1,877 research outputs found
Interactive cutting path analysis programs
The operation of numerically controlled machine tools is interactively simulated. Four programs were developed to graphically display the cutting paths for a Monarch lathe, Cintimatic mill, Strippit sheet metal punch, and the wiring path for a Standard wire wrap machine. These programs are run on a IMLAC PDS-ID graphic display system under the DOS-3 disk operating system. The cutting path analysis programs accept input via both paper tape and disk file
On the Non-Gaussianity Observed in the COBE-DMR Sky Maps
In this paper we pursue the origin of the non-Gaussianity determined by a
bispectrum analysis of the COBE-DMR 4-year sky maps. The robustness of the
statistic is demonstrated by the rebinning of the data into 12 coordinate
systems. By computing the bispectrum statistic as a function of various data
partitions - by channel, frequency, and time interval, we show that the
observed non-Gaussian signal is driven by the 53 GHz data. This frequency
dependence strongly rejects the hypothesis that the signal is cosmological in
origin. A jack-knife analysis of the coadded 53 and 90 GHz sky maps reveals
those sky pixels to which the bispectrum statistic is particularly sensitive.
We find that by removing data from the 53 GHz sky maps for periods of time
during which a known systematic effect perturbs the 31 GHz channels, the
amplitudes of the bispectrum coefficients become completely consistent with
that expected for a Gaussian sky. We conclude that the non-Gaussian signal
detected by the normalised bispectrum statistic in the publicly available DMR
sky maps is due to a systematic artifact. The impact of removing the affected
data on estimates of the normalisation of simple models of cosmological
anisotropy is negligible.Comment: 14 pages, plus 8 Postscript and 3 GIF figures. LaTeX2e document using
AASTeX v5.0 macros. Revised version accepted for publication in the
Astrophysical Journal: small changes to the text, minor modifications to
figures 1 and
Inspiring minds: How big questions can build students’ epistemic insight and improve attitudes towards STEM
This article examines the impact that an ‘epistemically insightful’ approach to informal science learning can have on students’ attitudes, aspirations and perceptions of STEM subjects. It uses interim findings from a research and outreach project, including sustained Saturday activity programmes for ages14–16 and residential summer schools for ages 15–19, designed to create confident scholars who can engage with difficult philosophical questions raised by current technological advances. The Inspiring Minds project at Canterbury Christ Church University, Kent, UK, delivers informal science learning in schools and informal settings based on an epistemic insight-led approach to STEM outreach and education
Study and implementation of urogenital schistosomiasis elimination in Zanzibar (Unguja and Pemba islands) using an integrated multidisciplinary approach
ABSTRACT: BACKGROUND: Schistosomiasis is a parasitic infection that continues to be a major public health problem in many developing countries being responsible for an estimated burden of at least 1.4 million disability-adjusted life years (DALYs) in Africa alone. However, morbidity due to schistosomiasis has been greatly reduced in some parts of the world, including Zanzibar. The Zanzibar government is now committed to eliminate urogenital schistosomiasis. Over the next 3--5 years, the whole at-risk population will be administered praziquantel (40 mg/kg) biannually. Additionally, snail control and behaviour change interventions will be implemented in selected communities and the impact measured in a randomized intervention trial. METHODS: In this 5-year research study, on both Unguja and Pemba islands, urogenital schistosomiasis will be assessed in 45 communities with urine filtration and reagent strips in 4,500 schoolchildren aged 9--12 years annually, and in 4,500 first-year schoolchildren and 2,250 adults in years 1 and 5. Additionally, from first-year schoolchildren, a finger-prick blood sample will be collected and examined for Schistosoma haematobium infection biomarkers. Changes in prevalence and infection intensity will be assessed annually. Among the 45 communities, 15 were randomized for biannual snail control with niclosamide, in concordance with preventive chemotherapy campaigns. The reduction of Bulinus globosus snail populations and S. haematobium-infected snails will be investigated. In 15 other communities, interventions triggering behaviour change have been designed and will be implemented in collaboration with the community. A change in knowledge, attitudes and practices will be assessed annually through focus group discussions and in-depth interviews with schoolchildren, teachers, parents and community leaders. In all 45 communities, changes in the health system, water and sanitation infrastructure will be annually tracked by standardized questionnaire-interviews with community leaders. Additional issues potentially impacting on study outcomes and all incurring costs will be monitored and recorded. DISCUSSION: Elimination of schistosomiasis has become a priority on the agenda of the Zanzibar government and the international community. Our study will contribute to identifying what, in addition to preventive chemotherapy, needs to be done to prevent, control, and ultimately eliminate schistosomiasis, and to draw lessons for current and future schistosomiasis elimination programmes in Africa and elsewhere.Trial registrationISRCTN4883768
Two-Dimensional Topology of the 2dF Galaxy Redshift Survey
We study the topology of the publicly available data released by the 2dFGRS.
The 2dFGRS data contains over 100,000 galaxy redshifts with a magnitude limit
of b_J=19.45 and is the largest such survey to date. The data lie over a wide
range of right ascension (75 degree strips) but only within a narrow range of
declination (10 degree and 15 degree strips). This allows measurements of the
two-dimensional genus to be made.
The NGP displays a slight meatball shift topology, whereas the SGP displays a
bubble like topology. The current SGP data also have a slightly higher genus
amplitude. In both cases, a slight excess of overdense regions are found over
underdense regions. We assess the significance of these features using mock
catalogs drawn from the Virgo Consortium's Hubble Volume LCDM z=0 simulation.
