5,158 research outputs found

    Evaluating the pharmacological response in fluorescence microscopy images: The Δm algorithm

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    Current drug discovery procedures require fast and effective quantification of the pharmacological response evoked in living cells by agonist compounds. In the case of G-protein coupled receptors (GPCRs), the efficacy of a particular drug to initiate the endocytosis process is related to the formation of endocytic vesicles or endosomes and their subsequent internalisation within intracellular compartments that can be observed with high spatial and temporal resolution by fluorescence microscopy techniques. Recently, an algorithm has been proposed to evaluate the pharmacological response by estimating the number of endosomes per cell on time series of images. However, the algorithm was limited by the dependence on some manually set parameters and in some cases the quality of the image does not allow a reliable detection of the endosomes. Here we propose a simple, fast and automated image analysis method?the ?m algorithm- to quantify a pharmacological response with data obtained from fluorescence microscopy experiments. This algorithm does not require individual object detection and computes the relative increment of the third order moment in fluorescence microscopy images after filtering with the Laplacian of Gaussian function. It was tested on simulations demonstrating its ability to discriminate different experimental situations according to the number and the fluorescence signal intensity of the simulated endosomes. Finally and in order to validate this methodology with real data, the algorithm was applied to several time-course experiments based on the endocytosis of the mu opioid receptor (MOP) initiated by different agonist compounds. Each drug displayed a different ?m sigmoid time-response curve and statistically significant differences were observed among drugs in terms of efficacy and kinetic parameters

    In vitro regeneration of Calophyllum brasiliense Cambess: A valuable medicinal tree

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    Calophyllum brasiliense (Calophyllaceae) is a medicinal tree known mainly for producing calanolides, secondary metabolites against HIV-1 reverse transcriptase. This wild plant is listed as threatened and despite its outstanding medicinal value, no studies have been conducted on its propagation or preservation. This study standardized a procedure for the micropropagation of C. brasiliense with nodal segments from in vitro seedlings. The in vitro seed germination was 48.6%. The nodal explants displayed a high percentage of shoot induction (77.5%), shoots per segment (6.9), nodes per shoot (3.8), leaves per shoot (8.0) and shoot length (4.2 cm) when 0.5 mg L-1 indole-3-butyric acid plus 0.1 mg L-1 thidiazuron were used. Furthermore, maximum shoot rooting (63.5%) and root length (2.2 cm) were recovered using 1.0 mg L-1 indole-3-acetic acid. More than three-quarters of the acclimatized plants (77.5%) grew successfully in pots. Thus, this study developed an in vitro propagation protocol for C. brasiliense that can be used as a potential resource for restoring wild populations or performing phytopharmacological studies.Key words: Seed germination, plant growth regulators, micropropagation, nodal segments, medicinal plants

    New Physics effects in the flavor-changing neutral couplings of the Top quark

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    We survey the flavor-changing neutral couplings (FCNC) of the top quark predicted by some extensions of the Standard Model: THDM, SUSY, L-R symmetric, TC2, 331, and models with extra quarks. Since the expected sensitivity of the LHC and ILC for the tcV (V=\gamma,g,Z) and tcH couplings is of order of a few percent, we emphasize the importance of any new physics effect that gives a prediction for these FCNC couplings within this limit. We also review the constraints imposed on these couplings from low-energy precision measurements.Comment: 19 pages, 7 figures. Accepted as a review paper in Int. J. of Mod. Phys.

    Differences in Neuropsychological Performance between Refugee and Non-Refugee Children in Palestine

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    Neuropsychological studies on refugee children are scarce, but there are even less in the case of Palestinian children. This work aims to study the neuropsychological performance of Palestinian refugee children in Palestine compared to other Palestinian children living outside refugee camps. A comprehensive Neuropsychological battery was administrated to 584 Palestinian school children (464 refugees and 120 non-refugees) aged 6, 7, and 8 years old. Results showed that non-refugee children outperformed refugee children in sustained attention, verbal comprehension, verbal memory, and visual memory. This study is the first to have performed a comprehensive neuropsychological assessment, based on a standardized and validated battery with the Palestinian refugee children. It supports professionals in their evaluation of neurodevelopment and neuropsychological alterations in refugee and non-refugee children in Palestine.Center for Development Cooperation Initiatives (Centro de Iniciativas de Cooperación al Desarrollo—CICODE), Granada University, Spain (Reference No. C14P11_9359

    Testing Gaussianity on Archeops Data

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    A Gaussianity analysis using a goodness-of-fit test and the Minkowski functionals on the sphere has been performed to study the measured Archeops Cosmic Microwave Background (CMB) temperature anisotropy data for a 143 GHz Archeops bolometer. We consider large angular scales, greater than 1.8 degrees, and a large fraction of the North Galactic hemisphere, around 16%, with a galactic latitude b > 15 degrees. The considered goodness-of-fit test, first proposed by Rayner & Best (1989), has been applied to the data after a signal-to-noise decomposition. The three Minkowski functionals on the sphere have been used to construct a chi-square statistic using different thresholds. The first method has been calibrated using simulations of Archeops data containing the CMB signal and instrumental noise in order to check its asymptotic convergence. Two kind of maps produced with two different map-making techniques (coaddition and Mirage) have been analysed. Archeops maps for both Mirage and coaddition map-making, have been found to be compatible with Gaussianity. From these results we can exclude a dust and atmospheric contamination larger than 7.8% (90% CL). Also the non-linear coupling parameter f_{nl} can be constrained to be -800 < f_{nl} < 1100 at the 95% CL and on angular scales of 1.8 degrees. For comparison, the same method has been applied to data from the NASA WMAP satellite in the same region of sky. The 1-year and 3-year releases have been used. Results are compatible with those obtained with Archeops, implying in particular an upper limit for f_{nl} on degree angular scales.Comment: A&A accepted. The limits on the contamination and the fnl parameter have been improve

