5,838 research outputs found
Student Preferences for College and Career Information
This study examined the preferences of high school seniors (N = 2901) for receiving college and career information, an area not well-studied previously. Key findings are: Parents and peers are rated to be very helpful sources of college and career information; school counselors are a helpful source of information for first-generation and low-income students; and the internet is a helpful source of information, but email and one-on-one are more preferred sources of information. The findings of this study are useful for K-12 education, college access, and higher education professionals to consider when developing policies and programs to provide college and career information to students
Validation of Computational Approaches for Antiretroviral Dose Optimization (vol 60, pg 3838, 2016)
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Datasets related to in-land water for limnology and remote sensing applications: distance-to-land, distance-to-water, water-body identifier and lake-centre co-ordinates
Datasets containing information to locate and identify water bodies have been generated from data locating static-water-bodies with resolution of about 300 m (1/360 deg) recently released by the Land Cover Climate Change Initiative (LC CCI) of the European Space Agency. The LC CCI water-bodies dataset has been obtained from multi-temporal metrics based on time series of the backscattered intensity recorded by ASAR on Envisat between 2005 and 2010. The new derived datasets provide coherently: distance to land, distance to water, water-body identifiers and lake-centre locations. The water-body identifier dataset locates the water bodies assigning the identifiers of the Global Lakes and Wetlands Database (GLWD), and lake centres are defined for in-land waters for which GLWD IDs were determined. The new datasets therefore link recent lake/reservoir/wetlands extent to the GLWD, together with a set of coordinates which locates unambiguously the water bodies in the database. Information on distance-to-land for each water cell and the distance-to-water for each land cell has many potential applications in remote sensing, where the applicability of geophysical retrieval algorithms may be affected by the presence of water or land within a satellite field of view (image pixel).
During the generation and validation of the datasets some limitations of the GLWD database and of the LC CCI water-bodies mask have been found. Some examples of the inaccuracies/limitations are presented and discussed.
Temporal change in water-body extent is common. Future versions of the LC CCI dataset are planned to represent temporal variation, and this will permit these derived datasets to be updated
Factors affecting nitrate distribution in shallow groundwater under a beef farm in South Eastern Ireland
peer-reviewedGroundwater contamination was characterised using a methodology which combines shallow groundwater geochemistry data from 17 piezometers over a 2 yr period in a statistical framework and hydrogeological techniques. Nitrate–N (NO3-N) contaminant mass flux was calculated across three control planes (rows of piezometers) in six isolated plots. Results showed natural attenuation occurs on site although the method does not directly differentiate between dilution and denitrification. It was further investigated whether NO3-N concentration in shallow groundwater (<5 m below ground level) generated from an agricultural point source on a 4.2 ha site on a beef farm in SE Ireland could be predicted from saturated hydraulic conductivity (Ksat) measurements, ground elevation (m Above Ordnance Datum), elevation of groundwater sampling (screen opening interval) (m AOD) and distance from a dirty water point pollution source. Tobit regression, using a background concentration threshold of 2.6 mg NO3-N L−1 showed, when assessed individually in a step wise procedure, Ksat was significantly related to groundwater NO3-N concentration. Distance of the point dirty water pollution source becomes significant when included with Ksat in the model. The model relationships show areas with higher Ksat values have less time for denitrification to occur, whereas lower Ksat values allow denitrification to occur. Areas with higher permeability transport greater NO3-N fluxes to ground and surface waters. When the distribution of Cl− was examined by the model, Ksat and ground elevation had the most explanatory power but Ksat was not significant pointing to dilution having an effect. Areas with low NO3 concentration and unaffected Cl− concentration points to denitrification, low NO3 concentration and low Cl− chloride concentration points to dilution and combining these findings allows areas of denitrification and dilution to be inferred. The effect of denitrification is further supported as mean groundwater NO3-N was significantly (P < 0.05) related to groundwater N2/Ar ratio, redox potential (Eh), dissolved O2 and N2 and was close to being significant with N2O (P = 0.08). Calculating contaminant mass flux across more than one control plane is a useful tool to monitor natural attenuation. This tool allows the identification of hot spot areas where intervention other than natural attenuation may be needed to protect receptors.Research Stimulus Fund, Department of Agriculture Fisheries and Food (Ireland
Phenotypic change and induction of cytokeratin expression during in vitro culture of corneal stromal cells
Purpose: Cells of the corneal epithelium and stroma can be distinguished in vivo by different intermediate filaments, cytokeratins for corneal epithelial cells (CEC) and vimentin for keratocytes. Isolated and cultured keratocytes change phenotype, losing expression of keratocyte markers and gaining markers associated with mesenchymal stromal cells (MSC). This study investigates this change in phenotype in relation to intermediate filament expression in cultured corneal stromal cells (CSC) compared to CEC.
