2,969 research outputs found

    Impact of LGBTQ school climate policy on rates of suicide : planning and attempt among high school populations

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    This study was developed to observe the correlation between the implementation of policies to improve school climate for high school students who identify as LGBTQ (Lesbian, Gay, Bisexual, Transgender, Queer), and changes in self reported suicide planning and attempts among school populations. Current academic literature notes an increase in the suicidal behaviors among LGBTQ students, and notes social and environmental factors (e.g. school climate) as potential contributing factors to suicide risk. This study compares school policy data from 49 school districts across the state of Vermont to self-reported rates of suicidal planning and attempt collected by the Vermont Department of Health and aggregated at the school level. The study hypothesized that schools with a greater number of school climate policies (e.g. gender neutral bathrooms, LGBTQ organizations, anti-harassment policy and student antiharassment training) will exhibit lower rates of suicidal planning and attempts. The findings pointed to a slight reduction in rates of suicidal ideation and attempt among school employing three of the four interventions, as well as a negative correlation between the number of intervention implemented and the rates of suicidal planning and attempt. However, these findings lack the statistical significance required to rule out a null hypothesis. Further research is needed to exhibit a statistically significant impact, however these findings can be extrapolated to suggest that certain school policies cannot only improve students\u27 feelings of depression and outlook on life, but may prevent death by suicide

    Hybrid Method for Digits Recognition using Fixed-Frame Scores and Derived Pitch

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    This paper presents a procedure of frame normalization based on the traditional dynamic time warping (DTW) using the LPC coefficients. The redefined method is called as the DTW frame-fixing method (DTW-FF), it works by normalizing the word frames of the input against the reference frames. The enthusiasm to this study is due to neural network limitation that entails a fix number of input nodes for when processing multiple inputs in parallel. Due to this problem, this research is initiated to reduce the amount of computation and complexity in a neural network by reducing the number of inputs into the network. In this study, dynamic warping process is used, in which local distance scores of the warping path are fixed and collected so that their scores are of equal number of frames. Also studied in this paper is the consideration of pitch as a contributing feature to the speech recognition. Results showed a good performance and improvement when using pitch along with DTW-FF feature. The convergence rate between using the steepest gradient descent is also compared to another method namely conjugate gradient method. Convergence rate is also improved when conjugate gradient method is introduced in the back-propagation algorithm

    Neural network-based colonoscopic diagnosis using on-line learning and differential evolution

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    In this paper, on-line training of neural networks is investigated in the context of computer-assisted colonoscopic diagnosis. A memory-based adaptation of the learning rate for the on-line back-propagation (BP) is proposed and used to seed an on-line evolution process that applies a differential evolution (DE) strategy to (re-) adapt the neural network to modified environmental conditions. Our approach looks at on-line training from the perspective of tracking the changing location of an approximate solution of a pattern-based, and thus, dynamically changing, error function. The proposed hybrid strategy is compared with other standard training methods that have traditionally been used for training neural networks off-line. Results in interpreting colonoscopy images and frames of video sequences are promising and suggest that networks trained with this strategy detect malignant regions of interest with accuracy

    On ‘Organized Crime’ in the illicit antiquities trade: moving beyond the definitional debate

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    The extent to which ‘organized crime’ is involved in illicit antiquities trafficking is unknown and frequently debated. This paper explores the significance and scale of the illicit antiquities trade as a unique transnational criminal phenomenon that is often said to be perpetrated by and exhibit traits of so-called ‘organized crime.’ The definitional debate behind the term ‘organized crime’ is considered as a potential problem impeding our understanding of its existence or extent in illicit antiquities trafficking, and a basic progression-based model is then suggested as a new tool to move beyond the definitional debate for future research that may help to elucidate the actors, processes and criminal dynamics taking place within the illicit antiquities trade from source to market. The paper concludes that researchers should focus not on the question of whether organized criminals- particularly in a traditionally conceived, mafia-type stereotypical sense- are involved in the illicit antiquities trade, but instead on the structure and progression of antiquities trafficking itself that embody both organized and criminal dynamics

    Do the SCOFF items function differently by food-security status in U.S. college students?: Statistically, but not practically, significant differences

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    Despite food insecurity (FI) being associated with eating disorders (EDs), little research has examined if ED screening measures perform differently in individuals with FI. This study tested whether items on the SCOFF performed differently as a function of FI. As many people with FI hold multiple marginalized identities, this study also tested if the SCOFF performs differently as a function of food-security status in individuals with different gender identities and different perceived weight statuses. Data were from the 2020/2021 Healthy Minds Study (N = 122,269). Past-year FI was established using the two-item Hunger Vital Sign. Differential item functioning (DIF) assessed whether SCOFF items performed differently (i.e., had different probabilities of endorsement) in groups of individuals with FI versus those without. Both uniform DIF (constant between-group difference in item-endorsement probability across ED pathology) and non-uniform DIF (variable between-group difference in item-endorsement probability across ED pathology) were examined. Several SCOFF items demonstrated both statistically significant uniform and non-uniform DIF (ps < .001), but no instances of DIF reached practical significance (as indicated by effect sizes pseudo ΔR2 ≥ 0.035; all pseudo ΔR2's ≤ 0.006). When stratifying by gender identity and weight status, although most items demonstrated statistically significant DIF, only the SCOFF item measuring body-size perception showed practically significant non-uniform DIF for perceived weight status. Findings suggest the SCOFF is an appropriate screening measure for ED pathology among college students with FI and provide preliminary support for using the SCOFF in individuals with FI and certain marginalized identities

