2,708 research outputs found
Grafting vigour is associated with DNA de-methylation in eggplant.
In horticulture, grafting is a popular technique used to combine positive traits from two different plants. This is achieved by joining the plant top part (scion) onto a rootstock which contains the stem and roots. Rootstocks can provide resistance to stress and increase plant production, but despite their wide use, the biological mechanisms driving rootstock-induced alterations of the scion phenotype remain largely unknown. Given that epigenetics plays a relevant role during distance signalling in plants, we studied the genome-wide DNA methylation changes induced in eggplant (Solanum melongena) scion using two interspecific rootstocks to increase vigour. We found that vigour was associated with a change in scion gene expression and a genome-wide hypomethylation in the CHH context. Interestingly, this hypomethylation correlated with the downregulation of younger and potentially more active long terminal repeat retrotransposable elements (LTR-TEs), suggesting that graft-induced epigenetic modifications are associated with both physiological and molecular phenotypes in grafted plants. Our results indicate that the enhanced vigour induced by heterografting in eggplant is associated with epigenetic modifications, as also observed in some heterotic hybrids
Batako Berlubang Geopolimer Berbahan Dasar Lumpur Sidoarjo
Lumpur Sidoarjo merupakan material yang sedang dikembangkan sebagai pengganti semen. Alasan digunakannya lumpur Sidoarjo adalah jumlahnya yang melimpah dan telah terbukti memiliki kandungan yang dapat menggantikan fungsi semen. Oleh karena itu sebaiknya lumpur Sidoarjo dijadikan sebagai produk jadi yang berguna, untuk masyarakat secara luas. Salah satu produk yang cocok diproduksi dari lumpur Sidoarjo adalah batako geopolimer. Batako geopolimer sendiri mempunyai beberapa kelebihan daripada batako pada umumnya, antara lain dapat mengurangi pelepasan gas CO2 ke atmosfer karena tidak menggunakan semen, sehingga lebih ramah terhadap lingkungan, selain itu bahan geopolimer memiliki ketahanan serangan dari luar. Untuk mengolah lumpur agar siap pakai dalam pembuatan batako, lumpur harus melewati beberapa tahapan, antara lain lumpur harus dijemur selama 24 jam, kemudian dimasukkan ke oven selama 24 jam. Setelah itu lumpur dibakar dengan suhu 650ºC selama 9 jam agar sifat lumpur menjadi amorf sehingga dapat digunakan. Lumpur kemudian digiling sampai melewati ayakan nomor 200. Setelah siap dipakai, lumpur dicampurkan dengan pasir, NaOH, serta sodium silikat dengan perbandingan tertentu untuk dijadikan campuran mortar untuk pembuatan batako. Dari hasil penelitian yang telah dilakukan, kuat tekan dan penyerapan air dari mortar menunjukkan hasil yang baik, Sehingga produk batako geopolimer memenuhi syarat batako pada umumnya
A Survey of Atomic Carbon [C I] in High-redshift Main-Sequence Galaxies
We present the first results of an ALMA survey of the lower fine structure
line of atomic carbon [C I](^3P_1\,-\,^{3}P_0) in far infrared-selected
galaxies on the main sequence at in the COSMOS field. We compare our
sample with a comprehensive compilation of data available in the literature for
local and high-redshift starbursting systems and quasars. We show that the [C
I]() luminosity correlates on global scales with the
infrared luminosity similarly to low- CO transitions. We report
a systematic variation of L'_{\rm [C\,I]^3P_1\,-\, ^3P_0}/ as a
function of the galaxy type, with the ratio being larger for main-sequence
galaxies than for starbursts and sub-millimeter galaxies at fixed .
The L'_{\rm [C\,I]^3P_1\,-\, ^3P_0}/ and / mass ratios are similar for main-sequence galaxies and for
local and high-redshift starbursts within a 0.2 dex intrinsic scatter,
suggesting that [C I] is a good tracer of molecular gas mass as CO and dust. We
derive a fraction of %
of the total carbon mass in the atomic neutral phase. Moreover, we estimate the
neutral atomic carbon abundance, the fundamental ingredient to calibrate [C I]
as a gas tracer, by comparing L'_{\rm [C\,I]^3P_1\,-\, ^3P_0} and available
gas masses from CO lines and dust emission. We find lower [C I] abundances in
main-sequence galaxies than in starbursting systems and sub-millimeter
galaxies, as a consequence of the canonical and gas-to-dust
conversion factors. This argues against the application to different galaxy
populations of a universal standard [C I] abundance derived from highly biased
samples.Comment: 14 pages + Appendix. Accepted for publication in ApJ. All the data
tables in Appendix will be also released in electronic forma
T-duality and Differential K-Theory
We give a precise formulation of T-duality for Ramond-Ramond fields. This
gives a canonical isomorphism between the "geometrically invariant" subgroups
of the twisted differential K-theory of certain principal torus bundles. Our
result combines topological T-duality with the Buscher rules found in physics.Comment: 23 pages, typos corrected, submitted to Comm.Math.Phy
Ambiguous Tests of General Relativity on Cosmological Scales
There are a number of approaches to testing General Relativity (GR) on linear
scales using parameterized frameworks for modifying cosmological perturbation
theory. It is sometimes assumed that the details of any given parameterization
are unimportant if one uses it as a diagnostic for deviations from GR. In this
brief report we argue that this is not necessarily so. First we show that
adopting alternative combinations of modifications to the field equations
significantly changes the constraints that one obtains. In addition, we show
that using a parameterization with insufficient freedom significantly tightens
the apparent theoretical constraints. Fundamentally we argue that it is almost
never appropriate to consider modifications to the perturbed Einstein equations
as being constraints on the effective gravitational constant, for example, in
the same sense that solar system constraints are. The only consistent
modifications are either those that grant near-total freedom, as in
decomposition methods, or ones which map directly to a particular part of
theory space
The Bright and Dark Sides of High-Redshift starburst galaxies from {\it Herschel} and {\it Subaru} observations
We present rest-frame optical spectra from the FMOS-COSMOS survey of twelve
\textit{Herschel} starburst galaxies, with Star Formation Rate
(SFR) elevated by 8, on average, above the star-forming Main Sequence
(MS). Comparing the H to IR luminosity ratio and the Balmer Decrement
we find that the optically-thin regions of the sources contain on average only
percent of the total SFR whereas percent comes from an
extremely obscured component which is revealed only by far-IR observations and
is optically-thick even in H. We measure the [NII]/H
ratio, suggesting that the less obscured regions have a metal content similar
to that of the MS population at the same stellar masses and redshifts. However,
our objects appear to be metal-rich outliers from the metallicity-SFR
anticorrelation observed at fixed stellar mass for the MS population. The
[SII]/[SII] ratio from the average spectrum indicates an
electron density , larger than what
estimated for MS galaxies but only at the 1.5 level. Our results
provide supporting evidence that high- MS outliers are the analogous of
local ULIRGs, and are consistent with a major merger origin for the starburst
event.Comment: 6 pages, 4 figures, Accepted for publication in ApJ Letter
Characteristics of leptospirosis patients admitted to a tropical university hospital during the 2000 to 2010 period
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