Methods: Expression of epithelial markers (CK3, CK12, CK19, pan cytokeratin, E-cadherin), keratocyte markers (CD34, vimentin) and MSC markers (CD73, CD90 and CD105) were compared in CEC and CSC by immunocytochemistry and RT-qPCR. Expression was evaluated at different stages of CSC culture and compared to another stromal cell type, extracted from Wharton’s jelly (WJ-MSC).
Results: In vivo keratocytes did not express cytokeratins. However, cultured CSC expressed epithelial-associated CK3, CK12 and CK19 but other cytokeratins. Expression of cytokeratins increased as CSC were passaged and decreased as CSC were induced to become quiescent. Comparatively, WJ-MSC, expressed lower levels of CK3, CK12 and CK19, but also stained for pan cytokeratin and expressed KRT5.
Conclusions: Cultured CSC undergo phenotypic change during culture, expressing specific cytokeratin filaments normally associated with CEC. Cytokeratin expression begins as cells are cultured on plastic and increases with passage. This discovery may influence the way that differences are discerned between cultured CEC and CSC. Investigators need to be aware that the expression of cytokeratins does not necessarily represent epithelial contamination, and that CEC and CSC may be more related than previously recognised
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Parents’ experiences of introducing toddlers to fruits and vegetables through repeated exposure, with and without prior visual familiarization to foods: evidence from daily diaries
While repeated exposure is an established method for inducing food acceptance in young children, little is known about parents’ experiences of repeatedly offering new or disliked foods at home. In this study, parents kept structured diary records during a 15-day period in which they offered their 2-year-old child daily tastes of one fruit and one vegetable. We explored how children’s acceptance of foods (measured in terms of willingness to taste, liking and intake) and the ease and enjoyment of the process for parents changed from the early (days 1-5) to middle (days 6-10) to later (days 11-15) phases of exposure. In addition, we explored whether prior visual familiarization to foods affected children’s behavior and/or parents’ experiences during exposure. Families were randomly assigned to look at a picture book about one to-be-exposed food for the two weeks prior to the exposure phase (‘fruit book’ and ‘vegetable book’ groups) or to a control group, who did not receive a book. Measures obtained from parents’ diary records revealed increases in willingness to taste and intake of vegetables and increased liking of both fruits and vegetables with greater exposure. Prior visual familiarization to vegetables further boosted children’s willingness to taste and liking of vegetables, and the ease and enjoyment of introducing these for parents. Children’s acceptance of foods and parents’ positivity during exposure predicted children’s liking and intake of foods 3 months later. Results confirm the potential for vegetable picture books to support parents in engaging with repeated exposure regimes and in successfully introducing vegetables into toddlers’ diets
Dancing to the Partisan Beat: A First Analysis of Political Communication on TikTok
TikTok is a video-sharing social networking service, whose popularity is
increasing rapidly. It was the world's second-most downloaded app in 2019.
