457 research outputs found
Community-Based Settings and Sampling Strategies: Implications for Reducing Racial Health Disparities Among Black Men, New York City, 2010–2013
Introduction Rates of screening colonoscopies, an effective method of preventing colorectal cancer, have increased in New York City over the past decade, and racial disparities in screening have declined. However, vulnerable subsets of the population may not be reached by traditional surveillance and intervention efforts to improve colorectal cancer screening rates.
Methods We compared rates of screening colonoscopies among black men aged 50 or older from a citywide random-digit–dial sample and a location-based sample focused on hard-to-reach populations to evaluate the representativeness of the random-digit–dial sample. The location-based sample (N = 5,568) was recruited from 2010 through 2013 from community-based organizations in New York City. Descriptive statistics were used to compare these data with data for all black men aged 50 or older from the 2011 cohort of the Community Health Survey (weighted, N = 334) and to compare rates by community-based setting.
Results Significant differences in screening colonoscopy history were observed between the location-based and random-digit–dial samples (49.1% vs 62.8%, P \u3c .001). We observed significant differences between participants with and without a working telephone among the location-based sample and between community-based settings.
Conclusions Vulnerable subsets of the population such as those with inconsistent telephone access are excluded from random-digit–dial samples. Practitioners and researchers should consider the target population of proposed interventions to address disparities, and whether the type of setting reaches those most in need of services
Expression of human α1-proteinase inhibitor in Aspergillus niger
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
The role of Cra in regulating acetate excretion and osmotic tolerance in E. coli K-12 and E. coli B at high density growth
<p>Abstract</p> <p>Background</p> <p><it>E. coli </it>B (BL21), unlike <it>E.coli </it>K-12 (JM109) is insensitive to glucose concentration and, therefore, grows faster and produces less acetate than <it>E. coli </it>K-12, especially when growing to high cell densities at high glucose concentration. By performing genomic analysis, it was demonstrated that the cause of this difference in sensitivity to the glucose concentration is the result of the differences in the central carbon metabolism activity. We hypothesized that the global transcription regulator Cra (FruR) is constitutively expressed in <it>E. coli </it>B and may be responsible for the different behaviour of the two strains. To investigate this possibility and better understand the function of Cra in the two strains, <it>cra </it>- negative <it>E. coli </it>B (BL21) and <it>E. coli </it>K-12 (JM109) were prepared and their growth behaviour and gene expression at high glucose were evaluated using microarray and real-time PCR.</p> <p>Results</p> <p>The deletion of the <it>cra </it>gene in <it>E. coli </it>B (BL21) minimally affected the growth and maximal acetate accumulation, while the deletion of the same gene in <it>E.coli </it>K-12 (JM109) caused the cells to stop growing as soon as acetate concentration reached 6.6 g/L and the media conductivity reached 21 mS/cm. <it>ppsA </it>(gluconeogenesis gene), <it>aceBA </it>(the glyoxylate shunt genes) and <it>poxB </it>(the acetate producing gene) were down-regulated in both strains, while <it>acs </it>(acetate uptake gene) was down-regulated only in <it>E.coli </it>B (BL21). These transcriptional differences had little effect on acetate and pyruvate production. Additionally, it was found that the lower growth of <it>E. coli </it>K-12 (JM109) strain was the result of transcription inhibition of the osmoprotectant producing <it>bet </it>operon (<it>betABT</it>).</p> <p>Conclusions</p> <p>The transcriptional changes caused by the deletion of <it>cra </it>gene did not affect the activity of the central carbon metabolism, suggesting that Cra does not act alone; rather it interacts with other pleiotropic regulators to create a network of metabolic effects. An unexpected outcome of this work is the finding that <it>cra </it>deletion caused transcription inhibition of the <it>bet </it>operon in <it>E. coli </it>K-12 (JM109) but did not affect this operon transcription in <it>E. coli </it>B (BL21). This property, together with the insensitivity to high glucose concentrations, makes this the <it>E. coli </it>B (BL21) strain more resistant to environmental changes.</p
