Measurement of direct CP violation parameters in B± → J/ψK± and B± → J/ψπ± decays with 10.4 fb-1 of Tevatron data

We present a measurement of the direct CP-violating charge asymmetry in B(±) mesons decaying to J/ψK(±) and J/ψπ(±) where J/ψ decays to μ(+) μ(-), using the full run II data set of 10.4 fb(-1) of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. A difference in the yield of B(-) and B(+) mesons in these decays is found by fitting to the difference between their reconstructed invariant mass distributions resulting in asymmetries of A(J/ψK) = [0.59 ± 0.37]%, which is the most precise measurement to date, and A(J/ψπ) = [-4.2 ± 4.5]%. Both measurements are consistent with standard model predictions.

Evolution of aneuploidy up to Day 4 of human preimplantation development

STUDY QUESTION

What is the incidence of aneuploidy and mosaicism in all cells of top-quality Day-4 embryos analysed by array-based comparative genomic hybridization (array CGH)?

SUMMARY ANSWER

Our data show extensive abnormalities in Day-4 embryos.

WHAT IS KNOWN ALREADY

Numerous studies on human embryos at Day 3 and Day 5 of development show that they frequently contain aneuploid cells and are mosaic, although Day-5 embryos contain proportionally more normal cells than at Day 3. In contrast, only limited data exist on Day 4 of preimplantation development, despite the fact that it is the suggested stage for the initiation of the process of self-correction.

STUDY DESIGN, SIZE, DURATION

Thirteen embryos were analysed: four fresh good-quality preimplantation genetic diagnosis (PGD) embryos and nine good-quality surplus embryos cryopreserved on Day 3 and donated for research. On Day 4, following removal of the zona pellucida, all blastomeres were disaggregated and collected.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The genomic DNA of 283 single blastomeres from disaggregated embryos was amplified. Array CGH was carried out using 24SureTM Cytochip microarrays. After scanning of the microarray slides, the images were analysed using BlueFuse Software (BlueGnome). Combined with selective microsatellite analysis, hypothetical reconstructions of embryo chromosome complements were made following each of the first four cleavage divisions.

MAIN RESULTS AND THE ROLE OF CHANCE

No chromosome imbalance was detected for one PGD embryo, the other three were mosaic containing between 16 and 75% abnormal cells. All nine frozen-thawed embryos were abnormal. Six were mosaic with between 30 and 100% abnormal cells; three had abnormalities of meiotic origin, two of which displayed mitotic abnormalities. Evidence was also found of mitotic unbalanced structural chromosome rearrangements. The higher rate of abnormality of frozen-thawed embryos is based on a small number of embryos and cannot be tested statistically. The aneuploidy can mostly be explained by anaphase lag and non-disjunction. In some cases, we hypothesize endoreduplication followed by a cellular division with multipolar spindles to explain the results.

LIMITATIONS, REASONS FOR CAUTION

Array CGH technology determines relative quantification of chromosomal domains but does not allow for the visualization of chromosomal rearrangements, assessment of ploidy or detection of uniparental isodisomy. Conclusions drawn on segmental abnormalities should be treated with caution. The division trees presented are hypothetical models projecting back in time that try to explain observations in single blastomeres of Day 4 embryos. The limited number of embryos analysed does not allow drawing firm conclusions, but nevertheless provides valuable data on the origin of aneuploidy in human embryos.

WIDER IMPLICATIONS OF THE FINDINGS

Our data show extensive abnormalities in Day-4 embryos. We found no evidence of self-correction at this stage of development, suggesting that this process may start at a later stage of development.

Insight into the sharing of medical images: physician, other health care providers, and staff experience in a variety of medical settings

BACKGROUND

Scant knowledge exists describing health care providers' and staffs' experiences sharing imaging studies. Additional research is needed to determine the extent to which imaging studies are shared in diverse health care settings, and the extent to which provider or practice characteristics are associated with barriers to viewing external imaging studies on portable media.

OBJECTIVE

This analysis uses qualitative data to 1) examine how providers and their staff accessed outside medical imaging studies, 2) examine whether use or the desire to use imaging studies conducted at outside facilities varied by provider specialty or location (urban, suburban, and small town) and 3) delineate difficulties experienced by providers or staff as they attempted to view and use imaging studies available on portable media.

