258 research outputs found
SELDI-TOF-MS ProteinChip array profiling of T-cell clones propagated in long-term culture identifies human profilin-1 as a potential bio-marker of immunosenescence
<p>Abstract</p> <p>Background</p> <p>The adaptive immune response requires waves of T-cell clonal expansion on contact with pathogen and elimination after clearance of the source of antigen. However, lifelong persistent infections with common viruses cause chronic antigenic stimulation which takes its toll on adaptive immunity in late life. Chronic antigenic stress results in deregulation of the T-cell response and accumulation of anergic cells. Longitudinal studies of the elderly show that this impacts on survival. Identifying the nature of the defects in chronically-stimulated T-cells and protein bio-markers of these dysfunctional cells would help to understand age-associated compromised T-cell function (immunosenescence) and facilitate the development of targeted intervention strategies.</p> <p>The purpose of this work was to use surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) to analyse proteins associated with T-cell senescence in order to identify potential bio-markers. Clonal populations of T-cells isolated from elderly octogenarian and centenarian donors were grown <it>in vitro </it>until senescence, and early passage and late passage (pre-senescent) cells were analysed using SELDI-TOF-MS ProteinChip arrays.</p> <p>Results</p> <p>Discriminant analysis identified several protein or peptide peaks in the region of 14.5â16.5 kDa that were associated with T-cell clone senescence. Human profilin-1, a ubiquitous protein associated with actin remodelling and cellular motility was unambiguously identified. Altered expression of profilin-1 in senescent T-cell clones was confirmed by Western blot analysis.</p> <p>Conclusion</p> <p>Due to the proposed roles of profilin-1 in cellular survival, cytoskeleton remodelling, motility, and proliferation, it is hypothesised that differential expression of profilin-1 in ageing may contribute directly to immunosenescence.</p
Learning the rules of the âstudent gameâ: Transforming the âstudent habitusâ through [im]mobility
In recent years, a growing body of literature has emerged concerning the mobilities of students, specifically relating to the interactions between local and non-local students, which can accentuate unequal access to education; social interactions and learner outcomes. Central to much of this literature is a sense that being mobile in institutional choice is the most appropriate and expected approach to successful university life. Conversely, local students, disadvantaged by their age, history, external commitments and immobility, are thought to be unlikely to share the same âstudent experiencesâ as their traditional counterparts, leading to feelings of alienation within the student community. This paper will seek to problematise this binary by examining the experiences of a group of local and non-local students studying at the University of Portsmouth using Bourdieuâs reading of habitus and capital. This is useful as it provides a more critical insight into how studentsâ [dis]advantaged learner identities are [re]produced through their everyday sociability. Moreover, these findings extend previous discussions of first year transitions by questioning the influence of accommodation upon the formation of identities and the initial experiences of âbeingâ, or âbecomingâ students. This paper also seeks to extend previous theoretical tendencies that privilege identity formation through mobility rather than stasis
Measurement of Creep Deformation across Welds in 316H Stainless Steel Using Digital Image Correlation
Spatially resolved measurement of creep deformation across weldments at high temperature cannot be achieved using standard extensometry approaches. In this investigation, a Digital Image Correlation (DIC) based system has been developed for long-term high-temperature creep strain measurement in order to characterise the material deformation behaviour of separate regions of a multi-pass weld. The optical system was sufficiently stable to allow a sequence of photographs to be taken suitable for DIC analysis of creep specimens tested at a temperature of 545 °C for over 2000 h. The images were analysed to produce local creep deformation curves from two cross-weld samples cut from contrasting regions of a multi-pass V-groove weld joining thick-section AISI Type 316H austenitic stainless steel. It is shown that for this weld, the root pass is the weakest region of the structure in creep, most likely due to the large number of thermal cycles it has experienced during the fabrication process. The DIC based measurement method offers improved spatial resolution over conventional methods and greatly reduces the amount of material required for creep characterisation of weldments
Diluting education? An ethnographic study of change in an Australian Ministry of Education
This ethnographic study captures the processes that led to change in an Australian public education system. The changes were driven by strong neo-liberal discourses which resulted in a shift from a shared understanding about leading educational change in schools by knowledge transfer to managing educational change as a process, in other words, allowing the schools to decide how to change. Inside an Australian state education bureaucracy at a time when the organisation was restructured and services decentralised, this study helps show some of the disturbing trends resulting from the further entrenchment of neo-liberal strategies. Although control was re-centralised by legitimising performance mechanisms, in the form of national testing, there are indications that the focus on national tests may have alarming consequences for the content and context of education. I argue that the complexities of learning and fundamental pedagogies are being lost in preference for an over reliance on data systems that are based on a shallow and narrow set of standardised measures
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The Ï-plot, a multicomponent 1-D pole figure plot, to quantify the heterogeneity of plastic deformation
An approach is presented that allows multi-scale characterisations of heterogeneous deformation in crystalline materials by employing a range of characterisation techniques including: electron backscatter diffraction, digital image correlation and neutron diffraction powder measurements. The approach will be used to obtain critical information about the variations in parameters that characterise the deformed state in different crystallographic orientation texture components of a sample in a statistically significant way. These parameters include lattice strains, texture evolution, peak broadening, dislocation density, planar faults, phase changes and surface strain. This approach allows verification of models of plastic deformation to provide a more detailed view of plastic deformation heterogeneity at multiple length scales than obtained by other characterisation approaches. The approach demonstrated here is applied to two stainless steel alloys; an alloy that exhibits phase transformation during deformation and an alloy that remains the same phase all through deformation process
