Multi-view video coding (MVC) is showing a new demand in the video communications, video surveillance systems, video teleconferencing, TV communications, and 3D video games. New algorithms are needed ...to improve video compression and reduce the complexity of multiple views in order to improve the MVC systems. This paper presents the performance evaluation of the hypercube prediction algorithm (HPA) for MVC. The main objective is to minimize the chain view of the dependencies based on the hypercube structure. Using spatio-temporal predictions based on the hypercube structure we show that MVC compression efficiency can be improved while keeping the dependencies low. The proposed HPA for MVC provides increased flexibility in selecting prediction references by reducing the view dependency by a factor of 2. The performance is compared with a linear prediction algorithm (LPA) that uses one spatial and one temporal reference frame. We show that HPA can be used to allow flexible prediction structures that improve the encoding performance while keeping the sufficient the PSNR video quality.
This paper presents the results of the 3DTV quality evaluation on autostereoscopic displays using asymmetric view coding. Asymmetric view coding encodes the stereo views with different quality. It ...has been shown that the human visual system is able to compensate for this asymmetric view quality and present a good quality 3D video. Asymmetric video coding can be exploited to reduce the bandwidth requirements for 3DTV services. The key factors that affect the asymmetric video coding are the compression algorithms, the human visual system, and the 3D display. We conducted a subjective evaluation of 3D video with asymmetric view quality and encoded using MPEG-2. We also studied the impact of eye dominance on the perceived quality. We show that asymmetric view coding can be used to reduce the bandwidth requirements of 3DTV services based on MPEG-2 view coding.
In this work we investigate in detail the effects local environment (groups and pairs) has on galaxies with stellar mass similar to the Milky-Way (L* galaxies). A volume limited sample of 6,150 ...galaxies is classified to determine emission features, morphological type and presence of a disk. This sample allows for characteristics of galaxies to be isolated (e.g. stellar mass and group halo mass), and their codependencies determined. We observe that galaxy-galaxy interactions play the most important role in shaping the evolution within a group halo, the main role of halo mass is in gathering the galaxies together to encourage such interactions. Dominant pair galaxies find their overall star formation enhanced when the pair's mass ratio is close to 1, otherwise we observe the same galaxies as we would in an unpaired system. The minor galaxy in a pair is greatly affected by its companion galaxy, and whilst the star forming fraction is always suppressed relative to equivalent stellar mass unpaired galaxies, it becomes lower still when the mass ratio of a pair system increases. We find that, in general, the close galaxy-galaxy interaction rate drops as a function of halo mass for a given amount of stellar mass. We find evidence of a local peak of interactions for Milky-Way stellar mass galaxies in Milky-Way halo mass groups. Low mass halos, and in particular Local Group mass halos, are an important environment for understanding the typical evolutionary path of a unit of stellar mass. We find compelling evidence for galaxy conformity in both groups and pairs, where morphological type conformity is dominant in groups, and emission class conformity is dominant in pairs. This suggests that group scale conformity is the result of many galaxy encounters over an extended period of time, whilst pair conformity is a fairly instantaneous response to a transitory interaction.
High-pressure injection (HPI) injury of the hand is a serious injury that can be potentially devastating. There have been a number of publications on the results of its treatment, but we are not ...aware of a report on the functional outcome of these hands.
We assessed the functional outcome of 15 patients with HPI injuries. All patients were treated operatively, with a mean delay of 11.7 hours. The patients were examined by a doctor and an occupational therapist using a work simulator.
Our study revealed a significant reduction of static and dynamic muscle testing parameters compared with the uninjured hand. Six patients lost a digit and four patients had to change their occupation after the injury.
Deterioration of hand function is a predictable outcome of HPI injury. This information should be shared with the patient at the outset so as to avoid subsequent disappointment.
