18,834 research outputs found

    Spatial imaging of Zn and other elements in Huanglongbing-affected grapefruit by synchrotron-based micro X-ray fluorescence investigation

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    Huanglongbing (HLB) is a highly destructive, fast-spreading disease of citrus, causing substantial economic losses to the citrus industry worldwide. Nutrient levels and their cellular distribution patterns in stems and leaves of grapefruit were analysed after graft-inoculation with lemon scions containing 'Candidatus Liberibacter asiaticus' (Las), the heat-tolerant Asian type of the HLB bacterium. After 12 months, affected plants showed typical HLB symptoms and significantly reduced Zn concentrations in leaves. Micro-XRF imaging of Zn and other nutrients showed that preferential localization of Zn to phloem tissues was observed in the stems and leaves collected from healthy grapefruit plants, but was absent from HLB-affected samples. Quantitative analysis by using standard references revealed that Zn concentration in the phloem of veins in healthy leaves was more than 10 times higher than that in HLB-affected leaves. No significant variation was observed in the distribution patterns of other elements such as Ca in stems and leaves of grapefruit plants with or without graft-inoculation of infected lemon scions. These results suggest that reduced phloem transport of Zn is an important factor contributing to HLB-induced Zn deficiency in grapefruit. Our report provides the first in situ, cellular level visualization of elemental variations within the tissues of HLB-affected citrus. Β© 2014 Β© The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology

    Bacterial Infection Elicits Heat Shock Protein 72 Release from Pleural Mesothelial Cells

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    Heat shock protein 70 (HSP70) has been implicated in infection-related processes and has been found in body fluids during infection. This study aimed to determine whether pleural mesothelial cells release HSP70 in response to bacterial infection in vitro and in mouse models of serosal infection. In addition, the in vitro cytokine effects of the HSP70 isoform, Hsp72, on mesothelial cells were examined. Further, Hsp72 was measured in human pleural effusions and levels compared between non-infectious and infectious patients to determine the diagnostic accuracy of pleural fluid Hsp72 compared to traditional pleural fluid parameters. We showed that mesothelial release of Hsp72 was significantly raised when cells were treated with live and heat-killed Streptococcus pneumoniae. In mice, intraperitoneal injection of S. pneumoniae stimulated a 2-fold increase in Hsp72 levels in peritoneal lavage (p<0.01). Extracellular Hsp72 did not induce or inhibit mediator release from cultured mesothelial cells. Hsp72 levels were significantly higher in effusions of infectious origin compared to non-infectious effusions (p<0.05). The data establish that pleural mesothelial cells can release Hsp72 in response to bacterial infection and levels are raised in infectious pleural effusions. The biological role of HSP70 in pleural infection warrants exploration

    Rapid influx and death of plasmacytoid dendritic cells in lymph nodes mediate depletion in acute simian immunodeficiency virus infection

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    Plasmacytoid dendritic cells (pDC) are essential innate immune system cells that are lost from the circulation in human immunodeficiency virus (HIV)-infected individuals associated with CD4+ T cell decline and disease progression. pDC depletion is thought to be caused by migration to tissues or cell death, although few studies have addressed this directly. We used precise methods of enumeration and in vivo labeling with 5-bromo-2β€²-deoxyuridine to track recently divided pDC in blood and tissue compartments of monkeys with acute pathogenic simian immunodeficiency virus (SIV) infection. We show that pDC are lost from blood and peripheral lymph nodes within 14 days of infection, despite a normal frequency of pDC in bone marrow. Paradoxically, pDC loss masked a highly dynamic response characterized by rapid pDC mobilization into blood and a 10- to 20-fold increase in recruitment to lymph nodes relative to uninfected animals. Within lymph nodes, pDC had increased levels of apoptosis and necrosis, were uniformly activated, and were infected at frequencies similar to CD4+ T cells. Nevertheless, remaining pDC had essentially normal functional responses to stimulation through Toll-like receptor 7, with half of lymph node pDC producing both TNF-Ξ± and IFN-Ξ±. These findings reveal that cell migration and death both contribute to pDC depletion in acute SIV infection. We propose that the rapid recruitment of pDC to inflamed lymph nodes in lentivirus infection has a pathologic consequence, bringing cells into close contact with virus, virus-infected cells, and pro-apoptotic factors leading to pDC death. Β© 2009 Brown et al

