205 research outputs found
Effect of elevated inorganic carbon on the cytosolic homeostasis of NO3- in the marine angiosperm Posidonia oceanica (L.) Delile
The marine angiosperm Posidonia oceanica is a mediterranean endemism of great ecological significance. As other marine plants, P. oceanica has adapted secondarily to the marine environment and develop anew different mechanisms to colonize it. Among others, this plant has developed a plasma membrane system for the direct uptake of bicarbonate. In this work we have developed both NO3- and Cl- selective microelectrodes for the continuous monitoring of the intracellular (cytosolic) NO3- and Cl-. In the light, leaf mesophyll cells show a cytosolic NO3- concentration of 5.7±0.2 mM (n=10), while in the dark cytosolic NO3- raises up to 8.7±1.1 mM; these values are in the range of concentrations quoted for Arabidopsis thaliana (Cookson et al., 2005). The enrichment of natural seawater (NSW) with 3 mM NaHCO3 caused a decrease of the cytosolic NO3- concentration of 1 mM and a decrease of the cytosolic concentration of Cl- of 3.5 mM. The saturation of NSW with 1000 µL CO2 L-1 produced a lower diminution of the cytosolic NO3- (0.3 mM). In the presence of 0.1 mM of the plasma membrane permeable inhibitor of the carbonic anhydrase (EZ) the diminution of cytosolic NO3- caused by the same concentration of CO2 was much lower, 0.1 mM. The addition of inorganic carbon, either HCO3- or CO2, has an effect on the cytosolic mechanisms for anionic homeostasis, one of which is the opening of the slow anion channels. These channels are permeable to NO3- and Cl- and could elicit the efflux of these ions. In P. oceanica, the response in the presence of EZ points out that the inorganic carbon species that cause the NO3-/Cl- efflux is HCO3-. This effect could contribute to plant biomass N dilution observed in elevated CO2.
References:
Cookson et al. 2005. Plant Physiology 138, 1097–1105.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
HCO3- enrichment causes cytosolic NO3- efflux in Posidonia oceanica leaf cells
Posidonia oceanica is a seagrass, the only group of vascular plants to colonize the marine environment. Seawater is an extreme yet stable environment, characterized by high salinity, alkaline pH and low availability of essential nutrients, such as nitrate or phosphate. In addition, in aquatic environments the supply of CO2 for the photosynthesis is limited by diffusion and therefore many aquatic plants use HCO3- as the inorganic carbon source for photosynthesis. Previous results have shown that Na+ -dependent transport systems operate on the plasma membrane of P. oceanica mesophyll leaf cells for the high-affinity NO3-, Pi or amino acids uptake. Also, a direct transport of HCO3- driven by H+ has been found in this species that provides inorganic carbon for photosynthesis and could be a significant component of a carbon concentrating mechanism in this species. Interestingly, this HCO3- direct uptake caused the efflux of chloride from the cytosol, probably through S-type anion channels, pointing that other anions could also be removed from the cytosol. This hypothesis could be relevant in the case of NO3-, since the decrease of cytosolic NO3- in response to HCO3- enrichment could limit N-assimilation. Here we analyse the effect of HCO3- increase on NO3- uptake and cytosolic homeostasis in P. oceanica. Enrichment of natural seawater with 3 mM HCO3- evokes the on-going decrease of cytosolic NO3-, from 5.7 ± 0.2 to 4.8 ± 0.7 mM after 40 min of treatment. The incubation of P. oceanica leaf pieces in 3 mM HCO3- NSW causes an initial increase of NO3- concentration in the medium. Maximum efflux (21 nmol NO3- gFM-1 min-1) occurs within the first minute of incubation. Then, external NO3- is depleted from the medium at lower net uptake rate than the value observed in non HCO3- -enriched natural seawater. These results fit the hypothesis that HCO3- enrichment causes the nitrogen loose and could impair nitrogen assimilation promoting N biomass impoverishment.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
Spanish MINECO, projects BFU2017-85117-R and BIO2016-81957-RED
Na+-dependent NO3- uptake in leaf cells of the seagrass Posidonia oceanica (L.) Delile
Posidonia oceanica (L.) Delile is an endemic Mediterranean seagrass of recognized ecological significance and, as other seagrasses, this species has secondarily adapted to live in the marine environment. In this alkaline medium with a high Na+ concentration (0.5 M), the high inwardly directed electrochemical potential gradient for sodium is used in the seagrass Zostera marina to energize the uptake of nitrate1 and phosphate that usually occur at concentration below 10 µM. Here we summarize several evidences for the operation of a sodium-dependent high-affinity nitrate transport system at the plasma membrane of the mesophyll leaf cells of P. oceanica.
