2,895 research outputs found

    A critical review of theory in social work journals: A replication study

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    Abstract: The purpose of this paper is multifold. Key aspects discussed include exploring the extent of theory discussion and progression in social work journals for the year 2004; discussing the necessity of theory in social work research and practice; reviewing previous research literature regarding evaluation of theory discussion and progression; proposing criteria for defining theory in social work journals; and presenting findings from the current study concerning theory discussion and progression in social work journals. Results: Of the 1,168 articles reviewed from 37 journals, 71 (approximately 6%) met the criteria for theory development with empirical base. Thus, a minimal number of articles (3 out of 71 or 4.2%) evaluated, based on the criteria in the theory quality scale (Table 1), received high quality ratings. Conclusion: Based on the results yielded by the analysis, we assert that social workers need to make a conscious effort to include theory in practice decisions. Keywords: Theory, social work theory, empirical assessment of theory, social work practice, theory progression, human behavior, and the social environment (HBSE

    A Young Stellar Cluster in the Nucleus of NGC 4449

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    We have obtained 1-2 A resolution optical Echellette spectra of the nuclear star cluster in the nearby starburst galaxy NGC 4449. The light is clearly dominated by a very young (6-10 Myr) population of stars. For our age dating, we have used recent population synthesis models to interpret the observed equivalent width of stellar absorption features such as the HI Balmer series and the CaII triplet around 8500 A. We also compare the observed spectrum of the nuclear cluster to synthesized spectra of simple stellar populations of varying ages. All these approaches yield a consistent cluster age. Metallicity estimates based on the relative intensities of various ionization lines yield no evidence for significant enrichment in the center of this low mass galaxy: the metallicity of the nuclear cluster is about one fourth of the solar value, in agreement with independent estimates for the disk material of NGC 4449.Comment: 24 pages (incl. 7 figures), accepted by AJ, March 2001 issue revised version with minor changes and additions, one additional figur

    Characterization of a far-red analog of ghrelin for imaging GHS-R in P19-derived cardiomyocytes.

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    Ghrelin and its receptor, the growth hormone secretagogue receptor (GHS-R), are expressed in the heart, and may function to promote cardiomyocyte survival, differentiation and contractility. Previously, we had generated a truncated analog of ghrelin conjugated to fluorescein isothiocyanate for the purposes of determining GHS-R expression in situ. We now report the generation and characterization of a far-red ghrelin analog, [Dpr(3)(octanoyl), Lys(19)(Cy5)]ghrelin (1-19), and show that it can be used to image changes in GHS-R in developing cardiomyocytes. We also generated the des-acyl analog, des-acyl [Lys(19)(Cy5)]ghrelin (1-19) and characterized its binding to mouse heart sections. Receptor binding affinity of Cy5-ghrelin as measured in HEK293 cells overexpressing GHS-R1a was within an order of magnitude of that of fluorescein-ghrelin and native human ghrelin, while the des-acyl Cy5-ghrelin did not bind GHS-R1a. Live cell imaging in HEK293/GHS-R1a cells showed cell surface labeling that was displaced by excess ghrelin. Interestingly, Cy5-ghrelin, but not the des-acyl analog, showed concentration-dependent binding in mouse heart tissue sections. We then used Cy5-ghrelin to track GHS-R expression in P19-derived cardiomyocytes. Live cell imaging at different time points after DMSO-induced differentiation showed that GHS-R expression preceded that of the differentiation marker aMHC and tracked with the contractility marker SERCA 2a. Our far-red analog of ghrelin adds to the tools we are developing to map GHS-R in developing and diseased cardiac tissues

    Family history of cancer and head and neck cancer survival

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137774/1/lary26524_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137774/2/lary26524.pd

    Stability of methylation markers in head and neck squamous cell carcinoma

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    BackgroundAs cancer progresses, methylation patterns change to promote the tumorigenic phenotype. However, stability of methylation markers over time and the extent that biopsy samples are representative of larger tumor specimens are unknown. This information is critical for clinical use of such biomarkers.MethodsNinety‐eight patients with tumor specimens from 2 timepoints were measured for DNA methylation in the promoter regions across 4 genes.ResultsThere were no significant differences in overall methylation of CCNA1 (cyclin A1), NDN (necdin), deleted in colorectal carcinoma (DCC), and cluster of differentiation 1a (CD1A) within paired specimens (p values = .56, .17, .66, and .58, respectively). All genes showed strong correlations between paired specimens across time. Methylation was most consistent for CCNA1 and NDN over time.ConclusionThis report provides the first evidence that methylation markers measured in biopsy samples are representative of gene methylation in later specimens and suggests that biopsy markers could be representative biomarkers for use in defining personalized treatment utilizing epigenetic changes. © 2015 Wiley Periodicals, Head Neck 38: E1325–E1331, 2016Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137576/1/hed24223.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137576/2/hed24223_am.pd

    Holographic Domains of Anti-de Sitter Space

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    An AdS_4 brane embedded in AdS_5 exhibits the novel feature that a four-dimensional graviton is localized near the brane, but the majority of the infinite bulk away from the brane where the warp factor diverges does not see four-dimensional gravity. A naive application of the holographic principle from the point of view of the four-dimensional observer would lead to a paradox; a global holographic mapping would require infinite entropy density. In this paper, we show that this paradox is resolved by the proper covariant formulation of the holographic principle. This is the first explicit example of a time-independent metric for which the spacelike formulation of the holographic principle is manifestly inadequate. Further confirmation of the correctness of this approach is that light-rays leaving the brane intersect at the location where we expect four-dimensional gravity to no longer dominate. We also present a simple method of locating CFT excitations dual to a particle in the bulk. We find that the holographic image on the brane moves off to infinity precisely when the particle exits the brane's holographic domain. Our analysis yields an improved understanding of the physics of the AdS_4/AdS_5 model.Comment: 29 pages, 6 figure

    Molecular dissection of box jellyfish venom cytotoxicity highlights an effective venom antidote

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    The box jellyfish Chironex fleckeri is extremely venomous, and envenoming causes tissue necrosis, extreme pain and death within minutes after severe exposure. Despite rapid and potent venom action, basic mechanistic insight is lacking. Here we perform molecular dissection of a jellyfish venom-induced cell death pathway by screening for host components required for venom exposure-induced cell death using genome-scale lenti-CRISPR mutagenesis. We identify the peripheral membrane protein ATP2B1, a calcium transporting ATPase, as one host factor required for venom cytotoxicity. Targeting ATP2B1 prevents venom action and confers long lasting protection. Informatics analysis of host genes required for venom cytotoxicity reveal pathways not previously implicated in cell death. We also discover a venom antidote that functions up to 15 minutes after exposure and suppresses tissue necrosis and pain in mice. These results highlight the power of whole genome CRISPR screening to investigate venom mechanisms of action and to rapidly identify new medicines

    A bioreactor for in-cell protein NMR

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    The inside of the cell is a complex environment that is difficult to simulate when studying proteins and other molecules in vitro. We have developed a device and system that provides a controlled environment for Nuclear Magnetic Resonance (NMR) experiments involving living cells. Our device comprises two main parts, an NMR detection region and a circulation system. The flow of medium from the bottom of the device pushes alginate encapsulated cells into the circulation chamber. In the chamber, the exchange of oxygen and nutrients occurs between the media and the encapsulated cells. When the media flow is stopped, the encapsulated cells fall back into the NMR detection region, and spectra can be acquired. We have utilized the bioreactor to study the expression of the natively disordered protein α-synuclein, inside Escherichia coli cells
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