We measure the two-point angular correlation function of a sample of 4,289,223 galaxies with r < 19.4 mag from the Sloan Digital Sky Survey as a function of photometric redshift, absolute magnitude ...and colour down to M_r - 5log h = -14 mag. Photometric redshifts are estimated from ugriz model magnitudes and two Petrosian radii using the artificial neural network package ANNz, taking advantage of the Galaxy and Mass Assembly (GAMA) spectroscopic sample as our training set. The photometric redshifts are then used to determine absolute magnitudes and colours. For all our samples, we estimate the underlying redshift and absolute magnitude distributions using Monte-Carlo resampling. These redshift distributions are used in Limber's equation to obtain spatial correlation function parameters from power law fits to the angular correlation function. We confirm an increase in clustering strength for sub-L* red galaxies compared with ~L* red galaxies at small scales in all redshift bins, whereas for the blue population the correlation length is almost independent of luminosity for ~L* galaxies and fainter. A linear relation between relative bias and log luminosity is found to hold down to luminosities L~0.03L*. We find that the redshift dependence of the bias of the L* population can be described by the passive evolution model of Tegmark & Peebles (1998). A visual inspection of a random sample of our r < 19.4 sample of SDSS galaxies reveals that about 10 per cent are spurious, with a higher contamination rate towards very faint absolute magnitudes due to over-deblended nearby galaxies. We correct for this contamination in our clustering analysis.
The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters ...and trace the evolution of X-ray scaling relations. In this paper we present the first data release from the XMM Cluster Survey (XCS-DR1). This consists of 503 optically confirmed, serendipitously detected, X-ray clusters. Of these clusters, 255 are new to the literature and 356 are new X-ray discoveries. We present 464 clusters with a redshift estimate (0.06 < z < 1.46), including 261 clusters with spectroscopic redshifts. In addition, we have measured X-ray temperatures (Tx) for 402 clusters (0.4 < Tx < 14.7 keV). We highlight seven interesting subsamples of XCS-DR1 clusters: (i) 10 clusters at high redshift (z > 1.0, including a new spectroscopically-confirmed cluster at z = 1.01); (ii) 67 clusters with high Tx (> 5 keV); (iii) 131 clusters/groups with low Tx (< 2 keV); (iv) 27 clusters with measured Tx values in the SDSS `Stripe 82' co-add region; (v) 78 clusters with measured Tx values in the Dark Energy Survey region; (vi) 40 clusters detected with sufficient counts to permit mass measurements (under the assumption of hydrostatic equilibrium); (vii) 105 clusters that can be used for applications such as the derivation of cosmological parameters and the measurement of cluster scaling relations. The X-ray analysis methodology used to construct and analyse the XCS-DR1 cluster sample has been presented in a companion paper, Lloyd-Davies et al. (2010).
Of 1322 patients with fractures of the proximal femur, 86 had muscular disturbances. Of these, 65 were suffering from paresis due to cerebrovascular stroke and 21 had Parkinson's disease. In the ...paretic patients, except for one case, the fracture occurred on the affected (paretic) side, and it was intertrochanteric in the majority of cases. In the patients with Parkinson's disease, cervical (intracapsular) fractures predominated. Muscle weakness or disturbance is a factor in the causation and location of hip fractures.
Abstract
STUDY QUESTION
To what extent does a trophectoderm (TE) biopsy reliably reflect the chromosomal constitution of the inner cell mass (ICM) in human blastocysts?
SUMMARY ANSWER
Concordance ...between TE and ICM was established in 62.1% of the embryos analysed.
WHAT IS KNOWN ALREADY
Next generation sequencing (NGS) platforms have recently been optimised for preimplantation genetic testing for aneuploidies (PGT-A). However, higher sensitivity has led to an increase in reports of chromosomal mosaicism within a single TE biopsy. This has raised substantial controversy surrounding the prevalence of mosaicism in human blastocysts and the clinical implications of heterogeneity between the TE and ICM.
STUDY DESIGN, SIZE, DURATION
To define the distribution and rate of mosaicism in human blastocysts, we assessed chromosomal profiles of the ICM and multiple TE portions obtained from the same embryo. We evaluated donated embryos with an unknown chromosomal profile (n = 34), as well as PGT-A blastocysts, previously diagnosed as abnormal or mosaic (n = 24). Our intra-embryo comparison included a total of 232 samples, obtained from 58 embryos.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Four embryo samples, including the ICM and three distinct TE portions, were acquired from good quality blastocysts by micromanipulation. Whole genome amplification (WGA), followed by NGS was performed on all embryo segments. Profiles were compared between samples from the same embryo, while the results from pretested blastocysts were further correlated to the original report. The embryos investigated in our untested group were obtained from good prognosis patients (n = 25), with maternal age ranging from 23 to 39 years. For the pretested embryo group, maternal age ranged from 23 to 40 years (n = 18).
