A possible observational bias in the estimation of the virial parameter in virialized clumps

The dynamics of massive clumps, the environment where massive stars originate, is still unclear. Many theories predict that these regions are in a state of near-virial equilibrium, or near energy equi-partition, while others predict that clumps are in a sub-virial state. Observationally, the majority of the massive clumps are in a sub-virial state with a clear anti-correlation between the virial parameter $\alpha_{vir}$ and the mass of the clumps $M_{c}$, which suggests that the more massive objects are also the more gravitationally bound. Although this trend is observed at all scales, from massive clouds down to star-forming cores, theories do not predict it. In this work we show how, starting from virialized clumps, an observational bias is introduced in the specific case where the kinetic and the gravitational energies are estimated in different volumes within clumps and how it can contribute to the spurious $\alpha_{vir}-M_{c}$ anti-correlation in these data. As a result, the observed effective virial parameter $\tilde{\alpha}_{eff}<\alpha_{vir}$, and in some circumstances it might not be representative of the virial state of the observed clumps.Comment: A&A letter, accepte

Investigations on the liquid crystalline phases of cation-induced condensed DNA

Viral and nonviral condensing agents are used in gene therapy to compact oligonucleotides and plasmid DNA into nanostructures for their efficient transport through the cell membranes. Whereas viral vectors are best by the toxic effects on the immune system, most of the nonviral delivery vehicles are not effective for use in clinical system. Recent investigations indicate that the supramolecular organization of DNA in the condensed state is liquid crystalline. The present level of understanding of the liquid crystalline phase of DNA is inadequate and a thorough investigation is required to understand the nature, stability, texture and the influence of various environmental conditions on the structure of the phase. The present study is mainly concerned with the physicochemical investigations on the liquid crystalline transitions during compaction of DNA by cationic species such as polyamines and metallic cations. As a preliminary to the above investigation, studies were conducted on the evolution of mesophase transitions of DNA with various cationic counterion species using polarized light microscopy. These studies indicated significant variations in the phase behaviour of DNA in the presence of Li and other ions. Apart from the neutralization of the charges on the DNA molecule, these ions are found to influence selectively the hydration sphere of DNA that in turn influences the induction and stabilization of the LC phases. The higher stability observed with the liquid crystalline phases of Li-DNA system could be useful in the production of nanostructured DNA. In the case of the polyamine, a structural specificity effect depending on the nature, charge and structure of the polyamine used has been found to be favoured in the crystallization of DNA

Hot Core, Outflows and Magnetic Fields in W43-MM1 (G30.79 FIR 10)

We present submillimeter spectral line and dust continuum polarization observations of a remarkable hot core and multiple outflows in the high-mass star-forming region W43-MM1 (G30.79 FIR 10), obtained using the Submillimeter Array (SMA). A temperature of $\sim$ 400 K is estimated for the hot-core using CH$_3$CN (J=19-18) lines, with detections of 11 K-ladder components. The high temperature and the mass estimates for the outflows indicate high-mass star-formation. The continuum polarization pattern shows an ordered distribution, and its orientation over the main outflow appears aligned to the outflow. The derived magnetic field indicates slightly super-critical conditions. While the magnetic and outflow energies are comparable, the B-field orientation appears to have changed from parsec scales to $\sim$ 0.1 pc scales during the core/star-formation process.Comment: accepted, ApJ Letter

Application of a Machine Learning Algorithm in a Multi Stage Production System

This paper examines a permutation flow-shop scheduling problem, which is a complex combinatorial problem encountered in many practical applications. The objective of the research is to reduce the maximum completion time, i.e., the makespan of all jobs. In order to increase productivity and to meet the demand, manufacturers are continuously under pressure to attain the shortest possible completion time. Estimation of accurate cycle time can tremendously help production planning and scheduling in manufacturing industries. Since production planning is characterised by NP-hardness and a wide range, traditional optimization methods and heuristic rules are unable to find satisfactory solutions. Q-learning, a type of reinforcement learning algorithm, is used in this paper to find a solution that is close to being optimal. Q-learning is a branch of machine learning referring to the way an intelligent agent should act in order to maximize the concept of cumulative reward in a given environment. To validate the performance of the algorithm, Taillard’s benchmark problems were solved and compared with the upper bound value. The results showed that the performance of the algorithm is better and has low computational time. Based on the performance of the proposed algorithm, two case studies were done and the solutions are compared with the performance of a metaheuristic algorithm. The result shows that the proposed algorithm can effectively and efficiently solve the problem stated above and that it is an interesting solution to resolving complex scheduling problems

