Towards Optimal Image Stitching for Virtual Microscopy

In this paper we present an image stitching method based on dynamic programming and describe its application to automated slide acquisition for Virtual Microscopy (VM). Given a large number of fields of view (FOVs) acquired from a single microscope slide, we composite these images into a single large 'virtual slide' image. The location of each FOV is determined using a new algorithm based on dynamic programming. We compare the performance of the proposed algorithm to an existing greedy algorithm. In a visual trial it is shown that the new algorithm provides a significant improvement in perceived image quality at image boundaries compared to the existing algorithm

Flow Injection Sample Introduction Methods for Atomic Absorption Spectrometry

The essential features of flow injection analysis are described and the use of flow injection methodology for sample introduction for flame atomic-absorption spectrometry is briefly reviewed. A flow injection analogue of the standard additions method has been devised and applied to the analysis of chromium in some BCS standard steels. The results showed good agreement with the certificate values. The use of a concentration gradient forming mixing chamber to provide a novel method of rapid, single-standard Calibration is described and the results of preliminary experiments with magnesium show the method to be viable. The potential usefulness of both methods is critically evaluated

IRAC Observations of M81

IRAC images of M81 show three distinct morphological constituents: a smooth distribution of evolved stars with bulge, disk, and spiral arm components; a clumpy distribution of dust emission tracing the spiral arms; and a pointlike nuclear source. The bulge stellar colors are consistent with M-type giants, and the disk colors are consistent with a slightly younger population. The dust emission generally follows the blue and ultraviolet emission, but there are large areas that have dust emission without ultraviolet and smaller areas with ultraviolet but little dust emission. The former are presumably caused by extinction, and the latter may be due to cavities in the gas and dust created by supernova explosions. The nucleus appears fainter at 8 um than expected from ground-based 10 um observations made four years ago.Comment: ApJS in press (Spitzer special issue); 15 pages, 3 figures. Changes: unused references removed, numbers and labels in Table 1 change

Depression and mortality: Artifact of measurement and analysis?

Background Previous research demonstrates various associations between depression, cardiovascular disease (CVD) incidence and mortality, possibly as a result of the different methodologies used to measure depression and analyse relationships. This analysis investigated the association between depression, CVD incidence (CVDI) and mortality from CVD (MCVD), smoking related conditions (MSRC), and all causes (MALL), in a sample data set, where depression was measured using items from a validated questionnaire and using items derived from the factor analysis of a larger questionnaire, and analyses were conducted based on continuous data and grouped data. Methods Data from the PRIME Study (N=9798 men) on depression and 10-year CVD incidence and mortality were analysed using Cox proportional hazards models. Results Using continuous data, both measures of depression resulted in the emergence of positive associations between depression and mortality (MCVD, MSRC, MALL). Using grouped data, however, associations between a validated measure of depression and MCVD, and between a measure of depression derived from factor analysis and all measures of mortality were lost. Limitations Low levels of depression, low numbers of individuals with high depression and low numbers of outcome events may limit these analyses, but levels are usual for the population studied. Conclusions These data demonstrate a possible association between depression and mortality but detecting this association is dependent on the measurement used and method of analysis. Different findings based on methodology present clear problems for the elucidation and determination of relationships. The differences here argue for the use of validated scales where possible and suggest against over-reduction via factor analysis and grouping. CrownCopyright © 2013PublishedbyElsevierB.V.Allrightsreserved

Probing the Evolution of the Galaxy Interaction/Merger Rate Using Collisional Ring Galaxies

We present the results from our program to determine the evolution of the galaxy interaction/merger rate with redshift using the unique star-forming characteristics of collisional ring galaxies. We have identified 25 distant collisional ring galaxy candidates (CRGCs) in a total of 162 deep Hubble Space Telescope Wide Field/Planetary Camera-2 images obtained from the HST Archives. Based on measured and estimated redshifts, these 25 CRGCs all lie in the redshift interval of 0.1 < z < 1. Using the local collisional ring galaxy volume density and the new ``standard'' cosmology, we find that in order to account for the number of identified CRGCs in our surveyed fields, the galaxy interaction/merger rate, parameterized as (1 + z)^m, must increase steeply with redshift.We determine a minimum value of m = 5.2 $\pm$ 0.7, though m could be as high as 7 or 8. We can rule out a non-evolving (m = 0) and weakly evolving (m = 1-2) galaxy interaction/merger rate at greater than the 4 sigma level of confidence.Comment: Accepted in the Astrophysical Journal (11 pages, 4 figures). Higher resolution version of the figures is available at http://www.astro.cornell.edu/~vassilis/papers

Doing challenging research studies in a patient centred way: qualitative study to inform a randomised controlled trial in the paediatric emergency care setting

