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- Author or Editor: M. Ventura x
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A new species of Diadiplosis, D. abacaxii sp. nov. (Diptera: Cecidomyiidae) is described and illustrated based on specimens collected in association with the pineapple scale insect pest Dysmicoccus brevipes (Coccoidea: Pseudococcidae) on Ananas comosus (L.) Merr. var. comosus (Bromeliaceae) in Espírito Santo, Brazil.
Abstract
Selenium daily intake was determined for two small groups of the Portuguese population, based on the analysis of duplicate diet portions. The total amount of food ingested during a day was collected for 18 workers of the Technological and Nuclear Institute (ITN-Sacavém) and for 6 females of Reguengos de Monsaraz, a small town in the south-eastern hinterland. The average selenium daily intake was 43 ± 20 and 32 ± 13 μg per person, respectively, both lower than the Recommended Dietary Allowance (RDA) of 55 μg day−1. Selenium in diet samples was determined by replicate sample neutron activation analysis (RSINAA). The method was considered accurate for the selenium determination.
Abstract
The replicate sample instrumental neutron activation method was optimized and used for the determination of selenium in foodstuffs. The method was reliable, yielding accurate results. Lower detections limits were obtained after each successive irradiation. Different irradiation conditions were used depending on the type of sample. For samples with higher selenium contents (meat, fish, eggs), the measured selenium in the first replicate is in all cases larger than the detection limit, but a better accuracy was obtained with a larger number of replicates (2–3 replicates). For samples with extremely low selenium contents (vegetable samples), at least seven replicates were necessary to obtain a concentration value two times larger than the detection limit.
Abstract
At ITN, PM10 and PM2.5 aerosols were collected on Nuclepore® polycarbonate filters of 47 mm diameter, using Gent samplers at 15–17 l/min air flux. Filters were analyzed by INAA and PIXE. The availability of certified filters was very scarce, viz.: (1) fly ash embedded in a methyl cellulose 47 mm foil 10 µm thick, BCR CRM128, (2) particle-size reduced air particulate matter (APM) to simulate PM2.5 aerosol matter deposited on a 47 mm polycarbonate filter membrane, NIST SRM 2783. The high price and scarcity of APM standards did not permit their frequent use for analytical quality control. At ITN, to control the filter results' accuracy, the chemical elements potassium, iron and zinc, determined by both techniques, were systematically compared. After a few improvements introduced in INAA, this technique was now considered at ITN as the reference technique in air particulate measurements. Comparison of INAA to PIXE was discussed. Compared to previously reported situation it was concluded that the results were in better agreement for iron and zinc, and potassium values were still biased to the same extent as before.
Abstract
Dipalmitoylphosphatidylcholine (DPPC) liposomes were employed as membrane models for the investigation of the interaction occurring between methotrexate (MTX) and bilayer lipid matrix. Liposomes were obtained by hydrating a lipid film with 50 mM Tris buffer (pH 7.4). The differential scanning calorimetry (DSC) evaluation of the thermotropic parameters associated with the phase transitions of DPPC liposomes gave useful information about the kind of drug-membrane interaction. The results showed an electrostatic interaction taking place with the negatively charged molecules of MTX and the phosphorylcholine head groups, constituting the outer part of DPPC bilayers. No interaction with the hydrophobic phospholipid bilayer domains was detected, revealing a poor capability of MTX to cross through lipid membranes to reach the interior compartment of a lipid bounded structure. These findings correlate well within vitro biological experiments on MTX cell susceptibility.
The aim of this research was to study the shelf-life of fresh-cut iceberg lettuce, testing a packaging film manufactured with and without addition of anti-UV compounds, and using two different protective atmospheres (N2/CO2 70/30% and Ar/CO2 80/20%). In order to simulate the most common retail storage conditions, the samples were stored at 6 °C under artificial light by using real supermarket refrigerated exposition stands. The data obtained showed that the use of an anti-UV film always causes a lower quality decay of the product; in any case, the best results were obtained when the anti-UV film was utilized in association with the packaging atmosphere consisting of Ar and CO2 (80/20%) gas mixture.