Leaf cells of P. oceanica possess a H+-ATPase as a primary pump, exhibit a plasma membrane potential (Em) of -174 ± 10 mV and show reduced Na+ permeability. The addition of micromolar nitrate concentrations induces membrane depolarizations that show saturation kinetics. Curve fitting of the values renders a semisaturation constant (Km) of 21.3 ± 6.6 μM and a maximum depolarization (Dmax) of 7 ± 1 mV. In dark conditions, Dmax decreases by fifty percent but no significant effect is observed on the Km value. On the other hand, nitrate induced depolarizations show sodium dependence. The depolarizations induced by 100 µM NO3- in media containing increasing Na+ concentrations (from 0 to 250 mM) show saturation kinetics, rendering a Km value of 16 ± 5 mM Na+. Moreover, the depolarization induced by 100 µM NO3- is accompanied by a simultaneous increase of cytosolic sodium, measured by Na+-sensitive microelectrodes, of 0.4 ± 0.2 mM above the resting cytosolic sodium concentration (17 ± 2 mM).
Finally, nitrate uptake rates, measured in depletion experiments, decreases by 50% and 80% in dark conditions and in the absence of Na+, respectively, compared with control conditions (0.5 M Na+ and light).
All together, these results strongly suggest that NO3- uptake in P. oceanica leaf cells is mediated by a high-affinity nitrate carrier that uses Na+ as the driving ion.
1 Rubio et al. (2005). J. Exp. Bot, 412: 613-622.
Project Funding: CTM 2011-30356. (MEC)Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
More cat than cute? Interpretable Prediction of Adjective-Noun Pairs
The increasing availability of affect-rich multimedia resources has bolstered
interest in understanding sentiment and emotions in and from visual content.
Adjective-noun pairs (ANP) are a popular mid-level semantic construct for
capturing affect via visually detectable concepts such as "cute dog" or
"beautiful landscape". Current state-of-the-art methods approach ANP prediction
by considering each of these compound concepts as individual tokens, ignoring
the underlying relationships in ANPs. This work aims at disentangling the
contributions of the `adjectives' and `nouns' in the visual prediction of ANPs.
Two specialised classifiers, one trained for detecting adjectives and another
for nouns, are fused to predict 553 different ANPs. The resulting ANP
prediction model is more interpretable as it allows us to study contributions
of the adjective and noun components. Source code and models are available at
https://imatge-upc.github.io/affective-2017-musa2/ .Comment: Oral paper at ACM Multimedia 2017 Workshop on Multimodal
Understanding of Social, Affective and Subjective Attributes (MUSA2
Plan de gestión fundamentado en la teoría de adaptación de Callista Roy. Centro quirúrgico, hospital base Almanzor Aguinaga Asenjo Essalud. Chiclayo, 2015
El crecimiento en el ámbito de atención de los asegurados, ha repercutido también en el Centro Quirúrgico, donde la demanda supera la oferta; esto presupone un concepto más idóneo de lo que significa la Gestora de los Servicios de Enfermería, dentro de la organización; su responsabilidad implica, conocimientos de la ciencia propia y administrativa, que garanticen el cuidado humano, seguro y digno; objetivo que se plasma administrativamente, en el presente Plan de Gestión. El cual está fundamentado en la Teoría de Adaptación de Callista Roy, concordante a la función gestora de la enfermera, quien demandan una rápida adaptación a su entorno para responder con eficiencia a los problemas del cotidiano, en bien de la integridad de la persona usuaria del Centro Quirúrgico del Hospital Base Almanzor Aguinaga Asenjo - EsSalud Chiclayo.2015. Para su realización intervinieron sus propios ejecutores, los trabajadores, quienes con su valioso aporte, lo hicieron más real, objetivo y participativo. El aporte Teórico - Administrativo fue Elton Mayo y su Teoría de las Relaciones Humanas. La identificación de los problemas se realizó con el método FODA, que permitió determinar los objetivos estratégicos del plan de gestión. La priorización de los seis problemas se determinó utilizando el método de Ponderación, determinando los objetivos, actividades, indicadores y cronograma de cumplimiento de cada actividad del Plan de Gestión de Enfermería. La Supervisión, control y monitoreo propone indicadores porcentuales de cumplimiento. Todo el proceso ha sido actuado bajo principios científicos de investigación, y de la ética personalista de E. Sgreccia
The problem of living in the sea: the uptake of inorganic carbon and nutrients in Posidonia oceanica (L.) Delile
The genus Posidonia exhibits a peculiar geographical distribution. It is composed by nine species, eight of which are distributed along the Australian coasts and only one, Posidonia oceanica (L.) Delile, is a Mediterranean endemism. Like other angiosperms, P. oceanica has adapted secondarily to the marine environment, and has developed anew mechanisms to face a liquid and alkaline medium (pH 8.2) that contains a high salt concentration (0.5 M NaCl). The liquid environment limits the diffusive flow of CO2 and nutrients and, furthermore, CO2 dissolves in water and forms HCO3-, the more abundant chemical species of inorganic carbon at pH 8.2.
