1,217 research outputs found

    Pectin methylesterification modulates cell wall properties to promote neighbour proximity-induced hypocotyl growth

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    Plants growing with neighbors compete for light and consequently increase the growth of their vegetative organs to enhance access to sunlight. This response, called shade avoidance syndrome (SAS), involves photoreceptors such as phytochromes as well as phytochrome interacting factors (PIFs), which regulate the expression of growth-mediating genes. Numerous cell wall-related genes belong to the putative targets of PIFs, and the importance of cell wall modifications for enabling growth was extensively shown in developmental models such as dark-grown hypocotyl. However, the contribution of the cell wall in the growth of de-etiolated seedlings regulated by shade cues remains poorly established. Through analyses of mechanical and biochemical properties of the cell wall coupled with transcriptomic analysis of cell wall-related genes from previously published data, we provide evidence suggesting that cell wall modifications are important for neighbor proximity-induced elongation. Further analysis using loss-of-function mutants impaired in the synthesis and remodeling of the main cell wall polymers corroborated this. We focused on the cgr2cgr3 double mutant that is defective in methylesterification of homogalacturonan (HG)-type pectins. By following hypocotyl growth kinetically and spatially and analyzing the mechanical and biochemical properties of cell walls, we found that methylesterification of HG-type pectins was required to enable global cell wall modifications underlying neighbor proximity-induced hypocotyl growth. Collectively, our work suggests that plant competition for light induces changes in the expression of numerous cell wall genes to enable modifications in biochemical and mechanical properties of cell walls that contribute to neighbor proximity-induced growth

    A theory of mobile library service delivery

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    Research indicates there is widespread acceptance that nomadicity of library users is a phenomenon that will continue to increase; however, mobile learning is a resource that relatively few academic libraries appear to be taking advantage of. This paper presents a model developed during an investigation using a grounded theory approach into factors that may contribute to the delivery of library services to mobile technologies. A sample of 42 professionally qualified library staff from the Australasian vocational education and training (VET) sector was investigated to determine how confident and capable library staff believed they were to respond to technology advancement challenges and the training and support required for that response. The resulting theoretical model explains the impact of mobile technologies on library services and highlights the complex factors contributing to mobile technology acceptance at both an organisational and individual level. The presence of a series of catalysing impacts forms a central core and their management can enable an organisation to move from a position of uncertainty to one where the consequences of mobile technologies have been normalised

    Common Variants in 40 Genes Assessed for Diabetes Incidence and Response to Metformin and Lifestyle Intervention in the Diabetes Prevention Program

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    OBJECTIVE: Genome-wide association studies have begun to elucidate the genetic architecture of type 2 diabetes. We examined whether single nucleotide polymorphisms (SNPs) identified through targeted complementary approaches affect diabetes incidence in the at-risk population of the Diabetes Prevention Program (DPP) and whether they influence a response to preventive interventions. RESEARCH DESIGN AND METHODS: We selected SNPs identified by prior genome-wide association studies for type 2 diabetes and related traits, or capturing common variation in 40 candidate genes previously associated with type 2 diabetes, implicated in monogenic diabetes, encoding type 2 diabetes drug targets or drug-metabolizing/transporting enzymes, or involved in relevant physiological processes. We analyzed 1,590 SNPs for association with incident diabetes and their interaction with response to metformin or lifestyle interventions in 2,994 DPP participants. We controlled for multiple hypothesis testing by assessing false discovery rates. RESULTS: We replicated the association of variants in the metformin transporter gene SLC47A1 with metformin response and detected nominal interactions in the AMP kinase (AMPK) gene STK11, the AMPK subunit genes PRKAA1 and PRKAA2, and a missense SNP in SLC22A1, which encodes another metformin transporter. The most significant association with diabetes incidence occurred in the AMPK subunit gene PRKAG2 (hazard ratio 1.24, 95% CI 1.09-1.40, P = 7 × 10(-4)). Overall, there were nominal associations with diabetes incidence at 85 SNPs and nominal interactions with the metformin and lifestyle interventions at 91 and 69 mostly nonoverlapping SNPs, respectively. The lowest P values were consistent with experiment-wide 33% false discovery rates. CONCLUSIONS: We have identified potential genetic determinants of metformin response. These results merit confirmation in independent samples

    Scaling Up Mental Health Services in Zambia: Challenges and Opportunities Reported in an Education Project.