Management of scombroid resources of India

Scombroids consisting of mackerels, seerfishes and tunas are an economically important pelagic fishes whose average landings during the 90s was 2.81 lakh t forming 11.7 % of the total marine fish production in India. Their demand in the domestic and export markets is on the rise and the group assumes topical importance in a situation where most of the coastal fishery resources are exploited to the near optimum level. Resource potential, status of exploitation and management and conservation issues regarding the scombroid resource in the coastal fishery sector are presented and discussed

Magnetic Field Uniformity Across the GF 9-2 YSO, L1082C Dense Core, and GF 9 Filamentary Dark Cloud

The orientation of the magnetic field (B-field) in the filamentary dark cloud GF 9 was traced from the periphery of the cloud into the L1082C dense core that contains the low-mass, low-luminosity Class 0 young stellar object (YSO) GF 9-2 (IRAS 20503+6006). This was done using SOFIA HAWC+ dust thermal emission polarimetry (TEP) at 216 um in combination with Mimir near-infrared background starlight polarimetry (BSP) conducted at H-band (1.6 um) and K-band (2.2 um). These observations were augmented with published I-band (0.77 um) BSP and Planck 850 um TEP to probe B-field orientations with offset from the YSO in a range spanning 6000 AU to 3 pc. No strong B-field orientation change with offset was found, indicating remarkable uniformity of the B-field from the cloud edge to the YSO environs. This finding disagrees with weak-field models of cloud core and YSO formation. The continuity of inferred B-field orientations for both TEP and BSP probes is strong evidence that both are sampling a common B-field that uniformly threads the cloud, core, and YSO region. Bayesian analysis of Gaia DR2 stars matched to the Mimir BSP stars finds a distance to GF 9 of 270 +/- 10 pc. No strong wavelength dependence of B-field orientation angle was found, contrary to previous claims.Comment: 18 pages, 6 figures ApJ, accepte

A True Human Tail in a Neonate : Case report and literature review

A true human tail is a benign vestigial caudal cutaneous structure composed of adipose, connective tissue, muscle, vessels, nerves and mechanoreceptors. A true human tail can be distinguished from a pseudotail as the latter is commonly associated with underlying spinal dysraphism, which requires specialised management. True human tails are very rare, with fewer than 40 cases reported to date. We report a healthy one-day-old male newborn who was referred to the Bharath Hospital, Kottayam, Kerala, India, in 2014 with a cutaneous appendage arising from the lumbosacral region. Magnetic resonance imaging of the spine ruled out spinal dysraphism. The appendage was removed by simple surgical excision. Clinicians should emphasise use of ‘true tail’ and ‘pseudotail’ as specific disparate terms as the clinical, radiological and histological findings of these conditions differ significantly, along with management strategies and outcomes

Prospects of development of marine fisheries resources in Lakshadweep

A good data base has already been developed by CMFRI on various marine resources of Lakshadweep islands and related conservation problems. In the present paper, the potentialities and the areas where future research and developmental activities need to be directed are briefly discussed

Massive and low-mass protostars in massive "starless" cores

The infrared dark clouds (IRDCs) G11.11$-$0.12 and G28.34$+$0.06 are two of the best-studied IRDCs in our Galaxy. These two clouds host clumps at different stages of evolution, including a massive dense clump in both clouds that is dark even at 70 and 100$\mu$m. Such seemingly quiescent massive dense clumps have been speculated to harbor cores that are precursors of high-mass stars and clusters. We observed these two "prestellar" regions at 1mm with the Submillimeter Array (SMA) with the aim of characterizing the nature of such cores. We show that the clumps fragment into several low- to high-mass cores within the filamentary structure of the enveloping cloud. However, while the overall physical properties of the clump may indicate a starless phase, we find that both regions host multiple outflows. The most massive core though 70 $\mu$m dark in both clumps is clearly associated with compact outflows. Such low-luminosity, massive cores are potentially the earliest stage in the evolution of a massive protostar. We also identify several outflow features distributed in the large environment around the most massive core. We infer that these outflows are being powered by young, low-mass protostars whose core mass is below our detection limit. These findings suggest that low-mass protostars have already formed or are coevally formed at the earliest phase of high-mass star formation.Comment: in print at A&