A Mission-Adaptive Variable Camber Flap Control System to Optimize High Lift and Cruise Lift-to-Drag Ratios of Future N+3 Transport Aircraft
Boeing and NASA are conducting a joint study program to design a wing flap system that will provide mission-adaptive lift and drag performance for future transport aircraft having light-weight, flexible wings. This Variable Camber Continuous Trailing Edge Flap (VCCTEF) system offers a lighter-weight lift control system having two performance objectives: (1) an efficient high lift capability for take-off and landing, and (2) reduction in cruise drag through control of the twist shape of the flexible wing. This control system during cruise will command varying flap settings along the span of the wing in order to establish an optimum wing twist for the current gross weight and cruise flight condition, and continue to change the wing twist as the aircraft changes gross weight and cruise conditions for each mission segment. Design weight of the flap control system is being minimized through use of light-weight shape memory alloy (SMA) actuation augmented with electric actuators. The VCCTEF program is developing better lift and drag performance of flexible wing transports with the further benefits of lighter-weight actuation and less drag using the variable camber shape of the flap
An Efficient, Highly Flexible Multi-Channel Digital Downconverter Architecture
In this innovation, a digital downconverter has been created that produces a large (16 or greater) number of output channels of smaller bandwidths. Additionally, this design has the flexibility to tune each channel independently to anywhere in the input bandwidth to cover a wide range of output bandwidths (from 32 MHz down to 1 kHz). Both the flexibility in channel frequency selection and the more than four orders of magnitude range in output bandwidths (decimation rates from 32 to 640,000) presented significant challenges to be solved. The solution involved breaking the digital downconversion process into a two-stage process. The first stage is a 2 oversampled filter bank that divides the whole input bandwidth as a real input signal into seven overlapping, contiguous channels represented with complex samples. Using the symmetry of the sine and cosine functions in a similar way to that of an FFT (fast Fourier transform), this downconversion is very efficient and gives seven channels fixed in frequency. An arbitrary number of smaller bandwidth channels can be formed from second-stage downconverters placed after the first stage of downconversion. Because of the overlapping of the first stage, there is no gap in coverage of the entire input bandwidth. The input to any of the second-stage downconverting channels has a multiplexer that chooses one of the seven wideband channels from the first stage. These second-stage downconverters take up fewer resources because they operate at lower bandwidths than doing the entire downconversion process from the input bandwidth for each independent channel. These second-stage downconverters are each independent with fine frequency control tuning, providing extreme flexibility in positioning the center frequency of a downconverted channel. Finally, these second-stage downconverters have flexible decimation factors over four orders of magnitude The algorithm was developed to run in an FPGA (field programmable gate array) at input data sampling rates of up to 1,280 MHz. The current implementation takes a 1,280-MHz real input, and first breaks it up into seven 160-MHz complex channels, each spaced 80 MHz apart. The eighth channel at baseband was not required for this implementation, and led to more optimization. Afterwards, 16 second stage narrow band channels with independently tunable center frequencies and bandwidth settings are implemented A future implementation in a larger Xilinx FPGA will hold up to 32 independent second-stage channels
Novel thermophilic cellulolytic isolates belonging to the phylum Chloroflexi
Current biofuel technologies utilize valuable foodstuffs, such as corn kernels and cane sugar, as sources of easily metabolized sugars. Microbes are used to ferment these sugars into bioethanol, a first-generation biofuel. However, in order to avoid diverting foodstuffs from the food supply, the development of second-generation biofuels technology is necessary. Second-generation biofuels are produced by converting structurally complex lignocellulosic biomass, such as agricultural and municipal wastes, to fermentable sugars or directly to biofuels.
