44 research outputs found

    HIV-1 Replication in the Central Nervous System Occurs in Two Distinct Cell Types

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    Human immunodeficiency virus type 1 (HIV-1) infection of the central nervous system (CNS) can lead to the development of HIV-1-associated dementia (HAD). We examined the virological characteristics of HIV-1 in the cerebrospinal fluid (CSF) of HAD subjects to explore the association between independent viral replication in the CNS and the development of overt dementia. We found that genetically compartmentalized CCR5-tropic (R5) T cell-tropic and macrophage-tropic HIV-1 populations were independently detected in the CSF of subjects diagnosed with HIV-1-associated dementia. Macrophage-tropic HIV-1 populations were genetically diverse, representing established CNS infections, while R5 T cell-tropic HIV-1 populations were clonally amplified and associated with pleocytosis. R5 T cell-tropic viruses required high levels of surface CD4 to enter cells, and their presence was correlated with rapid decay of virus in the CSF with therapy initiation (similar to virus in the blood that is replicating in activated T cells). Macrophage-tropic viruses could enter cells with low levels of CD4, and their presence was correlated with slow decay of virus in the CSF, demonstrating a separate long-lived cell as the source of the virus. These studies demonstrate two distinct virological states inferred from the CSF virus in subjects diagnosed with HAD. Finally, macrophage-tropic viruses were largely restricted to the CNS/CSF compartment and not the blood, and in one case we were able to identify the macrophage-tropic lineage as a minor variant nearly two years before its expansion in the CNS. These results suggest that HIV-1 variants in CSF can provide information about viral replication and evolution in the CNS, events that are likely to play an important role in HIV-associated neurocognitive disorders

    Dialogism in Corporate Social Responsibility Communications: Conceptualising Verbal Interactions between Organisations and their Audiences

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    We conceptualise CSR communication as a process of reciprocal influence between organisations and their audiences. We use an illustrative case study in the form of a conflict between firms and a powerful stakeholder which is played out in a series of 20 press releases over a 2-month period to develop a framework of analysis based on insights from linguistics. It focuses on three aspects of dialogism, namely (i) turn-taking (co-operating in a conversation by responding to the other party), (ii) inter-party moves (the nature and type of interaction characterising a turn, i.e. denial, apology or excuse) and (iii) intertextuality (the intensity and quality of verbal interaction between the parties). We address the question: What is the nature and type of verbal interactions between the parties? First we examine (a) whether the parties verbally interact and then (b) whether the parties listen to each other. We find evidence of dialogism suggesting that CSR communication is an interactive process which has to be understood as a function of the power relations between a firm and a specific stakeholder. Also, we find evidence of intertextuality in press releases by six firms which engage in verbal interaction with the stakeholder. We interpret this as linguistic evidence of isomorphic processes relating to CSR practices resulting from the pressure exerted by a powerful stakeholder. The lack of response by ten firms that fail to issue press releases suggests a strategy of ‘watch-and-wait’ with respect to the outcome of the conflict

    Ethical judgments: what do we know, where do we go?

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    Investigations into ethical judgments generally seem fuzzy as to the relevant research domain. We first attempted to clarify the construct and determine domain parameters. This attempt required addressing difficulties associated with pinpointing relevant literature, most notably the varied nomenclature used to refer to ethical judgments (individual evaluations of actions' ethicality). Given this variation in construct nomenclature and the difficulties it presented in identifying pertinent focal studies, we elected to focus on research that cited papers featuring prominent and often-used measures of ethical judgments (primarily, but not exclusively, the Multidimensional Ethics Scale). Our review of these studies indicated a preponderance of inferences and conclusions unwarranted by empirical evidence (likely attributable at least partly to inconsistent nomenclature). Moreover, ethical judgments related consistently to few respondent characteristics or any other variables, emergent relationships may not always be especially meaningful, and much research seems inclined to repetition of already verified findings. Although we concluded that knowledge about ethical judgments seems not to have advanced appreciably after decades of investigation, we suggested a possible path forward that focuses on the content of what is actually being judged as reflected in the myriad of vignettes used in the literature to elicit judgments
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