Like other green plants P. oceanica uses CO2 for photosynthesis. In addition, this species shows a transport system in the plasma membrane for the direct uptake of HCO3-, that uses H+ as the driving ion. The addition of HCO3- provokes a transient hyperpolarization of the plasma membrane followed by a depolarization; at the same time, the cytosolic pH (pHc) becomes transiently acidic and next it gets alkaline, and remains alkaline throughout the HCO3- pulse. The alkalinization of the pHc is due to the cytosolic accumulation of HCO3- and OH- and it is sensitive to the addition of ethoxyzolamide, an inhibitor of the internal carbonic anhydrase. The increase of negative charges in the cytosol triggers the release of Cl- to recover the values of the resting membrane potential. The plasmalemma of P. oceanica exhibits a reduced Na+ permeability and shows a H+/Na+ antiporter activity that keeps low and relatively constant the cytosolic Na+ concentration (17 mM Na+). The inside negative membrane potential (-178 mV) and the low [Na+]c generate a tremendous Na+-motive force that this plant uses for the high affinity transport of NO3- (Km= 21 µM), and of the amino acids alanine (Km= 37 µM) and cysteine (Km= 10 µM). The uptake of these compounds shows a strict dependence on the presence of Na+ in the medium. Moreover, the addition of micromolar concentrations of NO3-, alanine or cysteine gives rise to millimolar increments of [Na+]c. Experiments with external LIX pH mini-electrodes show that the uptake of glucose is not Na+ but H+ dependent. Thus, the model for the ion transport energization in this species seems to be mixed, with a H+-ATPase as the primary pump and a series of carriers that use H+ (HCO3-, Na+, glucose) or Na+ (NO3-, amino acids) as the driving ion.
Project Funding: CTM 2011-30356 (MEC)Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Características da informação bibliográfica relevante para um grupo de pesquisa obtidas através de sua produção científica publicada: um estudo de caso
Estuda um grupo de pesquisa em física situado numa pequena cidade brasileira. Examina exaustivamente a literatura publicada por esse grupo num período de 30 anos, objetivando conhecer e caracterizar o suporte bibliográfico indispensável no período e sua disponibilidade. Obteve-se a distribuição dos títulos de periódicos onde os artigos foram publicados e dos artigos citados, relacionando-os com as linhas de pesquisa desenvolvidas e com informações sobre as próprias revistas. Entrevistas com pesquisadores escolhidos, segundo critérios previamente definidos, confirmaram e complementaram os resultados.
Characteristics of relevant bibliographic information for a research group through its published scientific literature: a case study
Abstract
A research group in physics located in a small city in Brazil is studied. The literature published by the group during thirty years is exhaustively analyzed, aiming to identify the bibliographical support needed in the period and its availability. The distribution of the journal titles where the group published and the ones they cited was obtained and related to the lines of research developed and with information about the journal titles themselves. Interviews with researchers especially selected against criteria previously defined confirmed and complemented the results
Peripartum Takotsubo Cardiomyopathy: A Review and Insights from a National Registry
Periparto; Pronóstico; Síndrome de TakotsuboPeripart; Pronòstic; Síndrome de TakotsuboPeripartum; Prognosis; Takotsubo syndromeTakotsubo syndrome (TTS) during the peripartum period is a relevant cause of morbidity in this population; its clinical course and prognosis, compared to the general TTS population, is yet to be elucidated. Our aim was to analyze the clinical features and prognosis of peripartum TTS in a nationwide prospective specifically oriented registry database and consider the published literature. Peripartum TTS patients from the prospective nationwide RETAKO registry—as well as peripartum TTS patients from the published literature—were included, and multiple comparisons between groups were performed in order to assess for statistically and clinically relevant prognostic differences between the groups. Patients with peripartum TTS exhibit a higher prevalence of secondary forms, dyspnea, atypical symptoms, and echocardiographic patterns, as well as less ST-segment elevation than the general TTS population. In the literature, patients with peripartum TTS had a higher Killip status on admission. TTS during the peripartum period has a higher prevalence of angina and dyspnea, as well as physical triggers, neither of which are related to a worse prognosis. Killip status on admission was higher in the literature for patients with TTS but with excellent mid- and long-term prognoses after the acute phase, despite mostly being secondary forms.This research received no external funding. The web page from the RETAKO registry has been funded with the help of a non-conditional grant from AstraZeneca
Efficient routes to racemic and enantiomerically pure (S)-BINOL diesters
A systematic study for esterification procedures to the synthesis of BINOL diesters is described. Reaction conditions with TFAA and 85% H3PO4 were selected as the best procedure to prepare enantiomerically pure (S)-BINOL diesters VIII to XI with almost quantitative yields and very low reaction times.Fil: Costantino, Andrea Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Ocampo, Romina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Montiel Schneider, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Fernandez, Gustavo Adrian. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; ArgentinaFil: Koll, Liliana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur; ArgentinaFil: Mandolesi, Sandra Delia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto de Química del Sur; Argentina. Universidad Nacional del Sur. Fundacion de la Universidad Nacional del Sur; Argentin
- …