    I wish he'd listen: Client-centered interviewing approaches are associated with higher compliance with behavioral modification advice in pet dog owners

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    In the UK, over 40,000 dogs are given up annually to shelters or euthanized due to problem behaviors. It may be possible to reduce these numbers through behavior counseling and development of a behavior modification plan (BMP) by a canine professional (CP). However, if the client does not or cannot adhere to the BMP the dog's prospects may be compromised. This study explored the experience of the initial behavior consultation and possible reasons for adhering to (or not) the BMP from the client's perspective. An online survey solicited the opinions of canine behavior clients who had sought professional help in the UK for their dog's unwanted behavior within the last 2 years. Principal Component Analysis of Likert scale statements revealed one significant PC (P < 0.001) that explained 57% of the variation in the data and was significantly correlated with BMP compliance (r = 0.567, P < 0.001). Specifically, believing the plan was right for their dog and having CP support throughout to achieve behavior improvement through the implementation of a mutually agreed BMP were important. Qualitative thematic analysis of free text responses regarding motivation for future client BMP compliance echoed these factors. Conversely, a negative consultation experience was created by CPs adopting an authoritarian or β€˜telling’ approach with their clients for example, making them feel judged. This was associated with a lack of BMP compliance. Essentially, CPs who involved their clients in BMP development were perceived as creating a positive experience of the initial behavior consultation and as a result were able to promote client BMP adherence and improvement in unwanted behavior improvement. This CP approach, which adopts a nurturing rather than an authoritarian strategy, has been termed Client-Centered Interviewing (CCI). The main thing about CCI is the client is an equal partner in the process. The core conditions are as per Rogers and Egan of empathy, congruence and unconditional positive regard. CCI builds on empathy with the client, avoids inappropriately challenging client beliefs by gently exploring options without being judgemental, clearly explains the likely cause of the behavior and the plan to resolve it, and provides a BMP that is bespoke and flexible. Future research is required to validate the findings, for example through a prospective comparison of Client-Centered Interviewing versus an instructional (authoritarian) approach. Crucially, the impact of Client-Centered Interviewing on canine welfare must also be evaluated

    Multimedia Bootcamp: a health sciences library provides basic training to promote faculty technology integration

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    BACKGROUND: Recent research has shown a backlash against the enthusiastic promotion of technological solutions as replacements for traditional educational content delivery. Many institutions, including the University of Virginia, have committed staff and resources to supporting state-of-the-art, showpiece educational technology projects. However, the Claude Moore Health Sciences Library has taken the approach of helping Health Sciences faculty be more comfortable using technology in incremental ways for instruction and research presentations. In July 2004, to raise awareness of self-service multimedia resources for instructional and professional development needs, the Library conducted a "Multimedia Bootcamp" for nine Health Sciences faculty and fellows. METHODS: Case study. RESULTS: Program stewardship by a single Library faculty member contributed to the delivery of an integrated learning experience. The amount of time required to attend the sessions and complete homework was the maximum fellows had to devote to such pursuits. The benefit of introducing technology unfamiliar to most fellows allowed program instructors to start everyone at the same baseline while not appearing to pass judgment on the technology literacy skills of faculty. The combination of wrapping the program in the trappings of a fellowship and selecting fellows who could commit to a majority of scheduled sessions yielded strong commitment from participants as evidenced by high attendance and a 100% rate of assignment completion. Response rates to follow-up evaluation requests, as well as continued use of Media Studio resources and Library expertise for projects begun or conceived during Bootcamp, bode well for the long-term success of this program. CONCLUSION: An incremental approach to integrating technology with current practices in instruction and presentation provided a supportive yet energizing environment for Health Sciences faculty. Keys to this program were its faculty focus, traditional hands-on instruction, unrestricted access to technology tools and support, and inclusion of criteria for evaluating when multimedia can augment pedagogical aims
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