    Dissemination and Systemic Colonization of Uropathogenic Escherichia coli in a Murine Model of Bacteremia

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    Infection with uropathogenic Escherichia coli (UPEC), the causative agent of most uncomplicated urinary tract infections, proceeds in an ascending manner and, if left untreated, may result in bacteremia and urosepsis. To examine the fate of UPEC after its entry into the bloodstream, we developed a murine model of sublethal bacteremia. CBA/J mice were inoculated intravenously with 1 × 106 CFU of pyelonephritis strain E. coli CFT073 carrying a bioluminescent reporter. Biophotonic imaging, used to monitor the infection over 48 h, demonstrated that the bacteria disseminated systemically and appeared to localize at discrete sites. UPEC was recovered from the spleen, liver, kidneys, lungs, heart, brain, and intestines as early as 20 min postinoculation, peaking at 24 h postinoculation. A nonpathogenic E. coli K-12 strain, however, disseminated at significantly lower levels (P < 0.01) and was cleared from the liver and cecum by 24 h postinoculation. Isogenic mutants lacking type 1 fimbriae, P fimbriae, capsule, TonB, the heme receptors Hma and ChuA, or particularly the sialic acid catabolism enzyme NanA were significantly outcompeted by wild-type CFT073 during bacteremia (P < 0.05), while flagellin and hemolysin mutants were not

    Spatially Resolved Mapping of Local Polarization Dynamics in an Ergodic Phase of Ferroelectric Relaxor

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    Spatial variability of polarization relaxation kinetics in relaxor ferroelectric 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 is studied using time-resolved Piezoresponse Force Microscopy. Local relaxation attributed to the reorientation of polar nanoregions is shown to follow stretched exponential dependence, exp(-(t/tau)^beta), with beta~~0.4, much larger than the macroscopic value determined from dielectric spectra (beta~~0.09). The spatial inhomogeneity of relaxation time distributions with the presence of 100-200 nm "fast" and "slow" regions is observed. The results are analyzed to map the Vogel-Fulcher temperatures on the nanoscale.Comment: 23 pages, 4 figures, supplementary materials attached; to be submitted to Phys. Rev. Let

    Mucosal Immunization with Iron Receptor Antigens Protects against Urinary Tract Infection

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    Uncomplicated infections of the urinary tract, caused by uropathogenic Escherichia coli, are among the most common diseases requiring medical intervention. A preventive vaccine to reduce the morbidity and fiscal burden these infections have upon the healthcare system would be beneficial. Here, we describe the results of a large-scale selection process that incorporates bioinformatic, genomic, transcriptomic, and proteomic screens to identify six vaccine candidates from the 5379 predicted proteins encoded by uropathogenic E. coli strain CFT073. The vaccine candidates, ChuA, Hma, Iha, IreA, IroN, and IutA, all belong to a functional class of molecules that is involved in iron acquisition, a process critical for pathogenesis in all microbes. Intranasal immunization of CBA/J mice with these outer membrane iron receptors elicited a systemic and mucosal immune response that included the production of antigen-specific IgM, IgG, and IgA antibodies. The cellular response to vaccination was characterized by the induction and secretion of IFN-γ and IL-17. Of the six potential vaccine candidates, IreA, Hma, and IutA provided significant protection from experimental infection. In immunized animals, class-switching from IgM to IgG and production of antigen-specific IgA in the urine represent immunological correlates of protection from E. coli bladder colonization. These findings are an important first step toward the development of a subunit vaccine to prevent urinary tract infections and demonstrate how targeting an entire class of molecules that are collectively required for pathogenesis may represent a fundamental strategy to combat infections

    Effect of Preirradiation Fluoride Treatment on the Physical Properties of Dentin

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    Objective. To determine the effects of preirradiation fluoride treatments on the Knoop hardness of dentin. Materials and Methods. Human posterior teeth mounted into acrylic resin molds were polished with silicon carbide (SiC) abrasives and 3-micron diamond paste. The Knoop hardness of dentin was measured with a Leco hardness instrument. The teeth were divided into groups of ten teeth per group as follows: no treatment (control), treatment with silver diamine fluoride (SDF), MI varnish (MI), and cavity shield (CS). The teeth were exposed to 2 Gy of daily radiation for six weeks using an X-Rad 320ix biological irradiator. Hardness was measured weekly, before, during, and after irradiation. The teeth were stored in artificial saliva at 37oC between radiation treatments. Results. In preirradiation dentin, a Knoop hardness value of 58.8 (14.1) KHN was obtained. Treatment with SDF significantly increased KHN before irradiation. Immediately after radiation treatment, hardness was significantly reduced in all experimental groups. Postirradiation fluoride treatments increased the hardness of dentin to varying degrees. Conclusions. Preirradiation fluoride treatment does not provide protection from decreases in the hardness of dentin. Treatment of teeth with fluoride formulations after radiation progressively restores the hardness of dentin to different degrees. © 2022 Francis K. Mante et al
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