39 research outputs found
Reducing The Impact Of Adaptive Optics Lag On Optical And Quantum Communications Rates From Rapidly Moving Sources
Wavefront of light passing through turbulent atmosphere gets distorted. This
causes signal loss in free-space optical communication as the light beam
spreads and wanders at the receiving end. Frequency and/or time division
multiplexing adaptive optics (AO) techniques have been used to conjugate this
kind of wavefront distortion. However, if the signal beam moves relative to the
atmosphere, the AO system performance degrades due to high temporal
anisoplanatism. Here we solve this problem by adding a pioneer beacon that is
spatially separated from the signal beam with time delay between spatially
separated pulses. More importantly, our protocol works irrespective of the
signal beam intensity and hence is also applicable to secret quantum
communication. In particular, using semi-empirical atmospheric turbulence
calculation, we show that for low earth orbit satellite-to-ground decoy state
quantum key distribution with the satellite at zenith angle , our
method increases the key rate by at least and for satellite
altitude ~km and ~km, respectively. Finally, we propose a
modification of existing wavelength division multiplexing systems as an
effective alternative solution to this problem.Comment: title changed to better reflect what we have done, to appear in AIP
Advances; 14 pages, 12 figure
Identification of a Functional Genetic Variant at 16q12.1 for Breast Cancer Risk: Results from the Asia Breast Cancer Consortium
Genetic factors play an important role in the etiology of breast cancer. We carried out a multi-stage genome-wide association (GWA) study in over 28,000 cases and controls recruited from 12 studies conducted in Asian and European American women to identify genetic susceptibility loci for breast cancer. After analyzing 684,457 SNPs in 2,073 cases and 2,084 controls in Chinese women, we evaluated 53 SNPs for fast-track replication in an independent set of 4,425 cases and 1,915 controls of Chinese origin. Four replicated SNPs were further investigated in an independent set of 6,173 cases and 6,340 controls from seven other studies conducted in Asian women. SNP rs4784227 was consistently associated with breast cancer risk across all studies with adjusted odds ratios (95% confidence intervals) of 1.25 (1.20−1.31) per allele (P = 3.2×10−25) in the pooled analysis of samples from all Asian samples. This SNP was also associated with breast cancer risk among European Americans (per allele OR = 1.19, 95% CI = 1.09−1.31, P = 1.3×10−4, 2,797 cases and 2,662 controls). SNP rs4784227 is located at 16q12.1, a region identified previously for breast cancer risk among Europeans. The association of this SNP with breast cancer risk remained highly statistically significant in Asians after adjusting for previously-reported SNPs in this region. In vitro experiments using both luciferase reporter and electrophoretic mobility shift assays demonstrated functional significance of this SNP. These results provide strong evidence implicating rs4784227 as a functional causal variant for breast cancer in the locus 16q12.1 and demonstrate the utility of conducting genetic association studies in populations with different genetic architectures
Genome-Wide Association Study in East Asians Identifies Novel Susceptibility Loci for Breast Cancer
Genetic factors play an important role in the etiology of both sporadic and familial breast cancer. We aimed to discover novel genetic susceptibility loci for breast cancer. We conducted a four-stage genome-wide association study (GWAS) in 19,091 cases and 20,606 controls of East-Asian descent including Chinese, Korean, and Japanese women. After analyzing 690,947 SNPs in 2,918 cases and 2,324 controls, we evaluated 5,365 SNPs for replication in 3,972 cases and 3,852 controls. Ninety-four SNPs were further evaluated in 5,203 cases and 5,138 controls, and finally the top 22 SNPs were investigated in up to 17,423 additional subjects (7,489 cases and 9,934 controls). SNP rs9485372, near the TGF-β activated kinase (TAB2) gene in chromosome 6q25.1, showed a consistent association with breast cancer risk across all four stages, with a P-value of 3.8×10−12 in the combined analysis of all samples. Adjusted odds ratios (95% confidence intervals) were 0.89 (0.85–0.94) and 0.80 (0.75–0.86) for the A/G and A/A genotypes, respectively, compared with the genotype G/G. SNP rs9383951 (P = 1.9×10−6 from the combined analysis of all samples), located in intron 5 of the ESR1 gene, and SNP rs7107217 (P = 4.6×10−7), located at 11q24.3, also showed a consistent association in each of the four stages. This study provides strong evidence for a novel breast cancer susceptibility locus represented by rs9485372, near the TAB2 gene (6q25.1), and identifies two possible susceptibility loci located in the ESR1 gene and 11q24.3, respectively
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
The effect of interaction between perceived environmental uncertainty and personality on management information requirements.