METHODS

Semi-structured interviews were conducted with 85 health care providers and medical facility staff from urban, suburban, and small town medical practices in North Carolina and Virginia. The interviews were audio recorded, transcribed, then systematically analyzed using ATLAS.ti.

RESULTS

Physicians at family and pediatric medicine practices rely primarily on written reports for medical studies other than X-rays; and thus do not report difficulties accessing outside imaging studies. Subspecialists in urban, suburban, and small towns view imaging studies through internal communication systems, internet portals, or portable media. Many subspecialists and their staff report experiencing difficulty and time delays in accessing and using imaging studies on portable media.

CONCLUSION

Subspecialists have distinct needs for viewing imaging studies that are not shared by typical primary care providers. As development and implementation of technical strategies to share medical records continue, this variation in need and use should be noted. The sharing and viewing of medical imaging studies on portable media is often inefficient and fails to meet the needs of many subspeciality physicians, and can lead to repeated imaging studies.

Genetic and epigenetic instability in human pluripotent stem cells

BACKGROUND

There is an increasing body of evidence that human pluripotent stem cells (hPSCs) are prone to (epi)genetic instability during in vitro culture. This review aims at giving a comprehensive overview of the current knowledge on culture-induced (epi)genetic alterations in hPSCs and their phenotypic consequences.

METHODS

Combinations of the following key words were applied as search criteria: human induced pluripotent stem cells and human embryonic stem cells in combination with malignancy, tumorigenicity, X inactivation, mitochondrial mutations, genomic integrity, chromosomal abnormalities, culture adaptation, aneuploidy and CD30. Only studies in English, on hPSCs and focused on (epi)genomic integrity were included. Further manuscripts were added from cross-references.

RESULTS

Numerous (epi)genetic aberrations have been detected in hPSCs. Recurrent genetic alterations give a selective advantage in culture to the altered cells leading to overgrowth of abnormal, culture-adapted cells. The functional effects of these alterations are not yet fully understood, but suggest a (pre)malignant transformation of abnormal cells with decreased differentiation and increased proliferative capacity.

CONCLUSIONS

Given the high degree of (epi)genetic alterations reported in the literature and altered phenotypic characteristics of the abnormal cells, controlling for the (epi)genetic integrity of hPSCs before any clinical application is an absolute necessity.

Wireless Real-Time Head Movement System Using a Personal Digital Assistant (PDA) for Control of a Power Wheelchair

Loss of mobility can occur for a variety of reasons,such as spinal cord injury or motor neurone disease. The onset of these conditions often brings with it an associated loss of personal independence, which is primarily due to the fact that the sufferer is no longer able to control their mobility. This project aims to address this problem through the creation of a head movement based wheelchair control system. Using a personal digital assistant (PDA) artificial intelligence techniques on an embedded LINUX operating system, a wireless head movement wheelchair control system has been designed and implemented. This system provides relief for sufferers of conditions which inhibit mobility through a method of wheelchair control which offers enhanced ease of use, attractiveness and independence.

Hands-free Head-movement Gesture Recognition using Artificial Neural Networks and the Magnified Gradient Function

This paper presents a hands-free head-movement gesture classification system using a Neural Network employing the Magnified Gradient Function (MGF) algorithm. The MGF increases the rate of convergence by magnifying the first order derivative of the activation function, whilst guaranteeing convergence. The MGF is tested on able-bodied and disabled users to measure its accuracy and performance. It is shown that for able-bodied users, a classification improvement from 98.25% to 99.85% is made, and 92.08% to 97.50% for disabled users.

Search for the standard model Higgs boson in associated WH production in 9.7 fb(-1) of pp collisions with the D0 detector

We present a search for the standard model Higgs boson in final states with a charged lepton (electron or muon), missing transverse energy, and two or three jets, at least one of which is identified as a b-quark jet. The search is primarily sensitive to WH→ℓνbb production and uses data corresponding to 9.7 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp Collider at √s = 1.96 TeV. We observe agreement between the data and the expected background. For a Higgs boson mass of 125 GeV, we set a 95% C.L. upper limit on the production of a standard model Higgs boson of 5.2 × σ(SM), where σ(SM) is the standard model Higgs boson production cross section, while the expected limit is 4.7 × σ(SM).