The major technological hurdle limiting the mass production of second-generation biofuels is the difficulty in efficiently converting structurally complex lignocellulosic materials to fermentable sugars or directly to biofuels. The discovery of novel thermophilic microorganisms and enzymes that have high activities or broad substrate ranges on plant polymers addresses this challenge
DEMONSTRATING ADAPTABILITY: ROLE MODELLING MULTIDISCIPLINARY LEARNING IN THE LAB, ONLINE AND AT HOME
In this paper we analyse changes required in the role of laboratory demonstrators to support students across a mid-semester move to online learning in response to COVID-19. ‘Multidisciplinary Laboratories’ is a large (~450 students) first-year, multi-campus course at the University of Newcastle that is organised around two multifaceted investigations: ‘Water – would you drink it?’, and ‘Energy – can it be sustainable?’. The course introduces students each week to diverse disciplinary perspectives, i.e. Environmental Science and Management, Biology, Chemistry, Psychology, Human Geography, Earth Sciences, and Physics. The teaching cohort in each laboratory session (~45 students) comprises a discipline-specific academic lead that changes weekly, and two demonstrators who remain with the class for the whole semester. As laboratories moved online, demonstrators supported students’ learning through synchronous live classes, experiments at home, virtual experiments and asynchronous materials including video tutorials. Importantly, demonstrators have role-modelled for students adaptability under conditions of uncertainty. Analysis of evaluative data including Blackboard engagement records, student surveys and demonstrators’ observations suggests effectively supporting students’ learning required nuanced and important changes in demonstrators’ roles including technical aspects, and techniques for engaging students and facilitating classes
Light-induced picosecond rotational disordering of the inorganic sublattice in hybrid perovskites.
Femtosecond resolution electron scattering techniques are applied to resolve the first atomic-scale steps following absorption of a photon in the prototypical hybrid perovskite methylammonium lead iodide. Following above-gap photoexcitation, we directly resolve the transfer of energy from hot carriers to the lattice by recording changes in the mean square atomic displacements on 10-ps time scales. Measurements of the time-dependent pair distribution function show an unexpected broadening of the iodine-iodine correlation function while preserving the Pb-I distance. This indicates the formation of a rotationally disordered halide octahedral structure developing on picosecond time scales. This work shows the important role of light-induced structural deformations within the inorganic sublattice in elucidating the unique optoelectronic functionality exhibited by hybrid perovskites and provides new understanding of hot carrier-lattice interactions, which fundamentally determine solar cell efficiencies
Awareness of high blood pressure by nativity among black men : implications for interpreting the immigrant health paradox
Unidad de excelencia MarÃa de Maeztu MdM-2015-0552This publication is in the public domain and is therefore without copyright. All text from this work may be reprinted freely. Use of these materials should be properly citedIntroduction: differences in the social determinants of health and cardiovascular health outcomes by nativity have implications for understanding the immigrant health paradox among black immigrants. We aimed to understand whether blood pressure awareness, a precursor to achieving blood pressure control among hypertensive patients, varied by nativity among a sample of black men. - Methods: data were collected from 2010 through 2014. In 2016, we conducted logistic regression models using data from a large sample of urban-dwelling middle-aged and older black men. All men in the study had measured high blood pressure at the time of enrollment and were also asked whether they were aware of having high blood pressure. Independent variables included demographics, socioeconomic status, access to care, and health-related behaviors. - Results: foreign-born participants were significantly less likely than US-born participants to report awareness of having high blood pressure (P < .001). We observed a significant positive relationship between proportion of life spent in the US and being aware of having hypertension (β = 0.863; 95% CI, 0.412-1.314; P < .001). This relationship remained after adjusting the model for salient independent variables (β = 0.337; 95% CI, 0.041-0.634; P = .03). - Conclusions: difference in hypertension awareness by nativity may skew surveillance estimates used to track health disparities by large heterogeneous racial categories. Our results also indicate that prior health care experience and circumstances should be considered when studying the immigrant health paradox
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