The 10 February 1977 lunar occultation of Uranus. Radius, limb darkening, and polar brightening at 6900 A

Contact timings, corrected for lunar limb effects, indicate an equatorial radius of 25700 + or - 500 km for the visible disk for Uranus. A modified Minnaert function is used to model limb darkening and polar brightening. Least squares fits to the observed light curve indicate that Uranus is slightly limb darkened in the passband of the observations (450 A FWHM centered near 6900 A) and that polar brightening is present

Bloodstream form trypanosoma brucei depend upon multiple metacaspases associated with RAB11-positive endosomes

Trypanosoma brucei possesses five metacaspase genes. Of these, MCA2 and MCA3 are expressed only in the mammalian bloodstream form of the parasite, whereas MCA5 is expressed also in the insect procyclic form. Triple RNAi analysis showed MCA2, MCA3 and MCA5 to be essential in the bloodstream form, with parasites accumulating pre-cytokinesis. Nevertheless, triple null mutants (Δmca2/3Δmca5) could be isolated after sequential gene deletion. Thereafter, Δmca2/3Δmca5 mutants were found to grow well both in vitro in culture and in vivo in mice. We hypothesise that metacaspases are essential for bloodstream form parasites, but they have overlapping functions and their progressive loss can be compensated for by activation of alternative biochemical pathways. Analysis of Δmca2/3Δmca5 revealed no greater or lesser susceptibility to stresses reported to initiate programmed cell death, such as treatment with prostaglandin D2. The metacaspases were found to colocalise with RAB11, a marker for recycling endosomes. However, variant surface glycoprotein (VSG) recycling processes and the degradation of internalised anti-VSG antibody were found to occur similarly in wild type, Δmca2/3Δmca5 and triple RNAi induced parasites. Thus, the data provide no support for the direct involvement of T. brucei metacaspases in programmed cell death and suggest that the proteins have a function associated with RAB11 vesicles that is independent of known recycling processes of RAB11-positive endosomes

Genetic exchange in <i>Trypanosoma brucei</i>: evidence for mating prior to metacyclic stage development

It is well established that genetic exchange occurs between Trypanosoma brucei parasites when two stocks are used to infect tsetse flies under laboratory conditions and a number of such crosses have been undertaken. Both cross and self-fertilisation can take place and, with the products of mating being the equivalent of F1 progeny in a Mendelian system and. Recently, analysis of a large collection of independent progeny using a series of polymorphic micro and minisatellite markers, has formally demonstrated that the allelic segregation at loci on each of the 11-megabase chromosomes conforms to ratios predicted for a classical diploid genetic system involving meiosis as well as independent assortment of markers on different chromosomes. Further extensive analysis of these F1 progeny, using a large panel of micro and minisatellite markers, has led to the construction of a genetic map of one parasite stock A. MacLeod, A. Tweedie and S. McLellan et al., The genetic map of Trypanosoma brucei, Nucleic Acids Res 33 (2005), pp. 6688–6693. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (10)

Pulmonary effects of inhalation of spark-generated silver nanoparticles in Brown-Norway and Sprague-Dawley rats

The increasing use of silver nanoparticles (AgNPs) in consumer products is concerning. We examined the potential toxic effects when inhaled in Brown-Norway (BN) rats with a pre-inflammatory state compared to Sprague-Dawley (SD) rats.We determined the effect of AgNPs generated from a spark generator (mass concentration: 600-800 μg/mm(3); mean diameter: 13-16 nm; total lung doses: 8 [Low] and 26-28 [High] μg) inhaled by the nasal route in both rat strains. Rats were sacrificed at day 1 and day 7 after exposure and measurement of lung function.In both strains, there was an increase in neutrophils in bronchoalveolar lavage (BAL) fluid at 24 h at the high dose, with concomitant eosinophilia in BN rats. While BAL inflammatory cells were mostly normalised by Day 7, lung inflammation scores remained increased although not the tissue eosinophil scores. Total protein levels were elevated at both lung doses in both strains. There was an increase in BAL IL-1β, KC, IL-17, CCL2 and CCL3 levels in both strains at Day 1, mostly at high dose. Phospholipid levels were increased at the high dose in SD rats at Day 1 and 7, while in BN rats, this was only seen at Day 1; surfactant protein D levels decreased at day 7 at the high dose in SD rats, but was increased at Day 1 at the low dose in BN rats. There was a transient increase in central airway resistance and in tissue elastance in BN rats at Day 1 but not in SD rats. Positive silver-staining was seen particularly in lung tissue macrophages in a dose and time-dependent response in both strains, maximal by day 7. Lung silver levels were relatively higher in BN rat and present at day 7 in both strains.Presence of cellular inflammation and increasing silver-positive macrophages in lungs at day 7, associated with significant levels of lung silver indicate that lung toxicity is persistent even with the absence of airway luminal inflammation at that time-point. The higher levels and persistence of lung silver in BN rats may be due to the pre-existing inflammatory state of the lungs

