Accelerating Universe in Hybrid and Logarithmic Teleparallel Gravity

Teleparallel gravity is a modified theory of gravity for which the Ricci scalar $R$ of the underlying geometry in the action is replaced by an arbitrary functional form of torsion scalar $T$. In doing so, cosmology in $$ gravity becomes greatly simplified owing to the fact that $T$ contains only the first derivatives of the vierbeins. The article exploits this appealing nature of $f(T)$ gravity and present cosmological scenarios from hybrid and logarithmic teleparallel gravity models of the form $$ and $f=D\log(bT)$ respectively, where $m$, $n$, $D$ and $b$ are free parameters constrained to suffice the late time acceleration. We employ a well motivated parametrization of the deceleration parameter having just one degree of freedom constrained with a $\chi^{2}$ test from 57 data points of Hubble data set in the redshift range $0.07<z<2.36$, to obtain the expressions of pressure, density and EoS parameter for both the teleparallel gravity models and study their temporal evolution. We find the deceleration parameter to experience a signature flipping for the $\chi^{2}$ value of the free parameter at $z_{tr}\simeq0.6$ which is consistent with latest Planck measurements. Next, we present few geometric diagnostics of this parametrization to understand the nature of dark energy and its deviation from the $\Lambda$CDM cosmology. Finally, we study the energy conditions to check the consistency of the parameter spaces for both the teleparallel gravity models. We find the SEC to violate for both the models which is an essential recipe to obtain an accelerating universe.Comment: Accepted version at Physics of the Dark Univers

Assess the antioxidant and antimicrobial activity of herbal popsicles prepared by Hibiscus sabdariffa L. and Clitorea ternatea floral waste

In this study, we extracted bio-colour from two commonly available flowers, Rosella (Hibiscus sabdariffa L.) and Butterfly pea flower (Clitoria ternatea), and evaluated their potential therapeutic benefits by examining their antioxidant and antibacterial activity. To assess the suitability and quality of the extracted bio-colour as a food additive, we formulated ice popsicles using bio-colour derived from H. sabdariffa and C. ternatea. The crude floral waste extract of H. sabdariffa showed the highest reducing capacity (FRAP assay), antioxidant activity (DPPH, ABTS assay), and antibacterial potential. This may be attributed to polyphenols, flavonoids, anthocyanins, ascorbic acids, organic acids, hibiscus acid, and other compounds in H. sabdariffa flower parts. The ice popsicles formulated with these two bio-colours contained significant polyphenol and flavonoid content, contributing to their antioxidant potential comparable to ice popsicles available in the local market. The formulated ice popsicles also retained better physical properties (texture, melting, smoothness/hardness) and sensory qualities (as per hedonic scale rating) than market-derived ice popsicles. Therefore, these two crude floral wastes can be utilized as functional food bio-colourants in the food industry

Repurposing Drugs, Ongoing Vaccine, and New Therapeutic Development Initiatives Against COVID-19

As the COVID-19 is still growing throughout the globe, a thorough investigation into the specific immunopathology of SARS-CoV-2, its interaction with the host immune system and pathogen evasion mechanism may provide a clear picture of how the pathogen can breach the host immune defenses in elderly patients and patients with comorbid conditions. Such studies will also reveal the underlying mechanism of how children and young patients can withstand the disease better. The study of the immune defense mechanisms and the prolonged immune memory from patients population with convalescent plasma may help in designing a suitable vaccine candidate not only for the current outbreak but also for similar outbreaks in the future. The vital drug candidates, which are being tested as potential vaccines or therapeutics against COVID-19, include live attenuated vaccine, inactivated or killed vaccine, subunit vaccine, antibodies, interferon treatment, repurposing existing drugs, and nucleic acid-based vaccines. Several organizations around the world have fast-tracked the development of a COVID-19 vaccine, and some drugs already went to phase III of clinical trials. Hence, here, we have tried to take a quick glimpse of the development stages of vaccines or therapeutic approaches to treat this deadly disease