1,382 research outputs found

    “Mirror, mirror
” A preliminary investigation of skin tone dissatisfaction and its impact among British adults

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    This study examined skin tone dissatisfaction, measured using a skin tone chart, among a multiethnic sample of British adults. A total of 648 British White individuals, 292 British South Asians, and 260 British African Caribbean participants completed a visual task in which they were asked to indicate their actual and ideal skin tones. They also completed measures of body appreciation, self-esteem, and ethnic identity attachment. Results showed that Asians had a lighter skin tone ideal than White and African Caribbean participants. Conversely, White participants had higher skin tone dissatisfaction (preferring a darker skin tone) than Asian and African Caribbean participants, who preferred a lighter skin tone. Results also showed that skin tone dissatisfaction predicted body appreciation once the effects of participant ethnicity, age, ethnic identity attachment, and self-esteem had been accounted for. Implications of our findings and suggestions for future research are discussed

    A Pseudo-Two-Dimensional (P2D) Model for FeS2 Conversion Cathode Batteries

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    Conversion cathode materials are gaining interest for secondary batteries due to their high theoretical energy and power density. However, practical application as a secondary battery material is currently limited by practical issues such as poor cyclability. To better understand these materials, we have developed a pseudo-two-dimensional model for conversion cathodes. We apply this model to FeS2 - a material that undergoes intercalation followed by conversion during discharge. The model is derived from the half-cell Doyle-Fuller-Newman model with additional loss terms added to reflect the converted shell resistance as the reaction progresses. We also account for polydisperse active material particles by incorporating a variable active surface area and effective particle radius. Using the model, we show that the leading loss mechanisms for FeS2 are associated with solid-state diffusion and electrical transport limitations through the converted shell material. The polydisperse simulations are also compared to a monodisperse system, and we show that polydispersity has very little effect on the intercalation behavior yet leads to capacity loss during the conversion reaction. We provide the code as an open-source Python Battery Mathematical Modelling (PyBaMM) model that can be used to identify performance limitations for other conversion cathode materials

    Continuous Hydrothermal Flow Synthesis of Blue-Luminescent, Excitation-Independent N-doped Carbon Quantum Dots as Nanosensors

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    Blue-luminescent N-doped carbon quantum dots (NCQDs) exhibiting rarely observed excitation independent optical properties are synthesised from citric acid in the presence of ammonia via a Continuous Hydrothermal Flow Synthesis (CHFS) approach. CHFS is an eco-friendly, rapid synthetic approach (within fractions of a second) facilitating ease of scale-up industrialization as well as offering materials with superior properties. The synthesised CQDs readily disperse in aqueous solution, have an average particle size of 3.3 ± 0.7 nm, with highest emission intensity at 441 nm (and a narrow full width at half maximum, FWHM ~78 nm) under a 360 nm excitation wavelength. Carbon quantum dots, without any further modification, exhibited a high selectivity and sensitivity as a nano-sensor for the highly toxic and carcinogenic chromium(VI) ions. The nano-chemo-sensor delivers significant advantages including simplicity of manufacturing via a continuous, cleaner technology (using targeted biomass precursor), high selectivity, sensitivity and fast response leading to potential applications in environmental industry as well photovoltaics, bio-tagging, bio-sensing and beyond

    B cells do not take up bacterial DNA: An essential role for antigen in exposure of DNA to toll-like receptor-9

