1,144 research outputs found

    Ethnicity, Gender, and the Education of Cambodian American Students in an Urban High School

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    This paper explores the role of gender and ethnicity in the education of Cambodian American high school students. Using a qualitative approach, we interviewed ninth-grade Cambodian American students (n=10), teachers (n=4), and administrators (n=2) from a California high school. The data revealed that Cambodian students are often mistaken for other Asian groups and due to stereotypes, expected to excel academically. Fearing that they would disappoint their teachers or be ridiculed by other students, students remain silent about their academic struggles. Culturally-based gender and familial expectations also play prominent roles for both Cambodian boys and girls and their academic progress

    Testing for Instability in Factor Structure of Yield Curves

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    A widely relied upon but a formally untested consideration is the issue of stability in actors underlying the term structure of interest rates. In testing for stability, practitioners as well as academics have employed ad hoc techniques such as splitting the sample into a few sub-periods and determining whether the factor loadings have appeared to be similar over all sub-periods. Various authors have found mixed evidence on stability in the actors. In this paper we develop a formal testing procedure to evaluate the factor structure stability of the US zero coupon yield term structure. We find the factor structure of level to be unstable over the sample period considered. The slope and curvature factor structures are however found to be stable. Common structural changes affecting all interest rate maturities have fostered instability in the level factor. We corroborate the literature that variances (volatility) explained by the level, slope, and curvature factors are unstable over time. We find that the volatility of slope factor is sensitive to shocks affecting the short rates and the volatility of curvature factor is sensitive to shocks affecting the medium and long rates. Finally, we find evidence of the presence of common economic shocks affecting the level and slope factors, unlike slope and curvature factors that responded differently to economic shocks and were unaffected by any common instabilities

    The super-oscillating superlens

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    We demonstrate a lens that creates a sub-wavelength focal spot beyond the near-field by exploiting the phenomenon of super-oscillation

    Onco-miR-155 targets SHIP1 to promote TNFalpha-dependent growth of B cell lymphomas.

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    Non-coding microRNAs (miRs) are a vital component of post-transcriptional modulation of protein expression and, like coding mRNAs harbour oncogenic properties. However, the mechanisms governing miR expression and the identity of the affected transcripts remain poorly understood. Here we identify the inositol phosphatase SHIP1 as a bonafide target of the oncogenic miR-155. We demonstrate that in diffuse large B cell lymphoma (DLBCL) elevated levels of miR-155, and consequent diminished SHIP1 expression are the result of autocrine stimulation by the pro-inflammatory cytokine tumour necrosis factor a (TNFalpha). Anti-TNFalpha regimen such as eternacept or infliximab were sufficient to reduce miR-155 levels and restored SHIP1 expression in DLBCL cells with an accompanying reduction in cell proliferation. Furthermore, we observed a substantial decrease in tumour burden in DLBCL xenografts in response to eternacept. These findings strongly support the concept that cytokine-regulated miRs can function as a crucial link between inflammation and cancer, and illustrate the feasibility of anti-TNFalpha therapy as a novel and immediately accessible (co)treatment for DLBCL

    FedZero: Leveraging Renewable Excess Energy in Federated Learning

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    Federated Learning (FL) is an emerging machine learning technique that enables distributed model training across data silos or edge devices without data sharing. Yet, FL inevitably introduces inefficiencies compared to centralized model training, which will further increase the already high energy usage and associated carbon emissions of machine learning in the future. Although the scheduling of workloads based on the availability of low-carbon energy has received considerable attention in recent years, it has not yet been investigated in the context of FL. However, FL is a highly promising use case for carbon-aware computing, as training jobs constitute of energy-intensive batch processes scheduled in geo-distributed environments. We propose FedZero, a FL system that operates exclusively on renewable excess energy and spare capacity of compute infrastructure to effectively reduce the training's operational carbon emissions to zero. Based on energy and load forecasts, FedZero leverages the spatio-temporal availability of excess energy by cherry-picking clients for fast convergence and fair participation. Our evaluation, based on real solar and load traces, shows that FedZero converges considerably faster under the mentioned constraints than state-of-the-art approaches, is highly scalable, and is robust against forecasting errors

    Physical Activity among Asian American Adults: Data from the 2010 Health of Houston Survey

