146 research outputs found

    Effective Vocabulary Instruction Using the Four Domains of Language

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    The purpose of this action research study was to determine whether using the four domains of language (listening, speaking, reading, and writing) during vocabulary instruction in reading and math would impact students’ vocabulary knowledge. The sample population consisted of high school students who were receiving Title I services in both reading and math. In total, 14 African-American students participated. These 14 participants were taught weekly target words in both reading and math during an eight-week period. The study was divided into a four-week nonintervention period and a four-week intervention period. During the nonintervention period, students utilized listening and speaking to discuss each word in different contexts. During the intervention period, the same students utilized reading and writing, as well as listening and speaking, to interact with each word in multiple contexts. Additionally, throughout the nonintervention and intervention, students self-assessed their knowledge of the terms via the Vocabulary Knowledge Rating Chart. Data comparing the nonintervention and the intervention pre- and posttest vocabulary scores revealed that students made significant gains in their ability to define the target words, compose sentences utilizing the words in context, and complete a cloze activity after receiving the intervention. Likewise, students overall increased their self-rating of the terms via the Vocabulary Knowledge Rating Chart, meaning students believed they could better define and use the terms after receiving the intervention. Limitations of the study included a small sample population (14 students) over a short duration (eight weeks). As a result of this study, the following recommendations for effective vocabulary instruction were made for classroom teachers: provide explicit instruction in metacognition, focus on a limited number of words in multiple contexts, and incorporate the four domains of language

    Gene expression profiling reveals effects of Cimicifuga racemosa (L.) NUTT. (black cohosh) on the estrogen receptor positive human breast cancer cell line MCF-7

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    BACKGROUND: Extracts from the rhizome of Cimicifuga racemosa (black cohosh) are increasingly popular as herbal alternative to hormone replacement therapy (HRT) for the alleviation of postmenopausal disorders. However, the molecular mode of action and the active principles are presently not clear. Previously published data have been largely contradictory. We, therefore, investigated the effects of a lipophilic black cohosh rhizome extract and cycloartane-type triterpenoids on the estrogen receptor positive human breast cancer cell line MCF-7. RESULTS: Both extract and purified compounds clearly inhibited cellular proliferation. Gene expression profiling with the extract allowed us to identify 431 regulated genes with high significance. The extract induced expression pattern differed from those of 17beta-estradiol or the estrogen receptor antagonist tamoxifen. We observed a significant enrichment of genes in an anti-proliferative and apoptosis-sensitizing manner, as well as an increase of mRNAs coding for gene products involved in several stress response pathways. These functional groups were highly overrepresented among all regulated genes. Also several transcripts coding for oxidoreductases were induced, as for example the cytochrome P450 family members 1A1 and 1B1. In addition, some transcripts associated with antitumor but also tumor-promoting activity were regulated. Real-Time RT-PCR analysis of 13 selected genes was conducted after treatment with purified compounds - the cycloartane-type triterpene glycoside actein and triterpene aglycons - showing similar expression levels compared to the extract. CONCLUSION: No estrogenic but antiproliferative and proapoptotic gene expression was shown for black cohosh in MCF-7 cells at the transcriptional level. The effects may be results of the activation of different pathways. The cycloartane glycosides and - for the first time - their aglycons could be identified as an active principle in black cohosh

    Restarts and Nogood Recording in Qualitative Constraint-based Reasoning

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    This paper introduces restart and nogood recording techniques in the domain of qualitative spatial and temporal reasoning. Nogoods and restarts can be applied orthogonally to usual methods for solving qualitative constraint satisfaction problems. In particular, we propose a more general definition of nogoods that allows for exploiting information about nogoods and tractable subclasses during backtracking search. First evaluations of the proposed techniques show promising results

    Experimental evidence for crustacean zooplankton grazing activity on mixotrophic ciliates