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    yesThe need to increase the capacity of developing countries to meet the mental health needs of their populations is widely acknowledged. This article examines some of the challenges associated with a British Council DelPHE project aimed at strengthening the capacity of mental health educators to prepare the mental health workforce in Zambia for a shift from an institutional to a community-based model of care. The analysis draws on data from two focus groups in which the participants were drawn from college educators who had taken part in workshops intended to enhance curriculum alignment to ensure that the education and training provided for clinical officers (psychiatry) and mental health nurses was "fit for purpose." In particular, the article highlights their perspectives on some of the tensions in focusing on mental health as opposed to broader health care and in ensuring appropriate opportunities for practice or field placements. The continuing impact of stigma and limited resources available for mental ill-health is acknowledged within the wider context of inequities in mental health care. Findings of this evaluation may be applicable to other sub-Saharan contexts, but should be understood only within the Zambian context

    Impact of dissolved oxygen during UV-irradiation on the chemical composition and function of CHO cell culture media

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    Ultraviolet (UV) irradiation is advantageous as a sterilization technique in the biopharmaceutical industry since it is capable of targeting non-enveloped viruses that are typically challenging to destroy, as well as smaller viruses that can be difficult to remove via conventional separation techniques. In this work, we investigated the influence of oxygen in the media during UV irradiation and characterized the effect on chemical composition using NMR and LC-MS, as well as the ability of the irradiated media to support cell culture. Chemically defined Chinese hamster ovary cell growth media was irradiated at high fluences in a continuous-flow UV reactor. UV-irradiation caused the depletion of pyridoxamine, pyridoxine, pyruvate, riboflavin, tryptophan, and tyrosine; and accumulation of acetate, formate, kynurenine, lumichrome, and sarcosine. Pyridoxamine was the only compound to undergo complete degradation within the fluences considered; complete depletion of pyridoxamine was observed at 200 mJ/cm2. Although in both oxygen- and nitrogen-saturated media, the cell culture performance was affected at fluences above 200 mJ/cm2, there was less of an impact on cell culture performance in the nitrogen-saturated media. Based on these results, minimization of oxygen in cell culture media prior to UV treatment is recommended to minimize the negative impact on sensitive media. © 2016 Meunier et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    Establishing a core outcome set for peritoneal dialysis : report of the SONG-PD (standardized outcomes in nephrology-peritoneal dialysis) consensus workshop

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    Outcomes reported in randomized controlled trials in peritoneal dialysis (PD) are diverse, are measured inconsistently, and may not be important to patients, families, and clinicians. The Standardized Outcomes in Nephrology-Peritoneal Dialysis (SONG-PD) initiative aims to establish a core outcome set for trials in PD based on the shared priorities of all stakeholders. We convened an international SONG-PD stakeholder consensus workshop in May 2018 in Vancouver, Canada. Nineteen patients/caregivers and 51 health professionals attended. Participants discussed core outcome domains and implementation in trials in PD. Four themes relating to the formation of core outcome domains were identified: life participation as a main goal of PD, impact of fatigue, empowerment for preparation and planning, and separation of contributing factors from core factors. Considerations for implementation were identified: standardizing patient-reported outcomes, requiring a validated and feasible measure, simplicity of binary outcomes, responsiveness to interventions, and using positive terminology. All stakeholders supported inclusion of PD-related infection, cardiovascular disease, mortality, technique survival, and life participation as the core outcome domains for PD

    Involvement of KCa3.1 channel activity in immediate perioperative cognitive and neuroinflammatory outcomes.

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    peer reviewed[en] BACKGROUND: Potassium channels (KCa3.1; Kv1.3; Kir2.1) are necessary for microglial activation, a pivotal requirement for the development of Perioperative Neurocognitive Disorders (PNDs). We previously reported on the role of microglial Kv1.3 for PNDs; the present study sought to determine whether inhibiting KCa3.1 channel activity affects neuroinflammation and prevents development of PND. METHODS: Mice (wild-type [WT] and KCa3.1-/-) underwent aseptic tibial fracture trauma under isoflurane anesthesia or received anesthesia alone. WT mice received either TRAM34 (a specific KCa3.1 channel inhibitor) dissolved in its vehicle (miglyol) or miglyol alone. Spatial memory was assessed in the Y-maze paradigm 6 h post-surgery/anesthesia. Circulating interleukin-6 (IL-6) and high mobility group box-1 protein (HMGB1) were assessed by ELISA, and microglial activitation Iba-1 staining. RESULTS: In WT mice surgery induced significant cognitive decline in the Y-maze test, p = 0.019), microgliosis (p = 0.001), and increases in plasma IL-6 (p = 0.002) and HMGB1 (p = 0.001) when compared to anesthesia alone. TRAM34 administration attenuated the surgery-induced changes in cognition, microglial activation, and HMGB1 but not circulating IL-6 levels. In KCa3.1-/- mice surgery neither affected cognition nor microgliosis, although circulating IL-6 levels did increase (p < 0.001). CONCLUSION: Similar to our earlier report with Kv1.3, perioperative microglial KCa3.1 blockade decreases immediate perioperative cognitive changes, microgliosis as well as the peripheral trauma marker HMGB1 although surgery-induced IL-6 elevation was unchanged. Future research should address whether a synergistic interaction exists between blockade of Kv1.3 and KCa3.1 for preventing PNDs
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