6 research outputs found

    Advisor and Student Experiences of Summer Support for College-intending, Low-income high school graduates

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    Summer melt occurs when students who have been accepted to college and intend to enroll fail to matriculate in college in the fall semester after high school. A high rate of summer melt contributes to the lower postsecondary attainment rates of low-income students, in particular. This article presents qualitative findings from two interventions intended to reduce summer melt among low-income, urban high school graduates who had been accepted to college and indicated their intention to enroll. Results from student and counselor surveys, interviews, and focus groups point to a web of personal and contextual factors that collectively influence students' college preparation behaviors and provide insight into the areas of summer supports from which students like these can benefit. The data fit an ecological perspective, in which personal, institutional, societal, and temporal factors interact to affect students' behaviors and outcomes. A model of summer intervention shows that obstacles in completing college financing and informational tasks can lead college-intending students to re-open the question of where or whether to attend college in the fall after high school graduation. Given the pressure of concerns about how to actualize their offer of admission, students rarely engage in the anticipatory socialization activities that might help them make optimal transitions into college

    Root-Associated Streptomyces Isolates Harboring melC Genes Demonstrate Enhanced Plant Colonization

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    Streptomycetaceae assemble into the internal, root endophytic compartment of a wide variety of plants grown in soils worldwide, suggesting their ability to survive during root microbiome assembly. A previous study found that among four nonpathogenic, root-isolated Streptomyces strains (303, 299, CL18, and 136), only 303 and 299 colonized endophytic root tissue of the majority of Arabidopsis thaliana roots when inoculated with 34 other bacterial isolates. Here we demonstrate that 303 and 299 also colonize significantly more in singly inoculated A. thaliana seedlings. The genomes of melanin-producing 303 and 299 each contain two copies of the gene encoding tyrosinase (melC2 and melD2), an enzyme necessary for melanin biosynthesis in Streptomyces. These genes were not found in the genomes of 136 or CL18. Tyrosinase activity was detected in 303 and 299 whole cell and supernatant protein extracts, suggesting functional intracellular and extracellular enzymes.. Because tyrosinase oxidizes phenolic compounds and Streptomyces colonization of A. thaliana appears to be influenced by the phenolic compound salicylic acid (SA), we measured direct sensitivity of Streptomyces isolates to the phenolic compounds catechol, ferulic acid (FA), and SA in vitro. While both 303 and 299 showed higher numbers of surviving colonies than CL18 and 136 in the presence of catechol, only 303 demonstrated a higher number of surviving colonies when isolates were challenges with FA and SA. Finally, when seedlings were singly inoculated with a collection of related plant-associated Streptomyces isolates, colonization was significantly higher in isolates possessing two tyrosinase gene copies than isolates with zero or one gene copy. Overall, we describe a connection between microbial tyrosinase activity and increased seedling colonization of nonpathogenic Streptomyces isolates in A. thaliana. We propose tyrosinase activity in Streptomyces partially protects against harmful plant-produced phenolic compounds as they transition into an endophytic lifestyle

    A diagnostic classifier for pediatric chronic graft-versus-host disease: results of the ABLE/PBMTC 1202 study

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    The National Institutes of Health Consensus criteria for chronic graft-versus-host disease (cGVHD) diagnosis can be challenging to apply in children, making pediatric cGVHD diagnosis difficult. We aimed to identify diagnostic pediatric cGVHD biomarkers that would complement the current clinical criteria and help differentiate cGVHD from non-cGVHD. The Applied Biomarkers of Late Effects of Childhood Cancer (ABLE) study, open at 27 transplant centers, prospectively evaluated 302 pediatric patients after hematopoietic cell transplant (234 evaluable). Forty-four patients developed cGVHD. Mixed and fixed effect regression analyses were performed on diagnostic cGVHD onset blood samples for cellular and plasma biomarkers, with individual markers declared relevant if they met 3 criteria: an effect ratio ≥1.3 or ≤0.75; an area under the curve (AUC) of ≥0.60; and a P value \u3c5.814 × 10-4 (Bonferroni correction) (mixed effect) or \u3c.05 (fixed effect). To address the complexity of cGVHD diagnosis in children, we built a machine learning-based classifier that combined multiple cellular and plasma biomarkers with clinical factors. Decreases in regulatory natural killer cells, naïve CD4 T helper cells, and naïve regulatory T cells, and elevated levels of CXCL9, CXCL10, CXCL11, ST2, ICAM-1, and soluble CD13 (sCD13) characterize the onset of cGVHD. Evaluation of the time dependence revealed that sCD13, ST2, and ICAM-1 levels varied with the timing of cGVHD onset. The cGVHD diagnostic classifier achieved an AUC of 0.89, with a positive predictive value of 82% and a negative predictive value of 80% for diagnosing cGVHD. Our polyomic approach to building a diagnostic classifier could help improve the diagnosis of cGVHD in children but requires validation in future prospective studies. This trial was registered at www.clinicaltrials.gov as #NCT02067832
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