On the Core-Collapse Supernova Explanation for LAMOST J1010+2358

Low-metallicity very massive stars with an initial mass of $\sim 140$--$260\, {\rm M_\odot}$ are expected to end their lives as pair-instability supernovae (PISNe). The abundance pattern resulting from a PISN differs drastically from regular core-collapse supernova (CCSN) models and is expected to be seen in very metal-poor (VMP) stars of ${\rm[Fe/H]}\lesssim -2$. Despite the routine discovery of many VMP stars, the unique abundance pattern expected from PISNe has not been unambiguously detected. The recently discovered VMP star LAMOST J1010+2358, however, shows a peculiar abundance pattern that is remarkably well fit by a PISN, indicating the potential first discovery of a bonafide star born from gas polluted by a PISN. In this paper, we study the detailed nucleosynthesis in a large set of models of CCSN of Pop III and Pop II star of metallicity ${\rm[Fe/H]}=-3$ with masses ranging from $12$--$30\,{\rm M_\odot}$. We find that the observed abundance pattern in LAMOST J1010+2358 can be fit at least equally well by CCSN models of $\sim 12$--$14\,{\rm M_\odot}$ that undergo negligible fallback following the explosion. The best-fit CCSN models provide a fit that is even marginally better than the best-fit PISN model. We conclude the measured abundance pattern in LAMOST J1010+2358 could have originated from a CCSN and therefore cannot be unambiguously identified with a PISN given the set of elements measured in it to date. We identify key elements that need to be measured in future detections in stars like LAMOST J1010+2358 that can differentiate between CCSN and PISN origin.Comment: 7 pages, 5 figures, Accepted in MNRA

Surgical resection for hepatic space occupying lesions: a histopathological analysis

Background: Hepatic resections are done for both neoplastic and non-neoplastic diseases of liver with malignancies constituting a major share of cases. The objective of this study was to assess the various neoplatic and non-neoplastic lesions in hepatic resection specimens and to categorize the various histopathological types of primary and secondary liver tumors.Methods: The study was conducted in the Department of Pathology, Academy of Medical sciences, Pariyaram. This was a hospital based study which included 79 patients who underwent hepatic resection for space occupying lesions over a period of 5 years from January 2012 to December 2016. IHC was performed in cases with diagnostic dilemma.Results: Of the 79 cases, there were 45 males and 34 females with the age range of 22-85 years. There were 70 neoplastic lesions out of which 11 were benign with 6 cavernous hemangiomas, 3 hepatic adenomas and one each of intraductal papillary neoplasm and mucinous cystic neoplasm. Among the 59 malignant lesions, hepatocellular carcinomas predominated followed by metastatic malignancies and cholangiocarcinomas. Of the metastatic malignancies, adenocarcinoma from gastrointestinal primary was the commonest followed by metastatic gastrointestinal stromal tumor.Conclusions: Liver is a frequent site for many neoplastic and non-neoplastic diseases with malignant neoplasms forming the major bulk. Non-neoplastic lesions like simple liver cysts and focal nodular hyperplasia showed female predominance while benign neoplasms like cavernous hemangioma and hepatic adenomas were seen exclusively in females. Of the malignant liver tumors, hepatocellular carcinoma was the commonest followed by metastatic malignancy, gastrointestinal tract being the commonest source of primary tumor

Vaccine Approaches for Pandemic COVID-19: An Overview

The coronavirus strain, SARS-CoV-2 causative agent of the pandemic viral pneumonia disease COVID-19, identified in the late 2019. Unfortunately, there is no vaccine or therapeutics available to control the disease. Although, earlier research efforts of SARS pandemic (2003) provides the precious information to the researchers for fast track vaccine development. Research efforts for vaccine development of COVID-19 pandemic are unprecedented in terms of promising time period. The inactivated whole virus-based SARS-CoV-2 vaccine is first one developed and entered into clinical trial. However, later on after announce of complete genome sequence of SARS-CoV-2, vaccine based on recombinant viral vector, nucleic acid and immunogenic fragment also introduced. Previous experience of undesired immunopotentiation in SARS-CoV studies represents, vaccine safety should be the main concern.  Researchers believe that next generation vaccine approaches using recombinant technology such as viral vector or subunit protein-based vaccine will be more effective and safer. This review describes brief information of the major vaccine candidates and the current scenario of vaccine approaches against COVID-19 pandemic

