Reprogramming, oscillations and transdifferentiation in epigenetic landscapes

Waddington's epigenetic landscape provides a phenomenological understanding of the cell differentiation pathways from the pluripotent to mature lineage-committed cell lines. In light of recent successes in the reverse programming process there has been significant interest in quantifying the underlying landscape picture through the mathematics of gene regulatory networks. We investigate the role of time delays arising from multi-step chemical reactions and epigenetic rearrangement on the cell differentiation landscape for a realistic two-gene regulatory network, consisting of self-promoting and mutually inhibiting genes. Our work provides the first theoretical basis of the transdifferentiation process in the presence of delays, where one differentiated cell type can transition to another directly without passing through the undifferentiated state. Additionally, the interplay of time-delayed feedback and a time dependent chemical drive leads to long-lived oscillatory states in appropriate parameter regimes. This work emphasizes the important role played by time-delayed feedback loops in gene regulatory circuits and provides a framework for the characterization of epigenetic landscapes

Gravitational uncertainties from dimension-six operators on supersymmetric GUT predictions

We consider the gravity induced dimension six terms in addition to the dimension five terms in the SUSY GUT Lagrangian and find that the prediction for $\alpha_s$ may be washed out completely in supersymmetric grand unified theories unless the triplet higgs mass is smaller than $7\times 10^{16}$ GeV.Comment: 7 pages,latex.Title of original version changed,text added and a figure has been added.Figure is available on request.To appear as a brief Report in Phys.Rev.

Tribology and rheology of potato protein and pectin mixtures and Maillard conjugates

This study aimed to compare the tribological and rheological properties of plant proteins versus their mixtures or conjugates with polysaccharides. We hypothesize that combining potato proteins (Po) with pectin (Pe) at various concentrations (0.5–5.0 wt%, ratios 1:1 and 1:2 w/w) will improve the lubrication performance of plant proteins by virtue of viscosity modification and boundary lubrication. Po showed shear thinning behavior with limited concentration-dependence in boundary and mixed lubricity. Pe on the other hand showed pronounced concentration-dependent flow and lubrication behavior delivering favorable boundary and viscous lubricity. Pe dominated the lubrication and high shear rate flow behavior in Po + Pe mixtures, governed mainly by the concentration of Pe and the hydrodynamic volume rather than the total concentration of the biopolymers. Maillard reaction (≤33% degree of conjugation) led to more negatively-charged protein-polysaccharide conjugates versus the sole biopolymers (p < 0.05). The conjugation decreased the second plateau shear viscosity of the Po + Pe mixtures and led to improvement in boundary and mixed lubricity when a reduced entrainment speed parameter was used. Findings from this study may inspire future studies combining plant proteins with polysaccharides to enhance their lubrication behavior and eventually improve the textural properties of plant-based foods

Epidemiology of HIV Infection Among Brothel-based Sex Workers in Kolkata, India

A cross-sectional study was carried out during January-June 2004 to assess the status of HIV infection among brothel-based sex workers in Kolkata city, India. Six hundred and twenty-two sex workers, selected from six brothels, were included in the study to assess their HIV status, and 362 sex workers, a subset of the above population, were interviewed to study their risk behaviour and practices. Blood samples were collected from each sex worker for testing HIV by an unlinked anonymous method. The prevalence of HIV infection was 9.6%, but was much higher among younger sex workers aged 20 years or less (27.7%) compared to the older age group (8.4%). This difference was statistically significant, indicating an association of younger ages with HIV infection [p=0.006 and odds ratio (OR)=4.18; (95% confidence interval (CI) 1.2-13.8)]. HIV was not associated with duration of sex work, average number of clients entertained per day, condom use, practice of sex during menstruation, precoital examination of penis for visible ulcer/discharge, suffering from sexually transmitted infections, and entertaining clients outside the brothel. There was a big gap between the reported and the evaluated condom use by sex workers. The results suggest that there is a need to develop suitable HIV intervention strategies, considering the socioeconomic and cultural aspects of city sex workers, with a provision for continuous monitoring and evaluation

Thermodynamics Inducing Massive Particles' Tunneling and Cosmic Censorship

By calculating the change of entropy, we prove that the first law of black hole thermodynamics leads to the tunneling probability of massive particles through the horizon, including the tunneling probability of massive charged particles from the Reissner-Nordstr\"om black hole and the Kerr-Newman black hole. Novelly, we find the trajectories of massive particles are close to that of massless particles near the horizon, although the trajectories of massive charged particles may be affected by electromagnetic forces. We show that Hawking radiation as massive particles tunneling does not lead to violation of the weak cosmic-censorship conjecture

IL-27 signaling activates skin cells to induce innate antiviral proteins and protects against Zika virus infection

In the skin, antiviral proteins and other immune molecules serve as the first line of innate antiviral defense. Here, we identify and characterize the induction of cutaneous innate antiviral proteins in response to IL-27 and its functional role during cutaneous defense against Zika virus infection. Transcriptional and phenotypic profiling of epidermal keratinocytes treated with IL-27 demonstrated activation of antiviral proteins OAS1, OAS2, OASL, and MX1 in the skin of both mice and humans. IL-27–mediated antiviral protein induction was found to occur in a STAT1- and IRF3-dependent but STAT2-independent manner. Moreover, using IL27ra mice, we demonstrate a significant role for IL-27 in inhibiting Zika virus morbidity and mortality following cutaneous, but not intravenous, inoculation. Together, our results demonstrate a critical and previously unrecognized role for IL-27 in cutaneous innate antiviral immunity against Zika virus

