5,885 research outputs found
Effect of agronomic and environmental factors on CO2 emissions on a dryland rotation
Agriculture is a substantial source of greenhouse gas emissions (GHG) in many countries.
Conservation agriculture includes soil management systems that help to reduce CO2 emission levels.
However, there are many factors involved in the production of these emissions such as soil management type and time at which the agriculture operations are performed, crop phenological state, the weather, and handling of the residue amongst others. In the long term, the relationships that exist between these factors seem to determine the balance of these emissions.
In this study, we analyzed the influence of the soil management system as well as the climatology of the different seasons studied and the phenological state of the different crops implanted.
For this purpose a field trial was conducted in Las Cabezas de San Juán (Seville). This pilot farm consisted of six experimental plots with an approximate area of 5 ha; conservation agriculture practices were employed in three of the six plots while traditional tillage management was used in the other three. Within these plots the three crops of the wheat-sunflower-legume rotation were tested simultaneously.
The study was conducted over four agricultural seasons - 2009/10, 2010/11, 2011/12 and 2012/13.
Each of these cropping seasons were characterised by very different rainfall amounts, registering a total of 814.4, 721.6, 268.2 and 676.4 l/m2, respectively.
When we studied the evolution of emissions over four seasons, an increase could be observed for
both management systems during the time in which the crops were established due to the roots respiration processes. These increases were heavily influenced by the rainfall recorded during the
time in which the crop was in place.
In the case of wheat, higher emissions were produced during the cultivation time of the first and fourth season during which 84% and 60% of the total rainfall of each season was recorded. These emissions were 9 and 5 kg CO2/ha for conventional tillage and no tillage, respectively for the 2009/10 season and 11.7 and 6.8 kg CO2/ha, respectively in the 2012/13 season. Conversely during the 2011/12 season, a season in which lower precipitation was registered, the higher emissions were comparatively minor with respect to the previous values, specifically 3.7 and 1.9 kg CO2/ha for non-tillage and conventional tillage
Molecular gas at supernova local environments unveiled by EDGE
CO observations allow estimations of the gas content of molecular clouds,
which trace the reservoir of cold gas fuelling star formation, as well as to
determine extinction via H column density, N(H). Here, we studied
millimetric and optical properties at 26 supernovae (SNe) locations of
different types in a sample of 23 nearby galaxies by combining molecular
CO (J = 1 0) resolved maps from the EDGE survey and
optical Integral Field Spectroscopy from the CALIFA survey. We found an even
clearer separation between type II and type Ibc SNe in terms of molecular gas
than what we found in the optical using H emission as a proxy for
current SF rate, which reinforces the fact that SNe Ibc are more associated
with SF-environments. While A at SN locations is similar for SNe II and SNe
Ibc, and higher compared to SNe Ia, N(H) is significantly higher for SNe
Ibc than for SNe II and SNe Ia. When compared to alternative extinction
estimations directly from SN photometry and spectroscopy, we find that our SNe
Ibc have also redder color excess but showed standard Na I D absorption
pseudo-equivalent widths (1 \AA). In some cases we find no extinction
when estimated from the environment, but high amounts of extinction when
measured from SN observations, which suggests that circumstellar material or
dust sublimation may be playing a role. This work serves as a benchmark for
future studies combining last generation millimeter and optical IFS instruments
to reveal the local environmental properties of extragalactic SNe.Comment: MNRAS accepted, 17 pages, 8 Figures, 4 Table
Is there an association between sleep disorders and diabetic foot? A scoping review
Diabetic foot is associated with a low quality of life since physical disabilities, mood
disturbances and psychological disorders are frequent. One of the most important biological processes
to ensure quality of life is sleep. Sleep disorders can impair glycemic control in patients with
diabetes mellitus or even cause long-term type 2 diabetes mellitus. The aim of this study is to
carry out a scoping review about the association between sleep cycle disorders and diabetic foot.
PubMed, Scopus, CINAHL, PEDro, Cochrane Library, SCIELO and EMBASE databases were chosen
for the search and the following terms were used: “diabetic foot”,“sleep*”,“rest-activity”,“mood”
and“behavior”. All the studies should include outcome variables about sleep and diabetic foot.
