A structured jet explains the extreme GRB 221009A.

Long-duration gamma-ray bursts (GRBs) are powerful cosmic explosions, signaling the death of massive stars. Among them, GRB 221009A is by far the brightest burst ever observed. Because of its enormous energy (Eiso ≈ 1055 erg) and proximity (z ≈ 0.15), GRB 221009A is an exceptionally rare event that pushes the limits of our theories. We present multiwavelength observations covering the first 3 months of its afterglow evolution. The x-ray brightness decays as a power law with slope ≈t-1.66, which is not consistent with standard predictions for jetted emission. We attribute this behavior to a shallow energy profile of the relativistic jet. A similar trend is observed in other energetic GRBs, suggesting that the most extreme explosions may be powered by structured jets launched by a common central engine.

A very luminous jet from the disruption of a star by a massive black hole.

Tidal disruption events (TDEs) are bursts of electromagnetic energy that are released when supermassive black holes at the centres of galaxies violently disrupt a star that passes too close1. TDEs provide a window through which to study accretion onto supermassive black holes; in some rare cases, this accretion leads to launching of a relativistic jet2-9, but the necessary conditions are not fully understood. The best-studied jetted TDE so far is Swift J1644+57, which was discovered in γ-rays, but was too obscured by dust to be seen at optical wavelengths. Here we report the optical detection of AT2022cmc, a rapidly fading source at cosmological distance (redshift z = 1.19325) the unique light curve of which transitioned into a luminous plateau within days. Observations of a bright counterpart at other wavelengths, including X-ray, submillimetre and radio, supports the interpretation of AT2022cmc as a jetted TDE containing a synchrotron 'afterglow', probably launched by a supermassive black hole with spin greater than approximately 0.3. Using four years of Zwicky Transient Facility10 survey data, we calculate a rate of [Formula: see text] per gigapascals cubed per year for on-axis jetted TDEs on the basis of the luminous, fast-fading red component, thus providing a measurement complementary to the rates derived from X-ray and radio observations11. Correcting for the beaming angle effects, this rate confirms that approximately 1 per cent of TDEs have relativistic jets. Optical surveys can use AT2022cmc as a prototype to unveil a population of jetted TDEs.

Candidate Tidal Disruption Event AT2019fdr Coincident with a High-Energy Neutrino.

The origins of the high-energy cosmic neutrino flux remain largely unknown. Recently, one high-energy neutrino was associated with a tidal disruption event (TDE). Here we present AT2019fdr, an exceptionally luminous TDE candidate, coincident with another high-energy neutrino. Our observations, including a bright dust echo and soft late-time x-ray emission, further support a TDE origin of this flare. The probability of finding two such bright events by chance is just 0.034%. We evaluate several models for neutrino production and show that AT2019fdr is capable of producing the observed high-energy neutrino, reinforcing the case for TDEs as neutrino sources.

An insight to flux-balance analysis for biochemical networks.

Systems biology is one of the integrated ways to study biological systems and is more favourable than the earlier used approaches. It includes metabolic pathway analysis, modelling, and regulatory as well as signal transduction for getting insights into cellular behaviour. Among the various techniques of modelling, simulation, analysis of networks and pathways, flux-based analysis (FBA) has been recognised because of its extensibility as well as simplicity. It is widely accepted because it is not like a mechanistic simulation which depends on accurate kinetic data. The study of fluxes through the network is informative and can give insights even in the absence of kinetic data. FBA is one of the widely used tools to study biochemical networks and needs information of reaction stoichiometry, growth requirements, specific measurement parameters of the biological system, in particular the reconstruction of the metabolic network for the genome-scale, many of which have already been built previously. It defines the boundaries of flux distributions which are possible and achievable with a defined set of genes. This review article gives an insight into FBA, from the extension of flux balancing to mathematical representation followed by a discussion about the formulation of flux-balance analysis problems, defining constraints for the stoichiometry of the pathways and the tools that can be used in FBA such as FASIMA, COBRA toolbox, and OptFlux. It also includes broader areas in terms of applications which can be covered by FBA as well as the queries which can be addressed through FBA.

Insight into the kinetically and thermodynamically controlled biosynthesis of silver nanoparticles.

The mechanism of nanoparticles (NPs) synthesis is a crucial prerequisite for the engineering of desirable material properties and is elusive due to the difficulty of studying the synthesis path and also due to lack of published work. The present study moves beyond the current conventional study of characterisation of NPs synthesis. It focuses on study of classical kinetics of metal NP using silver as a model metal to perform the required experiments, it aimed at understanding the crystallisation process which is the major root for the synthesis of metal NP. The authors have chosen biological approach to explain the process of synthesis of metal NP using inductively coupled plasma - optical emission spectroscopy that directly analyses the concentration of metal NPs. Alpha-amylase solution, when incubated with silver nitrate solution, turned brown at a specific concentration of enzyme and substrate, which shows the formation of silver NPs. Inductively coupled plasma data and dynamic light scattering spectra were studied to understand the kinetics and the kinetics model was obtained. The enthalpy (ΔH*), activation energy (ΔE*), and equilibrium constant (K) were calculated for understanding the thermodynamics of the reaction. The process of NP synthesis is dependent on the kinetics of the reaction, and other process parameters limit the thermodynamics of the process.

An analytics based clinical decision support system for CVD risk assessment and management.

Cardiovascular disease (CVD) is a major cause of disability and premature death throughout the world. Acute coronary events and other cardiovascular events frequently occur suddenly, and are often fatal before medical care can be given. Risk factor modification can reduce clinical events and premature death in people with established cardiovascular disease as well as in those who are at high cardiovascular risk due to one or more risk factors. In this work, India specific World Health Organization-International Society of Hypertension (WHO-ISH) guidelines has been implemented to stratify the subjects by their risk profile. It provides simplified approach to detect those people at high risk and provides guidance on what should be done for prevention of heart attack. Further, based on the risk stratification, lifestyle coaching, medication management and the next tests are advised to the subjects. This approach will help in early detection of cardiovascular risk subjects and provide necessary interventions at appropriate time frame. Also, it acts as motivation to the individuals to comply with recommended lifestyle changes.