Economic assessment of use of pond ash in pavements

The paper introduces a new type of industrial waste-based subbase material which can replace conventional subbase material (CSM) in pavement construction. Utilisation of this industrial waste, namely pond coal ash produced from a thermal power plant in road construction will help to reduce the disposal problem of this waste and also will help to reduce the problem of scarcity of CSM. Lime and fibre were also added to the pond ash at various percentages to improve the suitability of this type of mix as subbase material. The optimum service life of pavement is studied with the help of numerical modelling and the cost benefit is also presented in the current study. The study reveals that stabilisation of the coal ash with 2% lime may produce an optimal material and, even though a greater thickness may be required to deliver the same pavement performance, direct cost savings of around 10% may be achieved in addition to less easily quantifiable environmental benefits. Design charts are provided to exploit the findings

Yield response, nutritional quality and water productivity of tomato (Solanum lycopersicum L.) are influenced by drip irrigation and straw mulch in the coastal saline ecosystem of Ganges Delta, India

In the coastal zone of the Ganges Delta, water shortages due to soil salinity limit the yield of dry season crops. To alleviate water shortage as a consequence of salinity stress in the coastal saline ecosystem, the effect of different water-saving (WS) and water-conserving options was assessed on growth, yield and water use of tomato; two field experiments were carried out at Gosaba, West Bengal, India in consecutive seasons during the winter of 2016–17 and 2017–18. The experiment was laid out in a randomized block design with five treatments viz., surface irrigation, surface irrigation + straw mulching, drip irrigation at 100% reference evapotranspiration (ET0), drip irrigation at 80% ET0, drip irrigation at 80% ET0 + straw mulching. Application of drip irrigation at 80% ET0 + straw mulching brought about significantly the highest fruit as well as the marketable yield of tomato (Solanum lycopersicum L.). The soil reaction (pH), post-harvest organic carbon, nitrogen, phosphorus and potassium (N, P and K) status and soil microbial population along with the biochemical quality parameters of tomato (juice pH, ascorbic acid, total soluble solids and sugar content of fruits) were significantly influenced by combined application of drip irrigation and straw mulching. Surface irrigation significantly increased the salinity level in surface and sub-surface soil layers while the least salinity development was observed in surface mulched plots receiving irrigation water through drip irrigation. The highest water productivity was also improved from drip irrigation at 80% ET0 + straw mulched plots irrespective of the year of experimentation. Such intervention also helped in reducing salinity stress for the tomato crop. Thus, straw mulching along with drip irrigation at 80% ET0 can be recommended as the most suitable irrigation option for tomato crop in the study area as well as coastal saline regions of South Asia. Finally, it can be concluded that the judicious application of irrigation water not only increased growth, yield and quality tomatoes but also minimized the negative impact of soil salinity on tomatoes grown in the coastal saline ecosystem of Ganges Delta

Corrections to Hawking-like Radiation for a Friedmann-Robertson-Walker Universe

Recently, a Hamilton-Jacobi method beyond semiclassical approximation in black hole physics was developed by \emph{Banerjee} and \emph{Majhi}\cite{beyond0}. In this paper, we generalize their analysis of black holes to the case of Friedmann-Robertson-Walker (FRW) universe. It is shown that all the higher order quantum corrections in the single particle action are proportional to the usual semiclassical contribution. The corrections to the Hawking-like temperature and entropy of apparent horizon for FRW universe are also obtained. In the corrected entropy, the area law involves logarithmic area correction together with the standard inverse power of area term.Comment: 10 pages, no figures, comments are welcome; v2: references added and some typoes corrected, to appear in Euro.Phys.J.C; v3:a defect corrected. We thank Dr.Elias Vagenas for pointing out a defect of our pape

Leptogenesis and rescattering in supersymmetric models

The observed baryon asymmetry of the Universe can be due to the $B-L$ violating decay of heavy right handed (s)neutrinos. The amount of the asymmetry depends crucially on their number density. If the (s)neutrinos are generated thermally, in supersymmetric models there is limited parameter space leading to enough baryons. For this reason, several alternative mechanisms have been proposed. We discuss the nonperturbative production of sneutrino quanta by a direct coupling to the inflaton. This production dominates over the corresponding creation of neutrinos, and it can easily (i.e. even for a rather small inflaton-sneutrino coupling) lead to a sufficient baryon asymmetry. We then study the amplification of MSSM degrees of freedom, via their coupling to the sneutrinos, during the rescattering phase which follows the nonperturbative production. This process, which mainly influences the (MSSM) $D-$flat directions, is very efficient as long as the sneutrinos quanta are in the relativistic regime. The rapid amplification of the light degrees of freedom may potentially lead to a gravitino problem. We estimate the gravitino production by means of a perturbative calculation, discussing the regime in which we expect it to be reliable.Comment: (20 pages, 6 figures), references added, typos corrected. Final version in revte