156 research outputs found
EchoFusion: Tracking and Reconstruction of Objects in 4D Freehand Ultrasound Imaging without External Trackers
Ultrasound (US) is the most widely used fetal imaging technique. However, US
images have limited capture range, and suffer from view dependent artefacts
such as acoustic shadows. Compounding of overlapping 3D US acquisitions into a
high-resolution volume can extend the field of view and remove image artefacts,
which is useful for retrospective analysis including population based studies.
However, such volume reconstructions require information about relative
transformations between probe positions from which the individual volumes were
acquired. In prenatal US scans, the fetus can move independently from the
mother, making external trackers such as electromagnetic or optical tracking
unable to track the motion between probe position and the moving fetus. We
provide a novel methodology for image-based tracking and volume reconstruction
by combining recent advances in deep learning and simultaneous localisation and
mapping (SLAM). Tracking semantics are established through the use of a
Residual 3D U-Net and the output is fed to the SLAM algorithm. As a proof of
concept, experiments are conducted on US volumes taken from a whole body fetal
phantom, and from the heads of real fetuses. For the fetal head segmentation,
we also introduce a novel weak annotation approach to minimise the required
manual effort for ground truth annotation. We evaluate our method
qualitatively, and quantitatively with respect to tissue discrimination
accuracy and tracking robustness.Comment: MICCAI Workshop on Perinatal, Preterm and Paediatric Image analysis
(PIPPI), 201
The core symptoms of bulimia nervosa, anxiety, and depression: A network analysis.
Bulimia nervosa (BN) is characterized by symptoms of binge eating and compensatory behavior, and overevaluation of weight and shape, which often co-occur with symptoms of anxiety and depression. However, there is little research identifying which specific BN symptoms maintain BN psychopathology and how they are associated with symptoms of depression and anxiety. Network analyses represent an emerging method in psychopathology research to examine how symptoms interact and may become self-reinforcing. In the current study of adults with a Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition (DSM-IV) diagnosis of BN (N = 196), we used network analysis to identify the central symptoms of BN, as well as symptoms that may bridge the association between BN symptoms and anxiety and depression symptoms. Results showed that fear of weight gain was central to BN psychopathology, whereas binge eating, purging, and restriction were less central in the symptom network. Symptoms related to sensitivity to physical sensations (e.g., changes in appetite, feeling dizzy, and wobbly) were identified as bridge symptoms between BN, and anxiety and depressive symptoms. We discuss our findings with respect to cognitive-behavioral treatment approaches for BN. These findings suggest that treatments for BN should focus on fear of weight gain, perhaps through exposure therapies. Further, interventions focusing on exposure to physical sensations may also address BN psychopathology, as well as co-occurring anxiety and depressive symptoms. (PsycINFO Database Recor
High-Mass X-ray Binaries and the Spiral Structure of the Host Galaxy
We investigate the manifestation of the spiral structure in the distribution
of high-mass X-ray binaries (HMXBs) over the host galaxy. We construct the
simple kinematic model. It shows that the HMXBs should be displaced relative to
the spiral structure observed in such traditional star formation rate
indicators as the Halpha and FIR emissions because of their finite lifetimes.
Using Chandra observations of M51, we have studied the distribution of X-ray
sources relative to the spiral arms of this galaxy observed in Halpha. Based on
K-band data and background source number counts, we have separated the
contributions from high-mass and low-mass X-ray binaries and active galactic
nuclei. In agreement with model predictions, the distribution of HMXBs is wider
than that of bright HII regions concentrated in the region of ongoing star
formation. However, the statistical significance of this result is low, as is
the significance of the concentration of the total population of X-ray sources
to the spiral arms. We also predict the distribution of HMXBs in our Galaxy in
Galactic longitude. The distribution depends on the mean HMXB age and can
differ significantly from the distributions of such young objects as
ultracompact HII regions.Comment: 18 pages, 6 figures; Astronomy Letters, Vol. 33, No. 5, 2007, pp.
299-30
Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) -- I: Introduction to the Survey
We introduce a new survey to map the radio continuum halos of a sample of 35
edge-on spiral galaxies at 1.5 GHz and 6 GHz in all polarization products. The
survey is exploiting the new wide bandwidth capabilities of the Karl G. Jansky
Very Large Array (i.e. the Expanded Very Large Array, or EVLA) in a variety of
array configurations (B, C, and D) in order to compile the most comprehensive
data set yet obtained for the study of radio halo properties. This is the first
survey of radio halos to include all polarization products.
