3,537 research outputs found

    Insider and Outsider Perspective in Ethnographic Research

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    Emic and etic perspectives are consequential for research because they impact the research process, the findings of a study, and the argument made by the researcher about the implications of these findings. Moreover, because the nature of ethnographic work involves the interpretation of cultures (Geertz, 1973), there is a responsibility on the part of the researcher to the culture being studied because the perspective the researcher takes impacts the knowledge produced about the cultural group that is studied.Contributors to this discussion represent a variety of research areas including rhetoric, library studies, family, media, and intercultural communication. Recurrant themes include awareness, bias avoidance, personal distance, appreciation of one\u27s insider/ outsider status

    A Cholecystokinin B Receptor-Specific Aptamer Does Not Activate Receptor Signaling

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    Targeted nanoparticles which deliver effective doses of chemotherapeutic drugs directly to pancreatic tumors could improve treatment efficacy without the toxicities associated with systemic drug administration. One protein on tumor cells that can be targeted by nanoparticles is a G-protein coupled cell surface receptor, the cholecystokinin B receptor (CCKBR). Previously, we had shown that attaching the CCKBR ligand gastrin to the surface of nanoparticles can enhance their up-take by tumors. The drawback of using gastrin is that it can also activate the receptor, causing tumor cell growth. This study shows that a DNA aptamer that binds to the CCKBR and enhances nanoparticle up-take by tumors does not activate this receptor. PANC-1 cells, a cultured human pancreatic cancer cell line, were treated for 24 h with CCKBR aptamer 1153. Cell lysates were run on Bis-Tris gels, transferred to membranes, blocked in 5% BSA and incubated overnight with primary antibodies, including antibodies directly against phosphorylated-Akt (Ser473), total Akt, and beta-actin, a protein loading control. Although the CCKBR aptamer 1153 is internalized by pancreatic cancer cells in a receptor-mediated fashion, it does not stimulate cell proliferation. Because of this, we anticipate that it will not activate CCKBR signaling. If aptamer 1153 does not activate downstream receptor signaling, our future work will test whether the aptamer could be used to specifically direct drug-containing nanoparticles to tumors, making chemotherapy treatments for pancreatic cancer patients more effective with fewer off-target effects and toxicity

    A semiparametric model for heterogeneous panel data with fixed effects

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    © 2015 Elsevier B.V. All rights reservedfor semiparametric panel data models in a setting where both the time series and the cross section are large. Such settings are common in finance and other areas of economics. Our model allows for heterogeneous nonparametric covariate effects as well as unobserved time and individual specific effects that may depend on the covariates in an arbitrary way. To model the covariate effects parsimoniously, we impose a dimensionality reducing common component structure on them. In the theoretical part of the paper, we derive the asymptotic theory for the proposed procedure. In particular, we provide the convergence rates and the asymptotic distribution of our estimators. In the empirical part, we apply our methodology to a specific application that has been the subject of recent policy interest, that is, the effect of trading venue fragmentation on market quality. We use a unique dataset that reports the location and volume of trading on the FTSE 100 and FTSE 250 companies from 2008 to 2011 at the weekly frequency. We find that the effect of fragmentation on market quality is nonlinear and non-monotonic. The implied quality of the market under perfect competition is superior to that under monopoly provision, but the transition between the two is complicated

    Relationships between catches in flight and emergence traps of the mountain pine beetle, Dendroctonus ponderosae Hopk. (Col.: Scolytidae)

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    Daily emergence of the mountain pine beetle from lodgepole pine trees was monitored in the field by using caged bolts and by counting emergence holes on standing trees. Flying mountain pine beetles, pine engraver beetles and Pityogenes plagiatus knechteli (Swaine) were captured daily in two types of barrier traps. Daily totals of emergence holes and emergence into cages were moderately correlated with daily captures by both types of barrier traps. A simple model of daily emergence was developed based on estimates of brood density, daily proportions of brood adults, and daily proportions of brood adults ready to emerge. Daily catches of pine engravers and P. plagiatus knechteli were highly intercorrelated, but correlations with catches of mountain pine beetle were low for both species. The results are discussed in relation to beetle emergence and flight behaviour

    Lithic Management in the Chassey Culture Neolithic

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    The integrated technological approach of the lithic industries in Southern France Chassey culture and neighbouring cultures is a way to highlight a complex organisation of space. The development of long distance diffusion networks of lithic products from western Provence creates interdependence between producing-exporting sites and receiving-consuming sites. The analysis of their functioning, from raw material sources until remote consuming sites, is undergone on various scales (from supra-regional to local), through lithic technology and use wear analysis

    Development of real-time PCR and hybridization methods for detection and identification of thermophilic Campylobacter spp. in pig faecal samples

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    Aims: To develop a real-time (rt) PCR for species differentiation of thermophilic Campylobacter and to develop a method for assessing co-colonization of pigs by Campylobacter spp. Methods and results: The specificity of a developed 5’nuclease rt-PCR for species-specific identification of C. jejuni, C. coli, C. lari, C. upsaliensis and of a hipO gene nucleotide probe for detection of C. jejuni by colony-blot hybridization were determined by testing a total of 75 reference strains of Campylobacter spp. and related organisms. The rt-PCR method allowed species-specific detection of Campylobacter spp. in naturally infected pig faecal samples after an enrichment step, whereas the hybridization approach enhanced the specific isolation of C. jejuni (present in minority to C. coli) from pigs. Conclusions: The rt-PCR was specific for Campylobacter jejuni, C. coli, C. lari, and C. upsaliensis and the colony-blot hybridization approach provided an effective tool for isolation of C. jejuni from pig faecal samples typically dominated by C. coli. Significance and impact of study: Species differentiation between thermophilic Campylobacter is difficult by phenotypic methods and the developed rt-PCR provides an easy and fast method for such differentiation. Detection of C. jejuni by colony hybridization may increase the isolation rate of this species from pig feces
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