39,375 research outputs found
Toxoplasma gondii major surface antigen (SAG1): in vitro analysis of host cell binding
Previous studies have indicated that SAG1, the major surface molecule of the protozoan parasite Toxoplasma gondii, is an important attachment ligand for the host cell. However, the research data that supports this claim comes largely from studies investigating tachyzoite binding, and not SAG1 binding per se.
In this study we successfully developed an in vitro attachment assay to directly evaluate the mechanism of SAG1-host cell binding. Competition experiments were then performed using SAG1 that had been pre-treated with the neoglycoprotein BSA-glucosamide or with antibody. Soluble BSA-glucosamide blocked SAG1 attachment to MDBK cells in a dose-dependent manner, implying that SAG1 binding is mediated, in part, via attachment to host cell surface glucosamine. Interestingly, pre-incubation of SAG1 in polyclonal sera from chronically infected mice failed to block binding. This challenges the assumption that anti-SAG1 antibodies block parasite attachment through the masking of SAG1 host cell binding domains. Taken together, this evidence presents new strategies for understanding SAG1-mediated attachment
Mars Mariner 4 - Identification of some Martian surface features
Martian surface features identified from photographs by Mariner 4 space prob
Environmental capacity in the East Midlands: an evidence base fit for purpose
This report relates to the initial study into the measurement of Environmental Capacity within the East Midlands Region considering what indicators/measures of Environmental Capacity can be put into place in the near future within the region and what are the aspirations regarding longer term indicators / measures of Environmental Capacity in the region. The study involved in depth interviews with relevant employees from local authorities and other key agencies within the region covering the current data collected/used in monitoring and the possible link to the monitoring of Environmental Capacity as well as the interviewees' awareness of and attitudes towards Environmental Capacity as a monitoring tool
The effects of new information technology on the less-favoured regions of the Community. Studies: Regional Policy Series 23
Follow-up services for improving long-term outcomes in intensive care unit (ICU) survivors
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
Our main objective is to assess the effectiveness of follow-up services for ICU survivors that aim to identify and address unmet health needs related to the ICU period. We aim to assess the effectiveness in relation to health-related quality of life, mortality, depression and anxiety, post-traumatic stress disorder, physical function, cognitive function, ability to return to work or education and adverse events.
Our secondary objectives are, in general, to examine both the various ways that follow-up services are provided and any major influencing factors. Specifically, we aim to explore: the effectiveness of service organisation (physician versus nurse led, face to face versus remote, timing of follow-up service); possible differences in services related to country (developed versus developing country); and whether participants had delirium within the ICU setting
Enamel maturation: a brief background with implications for some enamel dysplasias
The maturation stage of enamel development begins once the final tissue thickness has been laid down. Maturation includes an initial transitional pre-stage during which morphology and function of the enamel organ cells change. When this is complete, maturation proper begins. Fully functional maturation stage cells are concerned with final proteolytic degradation and removal of secretory matrix components which are replaced by tissue fluid. Crystals, initiated during the secretory stage, then grow replacing the tissue fluid. Crystals grow in both width and thickness until crystals abut each other occupying most of the tissue volume i.e. full maturation. If this is not complete at eruption, a further post eruptive maturation can occur via mineral ions from the saliva. During maturation calcium and phosphate enter the tissue to facilitate crystal growth. Whether transport is entirely active or not is unclear. Ion transport is also not unidirectional and phosphate, for example, can diffuse out again especially during transition and early maturation. Fluoride and magnesium, selectively taken up at this stage can also diffuse both in an out of the tissue. Crystal growth can be compromised by excessive fluoride and by ingress of other exogenous molecules such as albumin and tetracycline. This may be exacerbated by the relatively long duration of this stage, 10 days or so in a rat incisor and up to several years in human teeth rendering this stage particularly vulnerable to ingress of foreign materials, incompletely mature enamel being the result
Probing Spatial Variation Of The Fine-Structure Constant Using The CMB
The fine-structure constant, α, controls the strength of the electromagnetic interaction. There are extensions of the standard model in which α is dynamical on cosmological length and time scales. The physics of the cosmic microwave background (CMB) depends on the value of α. The effects of spatial variation in α on the CMB are similar to those produced by weak lensing: smoothing of the power spectrum, and generation of non-Gaussian features. These would induce a bias to estimates of the weak-lensing potential power spectrum of the CMB. Using this effect, Planck measurements of the temperature and polarization power spectrum, as well as estimates of CMB lensing, are used to place limits (95% C.L.) on the amplitude of a scale-invariant angular power spectrum of α fluctuations relative to the mean value (CαL=AαSI/[L(L+1)]) of AαSI≤1.6×10−5. The limits depend on the assumed shape of the α-fluctuation power spectrum. For example, for a white-noise angular power spectrum (CαL=AαWN), the limit is AαWN≤2.3×10−8. It is found that the response of the CMB to α fluctuations depends on a separate-universe approximation, such that theoretical predictions are only reliable for α multipoles with L≲100. An optimal trispectrum estimator can be constructed and it is found that it is only marginally more sensitive than lensing techniques for Planck but significantly more sensitive when considering the next generation of experiments. For a future CMB experiment with cosmic-variance limited polarization sensitivity (e.g., CMB-S4), the optimal estimator could detect α fluctuations with AαSI\u3e1.9×10−6 and AαWN\u3e1.4×10−9
The Real Deal: Hip-hop Mixtape Artwork and Black Masculinity
Despite hip-hop’s status as a means of resistance to myriad systems of institutionalized racism, oppression, and poverty, its rise in mainstream popularity has caused a dramatic increase in its corporate monetization. This causes a transfer of control from the artist to the record label, at times jeopardizing hip-hop’s fundamental principles of rebellion, resistance, and risk. An alternative mode of expression, however – the mixtape – puts power back into the hands of hip-hop artists, becoming a crucial vessel for unmitigated artistic expression and meaning. One of the most significant and immediately striking aspects of the mixtape is the cover art. By honing in on the visual aspects of five select mixtapes, it becomes evident that the images presented on their covers advance male hip-hop artists’ freedom of expression of black masculinity. These images, though at times problematic in their own way, become a crucial source of meaning not only in the realm of hip-hop, but in the genre’s relationship with broader societal perceptions of the black male. 
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