2,619,722 research outputs found

    Exploring Students’ Weaknesses in Reading Through Diagnostic Test

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    This thesis is entitled “Exploring students’ weaknesses in reading through diagnostic test”. Reading is the ability to achieve the meaning from written material. Reading is a substantial skill that needs to be taught in junior high school based on the ministry of the national education’s policy. Diagnostic test is used to identify students’ strength and weaknesses. This research is aimed to know whether Diagnostic Test could identify the problems faced by the students’ in reading. This research utilized quantitative approach by using test as an instrument. The population of this research was the second year students of SMP Negeri 5 Banda Aceh, and the sample was the students of class VIII 1. To collect the data, the researcher gave a test to the students. To analyze the result of the test percentages formula was used. Based on the findings, diagnostic test could find out students problems in reading. The result indicated that most of student (less than 50%) in understanding reading text, functional, but have serious problems in understanding main idea, supporting idea, synonym words and the purpose of the text(100%)

    Exploring atmospheric radon with airborne gamma-ray spectroscopy

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    222^{222}Rn is a noble radioactive gas produced along the 238^{238}U decay chain, which is present in the majority of soils and rocks. As 222^{222}Rn is the most relevant source of natural background radiation, understanding its distribution in the environment is of great concern for investigating the health impacts of low-level radioactivity and for supporting regulation of human exposure to ionizing radiation in modern society. At the same time, 222^{222}Rn is a widespread atmospheric tracer whose spatial distribution is generally used as a proxy for climate and pollution studies. Airborne gamma-ray spectroscopy (AGRS) always treated 222^{222}Rn as a source of background since it affects the indirect estimate of equivalent 238^{238}U concentration. In this work the AGRS method is used for the first time for quantifying the presence of 222^{222}Rn in the atmosphere and assessing its vertical profile. High statistics radiometric data acquired during an offshore survey are fitted as a superposition of a constant component due to the experimental setup background radioactivity plus a height dependent contribution due to cosmic radiation and atmospheric 222^{222}Rn. The refined statistical analysis provides not only a conclusive evidence of AGRS 222^{222}Rn detection but also a (0.96 ±\pm 0.07) Bq/m3^{3} 222^{222}Rn concentration and a (1318 ±\pm 22) m atmospheric layer depth fully compatible with literature data.Comment: 17 pages, 8 figures, 2 table

    Exosome-mediated transfer of miR-222 is sufficient to increase tumor malignancy in melanoma

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    BACKGROUND: Growing evidence is showing that metastatic cell populations are able to transfer their characteristics to less malignant cells. Exosomes (EXOs) are membrane vesicles of endocytic origin able to convey their cargo of mRNAs, microRNAs (miRs), proteins and lipids from donors to proximal as well as distant acceptor cells. Our previous results indicated that miR-221&222 are key factors for melanoma development and dissemination. The aim of this study was to verify whether the tumorigenic properties associated with miR-222 overexpression can be also propagated by miR-222-containing EXOs. METHODS: EXOs were isolated by UltraCentrifugation or Exoquick-TC(®) methods. Preparations of melanoma-derived vesicles were characterized by using the Nanosight™ technology and the expression of exosome markers analyzed by western blot. The expression levels of endogenous and exosomal miRNAs were examined by real time PCR. Confocal microscopy was used to evaluate transfer and uptake of microvesicles from donor to recipient cells. The functional significance of exosomal miR-222 was estimated by analyzing the vessel-like process formation, as well as cell cycle rates, invasive and chemotactic capabilities. RESULTS: Besides microvesicle marker characterization, we evidenced that miR-222 exosomal expression mostly reflected its abundance in the cells of origin, correctly paralleled by repression of its target genes, such as p27Kip1, and induction of the PI3K/AKT pathway, thus confirming its functional implication in cancer. The possible differential significance of PI3K/AKT blockade was assessed by using the BKM120 inhibitor in miR-222-transduced cell lines. In addition, in vitro cultures showed that vesicles released by miR-222-overexpressing cells were able to transfer miR-222-dependent malignancy when taken-up by recipient primary melanomas. Results were confirmed by antagomiR-221&222 treatments and by functional observations after internalization of EXOs devoid of these miRs

    MicroRNA-222 regulates muscle alternative splicing through Rbm24 during differentiation of skeletal muscle cells

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    A number of microRNAs have been shown to regulate skeletal muscle development and differentiation. MicroRNA-222 is downregulated during myogenic differentiation and its overexpression leads to alteration of muscle differentiation process and specialized structures. By using RNA-induced silencing complex (RISC) pulldown followed by RNA sequencing, combined with in silico microRNA target prediction, we have identified two new targets of microRNA-222 involved in the regulation of myogenic differentiation, Ahnak and Rbm24. Specifically, the RNA-binding protein Rbm24 is a major regulator of muscle-specific alternative splicing and its downregulation by microRNA-222 results in defective exon inclusion impairing the production of muscle-specific isoforms of Coro6, Fxr1 and NACA transcripts. Reconstitution of normal levels of Rbm24 in cells overexpressing microRNA-222 rescues muscle-specific splicing. In conclusion, we have identified a new function of microRNA-222 leading to alteration of myogenic differentiation at the level of alternative splicing, and we provide evidence that this effect is mediated by Rbm24 protei