In this first paper, we outline the scientific motivation of the survey, the
specific science goals, and the expected improvements in noise levels and
spatial coverage from the survey. Our goals include investigating the physical
conditions and origin of halos, characterizing cosmic ray transport and wind
speed, measuring Faraday rotation and mapping the magnetic field, probing the
in-disk and extraplanar far-infrared - radio continuum relation, and
reconciling non-thermal radio emission with high-energy gamma-ray models. The
sample size allows us to search for correlations between radio halos and other
properties, including environment, star formation rate, and the presence of
AGNs. In a companion paper (Paper II) we outline the data reduction steps and
present the first results of the survey for the galaxy, NGC 4631.Comment: 17 pages, 1 figure, accepted to the Astronomical Journal, Version 2
changes: added acknowledgement to NRA
Factors affecting phage D29 infection: a tool to investigate different growth states of mycobacteria
Bacteriophages D29 and TM4 are able to infect a wide range of mycobacteria, including pathogenic and non pathogenic species. Successful phage infection of both fast- and slow-growing mycobacteria can be rapidly detected using the phage amplification assay. Using this method, the effect of oxygen limitation during culture of mycobacteria on the success of phage infection was studied. Both D29 and TM4 were able to infect cultures of M. smegmatis and Mycobacterium avium subspecies paratuberculosis (MAP) grown in liquid with aeration. However when cultures were grown under oxygen limiting conditions, only TM4 could productively infect the cells. Cell attachment assays showed that D29 could bind to the cells surface but did not complete the lytic cycle. The ability of D29 to productively infect the cells was rapidly recovered (within 1 day) when the cultures were returned to an aerobic environment and this recovery required de novo RNA synthesis. These results indicated that under oxygen limiting conditions the cells are entering a growth state which inhibits phage D29 replication, and this change in host cell biology which can be detected by using both phage D29 and TM4 in the phage amplification assay
Estimating Incidence Curves of Several Infections Using Symptom Surveillance Data
We introduce a method for estimating incidence curves of several co-circulating infectious pathogens, where each infection has its own probabilities of particular symptom profiles. Our deconvolution method utilizes weekly surveillance data on symptoms from a defined population as well as additional data on symptoms from a sample of virologically confirmed infectious episodes. We illustrate this method by numerical simulations and by using data from a survey conducted on the University of Michigan campus. Last, we describe the data needs to make such estimates accurate
Tissue microarray analysis of eIF4E and its downstream effector proteins in human breast cancer
Correction to Kleiner HE, Krishnan P, Tubbs J, Smith M, Meschonat C, Shi R, Lowery-Nordberg M, Adegboyega P, Unger M, Cardelli J et al: Tissue microarray analysis of eIF4E and its downstream effector proteins in human breast cancer. J Exp Clin Cancer Res 2009, 28:5
Risk Factors and Immunity in a Nationally Representative Population following the 2009 Influenza A(H1N1) Pandemic
Understanding immunity, incidence and risk factors of the 2009 influenza A(H1N1) pandemic (2009 H1N1) through a national seroprevalence study is necessary for informing public health interventions and disease modelling.We collected 1687 serum samples and individual risk factor data between November-2009 to March-2010, three months after the end of the 2009 H1N1 wave in New Zealand. Participants were randomly sampled from selected general practices countrywide and hospitals in the Auckland region. Baseline immunity was measured from 521 sera collected during 2004 to April-2009. Haemagglutination inhibition (HI) antibody titres of ≥1∶40 against 2009 H1N1 were considered seroprotective as well as seropositive. The overall community seroprevalence was 26.7% (CI:22.6–29.4). The seroprevalence varied across age and ethnicity. Children aged 5–19 years had the highest seroprevalence (46.7%;CI:38.3–55.0), a significant increase from the baseline (14%;CI:7.2–20.8). Older adults aged ≥60 had no significant difference in seroprevalence between the serosurvey (24.8%;CI:18.7–30.9) and baseline (22.6%;CI:15.3–30.0). Pacific peoples had the highest seroprevalence (49.5%;CI:35.1–64.0). There was no significant difference in seroprevalence between both primary (29.6%;CI:22.6–36.5) and secondary healthcare workers (25.3%;CI:20.8–29.8) and community participants. No significant regional variation was observed. Multivariate analysis indicated age as the most important risk factor followed by ethnicity. Previous seasonal influenza vaccination was associated with higher HI titres. Approximately 45.2% of seropositive individuals reported no symptoms.Based on age and ethnicity standardisation to the New Zealand Population, about 29.5% of New Zealanders had antibody titers at a level consistent with immunity to 2009 H1N1. Around 18.3% of New Zealanders were infected with the virus during the first wave including about one child in every three. Older people were protected due to pre-existing immunity. Age was the most important factor associated with infection followed by ethnicity. Healthcare workers did not appear to have an increased risk of infection compared with the general population
Distinct Cerebrospinal Fluid Proteomes Differentiate Post-Treatment Lyme Disease from Chronic Fatigue Syndrome
Neurologic Post Treatment Lyme disease (nPTLS) and Chronic Fatigue (CFS) are syndromes of unknown etiology. They share features of fatigue and cognitive dysfunction, making it difficult to differentiate them. Unresolved is whether nPTLS is a subset of CFS. Methods and Principal Findings: Pooled cerebrospinal fluid (CSF) samples from nPTLS patients, CFS patients, and healthy volunteers were comprehensively analyzed using high-resolution mass spectrometry (MS), coupled with immunoaffinity depletion methods to reduce protein-masking by abundant proteins. Individual patient and healthy control CSF samples were analyzed directly employing a MS-based label-free quantitative proteomics approach. We found that both groups, and individuals within the groups, could be distinguished from each other and normals based on their specific CSF proteins (p&0.01). CFS (n = 43) had 2,783 non-redundant proteins, nPTLS (n = 25) contained 2,768 proteins, and healthy normals had 2,630 proteins. Preliminary pathway analysis demonstrated that the data could be useful for hypothesis generation on the pathogenetic mechanisms underlying these two related syndromes. Conclusions: nPTLS and CFS have distinguishing CSF protein complements. Each condition has a number of CSF proteins that can be useful in providing candidates for future validation studies and insights on the respective mechanisms of pathogenesis. Distinguishing nPTLS and CFS permits more focused study of each condition, and can lead to novel diagnostics and therapeutic interventions
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