559 research outputs found
Optical IP switching a solution to dynamic lightpath establishment in disaggregated network architectures
The landscape of the telecommunications environment is constantly evolving; in terms of architecture and increasing data-rate. Ensuring that routing decisions are taken at the lowest possible layer offers the possibility of greatest data throughput. We propose using wavelengths in a DWDM scheme as dedicated channels that bypass the routing lookup in a router. The future trend of telecommunications industry is, however, toward larger numbers of interlinked competing operator networks. This in turn means there is a lack of a unified control plane to allow current networks to dynamically provision optical paths. This paper will report on the concept of optical IP switching. This concept seeks to address optical control plane issues in disaggregated networks while providing a means to dynamically provision optical paths to cater for large data flows
Understanding how institutions may support the development of transdisciplinary approaches to sustainability research
This article analyses the approaches of academics seeking to engage with private, public and community-based stakeholders through transdisciplinary research about pressing sustainability challenges and, in particular, climate change; it outlines aspects of the institutional factors which influence transdisciplinary research. A qualitative approach was employed in conducting 10 semi-structured interviews to analyse the challenges and motivations of academic researchers when working with a range of other stakeholders through transdisciplinary practice. Two key contributions are made through this work. First, this article adds to the existing literature on motivations and challenges for undertaking research with private, public and community stakeholders in a cross-disciplinary manner. Second, the current institutional circumstances influencing such research practices are outlined, alongside potential ways forward. The research presented here has been undertaken in light of the experiences of the two lead co-authors as early career researchers coming from the disciplines of sociology and energy engineering, engaging in transdisciplinary research within a local community context in relation to a regional energy transition project
Toll-Like Receptor mRNA Expression Is Selectively Increased in the Colonic Mucosa of Two Animal Models Relevant to Irritable Bowel Syndrome
Background: Irritable bowel syndrome (IBS) is largely viewed as a stress-related disorder caused by aberrant brain-gut–
immune communication and altered gastrointestinal (GI) homeostasis. Accumulating evidence demonstrates that stress
modulates innate immune responses; however, very little is known on the immunological effects of stress on the GI tract.
Toll-like receptors (TLRs) are critical pattern recognition molecules of the innate immune system. Activation of TLRs by
bacterial and viral molecules leads to activation of NF-kB and an increase in inflammatory cytokine expression. It was our
hypothesis that innate immune receptor expression may be changed in the gastrointestinal tract of animals with stressinduced
IBS-like symptoms.
Methodology/Principal Findings: In this study, our objective was to evaluate the TLR expression profile in the colonic
mucosa of two rat strains that display colonic visceral hypersensivity; the stress-sensitive Wistar-Kyoto (WKY) rat and the
maternally separated (MS) rat. Quantitative PCR of TLR2-10 mRNA in both the proximal and distal colonic mucosae was
carried out in adulthood. Significant increases are seen in the mRNA levels of TLR3, 4 & 5 in both the distal and proximal
colonic mucosa of MS rats compared with controls. No significant differences were noted for TLR 2, 7, 9 & 10 while TLR 6
could not be detected in any samples in both rat strains. The WKY strain have increased levels of mRNA expression of TLR3,
4, 5, 7, 8, 9 & 10 in both the distal and proximal colonic mucosa compared to the control Sprague-Dawley strain. No
significant differences in expression were found for TLR2 while as before TLR6 could not be detected in all samples in both
strains.