    Action of HMGB1 on miR221/222 cluster in neuroblastoma cell lines

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    microRNA (miR/miRNA) are small non-coding RNAs that control gene expression at the post-transcriptional level by targeting mRNAs. Aberrant expression of miRNAs is often observed in different types of cancer. Specific miRNAs function as tumor suppressors or oncogenes and interfere with various aspects of carcinogenesis, including differentiation, proliferation and invasion. Upregulation of miRNAs 221 and 222 has been shown to induce a malignant phenotype in numerous human cancers via inhibition of phosphatase and tensin homolog (PTEN) expression. Neuroblastoma is the most common extracranial solid malignancy in children, which is characterized by cellular heterogeneity that corresponds to different clinical outcomes. The different cellular phenotypes are associated with different gene mutations and miRs that control genetic and epigenetic factors. For this reason miRs are considered a potential therapeutic target in neuroblastoma. The aim of the present study was to investigate the mechanisms by which extracellular high mobility group box 1 (HMGB1) promotes cell growth in neuroblastoma. SK-N-BE(2) and SH-SY5Y neuroblastoma derived cell lines were transfected with the antisense oligonucleotides, anti-miR-221 and -222, followed by treatment with HMGB1 to investigate the expression of the oncosuppressor PTEN. In this study, it was demonstrated that HMGB1, which is released by damaged cells and tumor cells, upregulates miR-221/222 oncogenic clusters in the two human neuroblastoma derived cell lines. The results revealed that the oncogenic cluster miRs 221/222 were more highly expressed by the most undifferentiated cell line [SK-N-BE(2)] compared with the the less tumorigenic cell line (SH-SY5Y) and that exogenous HMGB1 increases this expression. In addition, HMGB1 modulates PTEN expression via miR-221/222, as demonstrated by transiently blocking miR-221/222 with anti-sense oligonucleotides. These results may lead to the development of novel therapeutic strategies for neuroblastoma

    Synchronous collaborative information retrieval with relevance feedback

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    Collaboration has been identified as an important aspect in information seeking. People meet to discuss and share ideas and through this interaction an information need is quite often identified. However the process of resolving this information need, through interacting with a search engine and performing a search task, is still an individual activity. We propose an environment which allows users to collaborate to satisfy a shared information need. We discuss ways to divide the search task amongst collaborators and propose the use of relevance feedback, a common information retrieval process, to enable the transfer of knowledge across collaborators during a search session. We describe the process by which co-searchers can collaborate effectively with little redundancy and how we can combine relevance judgements from multiple searchers into a coherent model for synchronous collaborative information retrieva

    A STUDY ON TROY PHELAN TESTAMENT IN JOHN GRISHAM’S NOVEL “THE TESTAMENT”

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    This study concerned with John Grisham novel “The Testament”. The writer of this thesis appreciates particularly novel, because novel is one of literary work which has purpose for entertainment, enjoyment and information. Reading novel means reading the life of society. Literary work expresses a series of happening of human life, for instance, problem, and struggles of life on human’s of life. The writer of this thesis focuses on Troy Phelan’s “Testament” in John Grisham Novel “The Testament” as the topic of the thesis. The purpose of the analysis is to describe the content of Troy Phelan’s Testament, the background why Troy Phelan made the Testament, and the reaction Troy Phelan’s families toward his testament. This research used descriptive qualitative design because there was no treatment as in experimental research. This research just described or interpreted what exist with respect to conditional or situation. In this study the writer of the thesis did not need to study the author’s life, the back ground of the works, and the background of society, but just analyzed the work itself. The object of this study is the whole events or elements that exist in John Grisham novel “The Testament”. From the analysis, it is found that the content of the testament are: Troy Phelan’s testaments for his children and for his ex-wives. The backgrounds why Troy Phelan made the Testament are: (1) Troy Phelan’s felt that his family didn’t love him anymore. (2) Troy Phelan did not want to give his wealth to the stupid people such as his families. (3) Troy Phelan did not want his wealth to be spent by greedy people like his families. The reactions of Troy Phelan’s families toward to his testament are: first Troy families tried to prove that he was crazy, and second was class action together with their lawyer

    Recent exposure to ultrafine particles in school children alters miR-222 expression in the extracellular fraction of saliva

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    Background: Ultrafine particles (< 100 nm) are ubiquitous present in the air and may contribute to adverse cardiovascular effects. Exposure to air pollutants can alter miRNA expression, which can affect downstream signaling pathways. miRNAs are present both in the intracellular and extracellular environment. In adults, miR-222 and miR-146a were identified as associated with particulate matter exposure. However, there is little evidence of molecular effects of ambient air pollution in children. This study examined whether exposure to fine and ultrafine particulate matter (PM) is associated with changes in the extracellular content of miR-222 and miR-146a of children. Methods: Saliva was collected from 80 children at two different time points, circa 11 weeks apart and stabilized for RNA preservation. The extracellular fraction of saliva was obtained by means of differential centrifugation and ultracentrifugation. Expression levels of miR-222 and miR-146a were profiled by qPCR. We regressed the extracellular miRNA expression against recent exposure to ultrafine and fine particles measured at the school site using mixed models, while accounting for sex, age, BMI, passive smoking, maternal education, hours of television use, time of the day and day of the week. Results: Exposure to ultrafine particles (UFP) at the school site was positively associated with miR-222 expression in the extracellular fraction in saliva. For each IQR increase in particles in the class room (+8504 particles/cm(3)) or playground (+ 28776 particles/cm(3)), miR-222 was, respectively 23.5 % (95 % CI: 3.5 %-41.1 %; p = 0.021) or 29.9 % (95 % CI: 10.6 %-49.1 %; p = 0.0027) higher. No associations were found between miR-146a and recent exposure to fine and ultrafine particles. Conclusions: Our results suggest a possible epigenetic mechanism via which cells respond rapidly to small particles, as exemplified by miR-222 changes in the extracellular fraction of saliva

    Odyssey of the Eyes Intermediate Level

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    The purpose of this resource is to familiarize students with modeling as it relates to remote sensing and digitized images. Students will use the symbolic map created in the beginning activity to produce a digitized image and begin to see why ground verification of satellite data is necessary. Educational levels: Middle school, High school
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