Sondeo arqueológico Cueva Pintada corte 11,12 cierre sur [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

Observational Constraints of Modified Chaplygin Gas in Loop Quantum Cosmology

We have considered the FRW universe in loop quantum cosmology (LQC) model filled with the dark matter (perfect fluid with negligible pressure) and the modified Chaplygin gas (MCG) type dark energy. We present the Hubble parameter in terms of the observable parameters $\Omega_{m0}$, $\Omega_{x0}$ and $H_{0}$ with the redshift $z$ and the other parameters like $A$, $B$, $C$ and $\alpha$. From Stern data set (12 points), we have obtained the bounds of the arbitrary parameters by minimizing the $\chi^{2}$ test. The best-fit values of the parameters are obtained by 66%, 90% and 99% confidence levels. Next due to joint analysis with BAO and CMB observations, we have also obtained the bounds of the parameters ($B,C$) by fixing some other parameters $\alpha$ and $A$. From the best fit of distance modulus $\mu(z)$ for our theoretical MCG model in LQC, we concluded that our model is in agreement with the union2 sample data.Comment: 14 pages, 10 figures, Accepted in EPJC. arXiv admin note: text overlap with arXiv:astro-ph/0311622 by other author

How does Inflation Depend Upon the Nature of Fluids Filling Up the Universe in Brane World Scenario

By constructing different parameters which are able to give us the information about our universe during inflation,(specially at the start and the end of the inflationary universe) a brief idea of brane world inflation is given in this work. What will be the size of the universe at the end of inflation,i.e.,how many times will it grow than today's size is been speculated and analysed thereafter. Different kinds of fluids are taken to be the matter inside the brane. It is observed that in the case of highly positive pressure grower gas like polytropic,the size of the universe at the end of inflation is comparitively smaller. Whereas for negative pressure creators (like chaplygin gas) this size is much bigger. Except thse two cases, inflation has been studied for barotropic fluid and linear redshift parametrization $\omega(z) = \omega_{0} + \omega_{1} z$ too. For them the size of the universe after inflation is much more high. We also have seen that this size does not depend upon the potential energy at the end of the inflation. On the contrary, there is a high impact of the initial potential energy upon the size of inflation.Comment: 20 page

The N-glycan processing enzymes α-mannosidase and β-D-N-acetylhexosaminidase are involved in ripening-associated softening in the non-climacteric fruits of capsicum

Excessive softening of fruits during the ripening process leads to deterioration. This is of significant global importance as softening-mediated deterioration leads to huge postharvest losses. N-glycan processing enzymes are reported to play an important role during climacteric fruit softening: however, to date these enzymes have not been characterized in non-climacteric fruit. Two ripening-specific N-glycan processing enzymes, α-mannosidase (α-Man) and β-D-N-acetylhexosaminidase (β-Hex), have been identified and targeted to enhance the shelf life in non-climacteric fruits such as capsicum (Capsicum annuum). The purification, cloning, and functional characterization of α-Man and β-Hex from capsicum, which belong to glycosyl hydrolase (GH) families 38 and 20, respectively, are described here. α-Man and β-Hex are cell wall glycoproteins that are able to cleave terminal α-mannose and β-D-N-acetylglucosamine residues of N-glycans, respectively. α-Man and β-Hex transcripts as well as enzyme activity increase with the ripening and/or softening of capsicum. The function of α-Man and β-Hex in capsicum softening is investigated through RNA interference (RNAi) in fruits. α-Man and β-Hex RNAi fruits were approximately two times firmer compared with the control and fruit deterioration was delayed by approximately 7 d. It is shown that silencing of α-Man and β-Hex enhances fruit shelf life due to the reduced degradation of N-glycoproteins which resulted in delayed softening. Altogether, the results provide evidence for the involvement of N-glycan processing in non-climacteric fruit softening. In conclusion, genetic engineering of N-glycan processing can be a common strategy in both climacteric and non-climacteric species to reduce the post-harvest crop losses