Conclusions: These data suggest that both early life stress (MS) and a genetic predisposition (WKY) to stress affect the
expression of key sentinels of the innate immune system which may have direct relevance for the molecular
pathophysiology of IBS
Non-invasive characterization of pleural and pericardial effusions using T1 mapping by magnetic resonance imaging
AIMS: Differentiating exudative from transudative effusions is clinically important and is currently performed via biochemical analysis of invasively obtained samples using Light's criteria. Diagnostic performance is however limited. Biochemical composition can be measured with T1 mapping using cardiovascular magnetic resonance (CMR) and hence may offer diagnostic utility for assessment of effusions. METHODS AND RESULTS: A phantom consisting of serially diluted human albumin solutions (25-200 g/L) was constructed and scanned at 1.5 T to derive the relationship between fluid T1 values and fluid albumin concentration. Native T1 values of pleural and pericardial effusions from 86 patients undergoing clinical CMR studies retrospectively analysed at four tertiary centres. Effusions were classified using Light's criteria where biochemical data was available (n = 55) or clinically in decompensated heart failure patients with presumed transudative effusions (n = 31). Fluid T1 and protein values were inversely correlated both in the phantom (r = -0.992) and clinical samples (r = -0.663, P < 0.0001). T1 values were lower in exudative compared to transudative pleural (3252 ± 207 ms vs. 3596 ± 213 ms, P < 0.0001) and pericardial (2749 ± 373 ms vs. 3337 ± 245 ms, P < 0.0001) effusions. The diagnostic accuracy of T1 mapping for detecting transudates was very good for pleural and excellent for pericardial effusions, respectively [area under the curve 0.88, (95% CI 0.764-0.996), P = 0.001, 79% sensitivity, 89% specificity, and 0.93, (95% CI 0.855-1.000), P < 0.0001, 95% sensitivity; 81% specificity]. CONCLUSION: Native T1 values of effusions measured using CMR correlate well with protein concentrations and may be helpful for discriminating between transudates and exudates. This may help focus the requirement for invasive diagnostic sampling, avoiding unnecessary intervention in patients with unequivocal transudative effusions
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Comparative study of (0001) and (11-22) InGaN based light emitting diodes
We have systematically investigated the doping of (11-22) with Si and Mg by metal-organic vapour phase epitaxy for light emitting diodes (LEDs). By Si doping of GaN we reached electron concentrations close to 1020cm-3, but the topography degrades above mid 1019cm-3. By Mg doping we reached hole concentrations close to 5 × 1017cm-3, using Mg partial pressures about 3' higher than those for (0001). Exceeding the maximum Mg partial pressure led to a quick degradation of the sample. Low resistivities as well as high hole concentrations required a growth temperature of 900 °C or higher. At optimised conditions the electrical properties as well as the photoluminescence of (11-22) p-GaN were similar to (0001) p-GaN. The best ohmic p-contacts were achieved by NiAg metallisation. A single quantum well LED emitting at 465nm was realised on (0001) and (11-22). Droop (sub-linear increase of the light output power) occurred at much higher current densities on (11-22). However, the light output of the (0001) LED was higher than that of (11-22) until deep in the droop regime. Our LEDs as well as those in the literature indicate a reduction in efficiency from (0001) over semi-polar to non-polar orientations. We propose that reduced fields open a loss channel for carriers.This work was supported by EU-FP7 ALIGHT No. NMP-2011-280587. The data to produce the figures can be found under the permanent url https://www.repository.cam.ac.uk/handle/1810/253538
Allergen immunotherapy for IgE-mediated food allergy : a systematic review and meta-analysis
Background: The European Academy of Allergy and Clinical Immunology (EAACI) is developing Guidelines for Allergen Immunotherapy (AIT) for IgE-mediated Food Allergy. To inform the development of clinical recommendations, we sought to critically assess evidence on the effectiveness, safety and cost-effectiveness of AIT in the management of food allergy. Methods: We undertook a systematic review and meta-analysis that involved searching nine international electronic databases for randomized controlled trials (RCTs) and nonrandomized studies (NRS). Eligible studies were independently assessed by two reviewers against predefined eligibility criteria. The quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs and the Cochrane ACROBAT-NRS tool for quasi-RCTs. Random-effects meta-analyses were undertaken, with planned subgroup and sensitivity analyses. Results: We identified 1814 potentially relevant papers from which we selected 31 eligible studies, comprising of 25 RCTs and six NRS, studying a total of 1259 patients. Twenty-five trials evaluated oral immunotherapy (OIT), five studies investigated sublingual immunotherapy, and one study evaluated epicutaneous immunotherapy. The majority of these studies were in children. Twenty-seven studies assessed desensitization, and eight studies investigated sustained unresponsiveness postdiscontinuation of AIT. Meta-analyses demonstrated a substantial benefit in terms of desensitization (risk ratio (RR) = 0.16, 95% CI 0.10, 0.26) and suggested, but did not confirm sustained unresponsiveness (RR = 0.29, 95% CI 0.08, 1.13). Only one study reported on disease-specific quality of life (QoL), which reported no comparative results between OIT and control group. Meta-analyses revealed that the risk of experiencing a systemic adverse reaction was higher in those receiving AIT, with a more marked increase in the risk of local adverse reactions. Sensitivity analysis excluding those studies judged to be at high risk of bias demonstrated the robustness of summary estimates of effectiveness and safety of AIT for food allergy. None of the studies reported data on health economic analyses. Conclusions: AIT may be effective in raising the threshold of reactivity to a range of foods in children with IgE-mediated food allergy whilst receiving (i.e. desensitization) and post-discontinuation of AIT. It is, however, associated with a modest increased risk in serious systemic adverse reactions and a substantial increase in minor local adverse reactions. More data are needed in relation to adults, long term effects, the impact on QoL and the cost-effectiveness of AIT.Peer reviewe