Combined search for the standard model Higgs boson decaying to bb using the D0 run II data set

We present the results of the combination of searches for the standard model Higgs boson produced in association with a W or Z boson and decaying into bb using the data sample collected with the D0 detector in pp collisions at √s = 1.96 TeV at the Fermilab Tevatron Collider. We derive 95% C.L. upper limits on the Higgs boson cross section relative to the standard model prediction in the mass range 100 GeV ≤ M(H) ≤ 150 GeV, and we exclude Higgs bosons with masses smaller than 102 GeV at the 95% C.L. In the mass range 120 GeV ≤ M(H) ≤145 GeV, the data exhibit an excess above the background prediction with a global significance of 1.5 standard deviations, consistent with the expectation in the presence of a standard model Higgs boson.

Search for the standard model Higgs boson in ZH→ℓ(+)ℓ(-)bb production with the D0 detector in 9.7 fb(-1) of pp collisions at √s = 1.96 TeV

We present a search for the standard model (SM) Higgs boson produced in association with a Z boson in 9.7 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider at √s = 1.96 TeV. Selected events contain one reconstructed Z→e(+)e(-) or Z→μ(+)μ(-) candidate and at least two jets, including at least one jet identified as likely to contain a b quark. To validate the search procedure, we also measure the cross section for ZZ production in the same final state. It is found to be consistent with its SM prediction. We set upper limits on the ZH production cross section times branching ratio for H→bb at the 95% C.L. for Higgs boson masses 90 ≤ M(H) ≤ 150 GeV. The observed (expected) limit for M(H) = 125 GeV is 7.1 (5.1) times the SM cross section.

Indicators of quality use of medicines in South-East Asian countries: a systematic review

OBJECTIVES

To identify indicators of quality use of medicines used in South-East Asian region.

METHODS

A systematic review was conducted searching MEDLINE, Embase and The International Network for Rational Use of Drugs (INRUD) and The World Health Organization (WHO) website. Original studies or reports carried out in the South-East Asian region, explicitly using indicators to measure quality use of medicines, and published between January 2000 and July 2011 were included.

RESULTS

A total of 17 studies conducted in 7 of 11 countries in South-East Asia were included. WHO indicators focusing on general medication use in health facilities were most widely used (10 studies). Twelve studies used non-WHO indicators for measuring quality use of medicines in clinical areas (geriatrics and obstetrics) or specific diseases, such as diarrhoea and pneumonia. In five studies, WHO indicators were used along with non-WHO indicators. There was little information available about validity, reliability and feasibility of the non-WHO indicators. The majority of indicators measured process rather than structure or outcome. There were very few indicators addressing non-communicable diseases.

CONCLUSIONS

A limited number of studies have been published explicitly using indicators of quality use of medicines across South-East Asia. Importantly, existing indicators need to be complemented with valid, reliable and feasible indicators related to non-communicable diseases, particularly those with a high financial burden to meet the current medical challenges in the region.

Evidence for a particle produced in association with weak bosons and decaying to a bottom-antibottom quark pair in higgs boson searches at the tevatron

We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from Fermilab Tevatron pp collisions at √s = 1.96 TeV, correspond to integrated luminosities of up to 9.7 fb(-1). The searches are conducted for a Higgs boson with mass in the range 100-150 GeV/c(2). We observe an excess of events in the data compared with the background predictions, which is most significant in the mass range between 120 and 135 GeV/c(2). The largest local significance is 3.3 standard deviations, corresponding to a global significance of 3.1 standard deviations. We interpret this as evidence for the presence of a new particle consistent with the standard model Higgs boson, which is produced in association with a weak vector boson and decays to a bottom-antibottom quark pair.

Optimization of head movement recognition using Augmented Radial Basis Function Neural Network

For people with severe spine injury, head movement recognition control has been proven to be one of the most convenient and intuitive ways to control a power wheelchair. While substantial research has been done in this area, the challenge to improve system reliability and accuracy remains due to the diversity in movement tendencies and the presence of movement artifacts. We propose a Neural-Network Configuration which we call Augmented Radial Basis Function Neural-Network (ARBF-NN). This network is constructed as a Radial Basis Function Neural-Network (RBF-NN) with a Multilayer Perceptron (MLP) augmentation layer to negate optimization limitation posed by linear classifiers in conventional RBF-NN. The RBF centroid is optimized through Regrouping Particle Swarm Optimization (RegPSO) seeded with K-Means. The trial results of ARBF-NN on Head-movement show a significant improvement on recognition accuracy up to 98.1% in sensitivity.

