277 research outputs found

    Evocative gene-environment correlation between genetic risk for schizophrenia and bullying victimization

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    Bullying exposure concerns over 10% of adolescents in Europe. Moreover, bullying victimization is heritable and victims are liable to psychotic symptoms, partly because of shared heritability with psychosis. The genetic component of bullying victimization has been proposed to involve the social reactions elicited by victims – a mechanism called “evocative gene-environment correlation”. We hypothesized that genetic risk for schizophrenia, a heritable disease also associated with social stress during childhood and adolescence, is related with social experiences during adolescence and is involved in the risk of developing psychotic symptoms. We studied 908 individuals of the TRAILS sample and found that 13-14-year-old adolescents with greater genetic risk for schizophrenia are more exposed to bullying assessed via peer nomination scores than their peers with lower genetic risk. Importantly, bullying victimization mediated the path from genetic risk to the frequency of psychotic symptoms about three years later. These findings provide evidence of a previously unreported form of gene-environment interplay that may be a mechanism of risk for psychosis and schizophrenia. To the extent that genetic risk translation into clinical symptoms is mediated by environmental risk factors, this evidence supports mental health prevention aimed at antagonizing bullying victimization in vulnerable individuals

    Analysis of time-profiles with in-beam PET monitoring in charged particle therapy

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    Background: Treatment verification with PET imaging in charged particle therapy is conventionally done by comparing measurements of spatial distributions with Monte Carlo (MC) predictions. However, decay curves can provide additional independent information about the treatment and the irradiated tissue. Most studies performed so far focus on long time intervals. Here we investigate the reliability of MC predictions of space and time (decay rate) profiles shortly after irradiation, and we show how the decay rates can give an indication about the elements of which the phantom is made up. Methods and Materials: Various phantoms were irradiated in clinical and near-clinical conditions at the Cyclotron Centre of the Bronowice proton therapy centre. PET data were acquired with a planar 16x16 cm2^2 PET system. MC simulations of particle interactions and photon propagation in the phantoms were performed using the FLUKA code. The analysis included a comparison between experimental data and MC simulations of space and time profiles, as well as a fitting procedure to obtain the various isotope contributions in the phantoms. Results and conclusions: There was a good agreement between data and MC predictions in 1-dimensional space and decay rate distributions. The fractions of 11^{11}C, 15^{15}O and 10^{10}C that were obtained by fitting the decay rates with multiple simple exponentials generally agreed well with the MC expectations. We found a small excess of 10^{10}C in data compared to what was predicted in MC, which was clear especially in the PE phantom.Comment: 9 pages, 5 figures, 1 table. Proceedings of the 20th International Workshop on Radiation Imaging Detectors (iWorid2018), 24-28 June 2018, Sundsvall, Swede

    Assessment of the Effects of Edible Microalgae in a Canine Gut Model

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    Microalgae are a source of bioactive compounds having recently been studied for their possible application as health-promoting ingredients. The aim of the study was to evaluate in an in vitro canine gut model the effects of four microalgae, Arthrospira platensis (AP), Haematococcus pluvialis (HP), Phaeodactylum tricornutum (PT) and Chlorella vulgaris (CV), on some fecal microbial populations and metabolites. The four microalgae were subjected to an in vitro digestion procedure, and subsequently, the digested biomass underwent colonic in vitro fermentation. After 6 h of incubation, PT increased propionate (+36%) and butyrate (+24%), and decreased total BCFA (-47%), isobutyrate (-52%) and isovalerate (-43%) and C. hiranonis (-0.46 log10 copies/75 ng DNA). After 24 h, PT increased propionate (+21%) and isovalerate (+10%), and decreased the abundance of Turicibacter spp. (7.18 vs. 6.69 and 6.56 log10 copies/75 ng DNA for CTRL vs. PT, respectively); moreover, after 24 h, CV decreased C. coccoides (-1.12 log10 copies/75 ng DNA) and Enterococcus spp. (-0.37 log10 copies/75 ng DNA). In conclusion, the microbial saccharolytic activities and the shift in fecal bacterial composition were less pronounced than expected, based on current literature. This study should be considered as a preliminary assessment, and future investigations are required to better understand the role of microalgae in canine nutrition