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    Murine dendritic cells (DC) and macrophages respond to bacterial CpG DNA through toll-like receptor 9 (TLR9). Although it is frequently assumed that bacterial DNA is a direct stimulus for B cells, published work does not reliably show responses of purified B cells. Here we show that purified splenic B cells did not respond to Escherichia coli DNA with induction of CD86, despite readily responding to single-stranded (ss) phosphodiester CpG oligodeoxynucleotides (ODN). This was due to a combination of weak responses to both long and double-stranded (ds) DNA. B-cell DNA uptake was greatly reduced with increasing DNA length. This contrasts with macrophages where DNA uptake and subsequent responses were enhanced with increasing DNA length. However, when DNA was physically linked to hen egg lysozyme (HEL), HEL-specific B cells showed efficient uptake of DNA, and limited proliferation in response to the HEL-DNA complex. We propose that, in the absence of other signals, B cells have poor uptake and responses to long dsDNA to prevent polyclonal activation. Conversely, when DNA is physically linked to a B-cell receptor (BCR) ligand, its uptake is increased, allowing TLR9-dependent B-cell activation in an antigen-specific manner. We could not generate fragments of E. coli DNA by limited DNaseI digestion that could mimic the stimulatory effect of ss CpG ODN on naive B cells. We suggest that the frequently studied polyclonal B-cell responses to CpG ODN are relevant to therapeutic applications of phosphorothioate-modified CpG-containing ODN, but not to natural responses to foreign or host dsDNA. Immunology and Cell Biology (2011) 89, 517-525; doi:10.1038/icb.2010.112; published online 5 October 201

    The science of clinical practice: disease diagnosis or patient prognosis? Evidence about "what is likely to happen" should shape clinical practice.

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    BACKGROUND: Diagnosis is the traditional basis for decision-making in clinical practice. Evidence is often lacking about future benefits and harms of these decisions for patients diagnosed with and without disease. We propose that a model of clinical practice focused on patient prognosis and predicting the likelihood of future outcomes may be more useful. DISCUSSION: Disease diagnosis can provide crucial information for clinical decisions that influence outcome in serious acute illness. However, the central role of diagnosis in clinical practice is challenged by evidence that it does not always benefit patients and that factors other than disease are important in determining patient outcome. The concept of disease as a dichotomous 'yes' or 'no' is challenged by the frequent use of diagnostic indicators with continuous distributions, such as blood sugar, which are better understood as contributing information about the probability of a patient's future outcome. Moreover, many illnesses, such as chronic fatigue, cannot usefully be labelled from a disease-diagnosis perspective. In such cases, a prognostic model provides an alternative framework for clinical practice that extends beyond disease and diagnosis and incorporates a wide range of information to predict future patient outcomes and to guide decisions to improve them. Such information embraces non-disease factors and genetic and other biomarkers which influence outcome. SUMMARY: Patient prognosis can provide the framework for modern clinical practice to integrate information from the expanding biological, social, and clinical database for more effective and efficient care

    The relationship between the phonological strategies employed In reading and spelling

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    This paper summarises a longitudinal study which examined the relationship between the abilities of young children to read and spell phonologically. Empirical evidence of Bryant and Bradley (1980) and Cataldo and Ellis (1988) to show that children acquire the ability to use a phonological strategy for spelling before the ability to use an equivalent strategy for reading is confirmed. Implications for the teaching of reading are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73266/1/j.1467-9817.1991.tb00011.x.pd

    Protective Efficacy of Menthol Propylene Glycol Carbonate Compared to N, N-diethyl-Methylbenzamide Against Mosquito Bites in Northern Tanzania.