Although the platform is known for having users posting videos of themselves
dancing, lip-syncing, or showcasing other talents, user-videos expressing
political views have seen a recent spurt. This study aims to perform a primary
evaluation of political communication on TikTok. We collect a set of US
partisan Republican and Democratic videos to investigate how users communicated
with each other about political issues. With the help of computer vision,
natural language processing, and statistical tools, we illustrate that
political communication on TikTok is much more interactive in comparison to
other social media platforms, with users combining multiple information
channels to spread their messages. We show that political communication takes
place in the form of communication trees since users generate branches of
responses to existing content. In terms of user demographics, we find that
users belonging to both the US parties are young and behave similarly on the
platform. However, Republican users generated more political content and their
videos received more responses; on the other hand, Democratic users engaged
significantly more in cross-partisan discussions.Comment: Accepted as a full paper at the 12th International ACM Web Science
Conference (WebSci 2020). Please cite the WebSci version; Second version
includes corrected typo
Multiple effects of silymarin on the hepatitis C virus lifecycle
Silymarin, an extract from milk thistle (Silybum marianum), and its purified flavonolignans have been recently shown to inhibit hepatitis C virus (HCV) infection, both in vitro and in vivo. In the current study, we further characterized silymarin's antiviral actions. Silymarin had antiviral effects against hepatitis C virus cell culture (HCVcc) infection that included inhibition of virus entry, RNA and protein expression, and infectious virus production. Silymarin did not block HCVcc binding to cells but inhibited the entry of several viral pseudoparticles (pp), and fusion of HCVpp with liposomes. Silymarin but not silibinin inhibited genotype 2a NS5B RNA-dependent RNA polymerase (RdRp) activity at concentrations 5 to 10 times higher than required for anti-HCVcc effects. Furthermore, silymarin had inefficient activity on the genotype 1b BK and four 1b RDRPs derived from HCV-infected patients. Moreover, silymarin did not inhibit HCV replication in five independent genotype 1a, 1b, and 2a replicon cell lines that did not produce infectious virus. Silymarin inhibited microsomal triglyceride transfer protein activity, apolipoprotein B secretion, and infectious virion production into culture supernatants. Silymarin also blocked cell-to-cell spread of virus. CONCLUSION: Although inhibition of in vitro NS5B polymerase activity is demonstrable, the mechanisms of silymarin's antiviral action appear to include blocking of virus entry and transmission, possibly by targeting the host cell
Evaluation of cumulative cognitive deficits from electroconvulsive therapy
Background Electroconvulsive therapy (ECT) is the most effective acute treatment for severe depression, but widely held concerns about memory problems may limit its use. Aims To find out whether repeated or maintenance courses of ECT cause cumulative cognitive deterioration. Method Analysis of the results of 10 years of cognitive performance data collection from patients who have received ECT. The 199 patients had a total of 498 assessments, undertaken after a mean of 15.3 ECT sessions (range 0–186). A linear mixed-effect regression model was used, testing whether an increasing number of ECT sessions leads to deterioration in performance. Results The total number of previous ECT sessions had no effect on cognitive performance. The major factors affecting performance were age, followed by the severity of depression at the time of testing and the number of days since the last ECT session. Conclusions Repeated courses of ECT do not lead to cumulative cognitive deficits. This message is reassuring for patients, carers and prescribers who are concerned about memory problems and confusion during ECT. Electroconvulsive therapy (ECT) is the most effective acute treatment for severe depression,1 with reported remission rates above 50%.2,3 Although some reports demonstrate even higher remission rates (such as 75% in patients with psychotic depression4), these could be below 50% for treatment-resistant depression or in community settings.5,6 ECT is often portrayed in mainstream media as a barbaric treatment7 and its cognitive side-effects as profound and debilitating, leading to public, patient and carer concerns. ECT does cause retrograde amnesia and acute disorientation immediately following a treatment,8 however, research has suggested that this is only a short-lived side-effect. A meta-analysis by Semkovska & McLoughlin9 analysed the cognitive tests of 2981 patients from 84 studies, performed before and after single courses of ECT, and found that a decline in cognitive performance was limited to the first 3 days following a treatment. Patients showed no cognitive deterioration when tested 2 or more weeks after their last ECT session. This does not apply to retrograde amnesia, which was not part of this analysis, and it cannot be extended to cognitive functions that were not tested. Much less is known about the side-effects of long-term ECT, including maintenance ECT. A major concern of patients and some health professionals is that it could lead to progressive cognitive deficits, especially if given for prolonged periods of time. Small studies and case reports have addressed this question and have found no evidence to support this concern (see Discussion). Over the past 10 years we performed prospective cognitive tests on 199 patients, of whom 96 had >12 ECTsessions during their lifetime (the usual maximum duration of a single ECT course). We wanted to find out whether there was evidence that their cognitive performance deteriorated with the increasing number of ECT sessions
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