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    With their ultraoligotrophic status, the Chilean North Patagonian lakes have mixotrophic ciliates in their pelagic environments as producers, whereas the primary consumers are crustaceans that are low in abundance and species numbers. The aim of the present study was to determine the potential grazer role of mixotrophic ciliates on crustacean zooplankton collected in a lake without mixotrophic ciliates. Three experiments were conducted; one had a control with mixotrophic ciliates and an experimental treatment including the copepod Boeckella gracilipes obtained from Caburgua lake, whereas the second and third experiments had a control without zooplankton, and three treatments with the addition of Daphnia pulex and Mesocyclops araucanus, and a third treatment with equal amounts of both species. The results revealed grazing effects on the mixotrophic ciliates in the experimental treatments. This finding supports the evidence from the field and experiments suggesting that, in the transition from oligotrophy to mesotrophy with consequent changes in zooplankton, species number and abundance of mixotrophic ciliates decrease in their abundanc

    Distribuição vertical diária do zooplâncton em dois lagos oligo-mesotróficos ao norte da Patagônia (39º S, Chile)

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    The zooplankton communities often exhibit daily vertical migrations to avoid natural ultraviolet radiation and/or fish predation. However there is no information on this topic in Chilean North Patagonian lakes up to date. Therefore, this study deals with a first characterization of plankton crustacean daily vertical migration in two temperate, oligotrophic lakes (Villarrica and Panguipulli lakes, 39°S) in Southern Chile. Zooplankton were collected at different depths intervals (0-10m, 10-20 m, 20-30m, 30-40m) at early morning, middle day, evening and night in the studied site. The results revealed that zooplankton species (Daphnia pulex, Ceriodaphnia dubia, Neobosmina chilensis, Mesocyclops araucanus, and Tropocyclops prasinus) are abundant in surface zones at night, early morning and evening, whereas at middle day the zooplankton abundances are high at deep zones. The results agree with observations for Argentinean and North American lakes where these daily migration patterns in crustacean zooplankton species were reported due mainly natural ultraviolet radiation exposure, whereas for northern hemisphere lakes the vertical migration is due to combined effect of natural ultraviolet radiation and fish predation exposur

    Ownership of co-creation assets: driving B2B value propositions in the service economy

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    The benefits of specialization have been driving the rise of the service economy and pushing capability frontiers and economic growth. In service economies, almost any activity, asset, and skill can be bought on competitive markets, making it harder to build competitive advantage on any of those inputs. Against that background, the question emerges what constitutes sustainable value propositions of service providers. Drawing on an emerging stream of research on the non-ownership value of services, we argue that service providers create value by taking on ownership of service assets and thereby transform uncertainty of value creation into economic opportunities. In our view, service providers offer the essential value proposition of transforming their clients’ uncertainty downsides into opportunities related to assets such as vehicles, real estate, equipment and computing platforms. Clients benefit by delegating ownership of assets to the domain of a service provider. In turn, clients can focus their investment on their most promising assets. Service providers create sustainable competitive advantage by assuming ownership and excelling at the management of (a) unique physical assets, (b) unique intangible assets and (c) maintaining an appropriate architecture of social capital through customer relationships and business ecosystems

    On-target restoration of a split T cell-engaging antibody for precision immunotherapy

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    T cell-engaging immunotherapies are changing the landscape of current cancer care. However, suitable target antigens are scarce, restricting these strategies to very few tumor types. Here, we report on a T cell-engaging antibody derivative that comes in two complementary halves and addresses antigen combinations instead of single molecules. Each half, now coined hemibody, contains an antigen-specific single-chain variable fragment (scFv) fused to either the variable light (V-L) or variable heavy (V-H) chain domain of an anti-CD3 antibody. When the two hemibodies simultaneously bind their respective antigens on a single cell, they align and reconstitute the original CD3-binding site to engage T cells. Employing preclinical models for aggressive leukemia and breast cancer, we show that by the combinatorial nature of this approach, T lymphocytes exclusively eliminate dual antigen-positive cells while sparing single positive bystanders. This allows for precision targeting of cancers not amenable to current immunotherapies
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