MOLECULAR, GENETIC AND BIOCHEMICAL CHARACTERIZATION OF OLEIC ACID- AND GLYCEROL-MEDIATED SIGNALING IN PLANT DEFENSE

Oleic acid (18:1) is one of the important monounsaturated fatty acids, which is synthesized upon desaturation of stearic acid and this reaction is catalyzed by the SSI2 encoded stearoyl-acyl-carrier-protein-desaturase. A mutation in SSI2 leads to constitutive activation of salicylic acid (SA)-mediated defense responses. Consequently, these plants accumulate high levels of SA and show enhanced resistance to bacterial and oomycete pathogens. Replenishing 18:1 levels in ssi2 plants, via a second site mutation in GLY1 encoded glycerol-3-phosphate (G3P) dehydrogenase, suppresses all the ssi2-triggered phenotypes. Study of mechanism(s) underlying gly1-mediated suppression of ssi2 phenotypes showed that 18:1 levels are regulated via acylation with G3P and a balance between G3P and 18:1 is critical for the regulation of defense signaling pathways. To establish a role for 18:1 and G3P during host defense, interaction between Colletotrichum higginsianum and Arabidopsis was studied. Resistance to C. higginsianum correlated with host G3P levels. The gly1 plants showed increased susceptibility while act1 plants, defective in utilization of G3P, showed enhanced resistance. Plant overexpessing GLY1 showed enhanced resistance in both wild type as well as camalexin deficient backgrounds. Together, these results suggested that G3P conferred resistance acted downstream or independent of camalexin. Exogenous application of glycerol lowered 18:1 levels and produced ssi2-like phenotypes in wild-type plants. Furthermore, glycerol application or the ssi2 mutation produced similar phenotypes in fatty acid desaturation mutants and mutants defective in SA/resistance gene signaling. Expression studies showed that ssi2 phenotypes were likely due to increased expression of resistance genes. Epistatic analysis suggested that certain components of SA pathway had redundant function and were required for 18:1-regulated signaling

An Analytical Model for Explosive Compaction of Powder to Cylindrical Billets through Axial Detonation

An analytical model, describing an explosive compaction process performed axially on a powder assembly of cylindrical geometry, is discussed. The powder is encapsulated in a cylindrical metal container surrounded by an explosive pad, which is detonated parallel to the major axis of the compact. The pressure generated in the powder is a function of the nature and the thickness of the explosive material as well as the powder characteristics. The model is based on the principle of shock propagation in powder aggregate and, the detonation as well as the refraction wave characteristics of the explosives. For the purpose of validation and illustration, this investigation considers the explosive compaction of aluminium powder particles for different explosive pad thicknesses. The model brings-out a closed-form solution for densification of powders. The density of the final powder compact depends on the pad thickness. Inadequate pad thickness leads to under compacted core, while higher pad thickness leads to melting at the core leading to over all low density. The optimum pad thickness of the explosive to produce the highest densification is thus determined using the model. The densification depends on the size of the powder particles also, since; the heat generated by the high pressure shock wave melts the surface of the powder particles depending on the specific heat, thermal conductivity and the latent heat of the powder material. The study essentially covers the effect of the explosive pad thickness and the particle size of the powder on densification. The analytical results are compared with a few experimental data and the comparison is found to be satisfactory

Novel approach to store and use the rotated passwords for authentication for a privileged SSO in a distributed unsynchronized environment

There is a feature developed which would rotate the passwords of privileged accounts. Based on an organization’s compliance policy, the password rotation can be scheduled in an interval of time e.g. every 90 days or can be rotated immediately based on admin actions. As part of password rotation process, the new password is updated in the target system as well as its own primary and backup Credential Vault database. The primary credential vault synchronizes the updated password(s) to backup credential vault(s). While initiating a privileged session for an end user the invention uses the password stored in credential vault and injects in user’s session for a privileged SSO to target systems

Conservation status of the dhole Cuon alpinus in north-east India, with a focus on Dampa Tiger Reserve, Mizoram

