310 research outputs found

    Regulation of calmodulin gene expression by nuclear calcium in plants

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    Atmospheric H<sub>2</sub>S exposure does not affect stomatal aperture in maize

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    Main conclusion: Stomatal aperture in maize is not affected by exposure to a subtoxic concentration of atmospheric H2S. At least in maize, H2S, thus, is not a gaseous signal molecule that controls stomatal aperture. Abstract: Sulfur is an indispensable element for the physiological functioning of plants with hydrogen sulfide (H2S) potentially acting as gasotransmitter in the regulation of stomatal aperture. It is often assumed that H2S is metabolized into cysteine to stimulate stomatal closure. To study the significance of H2S for the regulation of stomatal closure, maize was exposed to a subtoxic atmospheric H2S level in the presence or absence of a sulfate supply to the root. Similar to other plants, maize could use H2S as a sulfur source for growth. Whereas sulfate-deprived plants had a lower biomass than sulfate-sufficient plants, exposure to H2S alleviated this growth reduction. Shoot sulfate, glutathione, and cysteine levels were significantly higher in H2S-fumigated plants compared to non-fumigated plants. Nevertheless, this was not associated with changes in the leaf area, stomatal density, stomatal resistance, and transpiration rate of plants, meaning that H2S exposure did not affect the transpiration rate per stoma. Hence, it did not affect stomatal aperture, indicating that, at least in maize, H2S is not a gaseous signal molecule controlling this aperture

    Enterococcal surface protein Esp is not essential for cell adhesion and intestinal colonization of Enterococcus faecium in mice

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    <p>Abstract</p> <p>Background</p> <p><it>Enterococcus faecium </it>has globally emerged as a cause of hospital-acquired infections with high colonization rates in hospitalized patients. The enterococcal surface protein Esp, identified as a potential virulence factor, is specifically linked to nosocomial clonal lineages that are genetically distinct from indigenous <it>E. faecium </it>strains. To investigate whether Esp facilitates bacterial adherence and intestinal colonization of <it>E. faecium</it>, we used human colorectal adenocarcinoma cells (Caco-2 cells) and an experimental colonization model in mice.</p> <p>Results</p> <p>No differences in adherence to Caco-2 cells were found between an Esp expressing strain of <it>E. faecium </it>(E1162) and its isogenic Esp-deficient mutant (E1162Δ<it>esp</it>). Mice, kept under ceftriaxone treatment, were inoculated orally with either E1162, E1162Δ<it>esp </it>or both strains simultaneously. Both E1162 and E1162Δ<it>esp </it>were able to colonize the murine intestines with high and comparable numbers. No differences were found in the contents of cecum and colon. Both E1162 and E1162Δ<it>esp </it>were able to translocate to the mesenteric lymph nodes.</p> <p>Conclusion</p> <p>These results suggest that Esp is not essential for Caco-2 cell adherence and intestinal colonization or translocation of <it>E. faecium </it>in mice.</p

    Cognitive predictors of children’s development in mathematics achievement: a latent growth modeling approach

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    Research has identified various domain-general and domain-specific cognitive abilities as predictors of children’s individual differences in mathematics achievement. However, research into the predictors of children’s individual growth rates, i.e., between-person differences in within-person change, in mathematics achievement is scarce. We assessed 334 children’s domain-general and mathematics-specific early cognitive abilities and their general mathematics achievement longitudinally across four time-points within the 1st and 2nd grade of primary school. As expected, a constellation of multiple cognitive abilities contributed to the children’s starting level of mathematical success. Specifically, latent growth modeling revealed that WM abilities, IQ, counting skills, nonsymbolic and symbolic approximate arithmetic and comparison skills explained individual differences in the children’s initial status on a curriculum-based general mathematics achievement test. Surprisingly, however, only one out of all the assessed cognitive abilities was a unique predictor of the children’s individual growth rates in mathematics achievement: their performance in the symbolic approximate addition task. In this task, children were asked to estimate the sum of two large numbers and decide if this estimated sum was smaller or larger compared to a third number. Our findings demonstrate the importance of multiple domain-general and mathematics-specific cognitive skills for identifying children at risk of struggling with mathematics and highlight the significance of early approximate arithmetic skills for the development of one’s mathematical success. We argue the need for more research focus on explaining children’s individual growth rates in mathematics achievement

    Frequency of occurrence of medication discrepancies and associated risk factors in cases of acute hospital admission

