177,223 research outputs found
Valutazione microbiologica del rischio cardiogeno in pazienti pediatrici HIV+: una spia di infezione da miceti
No full textEffect of HIV vertical transmission on the ontogeny of T cell antigens involved in the regulation of humoral immune response
No full textHIV infection causes progressive impairment of humoral immunity, including defective specific antibody production. To evaluate whether vertical HIV infection interferes with the expression on CD4+ lymphocytes of developmentally regulated molecules, that play a crucial role in the generation of immunological memory (CD45 isoforms) and in attainment of antibody responses (CD40L), 22 HIV-infected children and 36 seroreverted children born to HIV+ mothers were studied. The percentage of CD40L+ PBMC after activation in vitro with phorbol myristate acetate (PMA) plus ionomycin was lower in HIV-infected children than in controls (P < 0.004). This correlated with the depletion of CD4+ lymphocytes (r = 0.75; P < 0.001). CD40L expression rose progressively with age (r = 0.36; P = 0.03) in seroreverted children, but not in HIV-infected children, suggesting that while in normal children in vivo antigen stimulation results in progressive attainment of CD40L expression (and thus to effective T-B cell cooperation), this process is largely defective in HIV-infected children, contributing to the genesis of humoral immune deficiency. The proportion of CD4+ cells bearing the CD45RO isoform was increased among HIV-infected infants during the first years of life. However, the percentage of CD4+ CD45RO+ peripheral blood mononuclear cells (PBMC) progressively increased with age in controls (r = 0.69; P = 0.03), but not in HIV-infected children, showing that while vertical transmission of HIV does not prevent CD45RO expression early in life, it is associated with a disturbance of the physiological process of antigen priming, contributing to poor immunological memory to T cell-dependent antigens
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
How single node dynamics enhances synchronization in neural networks with electrical coupling
No full textThe stability of the completely synchronous state in neural networks with electrical coupling is analytically investigated applying both the Master Stability Function approach (MSF), developed by Pecora and Carroll (1998), and the Connection Graph Stability method (CGS) proposed by Belykh et al. (2004). The local dynamics is described by Morris-Lecar model for spiking neurons and by Hindmarsh-Rose model in spike, burst, irregular spike and irregular burst regimes. The combined application of both CGS and MSF methods provides an efficient estimate of the synchronization thresholds, namely bounds for the coupling strength ranges in which the synchronous state is stable. In all the considered cases, we observe that high values of coupling strength tend to synchronize the system. Furthermore, we observe a correlation between the single node attractor and the local stability properties given by MSF. The analytical results are compared with numerical simulations on a sample network, with excellent agreement
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Letter from R. R. Zellick, Assistant Trust Officer, Anglo California National Bank of San Francisco, to Joseph R. Goodman, October 2, 1942
No full textLetter from R. R. Zellick, Assistant Trust Officer at The Anglo California National Bank of San Francisco, to Joseph R. Goodman, regarding property owned by Dave Tatsuno. Zellick mentions a dispute between current tenants and Tatsuno, and that Tatsuno has asked Goodman to help locate trustworthy tenants.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
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