastfeeding initiation and duration in a population of urban,Latina mothers: a prospective cohort study

Background

The World Health Organization recommends exclusive breastfeeding until 6 months of age. Maternal attitudes toward infant feeding are correlated with chosen feeding method and breastfeeding duration. The Iowa Infant Feeding Attitude Scale (IIFAS) has been used to assess attitudes towards breastfeeding prenatally and is predictive of breastfeeding decisions in certain population groups.

Methods

In a cohort of pregnant Latina women recruited from two hospitals in the San Francisco Bay Area (n=185), we administered the IIFAS prior to delivery. Information regarding feeding choice, maternal sociodemographic information, and anthropometrics were collected at 6 months and 1 year postpartum. Analysis of predictors for breastfeeding initiation, breastfeeding at 6 and 12 months and exclusive breastfeeding at 6 months were evaluated using multivariate logistic regression adjusting for potential confounders.

Results

In our cohort of Latina mothers, breastfeeding a previous infant was associated with breastfeeding initiation (OR 8.29 [95% CI 1.00, 68.40] p = 0.05) and breastfeeding at 6 months (OR 18.34 [95% CI 2.01, 167.24] p = 0.01). College education was associated with increased exclusive breastfeeding at 6 months (OR 58.67 [95% CI 4.97, 692.08] p = 0.001) and having other children was associated with reduced breastfeeding at six months (OR 0.08 [95% CI 0.01, 0.70] p = 0.02). A higher IIFAS score was not associated with breastfeeding initiation, breastfeeding at 6 or 12 months or exclusive breastfeeding at 6 months of age.

Conclusions

Initial choices about breastfeeding will likely influence future breastfeeding decisions, so breastfeeding interventions should specifically target new mothers. Mothers with other children also need additional encouragement to maintain breastfeeding until 6 months of age. The IIFAS, while predictive of breastfeeding decisions in other population groups, was not associated with feeding decisions in our population of Latina mothers.

     

Local Inflammation Exacerbates the Severity of Staphylococcus aureus Skin Infection

Staphylococcus aureus is the leading cause of skin infections. In a mouse model of S. aureus skin infection, we found that lesion size did not correlate with bacterial burden. Athymic nude mice had smaller skin lesions that contained lower levels of myeloperoxidase, IL-17A, and CXCL1, compared with wild type mice, although there was no difference in bacterial burden. T cell deficiency did not explain the difference in lesion size, because TCR βδ (-/-) mice did not have smaller lesions, and adoptive transfer of congenic T cells into athymic nude mice prior to infection did not alter lesion size. The differences observed were specific to the skin, because mortality in a pneumonia model was not different between wild type and athymic nude mice. Thus, the clinical severity of S. aureus skin infection is driven by the inflammatory response to the bacteria, rather than bacterial burden, in a T cell independent manner.     

Turing learning: a metric-free approach to inferring behavior and its application to swarms

We propose Turing Learning, a novel system identification method for inferring the behavior of natural or artificial systems. Turing Learning simultaneously optimizes two populations of computer programs, one representing models of the behavior of the system under investigation, and the other representing classifiers. By observing the behavior of the system as well as the behaviors produced by the models, two sets of data samples are obtained. The classifiers are rewarded for discriminating between these two sets, that is, for correctly categorizing data samples as either genuine or counterfeit. Conversely, the models are rewarded for ‘tricking’ the classifiers into categorizing their data samples as genuine. Unlike other methods for system identification, Turing Learning does not require predefined metrics to quantify the difference between the system and its models. We present two case studies with swarms of simulated robots and prove that the underlying behaviors cannot be inferred by a metric-based system identification method. By contrast, Turing Learning infers the behaviors with high accuracy. It also produces a useful by-product—the classifiers—that can be used to detect abnormal behavior in the swarm. Moreover, we show that Turing Learning also successfully infers the behavior of physical robot swarms. The results show that collective behaviors can be directly inferred from motion trajectories of individuals in the swarm, which may have significant implications for the study of animal collectives. Furthermore, Turing Learning could prove useful whenever a behavior is not easily characterizable using metrics, making it suitable for a wide range of applications.     

Ancestral gene duplications in mosses characterized by integrated phylogenomic analyses

Mosses (Bryophyta) are a key group occupying an important phylogenetic position in land plant (embryophyte) evolution. The class Bryopsida represents the most diversified lineage, containing more than 95% of modern mosses, whereas other classes are species‐poor. Two branches with large numbers of gene duplications were elucidated by phylogenomic analyses, one in the ancestry of all mosses and another before the separation of the Bryopsida, Polytrichopsida, and Tetraphidopsida. The analysis of the phylogenetic progression of duplicated paralogs retained on genomic syntenic regions in the Physcomitrella patens genome confirmed that the whole‐genome duplication events WGD1 and WGD2 were re‐recognized as the ψ event and the Funarioideae duplication event, respectively. The ψ polyploidy event was tightly associated with the early diversification of Bryopsida, in the ancestor of Bryidae, Dicranidae, Timmiidae, and Funariidae. Together, four branches with large numbers of gene duplications were unveiled in the evolutionary past of P. patens. Gene retention patterns following the four large‐scale duplications in different moss lineages were analyzed and discussed. Recurrent significant retention of stress‐related genes may have contributed to their adaption to distinct ecological environments and the evolutionary success of this early‐diverging land plant lineage.