8,270 research outputs found

    Cost-Sensitive Decision Tree with Multiple Resource Constraints

    Get PDF
    Resource constraints are commonly found in classification tasks. For example, there could be a budget limit on implementation and a deadline for finishing the classification task. Applying the top-down approach for tree induction in this situation may have significant drawbacks. In particular, it is difficult, especially in an early stage of tree induction, to assess an attribute’s contribution to improving the total implementation cost and its impact on attribute selection in later stages because of the deadline constraint. To address this problem, we propose an innovative algorithm, namely, the Cost-Sensitive Associative Tree (CAT) algorithm. Essentially, the algorithm first extracts and retains association classification rules from the training data which satisfy resource constraints, and then uses the rules to construct the final decision tree. The approach has advantages over the traditional top-down approach, first because only feasible classification rules are considered in the tree induction and, second, because their costs and resource use are known. In contrast, in the top-down approach, the information is not available for selecting splitting attributes. The experiment results show that the CAT algorithm significantly outperforms the top-down approach and adapts very well to available resources.Cost-sensitive learning, mining methods and algorithms, decision trees

    Gratitude and athletes’ life satisfaction: a intra-individual analysis on the moderation of ambivalence over emotional expression

    Get PDF
    Research on gratitude usually focus on how trait gratitude can contribute to higher subjective well-being, but rarely focus on the role of state gratitude in shaping one’s subjective well-being at a given moment. Focusing on intra-individual differences, the first aim of this study is to examine whether state gratitude will contribute to higher state life satisfaction. Nevertheless, state gratitude may not always contribute to higher state life satisfaction. The second aim of this study is to determinate that when ambivalence over emotional expression in a given moment becomes higher, the association between state gratitude and state life satisfaction will become weaker. Twenty-nine elite student athletes were recruited and completed weekly questionnaires measuring gratitude, life satisfaction, and ambivalence over emotional expression across 10 weeks. Results of hierarchical linear modeling support hypotheses, showing that weekly gratitude positively predicted weekly life satisfaction, but this association was weaker when weekly ambivalence over emotional expression was higher than lower. Contributions to gratitude studies are discussed

    A systematic review of recruitment for older Chinese immigrants into clinical trials

    Full text link
    Purpose: To identify barriers and discuss strategies for recruitment of older Chinese immigrants into clinical research studies. Methods: A systematic review was conducted using Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA). PubMed, WEB of Science, CINAHL Plus, and the Cochrane Central Register of Controlled Trials were searched from 2001 to 2014. Empirical studies with Chinese immigrants aged 60 or older were identified and analyzed. Numerical analysis, such as calculation of response rates as indexes for recruitment outcomes, was conducted. Content analyses for recruitment barriers were abstracted. Results: Thirteen studies of 4753 subjects were analyzed. Response rates ranged from 39% to 99%. Recruitment barriers include younger old age (i.e., 60-70 years old), low health literacy, longer length of stay in the US, limited English speaking ability, low acculturation, time constraints, inadequate transportation, social stigma about diseases, and mistrust of researchers. Discussion: Recruitment can be facilitated by overcoming the aforementioned barriers, which include the following strategies: 1) using convenience sampling methods, particularly personal referral; 2) using special techniques to recruit younger subgroup of Chinese elders, such as doing outreach on holidays or weekends; 3) communicating effectively using participants’ native language; 4) exercising cultural competency; 5) establishing relationships of trust with participants and community leaders; 6) answering misconceptions about clinical trials; 7) providing incentives for participation; and 8) proper selection of research and interview locations

    Regulation of CLC-1 chloride channel biosynthesis by FKBP8 and Hsp90β.

    Get PDF
    Mutations in human CLC-1 chloride channel are associated with the skeletal muscle disorder myotonia congenita. The disease-causing mutant A531V manifests enhanced proteasomal degradation of CLC-1. We recently found that CLC-1 degradation is mediated by cullin 4 ubiquitin ligase complex. It is currently unclear how quality control and protein degradation systems coordinate with each other to process the biosynthesis of CLC-1. Herein we aim to ascertain the molecular nature of the protein quality control system for CLC-1. We identified three CLC-1-interacting proteins that are well-known heat shock protein 90 (Hsp90)-associated co-chaperones: FK506-binding protein 8 (FKBP8), activator of Hsp90 ATPase homolog 1 (Aha1), and Hsp70/Hsp90 organizing protein (HOP). These co-chaperones promote both the protein level and the functional expression of CLC-1 wild-type and A531V mutant. CLC-1 biosynthesis is also facilitated by the molecular chaperones Hsc70 and Hsp90β. The protein stability of CLC-1 is notably increased by FKBP8 and the Hsp90β inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) that substantially suppresses cullin 4 expression. We further confirmed that cullin 4 may interact with Hsp90β and FKBP8. Our data are consistent with the idea that FKBP8 and Hsp90β play an essential role in the late phase of CLC-1 quality control by dynamically coordinating protein folding and degradation