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    Purpose: The Asian American population represents the fastest growing minority groups in the US; yet, little is still known about physical activity (PA) among Asian Americans. This study examines PA among Asian American adults living in the Houston, TX area. Methods: Data on adults aged 18 and over were drawn from the Health of Houston Survey 2010—a population-based survey focused in the city of Houston and Harris County. PA was operationalized in two ways: number of moderate leisure-time PA days in the past week; and meeting CDC recommendations for aerobic exercise. Multivariate regression models (negative binomial and logistic) were used to compare the PA of Asian Americans with other racial/ethnic groups in the area (white, African American, and Hispanic) and to determine key predictors of PA among Asian Americans and specific Asian ethnic groups (Chinese, Vietnamese, and South Asians). Results: Asians emerged as the only racial/ethnic group that was significantly less likely than whites to have sufficient PA levels (OR=0.66). Both Asians and Hispanics had similarly lower expected numbers of PA days compared to whites (Incidence Rate Ratios or IRR=0.91 and 0.89, respectively), although the effect of being Asian was not significant. Within the Asian sample, Vietnamese had a significantly higher expected number of PA days, compared to their Chinese counterparts (IRR=1.36). Compared to the 18-24 age group, older Asians aged 65 and older had significantly higher expected number of PA days (almost one additional expected day; IRR=1.90) and were 61% more likely to have sufficient PA levels. Low educational achievement and immigrant status were key predictors of decreased PA. Conclusions: Results suggest that Asians are among the least physically active of the major racial/ethnic groups. In contrast to other racial/ethnic groups in the US, older Asians tend to be more active than younger Asians and Asian immigrants are less active than US-born Asians. These findings highlight the need for more targeted and culturally competent interventions to promote physical activity in Asian American communities

    Inhibition of Toxic IAPP Amyloid by Extracts of Common Fruits

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    The aggregation of the 37-amino acid polypeptide islet amyloid polypeptide (IAPP, amylin), as either insoluble amyloid or as small oligomers, appears to play a direct role in the death of pancreatic β-islet cells in type 2 diabetes. It is believed that inhibiting the aggregation of IAPP may slow down, if not prevent entirely, the progression of this disease. Extracts of thirteen different common fruits were analyzed for their ability to prevent the aggregation of amyloidogenic IAPP. Thioflavin T binding, immuno-detection and circular dichroism assays were performed to test the in vitro inhibitory potential of each extract. Atomic force microscopy was used to visualize the formation of amyloid fibrils with and without each fruit extract. Finally, extracts were tested for their ability to protect living mammalian cells from the toxic effects of amyloid IAPP. Several fruits showed substantial ability to inhibit IAPP aggregation and protect living cells from toxic IAPP amyloid

    Phylogenetic Structure and Sequential Dominance of Sub-Lineages of PRRSV Type-2 Lineage 1 in the United States

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    The genetic diversity and frequent emergence of novel genetic variants of porcine reproductive and respiratory syndrome virus type-2 (PRRSV) hinders control efforts, yet drivers of macro-evolutionary patterns of PRRSV remain poorly documented. Utilizing a comprehensive database of >20,000 orf5 sequences, our objective was to classify variants according to the phylogenetic structure of PRRSV co-circulating in the U.S., quantify evolutionary dynamics of sub-lineage emergence, and describe potential antigenic differences among sub-lineages. We subdivided the most prevalent lineage (Lineage 1, accounting for approximately 60% of available sequences) into eight sub-lineages. Bayesian coalescent SkyGrid models were used to estimate each sub-lineage’s effective population size over time. We show that a new sub-lineage emerged every 1 to 4 years and that the time between emergence and peak population size was 4.5 years on average (range: 2–8 years). A pattern of sequential dominance of different sub-lineages was identified, with a new dominant sub-lineage replacing its predecessor approximately every 3 years. Consensus amino acid sequences for each sub-lineage differed in key GP5 sites related to host immunity, suggesting that sub-lineage turnover may be linked to immune-mediated competition. This has important implications for understanding drivers of genetic diversity and emergence of new PRRSV variants in the U.S

    γ-H2AX Kinetics as a Novel Approach to High Content Screening for Small Molecule Radiosensitizers

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    Persistence of γ-H2AX after ionizing radiation (IR) or drug therapy is a robust reporter of unrepaired DNA double strand breaks in treated cells.DU-145 prostate cancer cells were treated with a chemical library ±IR and assayed for persistence of γ-H2AX using an automated 96-well immunocytochemistry assay at 4 hours after treatment. Hits that resulted in persistence of γ-H2AX foci were tested for effects on cell survival. The molecular targets of hits were validated by molecular, genetic and biochemical assays and in vivo activity was tested in a validated Drosophila cancer model.We identified 2 compounds, MS0019266 and MS0017509, which markedly increased persistence of γ-H2AX, apoptosis and radiosensitization in DU-145 cells. Chemical evaluation demonstrated that both compounds exhibited structurally similar and biochemical assays confirmed that these compounds inhibit ribonucleotide reductase. DNA microarray analysis and immunoblotting demonstrates that MS0019266 significantly decreased polo-like kinase 1 gene and protein expression. MS0019266 demonstrated in vivo antitumor activity without significant whole organism toxicity.MS0019266 and MS0017509 are promising compounds that may be candidates for further development as radiosensitizing compounds as inhibitors of ribonucleotide reductase
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