This research aims to biuld upon an earlier study by Fisher (1996) who investigates the moderating effect of locus of control on the relationship between perceived usefulness of information.Master of Business Administratio
Mode of Action: Synergistic Interaction of Peppermint (Mentha x piperita L. Carl) Essential Oil and Meropenem Against Plasmid-Mediated Resistant E. coli
This study investigated the bactericidal mechanism of peppermint essential oil (PEO) when used singly and in combination with meropenem against multidrug resistant Escherichia coli. Chemical compositions of PEO were identified via GC-MS, followed by time-kill analysis which was performed to evaluate the antibacterial activities of PEO and meropenem. Furthermore, outer membrane permeability test, zeta potential measurement and scanning electron microscopy were performed to evaluate the ability of PEO in bacterial membrane disruption. Next, anti-quorum sensing assay was performed to assess the ability of PEO in quorum sensing inhibition. A complete killing activity was observed within five minutes of treatment with PEO and meropenem at sub-lethal concentrations. In addition, the outer membrane permeability test and zeta potential measurement performed indicated increase in the membrane permeability and membrane disruption which can be observed in the scanning electron micrograph. Furthermore, significant decrease in the light production of E. coli pSB1075 treated by PEO indicates the presence of quorum sensing inhibitors within PEO. The findings suggest that PEO has the ability to disrupt the bacterial outer membrane which increases membrane permeability, in addition to the possible inhibition of bacterial quorum sensing ability in multidrug resistant E. coli, aiding in the reversal of antibiotic resistance
The Lower Serum Immunoglobulin G2 Level in Severe Cases than in Mild Cases of Pandemic H1N1 2009 Influenza Is Associated with Cytokine Dysregulation ▿
The majority of patients with pandemic influenza H1N1 2009 had mild illness, but some, including those with no risk factors for severe disease, may succumb to this infection. Besides viral factors such as the D222/225G substitution of the hemagglutinin, host factors such as IgG2 subclass deficiency recently was reported to be associated with severe disease in a cohort of Australian patients besides other known risk factors, including underlying chronic illness, extremes of age, and pregnancy. We conducted a case-control study of 38 Asian patients with respiratory failure due to severe pandemic influenza and compared the results to those for 36 mild cases. None had selective IgG2 deficiency, but the level of IgG2 subclass was significantly lower in the severe cases (3.55 g/liter versus 4.75 g/liter; P = 0.002), whereas the levels of IgG1, IgG3, and IgG4 were not significantly different from those of the mild cases. Previous studies suggested that some IgHG2 and FcγRIIa genotypes were associated with IgG2 deficiency. The allelic frequency of the IgHG2 genotypes in our severe cases was not correlated with their levels of IgG2, while that of FcγRIIa was not significantly different from that of the general Han Chinese population (P = 0.216). Only the overall cytokine/chemokine profile (P = 0.029) and serum globulin level (P = 0.005) were found to be independently associated with the IgG2 level by multivariate analysis. The lower IgG2 level in our severe group might be related to cytokine dysregulation rather than being a significant risk factor for severe pandemic influenza. The importance of this finding for therapeutic intervention will require further studies of larger cohorts of patients
Disseminated Penicilliosis, Recurrent Bacteremic Nontyphoidal Salmonellosis, and Burkholderiosis Associated with Acquired Immunodeficiency Due to Autoantibody against Gamma Interferon ▿
Acquired immunodeficiency due to autoantibody against gamma interferon has recently been associated with opportunistic nontuberculous mycobacteriosis, especially among Southeast Asians. We report another 8 cases, all except one apparently immunocompetent hosts who suffered from concomitant or sequential infections by other intracellular pathogens causing penicilliosis, extraintestinal nontyphoidal salmonellosis, and burkholderiosis. The only case with an underlying immunodeficiency syndrome had systemic lupus erythematosus that was quiescent throughout the multiple infective episodes. Eight out of 10 (80.0%) patients with serological evidence of penicilliosis, 5 out of 7 (71.4%) with culture-positive extraintestinal nontyphoidal salmonellosis, 5 out of 28 (17.9%) with serological evidence of melioidosis, and 7 out of 13 (53.8%) with culture-positive nontuberculous mycobacteriosis possessed autoantibody against gamma interferon, whereas only 1 out of 100 patients with systemic lupus erythematosus did. Our study represents the first and largest case series linking this emerging immunodeficiency syndrome with these atypical infections in apparently immunocompetent hosts. Thus, we advocate that any patient with unexplained recurrent or polymicrobial infections due to these intracellular pathogens should be screened for acquired immunodeficiency due to autoantibody against gamma interferon
Nanowire Magnetoscope Reveals a Cellular Torque with Left–Right Bias
Cellular force regulates many types
of cell mechanics and the associated
physiological behaviors. Recent evidence suggested that cell motion
with left–right (LR) bias may be the origin of LR asymmetry
in tissue architecture. As actomyosin activity was found essential
in the process, it predicts a type of cellular force that coordinates
the development of LR asymmetry in tissue formation. However, due
to the lack of appropriate platform, cellular force with LR bias has
not yet been found. Here we report a nanowire magnetoscope that reveals
a rotating forcetorqueexerted by cells. Ferromagnetic
nanowires were deposited and internalized by micropatterned cells.
Within a uniform, horizontal magnetic field, the nanowires that initially
aligned with the magnetic field were subsequently rotated due to the
cellular torque. We found that the torque is LR-biased depending on
cell types. While NIH 3T3 fibroblasts and human vascular endothelial
cells exhibited counterclockwise torque, C2C12 myoblasts showed torque
with slight clockwise bias. Moreover, an actin ring composed of transverse
arcs and radial fibers was identified as a major factor determining
the LR bias of cellular torque, since the disruption of actin ring
by biochemical inhibitors or elongated cell shape abrogated the counterclockwise
bias of NIH 3T3 fibroblasts. Our finding reveals a LR-biased torque
of single cells and a fundamental origin of cytoskeletal chirality.
More broadly, we anticipate that our method will provide a different
perspective on mechanics-related cell physiology and force transmission
necessary for LR propagation in tissue formation
Unionisation and firm performance in China's manufacturing industries
Using firm level data, this paper examines the link between unionisation and firm performance in China's manufacturing industries. The empirical results suggest that unionisation has not greatly benefitted workers in China's textile industry but it has contributed to much larger increase in average wages in both domestic and foreign invested firms in communication equipment, computer and other electronic equipment manufacturing industry. In the case of the general equipment manufacturing industry, unionised domestic firms pay higher average wages but there is no link between unionisation and average wage in foreign invested firms