We find that differences between the NGP and SGP genus curves are only
significant at the 1 sigma level. The average genus curve of the 2dFGRS agrees
well with that extracted from the LCDM mock catalogs.
We compare the amplitude of the 2dFGRS genus curve to the amplitude of a
Gaussian random field with the same power spectrum as the 2dFGRS and find,
contradictory to results for the 3D genus of other samples, that the amplitude
of the GRF genus curve is slightly lower than that of the 2dFGRS. This could be
due to a a feature in the current data set or the 2D genus may not be as
sensitive as the 3D genus to non-linear clustering due to the averaging over
the thickness of the slice in 2D. (Abridged)Comment: Submitted to ApJ A version with Figure 1 in higher resolution can be
obtained from http://www.physics.drexel.edu/~hoyle
Collaboration and contestation in further and higher education partnerships in England: a Bourdieusian field analysis
Internationally, ‘College for All’ policies are creating new forms of vocational higher education (HE), and shifting relationships between HE and further education (FE) institutions. In this paper, we consider the way in which this is being implemented in England, drawing on a detailed qualitative case study of a regional HE–FE partnership to widen participation. We focus on the complex mix of collaboration and contestation that arose within it, and how these affected socially differentiated groups of students following high- and low-status routes through its provision. We outline Bourdieu’s concept of ‘field’ as a framework for our analysis and interpretation, including its theoretical ambiguities regarding the definition and scale of fields. Through hermeneutic dialogue between data and theory, we tentatively suggest that such partnerships represent bridges between HE and FE. These bridges are strong between higher-status institutions, but highly contested between lower-status institutions competing closely for distinction. We conclude that the trajectories and outcomes for socially disadvantaged students require attention and collective action to address the inequalities they face, and that our theoretical approach may have wider international relevance beyond the English case
Raman Spectroscopic Analysis of Normal, Dysplastic and Cancerous Oral Mucosa: A Tissue Engineering Approach
Head and neck cancer (HNC) is the sixth most common malignancy worldwide. Squamous cell carcinoma, the primary cause of HNC, evolves from normal epithelium through dysplasia before invading the connective tissue to form a carcinoma. Only 5% of suspicious lesions progress to cancer and diagnosis currently relies on histopathological evaluation, which is invasive and time consuming. A non-invasive, real-time point-of-care method could overcome these problems and facilitate regular screening. Infrared (IR) and Raman spectroscopy (RS) can non-invasively provide information regarding biochemical differences between normal and abnormal tissues. In this study, RS was employed to distinguish between different tissues-engineered models. 3D tissue engineered models of normal, dysplastic and head and neck squamous cell carcinoma (HNSCC) using normal oral keratinocytes, dysplastic (D19, D20 and DOK) and HNSCC cell lines (Cal27 , SCC4 and FaDu) were constructed and their biochemical content predicted by interpretation of their spectral characteristics. Spectral features of normal tissue samples were mainly attributed to lipids, whereas, malignant tissue samples were observed to be protein dominant. Visible differences were found between the spectra of normal, dysplastic and cancerous models, specifically in the bands of amide I and III. The spectra of HNSCC models showed a broad and strong peak of amide I instead of the sharp and weak lipid peak in normal models at band centred at 1667 cm-1. A shift at 2937 cm-1 was only observed in DOK, differentiating them from the other tissue types. Principal Component Analysis (PCA) and Cluster Analysis (CA) distinguished noticeable differences between tissues
SiaA/D interconnects c-di-GMP and RsmA signaling to coordinate cellular aggregation of Pseudomonas aeruginosa in response to environmental conditions
© 2016 Colley, Dederer, Carnell, Kjelleberg, Rice and Klebensberger. Pseudomonas aeruginosa has emerged as an important opportunistic human pathogen that is often highly resistant to eradication strategies, mediated in part by the formation of multicellular aggregates. Cellular aggregates may occur attached to a surface (biofilm), at the air-liquid interface (pellicle), or as suspended aggregates. Compared to surface attached communities, knowledge about the regulatory processes involved in the formation of suspended cell aggregates is still limited. We have recently described the SiaA/D signal transduction module that regulates macroscopic cell aggregation during growth with, or in the presence of the surfactant SDS. Targets for SiaA/D mediated regulation include the Psl polysaccharide, the CdrAB two-partner secretion system and the CupA fimbriae. While the global regulators c-di-GMP and RsmA are known to inversely coordinate cell aggregation and regulate the expression of several adhesins, their potential impact on the expression of the cupA operon remains unknown. Here, we investigated the function of SiaA (a putative ser/thr phosphatase) and SiaD (a di-guanylate cyclase) in cupA1 expression using transcriptional reporter fusions and qRT-PCR. These studies revealed a novel interaction between the RsmA posttranscriptional regulatory system and SiaA/D mediated macroscopic aggregation. The RsmA/rsmY/Z system was found to affect macroscopic aggregate formation in the presence of surfactant by impacting the stability of the cupA1 mRNA transcript and we reveal that RsmA directly binds to the cupA1 leader sequence in vitro. We further identified that transcription of the RsmA antagonist rsmZ is controlled in a SiaA/D dependent manner during growth with SDS. Finally, we found that the siaD transcript is also under regulatory control of RsmA and that overproduction of RsmA or the deletion of siaD results in decreased cellular cyclic di-guanosine monophosphate (c-di-GMP) levels quantified by a transcriptional reporter, demonstrating that SiaA/D connects c-di-GMP and RsmA/rsmY/Z signaling to reciprocally regulate cell aggregation in response to environmental conditions
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