73 research outputs found
An integrated analysis of functional and genetic diversity in depicting the adaptive strategies of plants. The case study of Silene paradoxa.
Intraspecific trait variability and genetic diversity in the adaptive strategies of serpentine and non-serpentine populations of Silene paradoxa L
Effects of Wood Distillate (Pyroligneous Acid) on the Yield Parameters and Mineral Composition of Three Leguminous Crops
The excessive use of chemical fertilizers and pesticides in agriculture is increasing the demand for novel products to improve the quality of crops in a more sustainable way. Wood distillate (WD, pyroligneous acid) is a by-product obtained during the pyrolysis of plant biomass that can be successfully applied in agriculture due to its ability to enhance the growth, size, and weight of edible plant parts. However, there is little information concerning its plant yield-promoting effects on leguminous crops. The present work investigated the effects of WD on the yield, protein content and mineral composition of chickpea (Cicer arietinum L.), lentil (Lens culinaris L.) and bean (Phaseolus vulgaris L.) plants grown in field conditions. The application of WD showed remarkable yield-promoting effects mostly in lentil plants, which significantly increased plant and shoot biomass, the number and weight of both pods and seeds, as well as the total seed protein content. Furthermore, seeds from WD-treated plants differentially increased the concentration of elements with high nutritional value for human health, including Fe, Ca, Mg and K. These results suggest that the effects of WD among the legumes tested are species-specific and that WD could be an optimal candidate to grow high-yielding legumes with improved seed nutritional quality
The GUAPOS project: G31.41+0.31 Unbiased ALMA sPectral Observational Survey. IV. Phosphorus-bearing molecules and their relation with shock tracers
The astrochemistry of the important biogenic element phosphorus (P) is still
poorly understood, but observational evidence indicates that P-bearing
molecules are likely associated with shocks. We study P-bearing molecules, as
well as some shock tracers, towards one of the chemically richest hot molecular
core, G31.41+0.31, in the framework of the project "G31.41+0.31 Unbiased ALMA
sPectral Observational Survey" (GUAPOS), observed with the Atacama Large
Millimeter Array (ALMA). We have observed the molecules PN, PO, SO, SO2, SiO,
and SiS, through their rotational lines in the spectral range 84.05-115.91 GHz,
covered by the GUAPOS project. PN is clearly detected while PO is tentatively
detected. The PN emission arises from two regions southwest of the hot core
peak, "1" and "2", and is undetected or tentatively detected towards the hot
core peak. the PN and SiO lines are very similar both in spatial emission
morphology and spectral shape. Region "1" is in part overlapping with the hot
core and it is warmer than region "2", which is well separated from the hot
core and located along the outflows identified in previous studies. The column
density ratio SiO/PN remains constant in regions "1" and "2", while SO/PN,
SiS/PN, and SO2/PN decrease by about an order of magnitude from region "1" to
region "2", indicating that SiO and PN have a common origin even in regions
with different physical conditions. Our study firmly confirms previous
observational evidence that PN emission is tightly associated with SiO and it
is likely a product of shock-chemistry, as the lack of a clear detection of PN
towards the hot-core allows to rule out relevant formation pathways in hot gas.
We propose the PN emitting region "2" as a new astrophysical laboratory for
shock-chemistry studiesComment: 15 pages, 11 figures, accepted for publication in A&
Amides inventory towards the G+0.693-0.027 molecular cloud
Interstellar amides have attracted significant attentions as they are
potential precursors for a wide variety of organics essential to life. However,
our current understanding of their formation in space is heavily based on
observations in star-forming regions and hence the chemical networks lack the
constraints on their early origin. In this work, unbiased sensitive spectral
surveys with IRAM 30m and Yebes 40m telescopes are used to systematically study
a number of amides towards a quiescent Galactic Centre molecular cloud,
G+0.693-0.027. We report the first detection of acetamide (CH3C(O)NH2) and
trans-N-methylformamide (CH3NHCHO) towards this cloud. In addition, with the
wider frequency coverage of the survey, we revisited the detection of formamide
(NH2CHO) and urea (carbamide; NH2C(O)NH2), which had been reported previously
towards G+0.693-0.027. Our results are compared with those present in the
literature including recent laboratory experiments and chemical models. We find
constant abundance ratios independently of the evolutionary stages, suggesting
that amides related chemistry is triggered in early evolutionary stages of
molecular cloud and remain unaffected by the warm-up phase during the star
formation process. Although a correlation between more complex amides and
NH2CHO have been suggested, alternative formation routes involving other
precursors such as acetaldehyde (CH3CHO), methyl isocyanate (CH3NCO) and
methylamine (CH3NH2) may also contribute to the production of amides.
Observations of amides together with these species towards a larger sample of
sources can help to constrain the amide chemistry in the interstellar medium.Comment: 16 pages, 8 figures, 3 tables, accepted for publication in Monthly
Notices of the Royal Astronomical Societ
The first detection of SiC in the interstellar medium
We report the first detection of SiC in the interstellar medium. The
molecule was identified through six rotational transitions toward
G\,+0.6930.027, a molecular cloud located in the Galactic center. The
detection is based on a line survey carried out with the GBT, the Yebes 40m,
and the IRAM 30m telescopes covering a range of frequencies from 12 to 276 GHz.
We fit the observed spectra assuming local thermodynamic equilibrium and derive
a column density of ( cm, which gives a
fractional abundance of with respect to H, and an
excitation temperature of K. We conclude that SiC can be formed
in the shocked gas by a reaction between the sputtered atomic silicon and
CH, or it can be released directly from the dust grains due to
disruption. We also search for other Si-bearing molecules and detect eight
rotational transitions of SiS and four transitions of SiO. The derived
fractional abundances are and ,
respectively. All Si-bearing species toward G\,+0.6930.027 show fractional
abundances well below what is typically found in late-type evolved stars.Comment: 8 pages, 5 figure
Laser Cooling of Optically Trapped Molecules
Calcium monofluoride (CaF) molecules are loaded into an optical dipole trap
(ODT) and subsequently laser cooled within the trap. Starting with
magneto-optical trapping, we sub-Doppler cool CaF and then load CaF
molecules into an ODT. Enhanced loading by a factor of five is obtained when
sub-Doppler cooling light and trapping light are on simultaneously. For trapped
molecules, we directly observe efficient sub-Doppler cooling to a temperature
of . The trapped molecular density of
cm is an order of magnitude greater than in the initial sub-Doppler
cooled sample. The trap lifetime of 750(40) ms is dominated by background gas
collisions.Comment: 5 pages, 5 figure
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