Older adults’ experiences of sexual difficulties: Qualitative findings from the English Longitudinal Study on Ageing (ELSA)

There is a growing body of evidence demonstrating that sexual activity is important to the quality of life of older adults, and that it can be influenced by physical, psychological, and social factors. However, older adults’ experiences of sexual difficulties remain relatively unexplored. This article draws on qualitative data collected as part of the English Longitudinal Study of Ageing (ELSA). Participants answered a Sexual Relationships and Activities Questionnaire (SRA-Q), which included an open comment box for further details, 1,084 (1/7) of which were completed. These data were analyzed using Template Analysis, and findings on the experiences of sexual difficulties are presented in this article. Sexual difficulties were contextualized within the couple relationship and could be detrimental to the relationship, particularly if the partner would not seek professional help. Participants reported that sexual difficulties could also have a negative impact on psychological well-being, described mainly as frustration, depression, and sadness. For some participants the supportive nature of their relationship buffered these impacts. Few had sought professional help; those who had reported helpful and unhelpful experiences. These findings add to the limited evidence base and have implications for health care in the context of global aging and a growing recognition of older adults’ sexual rights

Walk to the Beat: A Case Report of the Use of a Novel Haptic Device to Improve Walking after Stroke

Background: Stroke affects 15 million people worldwide every year and leaves two-thirds of survivors with significant mobility deficits including reduced walking speed, increased unevenness of step length and asymmetry. Haptic cues, which utilise sensory stimulation and so are unaffected by visual or auditory interference could discreetly improve the gait of people after stroke. Therefore, the objective of this single mixed methods case study was to evaluate the use of a novel haptic device in a single participant after stroke.Context and purpose: After initial familiarisation, gait symmetry, walking speed and cadence of a 69 year old male stroke survivor were recorded using a Qualisys Motion Capture system whilst he walked on a ten metre walkway, firstly without and then with a haptic device on each leg, which provided a metronomic rhythmical vibratory cue. The participant then provided a user evaluation of the devices using a semi structured interview.Results: The haptic device was evaluated positively by the participant although he noted it needed to be refined to increase its wear-ability and acceptability for everyday use. Whilst gait speed and cadence remained unaltered, there was a 14% improvement in temporal gait symmetry when wearing the haptic device, suggesting it improved this aspect of gait.Conclusion: Whilst limited by its design, the findings of this single case study indicate that the haptic device could be a novel technology-based therapeutic adjunct to improve gait symmetry after stroke. It also provides key understanding of user needs which can be used to guide the development of a new prototype device for stroke survivors.Brief summary: Many stroke survivors have residual mobility problems. Haptic cueing may improve walking by providing a tactile cue that the participant follows to improve symmetry. This single case study suggests that gait symmetry could be improved by haptic cueing and indicates factors affecting the wear ability of such a device.</br

Salford postgraduate annual research conference (SPARC) 2012 proceedings

These proceedings bring together a selection of papers from the 2012 Salford Postgraduate Annual Research Conference (SPARC). They reflect the breadth and diversity of research interests showcased at the conference, at which over 130 researchers from Salford, the North West and other UK universities presented their work. 21 papers are collated here from the humanities, arts, social sciences, health, engineering, environment and life sciences, built environment and business

A blended user centred design study for wearable haptic gait rehabilitation following hemiparetic stroke

