9 research outputs found
Vegetative growth response of young olive trees (Olea europaea L., cv. Arbequina) to soil salinity and waterlogging
28 Pag., 10 Fig. The definitive version is available at: http://www.springerlink.com/content/0032-079x/High-density olive orchards are increasing around the world, many of which may be potentially affected by salinity and waterlogging (hypoxia), two important stresses common in irrigated fields in arid and semi-arid climates. However, the response of olive to these stresses under field conditions is not well established. Therefore, our objective was to evaluate the vegetative growth response of young olive trees (Olea europaea L., cv. Arbequina) grown in a spatially-variable waterlogged, saline-sodic field. We monitored the growth in trunk diameter of 341 three-year’s old olives between September 1999 and September 2000. Field contour maps were developed delineating soil salinity (ECa), relative ground elevation (RGE) and water table depth (WTD). Soil samples were also collected and analyzed for ECe and SARe in order to characterize the salinity and sodicity profiles and develop the ECa-ECe calibration equation. The infiltration rate (IR) of the crusted and uncrusted soil and the penetration resistance (PR) were also measured. The field was characterized by spatially variable ECe (2 to 15 dS m-1), SARe (3 to 40), RGE (-4 to +4 cm) and WTD (0.5 to 1.9 m, with corresponding ground water EC values between 12 and 6 dS m-1). Steady-state IR of crusted soil was only 7% of the uncrusted soil. Since the field was heavily irrigated by flooding, waterlogging conditions were related to low RGE values. Soil salinity was negatively correlated (R2 = 0.83, P 10 dS m-1), low RGE ( 0.1 cm and > 1.6 m, respectively. Thus, very small changes in ground elevation had a significant effect on olive’s survival or death. The coupled effects of salinity and waterlogging (hypoxia) stresses were most detrimental for olive’s growth.This study was partially supported by INIA (Instituto Nacional de Investigación y TecnologÃa Agraria y Alimentaria, Spain).Peer reviewe
Methyltransferase-directed covalent coupling of fluorophores to DNA
Highly efficient DNA labelling using an enzymatically-directed, strain-promoted azide–alkyne cycloaddition.</p
Static and dynamic bimolecular fluorescence quenching of porphyrin dendrimers in solution
The fluorescence quenching kinetics of two porphyrin dendrimer series (GnTPPH(2) and GnPZn) by different type of quenchers is reported. The microenvironment surrounding the core in GnPZn was probing by core-quencher interactions using benzimidazole. The dependence of quencher binding constant (K(a) ) on generation indicates the presence of a weak interaction between branches and the core of the porphyrin dendrimer. The similar free volume in dendrimers of third and fourth generation suggests that structural collapse in high generations occurs by packing of the dendrimer peripheral layer. Dynamic fluorescence quenching of the porphyrin core by 1,3-dicyanomethylene-2-methyl-2-pentyl-indan (PDCMI) in GnTPPH(2) is a distance dependent electron transfer process with an exponential attenuation factor beta=0.33 angstrom(-1). The quenching by 1,2-dibromobenzene occurs by diffusion process of the quencher toward to the porphyrin core, and its rate constant is practically independent of dendrimer generation.FAPESPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)CNP
Simplifying Electronic Data Capture in Clinical Trials : Workflow Embedded Image and Biosignal File Integration and Analysis via Web Services
To improve data quality and save cost, clinical trials are nowadays performed using electronic data capture systems (EDCS) providing electronic case report forms (eCRF) instead of paper-based CRFs. However, such EDCS are insufficiently integrated into the medical workflow and lack in interfacing with other study-related systems. In addition, most EDCS are unable to handle image and biosignal data, although electrocardiography (EGC, as example for one-dimensional (1D) data), ultrasound (2D data), or magnetic resonance imaging (3D data) have been established as surrogate endpoints in clinical trials. In this paper, an integrated workflow based on OpenClinica, one of the world’s largest EDCS, is presented. Our approach consists of three components for (i) sharing of study metadata, (ii) integration of large volume data into eCRFs, and (iii) automatic image and biosignal analysis. In all components, metadata is transferred between systems using web services and JavaScript, and binary large objects (BLOBs) are sent via the secure file transfer protocol and hypertext transfer protocol. We applied the close-looped workflow in a multicenter study, where long term (7 days/24 h) Holter ECG monitoring is acquired on subjects with diabetes. Study metadata is automatically transferred into OpenClinica, the 4 GB BLOBs are seamlessly integrated into the eCRF, automatically processed, and the results of signal analysis are written back into the eCRF immediately
BioX ++ - New Results and Conceptions Concerning the Intelligent Control of Biotechnological Processes
Methyltransferase-directed covalent coupling of fluorophores to DNA
We report an assay for determining the number of fluorophores conjugated to single plasmid DNA molecules and apply this to compare the efficiency of fluorophore coupling strategies for covalent DNA labelling. We compare a copper-catalyzed azide-alkyne cycloaddition reaction, amine to N-hydroxysuccinimidyl ester coupling reaction and strain-promoted azide-alkyne cycloaddition reaction for fluorescent DNA labelling. We found increased labelling efficiency going from the amine to N-hydroxysuccinimidyl ester coupling reaction to the copper-catalyzed azide-alkyne cycloaddition and found the highest degree of DNA labelling with the strain-promoted azide-alkyne cycloaddition reaction. We also examined the effect of labelling on the DNA structure using atomic force microscopy. We observe no distortions or damage to the DNA that was labeled using the amine to N-hydroxysuccinimidyl ester and strain-promoted azide-alkyne cycloaddition coupling reactions. This was in contrast to the copper-catalyzed azide-alkyne cycloaddition reaction, which, despite the use of copper-coordinating ligands in the labelling mixture, leads to some structural DNA damage (single-stranded DNA breaks).crosscheck: This document is CrossCheck deposited
related_data: Supplementary Information
identifier: Milena Helmer Lauer (ORCID)
identifier: Milena Helmer Lauer (ResearcherID)
identifier: Jochem Deen (ORCID)
identifier: Marcelo H. Gehlen (ResearcherID)
identifier: Johan Hofkens (ORCID)
identifier: Robert K. Neely (ORCID)
identifier: Robert K. Neely (ResearcherID)
copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal
copyright_licence: This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0)
history: Received 21 September 2016; Accepted 13 March 2017; Accepted Manuscript published 14 March 2017; Advance Article published 21 March 2017; Version of Record published 3 May 2017status: publishe