    Leisure Boating Environmental Footprint: A Study of Leisure Marinas in Palermo

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    Ports have played a significant role in the touristic development and further economic growth of Italy. It is the country with the highest number of berths among the nations in the Medi- terranean Sea; over time, Italy has created ports with a range of functions. Therefore, it is of vital importance to evaluate the potential pollutants generated from these docks and propose ways to eliminate those problems. A survey that asked about the carbon footprint and the quality of the water in the water footprint calculation was created and distributed to the management of the ma- rinas’ operations. After receiving the completed surveys, the data were analyzed and translated using emission factors into tons of CO2 equivalent. The amount of greenhouse gases generated by the investigated marinas was determined by calculating the carbon and water footprints of five rep- resentative Palermo marinas, and we aimed to better understand how these port-related operations affect the environment. To pinpoint the pollutant sources within the investigated marinas, an orig- inal P-Mapping/Pareto ratio approach was performed as supported by Pareto’s principle. The find- ings indicated that the primary operations of the marina sector are the main sources of pollution. However, a sizable portion of the emissions were also caused by pollution from supporting opera- tions. Based on the study, the origins of CO2 and pollution in marina operations were clarified. The results obtained enable the authors to make recommendations that all recreational boating activities should be closely supervised in order to reduce CO2 emissions and their input in relation to envi- ronmental degradation

    Analysis of the ULF electromagnetic emission related to seismic activity, Teoloyucan geomagnetic station, 1998-2001

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    Results of ULF geomagnetic measurements at station Teoloyucan (Central Mexico, 99.11'35.735''W, 19.44'45.100''N, 2280m height) in relation to seismic activity in the period 1998-2001 and their analysis are presented. Variations of spectral densities for horizontal and vertical components, polarization densities and spectrograms of magnetic field, their derivatives are analyzed as a part of traditional analysis in this study. Values of spectral density were calculated for 6 fixed frequencies <i>f</i>=1, 3, 10, 30, 100 and 300mHz. Fractal characteristics of spectra were analyzed in the conception of SOC (Self-Organized Criticality). 2 nighttime intervals, 0-3 and 3-6h by local time have been used to decrease the noise interference in row data. In order to exclude the intervals with a high geomagnetic activity from analysis we referred to <i>Ap</i> indices, calculated for corresponding time intervals. The contribution of seismic events to geomagnetic emission was estimated by seismic index <i>k<sub>s</sub></i>=10<sup>0.75<i>Ms</i></sup>/10<i>D</i>, where <i>Ms</i> is the amplitude of the earthquake and <i>D</i> is the distance from its epicenter to the station

    Silicon solar cell production line and key performance indicators: A case of study at front size serigraphy stage

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    Photovoltaic industry has devices power improvement as a main target. This implies that technological advances are continuously implemented in production lines and their power improvements have to be monitored with the suitable key performance indicators. In this work, front size serigraphy design has been selected as process improvement and laminated unit power and cell to module ratio has been defined as the main key performance indicator. Real size silicon PV cells with three different front finger morphologies have been produced in industrial production lines by the use of two front size serigraphy designs. The modification of the finger dimensions (wide/height) from (183.0 μm/31.6 μm) to (184.0 μm/37.6 μm) and (140.0 μm/40.8 μm) leads to a redistribution of the majority produced cell power range from [4.10–4.15) W to [4.10–4.15) W and [4.20–4.25) W respectively. Concerning the cell production, it has successfully been monitored by the laminated unit power indicator along a month when shows an increment from 3.95 W to 4.20 W. Concerning module level, cell to module ratio per process cell range is selected as suitable indicator and monitoring during a year. In the specific case of [4.30–4.35) W cell range, cell to module ratio decrease from 7.7 % to 6.5 %The authors are thankful to Erasmus+ Programme, SafeEngine project, contract no 2020-1-RO01-KA203-080085, Spanish Ministerio de Ciencia e Innovación through project PID2020-117832RB-100, UMA 18-FEDERJA-041 for their support and to Isofoton and J. Alcaide and J. Rando from 4TENERGY S.COOP:AND, for their collaboration. Funding for open access charge: Universidad de Málaga / CBU

    Synthesis and characterization of polymer/silica/QDs fluorescent nanocomposites with potential application as printing toner

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    In this work cadmium telluride quantum dots (CdTeQDs) were prepared via one-pot synthesis microwave assisted. Afterwards, CdTeQDs/silica (SiO2)/nigrosine (nigro)/poly (styrene co-methyl methacrylate) (PSCMM) fluorescent nanocomposite (CSNP) powders were prepared via ultrasonic treatment and post drying at 60 °C. The samples were characterized by UV-vis absorbance, x-ray diffraction (XRD) and transmission electron microscopy (TEM). Finally, successful printing tests were performed on security paper at 130 °C. These results show the potential of this nanocomposite to be used as security toner. This printing toner configuration is reported for first time
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