Restoring mobility and rehabilitation of gait are high priorities for post-stroke rehabilitation. Cueing using metronomic rhythmic sensory stimulation has been shown to improve gait, but most versions of this approach have used auditory and visual cues. In contrast, we developed a prototype wearable system for rhythmic cueing based on haptics, which was shown to be highly effective in an early pilot study. In this paper we describe a follow-up study with four stroke survivors to inform design, and to identify issues and requirements for such devices to be used in home-based or out-door settings. To this end, we present a blended user-centred design study of a wearable haptic gait rehabilitation system. This study draws on the combined views of physiotherapists, nurses, interaction designers and stroke survivors. Many of the findings were unanticipated, identifying issues outside the scope of initial designs, with important implications for future design and appropriate use

Modulation of human macrophage responses to mycobacterium tuberculosis by silver nanoparticles of different size and surface modification

Exposure to silver nanoparticles (AgNP) used in consumer products carries potential health risks including increased susceptibility to infectious pathogens. Systematic assessments of antimicrobial macrophage immune responses in the context of AgNP exposure are important because uptake of AgNP by macrophages may lead to alterations of innate immune cell functions. In this study we examined the effects of exposure to AgNP with different particle sizes (20 and 110 nm diameters) and surface chemistry (citrate or polyvinlypyrrolidone capping) on cellular toxicity and innate immune responses against Mycobacterium tuberculosis (M.tb) by human monocyte-derived macrophages (MDM). Exposures of MDM to AgNP significantly reduced cellular viability, increased IL8 and decreased IL10 mRNA expression. Exposure of M.tb-infected MDM to AgNP suppressed M.tb-induced expression of IL1B, IL10, and TNFA mRNA. Furthermore, M.tb-induced IL-1β, a cytokine critical for host resistance to M.tb, was inhibited by AgNP but not by carbon black particles indicating that the observed immunosuppressive effects of AgNP are particle specific. Suppressive effects of AgNP on the M.tb-induced host immune responses were in part due to AgNP-mediated interferences with the TLR signaling pathways that culminate in the activation of the transcription factor NF-κB. AgNP exposure suppressed M.tb-induced expression of a subset of NF-κB mediated genes (CSF2, CSF3, IFNG, IL1A, IL1B, IL6, IL10, TNFA, NFKB1A). In addition, AgNP exposure increased the expression of HSPA1A mRNA and the corresponding stress-induced Hsp72 protein. Up-regulation of Hsp72 by AgNP can suppress M.tb-induced NF-κB activation and host immune responses. The observed ability of AgNP to modulate infectious pathogen-induced immune responses has important public health implications

DNA adducts in human urinary bladder and other tissues.

Tobacco smoking is associated with an increased risk of cancer in a number of organs, including bladder and lung. Tobacco smoke contains at least 50 known chemical carcinogens that exert their biological effects through their covalent binding to cellular DNA. Examining human DNA for the presence of altered nucleotides is a means of monitoring exposure to genotoxic chemicals. DNA isolated from 73 human bladder biopsies has been analyzed by 32P-postlabeling for the presence of aromatic/hydrophobic adducts. Butanol extraction of DNA digests resulted in up to a 3-fold greater recovery of adducts than nuclease P1 digestion. Among 16 nonsmokers, adduct levels were in the range 3.2-20.8/10(8) nucleotides (mean 9.7). Eight ex-smokers had values in the range 2.6-12.3 (mean 7.1). Thirteen smokers had adduct levels between 1.3 and 26.7 adducts/10(8) nucleotides (mean 9.5, not different from nonsmokers). Six cigar smokers had higher levels of adducts (mean 12.1, range 7.3-15.0), but pipe smokers did not (five samples, mean 8.6, range 2.9-12.7). A further 8 samples from nonsmokers and 17 from smokers were examined in more detail. Although most of the DNA binding appears not to be smoking related, the levels of one adduct were found to be on average 2-fold higher in smokers (p < 0.005, one-tailed t test). Studies on tissues of the respiratory tract demonstrate a correlation between DNA adduct levels and exposure to tobacco smoke. Evidence to date on the influence of smoking on adducts in peripheral blood cells is equivocal; some studies demonstrate a significant effect, whereas others do not.(ABSTRACT TRUNCATED AT 250 WORDS