1A6/DRIM, a Novel t-UTP, Activates RNA Polymerase I Transcription and Promotes Cell Proliferation
BACKGROUND: Ribosome biogenesis is required for protein synthesis and cell proliferation. Ribosome subunits are assembled in the nucleolus following transcription of a 47S ribosome RNA precursor by RNA polymerase I and rRNA processing to produce mature 18S, 28S and 5.8S rRNAs. The 18S rRNA is incorporated into the ribosomal small subunit, whereas the 28S and 5.8S rRNAs are incorporated into the ribosomal large subunit. Pol I transcription and rRNA processing are coordinated processes and this coordination has been demonstrated to be mediated by a subset of U3 proteins known as t-UTPs. Up to date, five t-UTPs have been identified in humans but the mechanism(s) that function in the t-UTP(s) activation of Pol I remain unknown. In this study we have identified 1A6/DRIM, which was identified as UTP20 in our previous study, as a t-UTP. In the present study, we investigated the function and mechanism of 1A6/DRIM in Pol I transcription. METHODOLOGY/PRINCIPAL FINDINGS: Knockdown of 1A6/DRIM by siRNA resulted in a decreased 47S pre-rRNA level as determined by Northern blotting. Ectopic expression of 1A6/DRIM activated and knockdown of 1A6/DRIM inhibited the human rDNA promoter as evaluated with luciferase reporter. Chromatin immunoprecipitation (ChIP) experiments showed that 1A6/DRIM bound UBF and the rDNA promoter. Re-ChIP assay showed that 1A6/DRIM interacts with UBF at the rDNA promoter. Immunoprecipitation confirmed the interaction between 1A6/DRIM and the nucleolar acetyl-transferase hALP. It is of note that knockdown of 1A6/DRIM dramatically inhibited UBF acetylation. A finding of significance was that 1A6/DRIM depletion, as a kind of nucleolar stress, caused an increase in p53 level and inhibited cell proliferation by arresting cells at G1. CONCLUSIONS: We identify 1A6/DRIM as a novel t-UTP. Our results suggest that 1A6/DRIM activates Pol I transcription most likely by associating with both hALP and UBF and thereby affecting the acetylation of UBF
Efficacy and safety of treatment with omalizumab for chronic spontaneous urticaria: A systematic review for the EAACI Biologicals Guidelines
This systematic review evaluates the efficacy and safety of omalizumab for chronic spontaneous urticaria (CSU). PubMed, Embase, and Cochrane Library were searched for RCTs. Critical and important CSU-related outcomes were considered. The risk of bias and the certainty of the evidence were assessed using GRADE. Ten RCTs including 1620 subjects aged 12 to 75 years old treated with omalizumab for 16 to 40 weeks were evaluated. Omalizumab 150 mg does not result in clinically meaningful improvement (high certainty) of the urticaria activity score (UAS)7 (mean difference (MD) −5; 95%CI −7.75 to −2.25), and the itch severity score (ISS)7 (MD −2.15; 95% CI −3.2 to −1.1) does not increase (moderate certainty) quality of life (QoL) (Dermatology Life Quality Index (DLQI); MD −2.01; 95%CI −3.22 to −0.81) and decreases (moderate certainty) rescue medication use (MD −1.68; 95%CI −2.95 to −0.4). Omalizumab 300 mg results in clinically meaningful improvements (moderate certainty) of the UAS7 (MD −11.05; 95%CI −12.87 to −9.24), the ISS7 (MD −4.45; 95%CI −5.39 to −3.51), and QoL (high certainty) (DLQI; MD −4.03; 95% CI −5.56 to −2.5) and decreases (moderate certainty) rescue medication use (MD −2.04; 95%CI −3.19 to −0.88) and drug-related serious AEs (RR 0.77; 95%CI 0.20 to 2.91)
Inappropriate prescribing and adverse drug events in older people
Inappropriate prescribing (IP) in older patients is highly prevalent and is associated with an increased risk of adverse drug events (ADEs), morbidity, mortality and healthcare utilisation. Consequently, IP is a major safety concern and with changing population demographics, it is likely to become even more prevalent in the future. IP can be detected using explicit or implicit prescribing indicators. Theoretically, the routine clinical application of these IP criteria could represent an inexpensive and time efficient method to optimise prescribing practice. However, IP criteria must be sensitive, specific, have good inter-rater reliability and incorporate those medications most commonly associated with ADEs in older people. To be clinically relevant, use of prescribing appropriateness tools must translate into positive patient outcomes, such as reduced rates of ADEs. To accurately measure these outcomes, a reliable method of assessing the relationship between the administration of a drug and an adverse clinical event is required. The Naranjo criteria are the most widely used tool for assessing ADE causality, however, they are often difficult to interpret in the context of older patients. ADE causality criteria that allow for the multiple co-morbidities and prescribed medications in older people are required. Ultimately, the current high prevalence of IP and ADEs is unacceptable. IP screening criteria need to be tested as an intervention to assess their impact on the incidence of ADEs in vulnerable older patients. There is a role for IP screening tools in everyday clinical practice. These should enhance, not replace good clinical judgement, which in turn should be based on sound pharmacogeriatric training
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