4,373 research outputs found
Immunology presentation at the 1990 NASA/NSF Antarctica Biomedical Science Working Group
An overview of methodology used for determining human in vitro lymphocyte activation, proliferation and effector cell function was presented and results of previous manned space flight immunology studies from Apollo through Shuttle were reviewed. Until the Shuttle era, lymphocyte assays were not very sensitive and had such large variations among normal subjects that it was difficult to define a consistent effect of space flight. More sensitive assay, however, even with Shuttle missions as brief as 6 days indicate depressed T-cell proliferative responses are routinely observed following space flight. Using a slight modification of the Shuttle assay, five different human stress-immunology models have been studied over the last 6 years in our lab. These have included: academic examinations of medical students having blood drawn during major test periods on three separate groups of first year students and two hypoxia studies (at 25,000 feet in a 6 week chamber ascent to the equivalent of Mount Everest and twice on Pikes Peak at 14,000 feet). These studies are particularly pertinent to Antarctica, since the altitude equivalent of 11,000 feet at the South Pole may affect some of the variables that are being measured in immunology, physiology or cognitive studies. An extravehicular study was performed drawing blood from 35 individuals before and immediately following a chamber exposure study. Preliminary results from 30 Shuttle astronauts investigated immunophenotype analysis and the role of a novel monocyte population in modulating the previously observed suppressed in vitro immune function. The results of the Air Force Academy cadet stress study were also presented
The reclassification of non-Western art at UCL library
In 2019 UCL Library reclassified 2000 art books, covering art from countries outside the classical and Western canon, that were arranged alphabetically by country. This paper will look at the project to reclassify these books to try to mitigate its bias against non-classical and Western art, and how the Library implemented largescale processes in the interests of speed and cost. It will examine the reasons why this was necessary; the technical steps taken to tackle the relatively small but still considerable numbers as simply and quickly as possible; and the potential for similar work within UCL to address issues around decolonising and liberating the collections and catalogue
Wear transitions in a wear coefficient model
The frictional-work wear model has been used popularly for the prediction of wear phenomena such as rail corrugation. The accuracy of such models depends on the value chosen for the empirical wear coefficient in this wear model. Experimental results have widely shown that this wear coefficient is strongly dependent upon the type of wear process involved. The wear coefficient in the frictional-work wear model under two-disc contact and dry friction conditions proposed is a multi-step function of the friction power density corresponding to three types of wear. However, at present there is no clear means of predicting the transitions between wear types. This paper investigates wear transitions between the wear types are predicted using analytical models based on the wear mechanics involved
Ice Core Records of West Greenland Melt and Climate Forcing
Remote sensing observations and climate models indicate that the Greenland Ice Sheet (GrIS) has been losing mass since the late 1990s, mostly due to enhanced surface melting from rising summer temperatures. However, in situ observational records of GrIS melt rates over recent decades are rare. Here we develop a record of frozen meltwater in the west GrIS percolation zone preserved in seven firn cores. Quantifying ice layer distribution as a melt feature percentage (MFP), we find significant increases in MFP in the southernmost five cores over the past 50 years to unprecedented modern levels (since 1550 CE). Annual to decadal changes in summer temperatures and MFP are closely tied to changes in Greenland summer blocking activity and North Atlantic sea surface temperatures since 1870. However, summer warming of ~1.2°C since 1870–1900, in addition to warming attributable to recent sea surface temperature and blocking variability, is a critical driver of high modern MFP levels
Health visitors' work in a multi-ethnic society: A qualitative study of social exclusion
Health visiting is adopting an enabling model of practice, which may promote social inclusion, but is under pressure to justify itself. The article focuses on health visitors’ work with Pakistani women and comparable white women in Glasgow, examining the nature of health visiting and women’s responses to it. Health visitors’ perspectives involve the appreciation of cultural differences, building relationships with clients, and some stereotyping of clients. Techniques include highly valued home visiting, and processes of negotiation with clients. Problems faced include difficulties with interpreters, lack of training, relationships with other professions, recent changes in the NHS, and issues of stress and personal safety. Women’s views of health visitors are generally positive, especially concerning home visits, time spent with clients, and gate-keeping access to GPs. Negative views came mostly from white women, and concerned the more controlling models of health visiting. Thus, enabling health visiting practice was widely appreciated, and could act as an inclusionary force, facilitating access to and use of health services. Exclusion was operating at institutional level, towards minorities and women of lower socio-economic groups, but was being actively resisted by practitioners
Portable dynamic fundus instrument
A portable diagnostic image analysis instrument is disclosed for retinal funduscopy in which an eye fundus image is optically processed by a lens system to a charge coupled device (CCD) which produces recordable and viewable output data and is simultaneously viewable on an electronic view finder. The fundus image is processed to develop a representation of the vessel or vessels from the output data
Joint demodulation of low-entropy narrowband cochannel signals
Introducation to cochannel signals: many receivers today operate in an interference-limited environment. In a dense signal environment, the performance of a receiver is limited by interference from multiple signals at the receiver rather than signal-to-noise ratio. In the interference-limited environment, there is a diminishing return from investing additional resources into improving traditional receiver parameters such as noise figure. Advanced processing techniques exist that can help recover information that would otherwise be lost using a single-channel receiver. This work investigates some of these techniques. Interference may originate from many sources, such as users on the same or adjacent frequency band, unintended emissions, and intermodulation. This work investigates interference from cochannel information bearing signals. Cochannel interference is commonly defined as the reception of two or more signals at the receiver overlapping in frequency and in time.USA
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