Objective: To inform the design of a randomised controlled trial (called EcLiPSE) to improve the treatment of children with convulsive status epilepticus (CSE). EcLiPSE requires the use of a controversial deferred consent process. Design: Qualitative interview and focus group study. Setting: 8 UK support groups for parents of children who have chronic or acute health conditions and experience of paediatric emergency care. Participants: 17 parents, of whom 11 participated in telephone interviews (10 mothers, 1 father) and 6 in a focus group (5 mothers, 1 father). 6 parents (35%) were bereaved and 7 (41%) had children who had experienced seizures, including CSE. Results: Most parents had not heard of deferred consent, yet they supported its use to enable the progress of emergency care research providing a child's safety was not compromised by the research. Parents were reassured by tailored explanation, which focused their attention on aspects of EcLiPSE that addressed their priorities and concerns. These aspects included the safety of the interventions under investigation and how both EcLiPSE interventions are used in routine clinical practice. Parents made recommendations about the appropriate timing of a recruitment discussion, the need to individualise approaches to recruiting bereaved parents and the use of clear written information. Conclusions: Our study provided information to help ensure that a challenging trial was patient centred in its design. We will use our findings to help EcLiPSE practitioners to: discuss potentially threatening trial safety information with parents, use open-ended questions and prompts to identify their priorities and concerns and clarify related aspects of written trial information to assist understanding and decision-making

A flexible, extensible object oriented real-time near photorealistic visualization system:the system framework design

In this paper we describe a novel, extensible visualization system currently under development at Aston University. We introduce modern programming methods, such as the use of data driven programming, design patterns, and the careful definition of interfaces to allow easy extension using plug-ins, to 3D landscape visualization software. We combine this with modern developments in computer graphics, such as vertex and fragment shaders, to create an extremely flexible, extensible real-time near photorealistic visualization system. In this paper we show the design of the system and the main sub-components. We stress the role of modern programming practices and illustrate the benefits these bring to 3D visualization. © 2006 Springer-Verlag Berlin Heidelberg

The HI and Ionized Gas Disk of the Seyfert Galaxy NGC 1144 = Arp 118: A Violently Interacting Galaxy with Peculiar Kinematics

We present observations of the distribution and kinematics of neutral and ionized gas in NGC 1144, a galaxy that forms part of the Arp 118 system. Ionized gas is present over a huge spread in velocity (1100 km/s) in the disk of NGC 1144, but HI emission is detected over only 1/3 of this velocity range, in an area that corresponds to the NW half of the disk. In the nuclear region of NGC 1144, a jump in velocity in the ionized gas component of 600 km/s is observed. Faint, narrow HI absorption lines are also detected against radio sources in the SE part of the disk of NGC 1144, which includes regions of massive star formation and a Seyfert nucleus. The peculiar HI distribution, which is concentrated in the NW disk, seems to be the inverse of the molecular distribution which is concentrated in the SE disk. Although this may partly be the result of the destruction of HI clouds in the SE disk, there is circumstantial evidence that the entire HI emission spectrum of NGC 1144 is affected by a deep nuclear absorption line covering a range of 600 km/s, and is likely blueshifted with respect to the nucleus. In this picture, a high column-density HI stream is associated with the nuclear ionized gas velocity discontinuity, and the absorption effectively masks any HI emission that would be present in the SE disk of NGC 1144.Comment: manuscript, arp118.ps: 28 pages; 1 Table: arp118.tab1.ps; 16 Figures: arp118.fig1-16.ps; Accepted to Ap

Using Spitzer Colors as Diagnostics of Star Formation Regions: The Interacting Galaxy Arp 107

We present Spitzer infrared imaging of the peculiar galaxy pair Arp 107, and compare with an optical H-alpha map and a numerical model of the interaction. The [3.6 micron] - [4.5 micron] colors of clumps in the galaxy do not vary around the ring-like primary spiral arm and are consistent with those of stars, thus these bands are dominated by starlight. In contrast, the [5.8 micron] - [8.0 micron] colors are consistent with those of interstellar dust, and vary by about 0.2 magnitudes around the ring/spiral, with redder colors associated with regions with stronger star formation as indicated by H-alpha and mid-infrared luminosity. The [4.5 micron] - [5.8 micron] colors for clumps in this arm are bluer than dust and redder than stars, and vary by 1.3 magnitudes around the arm. This color is therefore a measure of the relative number of young stars to old stars, with a redder color indicating a higher proportion of young stars. There is a clear azimuthal sequence in the [4.5] - [5.8] color around the arm, indicating a sequence in average stellar age. The L(H-alpha)/L(8.0 micron) ratio varies around the arm by a factor of ~7; this variation may be due to extinction or to PAH excitation by non-ionizing photons. Our model of Arp 107 accounts for the general morphology of the system, and explains the age variation along the arm as the result of differences in the time of maximum compression in the arm. Using Spitzer colors, we are able to distinguish background quasars and foreground stars from star forming regions associated with Arp 107.Comment: Astronomical Journal, accepted. Figures at http://www.etsu.edu/physics/bsmith/research/sg/arp107/arp107_spitzer.htm