Finally, 12 articles were selected, all of whichwere observational. The most frequent variables were
those regarding diabetic foot ulcer aspects and diabetic neuropathy on one side, and obstructive
sleep apnea, sleep duration and sleep quality on the other side. The results suggest that there is a
possible association between obstructive sleep apnea and the presence or history of diabetic foot
ulcers. No direct associations between sleep quality or sleep duration and diabetic foot or diabetic
foot ulcer variables have been found
Integral field spectroscopy of type-II QSOs at z=0.3-0.4
We present and analyse integral-field observations of six type-II QSOs with
z=0.3-0.4, selected from the Sloan Digital Sky Survey (SDSS). Two of our sample
are found to be surrounded by a nebula of warm ionized gas, with the largest
nebula extending across 8" (40 kpc). Some regions of the extended nebulae show
kinematics that are consistent with gravitational motion, while other regions
show relatively perturbed kinematics: velocity shifts and line widths too large
to be readily explained by gravitational motion. We propose that a ~20 kpc x20
kpc outflow is present in one of the galaxies. Possible mechanisms for
triggering the outflow are discussed. In this object, we also find evidence for
ionization both by shocks and the radiation field of the AGN.Comment: 6 pages, 5 figures, accepted by MNRAS Letter
Central star formation and metallicity in CALIFA interacting galaxies
We use optical integral-field spectroscopic (IFS) data from 103 nearby
galaxies at different stages of the merging event, from close pairs to merger
remnants provided by the CALIFA survey, to study the impact of the interaction
in the specific star formation and oxygen abundance on different galactic
scales. To disentangle the effect of the interaction and merger from internal
processes, we compared our results with a control sample of 80 non-interacting
galaxies. We confirm the moderate enhancement (2-3 times) of specific star
formation for interacting galaxies in central regions as reported by previous
studies; however, the specific star formation is comparable when observed in
extended regions. We find that control and interacting star-forming galaxies
have similar oxygen abundances in their central regions, when normalized to
their stellar masses. Oxygen abundances of these interacting galaxies seem to
decrease compared to the control objects at the large aperture sizes measured
in effective radius. Although the enhancement in central star formation and
lower metallicities for interacting galaxies have been attributed to tidally
induced inflows, our results suggest that other processes such as stellar
feedback can contribute to the metal enrichment in interacting galaxies.Comment: 9 pages, 9 figures. Accepted for publication in Astronomy &
Astrophysic
Influencia del riego deficitario controlado precosecha sobre la calidad de la cereza ´Prime Giant`
El uso de redes de sensores para el manejo del riego deficitario controlado (RDC) en
cerezo puede incidir en la mejora de la productividad del agua, calidad de la fruta y en su
comportamiento poscosecha, al permitir el conocimiento y control del estado hídrico del
suelo y árbol en todo momento.
En el primer año de ensayo, el riego deficitario aplicado en precosecha para
satisfacer el 85% de las necesidades máximas del cultivo (ETcg) permitió un ahorro de agua
del 17% (380 m3 ha-1) respecto al tratamiento control, que se regó al 110% de la ETcg. Este
déficit hídrico ligero no afectó a la producción (16,13 t ha-1) e incluso mejoró la calidad del
fruto. Así, en el momento de la cosecha (t0) los frutos bajo déficit ligero presentaron matices
más rojos y mayor acidez que los de riego completo. Esta mayor acidez no afectó al índice
de madurez debido a la compensación por sólidos solubles totales (SST). El carácter de
mayor acidez perduró tras 30 días de conservación en frio (t1) y 5 días de simulación de las
condiciones de comercialización (t2). Igualmente, los frutos bajo déficit hídrico presentaron
una tendencia a menores pérdidas de peso por deshidratación a finales de los periodos de
conservación en frio y de simulación de la comercialización.Ministerio de Economía y Competitividad AGL2013-49047-C2-1
Thrombosed great saphenous vein aneurysm accompanied by venous thrombosis
AbstractSuperficial venous aneurysms of the lower extremities are considered rare and their clinical significance is poorly defined. The purpose of this article is to report a case of a 72-year-old woman with a thrombosed great saphenous vein aneurysm along with deep venous thrombosis and review its clinical presentation, diagnosis and treatment
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