Determination of Soluble Sugars in Arabidopsis thaliana Leaves by Anion Exchange Chromatography

Determination of soluble sugars is basic for the study of carbon metabolism in plants. Soluble sugar quantitation can be achieved by enzymatic methods implying different coupled reactions. Here we describe a simple method that allows rapid determination of the most abundant soluble sugars (glucose, fructose and sucrose) in Arabidopsis leaves by anion exchange chromatography. We have applied this method to study the levels of soluble sugars during the photoperiodic transition to flowering (Ortiz-Marchena et al., 2014).España, MINECO projects CSD2007-00057, BIO2008-02292, and BIO2011-28847-C02-00España, Junta de Andalucía P06-CVI-01450 and P08-AGR-0358

Purification of Starch Granules from Arabidopsis Leaves and Determination of Granule-Bound Starch Synthase Activity

Starch constitutes the most important carbon reserve in plants and is composed of branched amylopectin and linear amylose. The latter is synthesized exclusively by the Granule-Bound Starch Synthase (GBSS, EC 2.4.1.21). Here we report a readily reproducible, specific and highly sensitive protocol, which includes the isolation of intact starch granules from Arabidopsis thaliana leaves and the subsequent determination of GBSS activity. We have applied this method to study GBSS activity in diurnal cycles in vegetative growth and during the photoperiodic transition to flowering in Arabidopsis (Tenorio et al., 2003; Ortiz-Marchena et al., 2014).España,MINECO CSD2007-00057, BIO2008-02292, and BIO2011-28847-C02-00España, Junta de Andalucía P06-CVI-01450 and P08-AGR-0358

Strong Anisotropy in Liquid Water upon Librational Excitation using Terahertz Laser Fields

Tracking the excitation of water molecules in the homogeneous liquid is challenging due to the ultrafast dissipation of rotational excitation energy through the hydrogen-bonded network. Here we demonstrate strong transient anisotropy of liquid water through librational excitation using single-color pump-probe experiments at 12.3 THz. We deduce a third order response of chi^3 exceeding previously reported values in the optical range by three orders of magnitude. Using a theory that replaces the nonlinear response with a material response property amenable to molecular dynamics simulation, we show that the rotationally damped motion of water molecules in the librational band is resonantly driven at this frequency, which could explain the enhancement of the anisotropy in the liquid by the external Terahertz field. By addition of salt (MgSO4), the hydration water is instead dominated by the local electric field of the ions, resulting in reduction of water molecules that can be dynamically perturbed by THz pulses

Present-day heat flow model of Mars

Until the acquisition of in-situ measurements, the study of the present-day heat flow of Mars must rely on indirect methods, mainly based on the relation between the thermal state of the lithosphere and its mechanical strength, or on theoretical models of internal evolution. Here, we present a first-order global model for the present-day surface heat flow for Mars, based on the radiogenic heat production of the crust and mantle, on scaling of heat flow variations arising from crustal thickness and topography variations, and on the heat flow derived from the effective elastic thickness of the lithosphere beneath the North Polar Region. Our preferred model finds heat flows varying between 14 and 25 mW m−2, with an average value of 19 mW m−2. Similar results (although about ten percent higher) are obtained if we use heat flow based on the lithospheric strength of the South Polar Region. Moreover, expressing our results in terms of the Urey ratio (the ratio between total internal heat production and total heat loss through the surface), we estimate values close to 0.7–0.75, which indicates a moderate contribution of secular cooling to the heat flow of Mars (consistent with the low heat flow values deduced from lithosphere strength), unless heat-producing elements abundances for Mars are subchondritic

Secondary use of data extracted from a clinical information system to assess the adherence of tidal volume and its impact on outcomes.