Summary
Selenium is determined by instrumental neutron activation analysis (INAA), based on measurement of the long-lived 75Se nuclide. In the urban and industrialized areas of Portugal selenium contents have been found of the order of of 0.5-1 ng/m3 in PM10 and PM2.5, according to the data collected since 1994. From November 12, 2001 and for not more than 3 months, the Se contents in PM10 and PM2.5 increased by a factor of 1000 in the northern area of Lisbon. More than other nutrients, selenium illustrates the dichotomy between essentiality and toxicity. There is no legislation on Se for ambient air and on indoor ambient point threshold limit values (US and Germany legislation), were 100 times higher than the abnormal values found that winter. The increase was also visible for mercury although not to such an extent. Attempts were made to understand the trend, going into a study of the emission sources located in the area using both INAA and PIXE. It was concluded that the observation occurred due to abnormal meteorological wind direction, which pushed the pollutants towards the populated area, when usually they flow into the Tagus estuary.
Abstract
Examples of the application of k 0 standardized instrumental neutron activation analysis (k 0 -INAA) to aerosols and biological monitors in the last 10 years at Instituto Tecnológico e Nuclear (ITN) are given. As an analytical technique, INAA, in association with the k 0 method was applied to these materials in four different projects, aiming at monitoring concentrations of heavy metals and others elements in the atmosphere in the Portuguese territory. In these studies we analysed the lichen Parmelia sulcata Taylor and olive tree bark as monitors as well as aerosol samples. For each project some representative results are presented, followed by a discussion of the application of this technique to environmental studies.
The aim was to examine conditions of convective drying and spray-drying to improve preservation of lycopene content in tomatoes. The weight, size, colour, pH and °Brix values were evaluated in fresh fruit (FF) and colour (L, a, b), hue, and chrome indices were analysed from dried tomatoes, too. Tomato paste was dried (40, 50, 60, and 80 °C with times of 540, 390, 270, and 240 min) under convection conditions and pulverized. In the encapsulation treatments core material with tomato powders of 50, 60, and 70%, shell solution of maltodextrin/gum arabic 1:1, flow rate of 4, 6, 9, and 12 ml min–1, and inlet air T of 160, 170, and 180 °C were used. The physicochemical properties of FF corresponded to a degree of ripeness for consumption. The a, a/b, and hue values of dried tomatoes at 50 °C significantly correlated to red colouring and higher lycopene content (47.98±1.49 mg/100 g). The encapsulation with 50% and 60% of tomato powders, 170 °C and 9 ml min–1 treatments increased lycopene contents to 10.41 mg/100 g, 10.20 mg/100 g, and 11.51 mg/100 g, respectively. The results demonstrated that the physicochemical and functional properties were influenced by drying conditions, providing useful information for increasing the stability of lycopene in dried tomatoes.
Abstract
Background and aims
Negative/positive urgency (NU/PU) refers to the proneness to act rashly under negative/positive emotions. These traits are proxies to generalized emotion dysregulation, and are well-established predictors of gambling-related problems. We aimed to replicate a previous work (Quintero et al., 2020) showing NU to be related to faulty extinction of conditioned stimuli in an emotional conditioning task, to extend these findings to PU, and to clarify the role of urgency in the development of gambling-related craving and problems.
Methods
81 gamblers performed an acquisition-extinction task in which neutral, disgusting, erotic and gambling-related images were used as unconditioned stimuli (US), and color patches as conditioned stimuli (CS). Trial-by-trial predictive responses were analyzed using generalized linear mixed-effects models (GLME).
Results
PU was more strongly related than NU to craving and severity of gambling problems. PU did not influence acquisition in the associative task, whereas NU slightly slowed it. Extinction was hampered in individuals with high PU, and a follow-up analysis showed this effect to depend on relative preference for skill-based and casino games.
Discussion and conclusions
Results suggest that resistance to extinction of emotionally conditioned cues is a sign of malfunctioning emotion regulation in problematic gambling. In our work, the key effect was driven by PU (instead of NU), and gambling craving and symptoms were also more closely predicted by it. Future research should compare the involvement of PU and NU in emotion regulation and gambling problems, for gamblers with preference for different gambling modalities (e.g., pure chance vs skill games).