Ventricular repolarization variability for hypoglycemia detection

Hypoglycemia is the most acute and common complication of Type 1 diabetes and is a limiting factor in a glycemic management of diabetes. In this paper, two main contributions are presented; firstly, ventricular repolarization variabilities are introduced for hypoglycemia detection, and secondly, a swarm-based support vector machine (SVM) algorithm with the inputs of the repolarization variabilities is developed to detect hypoglycemia. By using the algorithm and including several repolarization variabilities as inputs, the best hypoglycemia detection performance is found with sensitivity and specificity of 82.14% and 60.19%, respectively.

Adaptation of a genotype 3 hepatitis E virus to efficient growth in cell culture depends on an inserted human gene segment acquired by recombination

An infectious cDNA clone of a genotype 3 strain of hepatitis E virus adapted to growth in HepG2/C3A human hepatoma cells was constructed. This virus was unusual in that the hypervariable region of the adapted virus contained a 171-nucleotide insertion that encoded 58 amino acids of human S17 ribosomal protein. Analyses of virus from six serial passages indicated that genomes with this insert, although initially rare, were selected during the first passage, suggesting it conferred a significant growth advantage. RNA transcripts from this cDNA and the viruses encoded by them were infectious for cells of both human and swine origin, the major host species for this zoonotic virus. Mutagenesis studies demonstrated that the S17 insert was a major factor in cell culture adaptation. Introduction of 54 synonymous mutations into the insert had no detectable effect, thus implicating protein, rather than RNA, as the important component. Truncation of the insert by 50% decreased the levels of successful transfection by ~3-fold. Substitution of the S17 sequence by a different ribosomal protein sequence or by GTPase-activating protein sequence resulted in a partial enhancement of transfection levels, whereas substitution with 58 amino acids of green fluorescent protein had no effect. Therefore, both the sequence length and the amino acid composition of the insert were important. The S17 sequence did not affect transfection of human hepatoma cells when inserted into the hypervariable region of a genotype 1 strain, but this chimeric genome acquired a dramatic ability to replicate in hamster cells.

Effect of surface chemistry on gene transfer efficiency mediated by surface-induced DNA-doped nanocomposites

Surface-induced biomineralization represents an effective way of immobilizing DNA molecules on biomaterial surfaces to introduce DNA into cells in contact with or at an approximate distance from the biomaterial surfaces. Previous studies have investigated how the composition of mineralizing solutions affects the composition and pH responsiveness of nanocomposites and thus gene transfer efficiency in different cell types. This study investigates how the functional groups of a biomaterial surface affect the induction and crystallographic properties of nanocomposites and thus the gene transfer efficiency. Self-assembled monolayers with different termini were used to control the functional groups of a surface. It is demonstrated that the induction of DNA-doped nanocomposites depends on the surface functional groups, which is consistent with previous studies. The crystallographic properties did not vary significantly with the functional groups. DNA-doped nanocomposites induced by different surface functional groups resulted in different cellular uptake of DNA and thus gene transfer efficiency. The differential cellular uptake may be attributed to the interactions between nanocomposites and functional groups. The weaker inducer resulted in higher cellular uptake, and thus higher gene transfer efficiency. Together with other previous studies, the current results suggest that surface-mediated gene transfer by DNA-doped nanocomposites can be modulated through both mineralizing solutions and surface chemistries.

Global optimization for human skin investigation in terahertz

In this paper, the electromagnetic interaction between human skin and terahertz radiation is investigated through the double Debye parameters' extraction algorithm. The changes of skin content are contrasted at the frequencies below one terahertz(THz) but the recent approaches could provide only a rough estimation. We propose an global optimization based identification, which results in globally accurate estimators in the frequency range up to two THz, and thus supports the validity of Debye model for Terahertz wave's propagation and reflection in skin. Simulation results confirm our prominent methodology.

A naturally occurring human/hepatitis E recombinant virus predominates in serum but not in faeces of a chronic hepatitis E patient and has a growth advantage in cell culture

Hepatitis E virus is the aetiological agent of acute hepatitis E, a self-limiting disease prevalent in developing countries. Molecular analysis of viral genomic RNA from a chronically infected patient confirmed the recent discovery that chronic infection correlated with extensive diversification of the virus quasispecies: the hypervariable region of some virus genomes in this USA patient contained large continuous deletions and a minor proportion of genomes in faeces and serum had acquired a mammalian sequence that encoded 39 aa of S19 ribosomal protein fused to the virus non-structural protein. Genomes with this insert were selected during virus passage in cultured cells to become the predominant species, suggesting that the inserted sequence promoted virus growth. The results demonstrated that hepatitis E virus can mutate dramatically during a prolonged infection and suggests it may be important to prevent or cure chronic infections before new variants with unpredictable properties arise.