    Assessment of a Chain Mower Performance for Weed Control under Tree Rows in an Alley Cropping Farming System

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    In the area under tree rows of alley cropping systems, coarse plant material as well as pruning material or stones may be present, so the use of a mower equipped with chains as cutting a tool could be advantageous. A mower designed for under-row weed control in orchards, equipped with an automatic tree-skipping mechanism, was modified by replacing blades with chains with the aim of evaluating its performance in an alley cropping system. A first trial was carried out in an open field to preliminarily compare the chain mower with the version equipped with blades in relation to different settings of working speed (1.6 and 2.4 km center dot h(-1)) and rotation speed of the cutting tool (1830 and 2500 rpm). Weed biomass reduction, weed cover reduction, weed height reduction, weed biomass regrowth, and clipping size were assessed. In a second trial, the performance of the mowers with different setting configurations was assessed in an alley cropping system under a more critical environmental condition for mowing, i.e., the presence of dew. Weed biomass reduction, weed cover reduction, weed height reduction, and the mowers' field capacity with different working speed settings were assessed. No major differences emerged between the mowers and the chain mower performance was comparable to that of the standard blade mower. The setting with the high working speed and high rotation speed of the cutting tool turns out to be the best compromise, obtaining a weed biomass reduction of 59.6%, a weed cover reduction of 40.9%, and a higher field capacity compared to the setting with the low working speed, with an increase of 47.9%

    Comparison of Travoprost and Bimatoprost plus timolol fixed combinations in open-angle glaucoma patients previously treated with latanoprost plus timolol fixed combination

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    To compare the ocular hypotensive effect of bimatoprost plus timolol and travoprost plus timolol fixed combinations in glaucoma patients whose disease was controlled but had not reached their target intraocular pressure (IOP) with the fixed combination of latanoprost plus timolol

    Trampling Analysis of Autonomous Mowers: Implications on Garden Designs

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    Several trials have been carried out by various authors concerning autonomous mowers, which are battery-powered machines. The effects of these machines on turfgrass quality and energy consumption have been thoroughly investigated. However, there are still some aspects that have not been studied. Among these, random trajectory overlapping is one of the most important. To investigate these aspects, two RTK-GPS devices along with the custom-built software used for previous trials has been upgraded in order to precisely calculate how many times the mower drives over the same spot using random trajectories. This parameter, the number of passages in the same position, was hypothesized to explain the autonomous mower's overlapping and trampling action. The trial has been carried out testing a commercial autonomous mower on three areas with different levels of complexity to assess its performances. The following variables were examined: the percentage of mowed area, the distance travelled, the number of intersections, the number of passages, and the autonomous mower's work efficiency. The average percentage of area mown (average value for the three areas) was 54.64% after one hour and 80.15% after two hours of work. Percentage of area mown was 15% higher for the area with no obstacles after two hours of work. The number of passages was slightly different among the three garden designs. The garden with no obstacles obtained the highest number of passages with an average of 37 passages. The highest working efficiency was obtained in the garden with an intermediate number of obstacles with a value of 0.40 after two hours of work. The estimated energy consumption resulted 0.31 Wh m(-2) after one hour and 0.42 Wh m(-2) after two hours of working. These results highlight how the correct settings of cutting time may be crucial to consistently save energy during the long period and may be useful for a complete automation of the maintenance of green areas

    Hot foam and nitrogen application to promote spring transition of “Diamond” zoysiagrass (Zoysia matrella (L.) Merr.) overseeded with perennial ryegrass (Lolium perenne L.).