Rapidly Rotating Massive Pop III stars: A Solution for High Carbon Enrichment in CEMP-no Stars

Very metal-poor stars that have $[\text{Fe}/\text{H}]<-2$ and that are enhanced in C relative to Fe ($[\text{C}/\text{Fe}]>+0.7$) but have no enhancement of heavy elements ($[\text{Ba}/\text{Fe}]<0$) are known as carbon-enhanced metal-poor (CEMP-no) stars. These stars are thought to be produced from a gas that was polluted by the supernova (SN) ejecta of the very first generation (Pop III) massive stars. The very high enrichment of C ($A(\text{C})\gtrsim 6$) observed in many of the CEMP-no stars is difficult to explain by current models of SN explosions from massive Pop III stars when a reasonable dilution of the SN ejecta, that is consistent with detailed simulation of metal mixing in minihaloes, is adopted. We explore rapidly rotating Pop III stars that undergo efficient mixing and reach a quasi-chemically homogeneous (QCH) state. We find that QCH stars can eject large amounts of C in the wind and that the resulting dilution of the wind ejecta in the interstellar medium can lead to a C enrichment of $A(\text{C})\lesssim7.75$. The core of QCH stars can produce up to an order of magnitude of more C than non-rotating progenitors of similar mass and the resulting SN can lead to a C enrichment of $A(\text{C})\lesssim7$. Our rapidly rotating massive Pop III stars cover almost the entire range of $A(\text{C})$ observed in CEMP-no stars and are a promising site for explaining the high C enhancement in the early Galaxy. Our work indicates that a substantial fraction of Pop III stars were likely rapid rotators.Comment: 16 pages, 8 figures, and 8 tables. Submitte

WRKY Transcription Factors: Molecular Regulation and Stress Responses in Plants

Plants in their natural habitat have to face multiple stresses simultaneously. Evolutionary adaptation of developmental, physiological and biochemical parameters give advantage over a single window of stress but not multiple. On the other hand transcription factors like WRKY can regulate diverse responses through a complicated network of genes. So molecular orchestration of WRKYs in plant may provide the most anticipated outcome of simultaneous multiple responses. Activation or repression through W-box and W-box like sequences is regulated at transcriptional, translational and domain level. Because of the tight regulation involved in specific recognition and binding of WRKYs to downstream promoters, they have become promising candidate for crop improvement. Epigenetic, retrograde and proteasome mediated regulation enable WRKYs to attain the dynamic cellular homeostatic reprograming. Overexpression of several WRKYs face the paradox of having several beneficial affects but with some unwanted traits. These overexpression-associated undesirable phenotypes need to be identified and removed for proper growth, development and yeild. Taken together, we have highlighted the diverse regulation and multiple stress response of WRKYs in plants along with the future prospects in this field of research

Community-level management of bio-resources for augmenting income from coconut-based farming systems in Kerala state, India

On-farm management of farm residues for mass multiplication of beneficial microbes plays an important role in organic farming as well as integrated nutrient management by improving soil health. Community-level production of organic inputs from crop residues can be a potential source of income for farmers’ groups also. A large scale operational research on community-based bio-resource management, along with soil test based nutrient management, was undertaken by ICAR-CPCRI with financial support from NABARD in the major organic tract of Kerala in the coastal belt - Kanjikuzhy block during 2014-2016. The bio-resource management components under technology integration included farm-level production of organics from crop residues, enrichment using bio-agents, utilization of enriched organics for soil and plant health management and production of bio-primed planting materials. For enhancing the efficiency of Trichoderma-enriched organic manure, two ideal media viz., coir pith compost + neem cake (4:1) and coir pith compost + neem cake + poultry manure + cow dung (2:1:1:1) were standardized. Coconut seedlings produced through bio-priming with Trichoderma sp. showed early germination (90%), higher recovery percentage (79.5%), higher collar girth (17 cm), more number of fronds (9) and height (160 cm). Farm-based participatory action management integrating cost-effective bio-resource management interventions in coconut-based farming systems resulted in improvements in income from coconut by 26 per cent and intercrops by 142.9 per cent, contributing to an increase in the average farm income by 149.8 per cent. The average knowledge index of the respondents related to bio-resource management increased by 115.8 per cent and that of integrated nutrient management by 74.5 per cent