Assessing the risk posed to free-living soil nematodes by a genetically modified maize expressing the insecticidal Cry3Bb1 protein

Before pest-resistant genetically modified maize can be grown commercially, the risks for soil-beneficial, non-target organisms must be determined. Here, a tiered approach was used to assess the risk to free-living soil nematodes posed by maize genetically modified to express the insecticidal Cry3Bb1 protein (event Mon88017), which confers resistance towards western corn rootworm (Diabrotica virgifera; Coleoptera). The toxicity of purified Cry3Bb1 for the nematode Caenorhabditis elegans was determined using a bioassay and gene expression analysis. In addition, a soil toxicity test was used to assess the effects on C. elegans of rhizosphere soil obtained from plots of an experimental field grown with Mon88017, the near-isogenic cultivar, or either of two conventional cultivars. Finally, the indigenous nematode communities from the experimental field site with Mon88017 and from the control cultivars were analyzed. The results showed a dose-dependent inhibitory effect of Cry3Bb1 on the growth and reproduction of C. elegans, with EC50 values of 22.3 mg l⁻¹ and 7.9 mg l⁻¹, respectively. Moreover, Cry-protein-specific defense genes were found to be up-regulated in the presence of either Cry1Ab or Cry3Bb1. However, C. elegans was not affected by rhizosphere soils from Mon88017 compared to the control plots, due to the very low Cry3Bb1 concentrations, as indicated by quantitative analyses (< 1 ng g⁻¹ soil). Nematode abundance and diversity were essentially the same between the various maize cultivars. At the last sampling date, nematode genus composition in Bt-maize plots differed significantly from that in two of the three non-Bt cultivars, including the near-isogenic maize, but the shift in genus composition did not influence the composition of functional guilds within the nematode communities. In conclusion, the risk to free-living soil nematodes posed by Mon88017 cultivation can be regarded as low, as long as Cry3Bb1 concentrations in soil remain four orders of magnitude below the toxicity threshold.

Discovery of a novel smectic-C{*} liquid-crystal phase with six-layer periodicity

We report the discovery of a new smectic-C{*} liquid-crystal phase with six-layer periodicity by resonant x-ray diffraction. Upon cooling, the new phase appears between the SmC{alpha}{*} phase having a helical structure and the SmC{d4}{*} phase with four-layer periodicity. This SmC{d6}{*} phase was identified in two mixtures which have an unusual reversed SmC{d4}{*}-SmC{*} phase sequence. The SmC{d6}{*} phase shows a distorted clock structure. Three theoretical models have predicted the existence of a six-layer phase. However, our experimental findings are not consistent with the theories.

Evolved fuzzy reasoning model for hypoglycaemic detection

Hypoglycaemia is a serious side effect of insulin therapy in patients with diabetes. We measure physiological parameters (heart rate, corrected QT interval of the electrocardiogram (ECG) signal) continuously to provide early detection of hypoglycemic episodes in Type 1 diabetes mellitus (T1DM) patients. Based on the physiological parameters, an evolved fuzzy reasoning model (FRM) to recognize the presence of hypoglycaemic episodes is developed. To optimize the fuzzy rules and the fuzzy membership functions of FRM, an evolutionary algorithm called hybrid particle swarm optimization with wavelet mutation operation is investigated. All data sets are collected from Department of Health, Government of Western Australia for a clinical study. The results show that the proposed algorithm performs well in terms of the clinical sensitivity and specificity.

Large area high efficiency broad bandwidth 800 nm dielectric gratings for high energy laser pulse compression

We have demonstrated broad bandwidth large area (229 mm x 114 mm) multilayer dielectric diffraction gratings for the efficient compression of high energy 800 nm laser pulses at high average power. The gratings are etched in the top layers of an aperiodic (Nb0.5Ta0.5)2O5-SiO2 multilayer coating deposited by ion beam sputtering. The mean efficiency of the grating across the area is better than 97% at the center wavelength and remains above 96% at wavelengths between 820 nm and 780 nm. The gratings were used to compress 5.5 J pulses from a Ti:sapphire laser with an efficiency above 80 percent.