Objectives To extract data from clinical information systems to automatically calculate high-resolution quality indicators to assess adherence to recommendations for low tidal volume. Design We devised two indicators: the percentage of time under mechanical ventilation with excessive tidal volume (>8 mL/kg predicted body weight) and the percentage of patients who received appropriate tidal volume (≤8 mL/kg PBW) at least 80% of the time under mechanical ventilation. We developed an algorithm to automatically calculate these indicators from clinical information system data and analyzed associations between them and patients’ characteristics and outcomes. Settings This study has been carried out in our 30-bed polyvalent intensive care unit between January 1, 2014 and November 30, 2019. Patients All patients admitted to intensive care unit ventilated >72 h were included. Intervention Use data collected automatically from the clinical information systems to assess adherence to tidal volume recommendations and its outcomes. Main variables of interest Mechanical ventilation days, ICU length of stay and mortality. Results Of all admitted patients, 340 met the inclusion criteria. Median percentage of time under mechanical ventilation with excessive tidal volume was 70% (23%–93%); only 22.3% of patients received appropriate tidal volume at least 80% of the time. Receiving appropriate tidal volume was associated with shorter duration of mechanical ventilation and intensive care unit stay. Patients receiving appropriate tidal volume were mostly male, younger, taller, and less severely ill. Adjusted intensive care unit mortality did not differ according to percentage of time with excessive tidal volume or to receiving appropriate tidal volume at least 80% of the time. Conclusions Automatic calculation of process-of-care indicators from clinical information systems high-resolution data can provide an accurate and continuous measure of adherence to recommendations. Adherence to tidal volume recommendations was associated with shorter duration of mechanical ventilation and intensive care unit stay.pre-print1126 K

Multi-phase generators viability for offshore wind farms with HVDC transmission

Política de Open Access indicada en la web del editor. No aparece la revista en Sherpa/RomeoThe interest in offshore wind farms has experienced a significant growth in recent years. Technical knowledge allow the design of wind farms at higher distances, making the high voltage dc (HVDC) transmission a real alternative to current high voltage ac (HVAC) transmission. When the network is decoupled from the wind farm by a dc link, there is no need for a mandatory use of three-phase generator. To the contrary, multi-phase generators can be used and the wind farm can benefit from inherent advantages and recent developments of multi-phase drives. This preliminary study shows some of the potential advantages of the dual three-phase generators in wind energy conversion systems (WECS)

A study of nuclear effect in F3F_3 structure function in the deep inelastic ν(νˉ)\nu(\bar\nu) reactions in nuclei

We study nuclear effect in the $F^A_3(x)$ structure function in the deep inelastic neutrino reactions on iron by taking into account Fermi motion, binding, target mass correction, shadowing and anti-shadowing corrections. Calculations have been done in a local density approximation using relativistic nuclear spectral functions which include nucleon correlations for nuclear matter. Results for $F^A_3(x)$ have been compared with the results reported at NuTeV and also with some of the older experiments reported in the literature.Comment: 4Pages, 4 Figures To appear in the AIP Proceedings of the Sixth International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region, May 18th - 22nd, 2009 held at Sitges, Barcelona (Spain

Conserved gene modules regulate light signals in algae and plants

In the Plant Development Unit (PDU) we aim to discover mechanisms that allowed photosynthetic organisms to reach the level of developmental complexity shown today. Plants are particularly good models as they have been evolving as light autotrophs for millions of years, ever since the first bacteria developed oxygenic photosynthesis and killed 99% of existing species in the process. But light is not only the main source of energy for plants, it is also one of the main regulators of their development, as endo-symbiotic cyanobacteria (chloroplasts) perfected their physiological synchronization with the emerging eukaryotes (1). Another important aspect of plant evolution was the transit to the aerial world and the acquisition of characteristics that allowed them to successfully colonise this new habitat (2). In the PDU we have followed the evolution of the day length response (photoperiod) that coordinates the daily physiological activities of plants and can be also used to regulate seasonal behaviours such as winter recesses or flowering time (3). When gene expression networks from photoperiod experiments from microalgae, bryophytes and higher plants are compared, a common nodular structure is discovered (4). Following these discoveries, we have isolated ancestor algal genes that show the same function as higher plants in the response to photoperiod such as the CONSTANS-DOF module (5). We are currently investigating common regulatory mechanisms in photoperiod sensing such as the effect on the circadian clock, senescence, retrograde signalling (6) and protein stability (7