Despite the efforts invested in their conservation, the status of many threatened carnivores in key conservation landscapes remains unknown. The dhole Cuon alpinus is an Endangered social carnivore whose geographical range has contracted by c. 80% since the early 20th century. North-east India is a critical link between South Asian and South-east Asian dhole populations. In this study we compiled presence records of dholes across north-east India, from multiple sources. We also conducted camera-trap surveys in one part of this region, Dampa Tiger Reserve in the state of Mizoram. We examined the influence of ecological and management factors on fine-scale site-use by dholes in Dampa Tiger Reserve, showing a positive association of dhole site-use with sambar Rusa unicolor encounters, distance to the forest boundary and presence of forest department personnel, underscoring the importance of prey and protection. Our findings also highlight the need for targeted, multi-scale assessments of dhole ecology across other sites in north-east India

Simulation of Arbitrary Level Contrast Dose in MRI Using an Iterative Global Transformer Model

Deep learning (DL) based contrast dose reduction and elimination in MRI imaging is gaining traction, given the detrimental effects of Gadolinium-based Contrast Agents (GBCAs). These DL algorithms are however limited by the availability of high quality low dose datasets. Additionally, different types of GBCAs and pathologies require different dose levels for the DL algorithms to work reliably. In this work, we formulate a novel transformer (Gformer) based iterative modelling approach for the synthesis of images with arbitrary contrast enhancement that corresponds to different dose levels. The proposed Gformer incorporates a sub-sampling based attention mechanism and a rotational shift module that captures the various contrast related features. Quantitative evaluation indicates that the proposed model performs better than other state-of-the-art methods. We further perform quantitative evaluation on downstream tasks such as dose reduction and tumor segmentation to demonstrate the clinical utility.Comment: Accepted in MICCAI 202

On Existence of Latency Optimal Uncoded Storage Schemes in Geo-Distributed Data Storage Systems

We consider the problem of geographically distributed data storage in a network of servers (or nodes) where the nodes are connected to each other via communication links having certain round-trip times (RTTs). Each node serves a specific set of clients, where a client can request for any of the files available in the distributed system. The parent node provides the requested file if available locally; else it contacts other nodes that have the data needed to retrieve the requested file. This inter-node communication incurs a delay resulting in a certain latency in servicing the data request. The worst-case latency incurred at a servicing node and the system average latency are important performance metrics of a storage system, which depend not only on inter-node RTTs, but also on how the data is stored across the nodes. Data files could be placed in the nodes as they are, i.e., in uncoded fashion, or can be coded and placed. This paper provides the necessary and sufficient conditions for the existence of uncoded storage schemes that are optimal in terms of both per-node worst-case latency and system average latency. In addition, the paper provides efficient binary storage codes for a specific case where optimal uncoded schemes do not exist

Changes in the root fungal microbiome of strawberry following application of residues of the biofumigant oilseed radish

Biofumigation has been proposed as an environmentally friendly method of plant protection against soil-borne pathogens, but its effects on microbial communities are still incompletely understood. Using high throughput DNA sequencing, we investigated the effects of oilseed radish residues on the root fungal microbiome of strawberry in the presence of a soil-borne fungal pathogen, Verticillium dahliae. Results of our greenhouse study show that early flowering occurred in response to residue addition, suggesting a plant stress-response and there was a significant decrease in berry yield. The fungal microbiome of roots was significantly restructured by both biofumigation and inoculation with Verticillium. In particular, the abundance of root endophyte- and arbuscular mycorrhizal functional guilds was reduced significantly as a result of biofumigant and V. dahliae addition, whereas the abundance of saprotrophs increased significantly when both treatments were applied together. Alpha diversity analyses of fungi associated with roots indicated a significant increase in species richness following Verticillium inoculation, whereas the biofumigant alone or in the presence of V. dahliae resulted in no significant effect, suggesting that apparently some rare taxa may have been enriched/stimulated in the presence of the pathogen. Further investigations should reveal whether negative effects of biofumigation on potentially beneficial root associated endophytes and arbuscular mycorrhizal fungi are host genotype- or soil-dependent