âNeither invisible nor abnormal!â Exploring the invisibility and pathologisation of LGBT people in the Greek National Health System
This article presents findings from a research study aiming at exploring in-depth experiences of lesbian, gay, bisexual and transgender (LGBT) individuals and communities in the Greek healthcare system. This was the first study of its kind in Greece. Data collected from interviews with LGBT groups and individuals, as well as doctors, suggest that homophobia and transphobia are profound factors of systematic exclusion and restriction from access to good quality healthcare. Our findings suggest that within the healthcare context, LGBT people are routinely invisibilised and/or pathologised. The authors emphasise the urgent need for challenging chronic and institutionalised invisibility experienced by LGBT people as a necessary precondition of social equality and genuine universalism within the Greek Health System
Memetic electromagnetism algorithm for surface reconstruction with rational bivariate Bernstein basis functions
Surface reconstruction is a very important issue with outstanding applications in fields such as medical imaging (computer tomography, magnetic resonance), biomedical engineering (customized prosthesis and medical implants), computer-aided design and manufacturing (reverse engineering for the automotive, aerospace and shipbuilding industries), rapid prototyping (scale models of physical parts from CAD data), computer animation and film industry (motion capture, character modeling), archaeology (digital representation and storage of archaeological sites and assets), virtual/augmented reality, and many others. In this paper we address the surface reconstruction problem by using rational BĂ©zier surfaces. This problem is by far more complex than the case for curves we solved in a previous paper. In addition, we deal with data points subjected to measurement noise and irregular sampling, replicating the usual conditions of real-world applications. Our method is based on a memetic approach combining a powerful metaheuristic method for global optimization (the electromagnetism algorithm) with a local search method. This method is applied to a benchmark of five illustrative examples exhibiting challenging features. Our experimental results show that the method performs very well, and it can recover the underlying shape of surfaces with very good accuracy.This research is kindly supported by the Computer Science National Program of the Spanish Ministry of Economy and Competitiveness, Project #TIN2012-30768, Toho University, and the University of Cantabria. The authors are particularly grateful to the Department of Information Science of Toho University for all the facilities given to carry out this work. We also thank the Editor and the two anonymous reviewers who helped us to improve our paper with several constructive comments and suggestions
Using trained dogs and organic semi-conducting sensors to identify asymptomatic and mild SARS-CoV-2 infections: an observational study
BACKGROUND:
A rapid, accurate, non-invasive diagnostic screen is needed to identify people with SARS-CoV-2 infection. We investigated whether organic semi-conducting (OSC) sensors and trained dogs could distinguish between people infected with asymptomatic or mild symptoms, and uninfected individuals, and the impact of screening at ports-of-entry.
METHODS:
Odour samples were collected from adults, and SARS-CoV-2 infection status confirmed using RT-PCR. OSC sensors captured the volatile organic compound (VOC) profile of odour samples. Trained dogs were tested in a double-blind trial to determine their ability to detect differences in VOCs between infected and uninfected individuals, with sensitivity and specificity as the primary outcome. Mathematical modelling was used to investigate the impact of bio-detection dogs for screening.
RESULTS:
About, 3921 adults were enrolled in the study and odour samples collected from 1097 SARS-CoV-2 infected and 2031 uninfected individuals. OSC sensors were able to distinguish between SARS-CoV-2 infected individuals and uninfected, with sensitivity from 98% (95% CI 95â100) to 100% and specificity from 99% (95% CI 97â100) to 100%. Six dogs were able to distinguish between samples with sensitivity ranging from 82% (95% CI 76â87) to 94% (95% CI 89â98) and specificity ranging from 76% (95% CI 70â82) to 92% (95% CI 88â96). Mathematical modelling suggests that dog screening plus a confirmatory PCR test could detect up to 89% of SARS-CoV-2 infections, averting up to 2.2 times as much transmission compared to isolation of symptomatic individuals only.
CONCLUSIONS:
People infected with SARS-CoV-2, with asymptomatic or mild symptoms, have a distinct odour that can be identified by sensors and trained dogs with a high degree of accuracy. Odour-based diagnostics using sensors and/or dogs may prove a rapid and effective tool for screening large numbers of people.
Trial Registration NCT04509713 (clinicaltrials.gov)
Influence of country and city images on studentsâ perception of host universities and their satisfaction with the assigned destination for their exchange programmes
ABSTRACT: This research focuses on the effect that country image, city image and university image has on studentsâ a priori satisfaction with the assigned destination for their international exchange programme (Bachelor and Master). In particular, this study establishes six hypotheses related to the causal relationships among the different typologies of image and their effects on studentsâ satisfaction with the assigned destination to study at least one semester in a host university. In order to contrast these hypotheses, a quantitative research was carried out in the Spanish city of Santander (Spain), by obtaining a sample of 245 international students who participated in an exchange programme at the University of Cantabria. The research findings are: (1) studentsâ satisfaction with the assigned destination is positively influenced by the university image; (2) the university image is positively influenced by the city image; and (3) the city image is positively influenced by the country image
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