MAIN RESULTS AND THE ROLE OF CHANCE
We uncover chromosomal mosaicism, involving both numerical and structural aberrations, in up to 37.9% of the blastocysts analysed. Within the untested group, the overall concordance between the ICM and all TE portions was 55.9%. A normal ICM was detected in 20.6% of blastocysts for which at least one TE portion showed a chromosomal aberration. Conversely, 17.6% of embryos presented with mosaic or uniform abnormalities within the ICM, while showing normal or mosaic TE profiles. For the pretested blastocysts, the overall concordance between the ICM and all TE samples was 70.8%. However, 50% of embryos previously diagnosed with mosaicism did not confirm the original diagnosis. Notably, 31.3% of embryos with a mosaic aberration reported in the original TE biopsy, revealed a euploid profile in the ICM and all three TE samples. Taken together, concordance between the ICM and all TE portions was established in 62.1% of blastocysts, across both embryo groups. Finally, we could not observe a significant effect of age on embryo mosaicism (P = 0.101 untested group; P = 0.7309 pretested group). Similarly, ICM and TE quality were not found to affect the occurrence of chromosomal mosaicism (P = 0.718 and P = 0.462 untested group; P = 1.000 and P = 0.2885 pretested group).
LARGE SCALE DATA
All data that support the findings of this study are available online in Vivar (http://cmgg.be/vivar) upon request.
LIMITATIONS, REASONS FOR CAUTION
Evaluating biological variation in some instances remains challenging. The technological limitations of sampling mitotic errors that lead to mosaicism, as well as WGA artefacts, warrant careful interpretation.
WIDER IMPLICATIONS OF THE FINDINGS
Our results highlight the complex nature of genetic (in)stability during early ontogenesis and indicate that blastocysts harbour a higher rate of chromosomal mosaicism than may have been anticipated. Moreover, our findings reveal an overall high diagnostic sensitivity and relatively low specificity in the context of PGT-A. This suggests that a considerable proportion of embryos are potentially being classified as clinically unsuitable. Ultimately, more precise quantification will benefit the clinical management of embryo mosaicism.
STUDY FUNDING/COMPETING INTEREST(S)
M.P. is supported by the Special Research Fund, Bijzonder Onderzoeksfonds (BOF01D08114). J.T. and L.D. are supported by the agency for innovation through science (131673, 141441). B.H. and this research are supported by the Special Research Fund, Bijzonder Onderzoeksfonds (BOF15/GOA/011). The authors declare no competing interests.
TRIAL REGISTRATION NUMBER
Not applicable.
In schizophrenia, abnormal neural metabolite concentrations may arise from cortical damage following neuroinflammatory processes implicated in acute episodes. Inflammation is associated with ...increased glutamate, whereas the antioxidant glutathione may protect against inflammation-induced oxidative stress. We hypothesized that patients with stable schizophrenia would exhibit a reduction in glutathione, glutamate, and/or glutamine in the cerebral cortex, consistent with a post-inflammatory response, and that this reduction would be most marked in patients with "residual schizophrenia", in whom an early stage with positive psychotic symptoms has progressed to a late stage characterized by long-term negative symptoms and impairments. We recruited 28 patients with stable schizophrenia and 45 healthy participants matched for age, gender, and parental socio-economic status. We measured glutathione, glutamate and glutamine concentrations in the anterior cingulate cortex (ACC), left insula, and visual cortex using 7T proton magnetic resonance spectroscopy (MRS). Glutathione and glutamate were significantly correlated in all three voxels. Glutamine concentrations across the three voxels were significantly correlated with each other. Principal components analysis (PCA) produced three clear components: an ACC glutathione-glutamate component; an insula-visual glutathione-glutamate component; and a glutamine component. Patients with stable schizophrenia had significantly lower scores on the ACC glutathione-glutamate component, an effect almost entirely leveraged by the sub-group of patients with residual schizophrenia. All three metabolite concentration values in the ACC were significantly reduced in this group. These findings are consistent with the hypothesis that excitotoxicity during the acute phase of illness leads to reduced glutathione and glutamate in the residual phase of the illness.
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