    Bacterial Colonization of Point-of-Use (PoU) Drinking Water Filters, Selection of Opportunistic Pathogens and Presence of Antibiotic Resistance Genes

    Full text link
    Commercial activated carbon block (ACB) point-of-use (PoU) drinking water filters are widely used to remove chemicals of concern from tap water. ACB PoU filters, however, are an incubator of bacteria because they remove disinfectant residual and adsorb organic compounds that can serve as bacterial substrates. The chemicals adsorbed on the ACB, such as disinfection byproducts (DBPs), may interact with colonizing bacteria. Bacterial growth in ACB PoU filters raises questions about whether waterborne bacteria that pose health risks can be enriched, such as enteric-related bacteria, opportunistic pathogens, and antibiotic resistant gene (ARG)-carrying bacteria. The goal of this dissertation is to understand how ACB PoU filters change the microbial ecology of drinking water using culture-based and culture-independent methods. A lab-scale ACB PoU filter system experiment was conducted to study the bacterial composition shifts across the filters with and without the addition of pentachlorophenol (PCP), a surrogate chlorinated phenolic disinfection byproduct. The results show that the PoU filter has a primary effect on altering the bacterial composition and increasing the abundance of Mycobacterium, while the influence of PCP was subtle. A field study was conducted to evaluate the prevalence of ARGs across the ACB PoU filters installed at different households in Flint, Michigan. The study indicates that ACB PoU filters raised the occurrence and abundance of some ARGs in the tap water. The increase in ARGs across filters was also detected in a lab-scale system in Ann Arbor. Lastly, the mechanism of bacterial migration through the ACB PoU filters was studied by spiking inert bacterial-sized particles (1 μm) and fluorescent-tagged Escherichia coli and Pseudomonas aeruginosa into the system. We found that preferential flow pathways existed in the ACB, allowing bacteria to pass through rapidly. Differences in growth, biofilm formation, and physical properties of the spiked species determine their migration and survival through the ACB PoU filters.PHDEnvironmental EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/147708/1/cchenwu_1.pd

    Comparison of Radical Scavenging Activity, Cytotoxic Effects and Apoptosis Induction in Human Melanoma Cells by Taiwanese Propolis from Different Sources

    Get PDF
    Propolis is a sticky substance that is collected from plants by honeybees. We previously demonstrated that propolins A, B, C, D, E and F, isolated from Taiwanese propolis (TP), could effectively induce human melanoma cell apoptosis and were strong antioxidant agents. In this study, we evaluated TP for free radical scavenging activity by DPPH (1,2-diphenyl-2-picrylhydrazyl). The phenolic concentrations were quantified by the Folin–Ciocalteu method. The apoptosis trigger activity in human melanoma cells was evaluated. TP contained a higher level of phenolic compounds and showed strong capability to scavenge free radicals. Additionally, TP1g, TP3, TP4 and TP7 exhibited a cytotoxic effect on human melanoma cells, with an IC(50) of ∼2.3, 2.0, 3.3 and 3.3 μg/ml, respectively. Flow cytometric analysis for DNA fragmentation indicated that TP1g, TP2, TP3 and TP7 could induce apoptosis in human melanoma cells and there is a marked loss of cells from the G2/M phase of the cell cycle. To address the mechanism of the apoptosis effect of TP, we evaluated its effects on induction of apoptosis-related proteins in human melanoma cells. The levels of procaspase-3 and PARP [poly(ADP-ribose) polymerase] were markedly decreased. Furthermore, propolins A, B, C, D, E and F in TP were determined using HPLC. The results indicate that TP is a rich source of these compounds. The findings suggest that TP induces apoptosis in human melanoma cells due to its high level of propolins

    Unpacking the role of self-esteem in career uncertainty: a self-determination perspective

    Get PDF
    The aim of this study is to explain why students with high self-esteem have lower career uncertainty than students with low self-esteem. Based on self-determination theory, students with high self-esteem would have higher efficacy in making decisions, which would encourage them to choose a major for self-concordance, such as interest and ability, and increase their course involvement. Both factors are assumed to be related to lower career uncertainty. Data from a national survey of the Taiwan Higher Education Database within the Survey Research Data Archive from juniors at 92 colleges and universities in Taiwan (N = 7418) were analyzed to examine the model. Results supported the proposed model by showing that students with high self-esteem had lower career uncertainty because they chose a major for self-concordant reasons and had a strong motivation to learn, both of which contribute to lower career uncertainty

    N,N′-Bis(6-methyl-2-pyrid­yl)oxamide

    Get PDF
    In the crystal structure of the title compound, C14H14N4O2, the mol­ecules are almost planar (mean deviation 0.028 Å) and a weak intra­molecular N—H⋯O hydrogen bond between the H atom bound to an oxamide N atom and a carbonyl O atom is found. The asymmetric unit consits of one half-mol­ecule which is located on a centre of inversion
    corecore