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    The reduction of malaria parasite transmission by preventing human-vector contact is critical in lowering disease transmission and its outcomes. This underscores the need for effective and long lasting arthropod/insect repellents. Despite the reduction in malaria transmission and outcomes in Tanzania, personal protection against mosquito bites is still not well investigated. This study sought to determine the efficacy of menthol propylene glycol carbonate (MR08), Ocimum suave as compared to the gold standard repellent N, N-diethyl-methylbenzamide (DEET), either as a single dose or in combination (blend), both in the laboratory and in the field against Anopheles gambiae s.l and Culex quinquefasciatus. In the laboratory evaluations, repellents were applied on one arm while the other arm of the same individual was treated with a base cream. Each arm was separately exposed in cages with unfed female mosquitoes. Repellents were evaluated either as a single dose or as a blend. Efficacy of each repellent was determined by the number of mosquitoes that landed and fed on treated arms as compared to the control or among them. In the field, evaluations were performed by human landing catches at hourly intervals from 18:00  hr to 01:00  hr. A total of 2,442 mosquitoes were collected during field evaluations, of which 2,376 (97.30%) were An. gambiae s.l while 66 (2.70%) were Cx. quinquefaciatus. MR08 and DEET had comparatively similar protective efficacy ranging from 92% to 100 for both single compound and blends. These findings indicate that MR08 has a similar protective efficacy as DEET for personal protection outside bed nets when used singly and in blends. Because of the personal protection provided by MR08, DEET and blends as topical applicants in laboratory and field situations, these findings suggest that, these repellents could be used efficiently in the community to complement existing tools. Overall, Cx. quinquefasciatus were significantly prevented from blood feeding compared to An. gambiae s.l. The incorporation of these topical repellents for protection against insect bites can be of additional value in the absence or presence of IRS and ITNs coverage. However, a combination of both the physical (bed nets) and the repellent should be used in an integrated manner for maximum protection, especially before going to bed. Additional research is needed to develop repellents with longer duration of protection

    Big data and data repurposing – using existing data to answer new questions in vascular dementia research

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    Introduction: Traditional approaches to clinical research have, as yet, failed to provide effective treatments for vascular dementia (VaD). Novel approaches to collation and synthesis of data may allow for time and cost efficient hypothesis generating and testing. These approaches may have particular utility in helping us understand and treat a complex condition such as VaD. Methods: We present an overview of new uses for existing data to progress VaD research. The overview is the result of consultation with various stakeholders, focused literature review and learning from the group’s experience of successful approaches to data repurposing. In particular, we benefitted from the expert discussion and input of delegates at the 9th International Congress on Vascular Dementia (Ljubljana, 16-18th October 2015). Results: We agreed on key areas that could be of relevance to VaD research: systematic review of existing studies; individual patient level analyses of existing trials and cohorts and linking electronic health record data to other datasets. We illustrated each theme with a case-study of an existing project that has utilised this approach. Conclusions: There are many opportunities for the VaD research community to make better use of existing data. The volume of potentially available data is increasing and the opportunities for using these resources to progress the VaD research agenda are exciting. Of course, these approaches come with inherent limitations and biases, as bigger datasets are not necessarily better datasets and maintaining rigour and critical analysis will be key to optimising data use

    Raised tone reveals ATP as a sympathetic neurotransmitter in the porcine mesenteric arterial bed

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    The relative importance of ATP as a functional sympathetic neurotransmitter in blood vessels has been shown to be increased when the level of preexisting vascular tone or pressure is increased, in studies carried out in rat mesenteric arteries. The aim of the present study was to determine whether tone influences the involvement of ATP as a sympathetic cotransmitter with noradrenaline in another species. We used the porcine perfused mesenteric arterial bed and porcine mesenteric large, medium and small arteries mounted for isometric tension recording, because purinergic cotransmission can vary depending on the size of the blood vessel. In the perfused mesenteric bed at basal tone, sympathetic neurogenic vasocontractile responses were abolished by prazosin, an α1- adrenoceptor antagonist, but there was no significant effect of α,ÎČ-methylene ATP, a P2X receptor-desensitizing agent. Submaximal precontraction of the mesenteric arterial bed with U46619, a thromboxane A2 mimetic, augmented the sympathetic neurogenic vasocontractile responses; under these conditions, both α,ÎČ-methylene ATP and prazosin attenuated the neurogenic responses. In the mesenteric large, medium and small arteries, prazosin attenuated the sympathetic neurogenic contractile responses under conditions of both basal and U46619-raised tone. α,ÎČ-Methylene ATP was effective in all of these arteries only under conditions of U46619- induced tone, causing a similar inhibition in all arteries, but had no significant effect on sympathetic neurogenic contractions at basal tone. These data show thatATP is a cotransmitter with noradrenaline in porcine mesenteric arteries; the purinergic component was revealed under conditions of partial precontraction, which is more relevant to physiological conditions
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