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    In transition areas, cool season turfgrasses are overseeded in autumn to maintain the high quality of dormant warm season turfgrasses, while in spring several agronomic methods (scalping, coring, topdressing, verticutting, irrigation, and targeted fertilization) or chemical desiccation are adopted to remove the cool season turfgrasses from the stand. To reduce chemical applications, several methods of “thermal weeding” have been experimented with, but little is known about these methods in zoysiagrass (Zoysia spp. Willd) spring transition. A study was conducted at the University of Pisa, Italy, on Manila grass (Zoysia matrella (L.) Merr., cv “Diamond”) (Zm) overseeded with perennial ryegrass (Lolium perenne L.) (Lp) with the aim of comparing different methods of cool season grass suppression (scalping and hot foam) and different application rates of nitrogen. To assess treatment effect, green cover, turf quality, turf color, shoot density, and some vegetation indices (GLI, DGCI and NDVI) were determined. An average green cover of at least 90% was obtained on all plots seven weeks after the treatments. While scalping had minor effects on turf appearance and on polystand composition, hot foam had a stronger effect on turf color, green cover, and turf quality in the weeks following application. Once it had recovered from the hot foam treatments, the turf had a greater number of Zm shoots and a relevant reduction of Lp shoots. The hot foam was very effective in suppressing Lp while maintaining Zm recovery capacity. quality of dormant warm season turfgrasses, while in spring several agronomic methods (scalping, coring, topdressing, verticutting, irrigation, and targeted fertilization) or chemical desiccation are adopted to remove the cool season turfgrasses from the stand. To reduce chemical applications, several methods of “thermal weeding” have been experimented with, but little is known about these methods in zoysiagrass (Zoysia spp. Willd) spring transition. A study was conducted at the University of Pisa, Italy, on Manila grass (Zoysia matrella (L.) Merr., cv “Diamond”) (Zm) overseeded with perennial ryegrass (Lolium perenne L.) (Lp) with the aim of comparing different methods of cool season grass suppression (scalping and hot foam) and different application rates of nitrogen. To assess treatment effect, green cover, turf quality, turf color, shoot density, and some vegetation indices (GLI, DGCI and NDVI) were determined. An average green cover of at least 90% was obtained on all plots seven weeks after the treatments. While scalping had minor effects on turf appearance and on polystand composition, hot foam had a stronger effect on turf color, green cover, and turf quality in the weeks following application. Once it had recovered from the hot foam treatments, the turf had a greater number of Zm shoots and a relevant reduction of Lp shoots. The hot foam was very effective in suppressing Lp while maintaining Zm recovery capacity

    Full-beam performances of a PET detector with synchrotron therapeutic proton beams

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    Treatment quality assessment is a crucial feature for both present and nextgeneration ion therapy facilities. Several approaches are being explored, based on prompt radiation emission or on PET signals by β+;-decaying isotopes generated by beam interactions with the body. In-beam PET monitoring at synchrotron-based ion therapy facilities has already been performed, either based on inter-spill data only, to avoid the influence of the prompt radiation, or including both in-spill and inter-spill data. However, the PET images either suffer of poor statistics (inter-spill) or are more influenced by the background induced by prompt radiation (in-spill). Both those problems are expected to worsen for accelerators with improved duty cycle where the inter-spill interval is reduced to shorten the treatment time. With the aim of assessing the detector performance and developing techniques for background reduction, a test of an in-beam PET detector prototype was performed at the CNAO synchrotron-based ion therapy facility in full-beam acquisition modality. Data taken with proton beams impinging on PMMA phantoms showed the system acquisition capability and the resulting activity distribution, separately reconstructed for the in-spill and the inter-spill data. The coincidence time resolution for in-spill and inter-spill data shows a good agreement, with a slight deterioration during the spill. The data selection technique allows the identification and rejection of most of the background originated during the beam delivery. The activity range difference between two different proton beam energies (68 and 72 MeV) was measured and found to be in submillimeter agreement with the expected result. However, a slightly longer (2 mm) absolute profile length is obtained for in-spill data when compared to inter-spill data
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