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    Background: Medication discrepancies are a common occurrence following hospital admission and carry the potential for causing harm. However, little is known about the potential risk factors involved in medication discrepancies. Objective: The objective of this study was to determine how frequently medication discrepancies occur and their associated risk factors, in patients hospitalized via the emergency department of the Spaarne Gasthuis Hospital, located in The Netherlands. Methods: This retrospective observational study examines 832 hospital admissions which took place between April 1st and June 30th, 2015. Medication reconciliation was performed within 24 hours of admission and medication discrepancies were registered. The primary outcome recorded in the study was the proportion of patients experiencing one or more medication discrepancies, as verified by the physician. As a secondary outcome, the association between these discrepancies and pre-specified variables was analyzed using univariate and multivariate logistic regression. Results: At least one medication discrepancy was found to have occurred with 97 of the 832 patients (11.7%), the most common discrepancies involving incorrect drug dose (44.9%) and omission of medication (36.4%). In the univariate analysis, age (OR=1.03 [95% CI 1.02:1.04] p<0.001) and number of pre-admission medications taken (OR=1.13 [95%CI 1.09:1.17] p<0.001) were revealed to be significantly associated with the risk of medication discrepancies. Sex, type of medical specialty, and surgical versus non-surgical specialty were found not to be significantly associated with discrepancies. In the multivariate analysis, both the number of pre-admission medications (OR=1.10 [95%CI 1.06:1.15] p<0.001) and age (OR=1.02 [95%CI 1.01:1.03] p=0.004) were independently associated with the risk of medication discrepancy. Conclusions: Of the total number of patients, 11.7% experienced one or more medication discrepancies following admission to the hospital. Elderly patients taking multiple drugs were found to be particularly at risk

    Anàlisi de l'empresa a partir de l'estat de fluxos d'efectiu

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    La finalitat bàsica d’aquesta tesi doctoral ha consistit en determinar d’una banda la rellevància de l’Estat de fluxos d’efectiu (EFE), dins de l’anàlisi d’estats comptables, demostrant que per poder realitzar una anàlisi complet de la situació patrimonial, econòmica i financera de l’empresa és imprescindible l’estudi i anàlisi de l’EFE i d’altra banda fer una proposta metodològica amb la finalitat de millorar l’actual estructura de l’EFE que ens presenta el Pla general de comptabilitat actual. Els objectius secundaris d’aquest treball d’investigació han estat determinar la importància de l’EFE en l’anàlisi de la situació financera a curt termini; demostrar la importància de l’activitat econòmica en l’estudi d’aquest document; i per últim demostrar la vàlua de la informació que aquest document aporta de forma individualitzada de les diferents activitats que l’empresa desenvolupa i sobre el grau d’interrelació existent entre elles.La finalidad básica de esta tesis doctoral ha consistido en determinar la relevancia del Estado de flujos de efectivo (EFE), dentro del análisis de estados contables, demostrando que para poder realizar un análisis completo de la situación patrimonial, económica y financiera de la empresa es imprescindible el estudio y análisis del EFE y por otro lado hacer una propuesta metodológica con el fin de mejorar la actual estructura del EFE que nos presenta el Plan general de contabilidad actual. Los objetivos secundarios de este trabajo de investigación han sido determinar la importancia del EFE en el análisis de la situación financiera a corto plazo; demostrar la importancia de la actividad económica en el estudio de este documento; y por último demostrar la importancia de la información que este documento aporta de forma individualizada de las diferentes actividades que la empresa desarrolla y sobre el grado de interrelación existente entre ellas

    Phospholipid Signaling Responses in Salt-Stressed Rice Leaves

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    Salinity is one of the major environmental factors limiting growth and productivity of rice plants. In this study, the effect of salt stress on phospholipid signaling responses in rice leaves was investigated. Leaf cuts were radiolabeled with 32P-orthophosphate and the lipids extracted and analyzed by thin-layer chromatography, autoradiography and phosphoimaging. Phospholipids were identified by co-migration of known standards. Results showed that 32Pi was rapidly incorporated into the minor lipids, phos-phatidylinositol bisphosphate (PIP2) and phosphatidic acid (PA) and, interestingly, also into the structural lipids phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), which normally label relatively slowly, like phosphatidylcholine (PC) and phosphatidylinositol (PI). Only very small amounts of PIP2 were found. However, in response to salt stress (NaCl), PIP2 levels rapidly (<30 min) increased up to 4-fold, in a time- and dose-dependent manner. PA and its phosphorylated product, diacylglyc-erolpyrophosphate (DGPP), also increased upon NaCl stress, while cardiolipin (CL) levels decreased. All other phospholipid levels remained unchanged. PA signaling can be generated via the combined action of phospholipase C (PLC) and diacylglycerol kinase (DGK) or directly via phospholipase D (PLD). The latter can be measured in vivo, using a transphosphatidylation assay. Interestingly, these measurements revealed that salt stress inhibited PLD activity, indicating that the salt stress-induced PA response was not due to PLD activity. Comparison of the 32P-lipid responses in salt-tolerant and salt-sensitive cultivars revealed no significant differences. Together these results show that salt stress rapidly activates several lipid responses in rice leaves but that these responses do not explain the difference in salt tolerance between sensitive and tolerant cultivars
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