The CHIME Pulsar Project: System Overview Amiri, M.; Bandura, K. M.; Boyle, P. J. ...
The Astrophysical journal. Supplement series,
07/2021, Volume:
255, Issue:
1
Journal Article
Peer reviewed
Open access
Abstract
We present the design, implementation, and performance of the digital pulsar observing system constructed for the Canadian Hydrogen Intensity Mapping Experiment (CHIME). Using accelerated ...computing, this system processes independent, digitally steered beams formed by the CHIME correlator to simultaneously observe up to 10 radio pulsars and transient sources. Each of these independent streams is processed by the CHIME/Pulsar back-end system, which can coherently dedisperse, in real time, up to dispersion measure values of 2500 pc cm
−3
. The tracking beams and real-time analysis system are autonomously controlled by a priority-based algorithm that schedules both known sources and positions of interest for observation with observing cadences as rapid as 1 day. Given the distribution of known pulsars and radio-transient sources and the dynamic scheduling, the CHIME/Pulsar system can monitor 400–500 positions once per sidereal day and observe most sources with declinations greater than −20° once every ∼4 weeks. We also discuss the extensive science program enabled through the current modes of data acquisition for CHIME/Pulsar that centers on timing and searching experiments.
To cite this article: Lu Y, Mak K‐K, van Bever HPS, Ng TP, Mak A, Ho RC‐M. Prevalence of anxiety and depressive symptoms in adolescents with asthma: A meta‐analysis and meta‐regression. Pediatr ...Allergy Immunol 2012: 23: 707–715.
It remains unclear whether anxiety and depressive symptoms are more prevalent in adolescents with asthma when compared with healthy individuals. This meta‐analysis aimed to evaluate the difference in the aggregate prevalence of depressive and anxiety symptoms between adolescents with asthma and healthy controls and to explore the underlying moderators that potentially explain the heterogeneity of the effect size. A meta‐analysis of published work was performed using the random effects model. The differences in aggregate prevalence of depressive and anxiety symptoms between adolescents with asthma and healthy controls were determined. Meta‐regression and subgroup analysis were performed to identify factors that may contribute to heterogeneity. A total of eight studies were eligible for analysis. The aggregate prevalence of depressive and anxiety symptoms was significantly higher among 3546 adolescents with asthma than that of 24,884 controls (depression, 0.27; 95% CI, 0.18.6–0.39 vs. 0.13; 95% CI, 0.09–0.19; anxiety, 0.33; 95% CI, 0.19–0.52 vs. 0.21; 95% CI, 0.12–0.33). The risk of developing depression and anxiety is significantly higher among adolescents with asthma when compared with controls (depression: pooled odds ratio, 2.09; 95% CI, 1.65–2.64; p < 0.001; anxiety: pooled odds ratio, 1.83; 95% CI, 1.63–2.07; p < 0.001). Meta‐regression revealed that the proportions of Caucasian (p = 0.008) and smokers (p < 0.001) were significant moderators which explained the significant heterogeneity when comparing the risk of developing depressive symptoms among adolescent asthma patients vs. controls while age, gender, and severity of asthma were not significant. Family doctors, pediatricians, and healthcare providers should formulate strategies to detect depressive and anxiety symptoms in adolescents with asthma and offer psychological interventions to reduce the burden of psychiatric comorbidity.
Objective
To estimate the accuracy of transvaginal ultrasound (TVS) measurement of endometrial thickness (ET) in diagnosing endometrial cancer in postmenopausal women with vaginal bleeding (PMB).
...Design
Retrospective cohort study.
Setting
One‐stop PMB clinic in a Hong Kong teaching hospital.
Population
A cohort of 4383 women with PMB.
Methods
Transvaginal ultrasonic measurement of ET and endometrial biopsies were obtained in women presenting with PMB between 2002 and 2013. Endometrial histology was used as the reference standard to calculate accuracy estimates.
Main outcome measures
Accuracy data for TVS ET presented as sensitivity, specificity, and area under the receiver operator characteristic (ROC) curve.
Results
Endometrial cancer was diagnosed in 3.8% of women. The median ET in those with endometrial cancer was significantly higher than those with benign conditions (15.7 versus 3.2 mm, P < 0.001). The area under the ROC curve was 0.92 (95% CI 0.89–0.94). The sensitivity for the detection of endometrial cancer at 3‐, 4‐, and 5‐mm cut‐offs were 97.0% (95% CI 94.5–99.6%), 94.1% (95% CI 90.5–97.6%), and 93.5% (95% CI 89.7–97.2%), respectively. The corresponding estimates of specificity at these thresholds were 45.3% (95% CI 43.8–46.8%), 66.8% (65.4–68.2%), and 74.0% (72.7–75.4%).
Conclusions
Transvaginal ultrasound using a 3‐mm cut‐off has high sensitivity for detecting endometrial cancer and can identify women with PMB who are highly unlikely to have endometrial cancer, thereby avoiding more invasive endometrial biopsy.
We have monitored Epstein-Barr virus (EBV) IgA antibody levels of 39 nasopharyngeal carcinoma (NPC) cases for up to 15 years before clinical onset of NPC, and assessed preclinical serologic status of ...another 68 cases. Our results identify a serologic window preceding diagnosis when antibody levels are raised and sustained. This window can persist for as long as 10 years, with a mean duration estimated to as 37+/-28 months. Ninety-seven of these 107 NPC cases exhibited such a window. Cases that did not may reflect individual antibody response to EBV. Serologic screening at enrollment identified those cases who had already entered the window and became clinically manifested earlier (median=28 months) than those who entered the window after enrollment (median=90 months). The former account for 19 of 21 cases diagnosed within 2 years of screening. Nasopharyngeal carcinoma risk levels among seropositive subjects were also highest during this period. Both prediction rates and risk levels declined thereafter; cases detected at later times were composed of increasing proportions of individuals who entered the serological window after screening. Our findings establish EBV antibody as an early marker of NPC and suggest that repeated screening to monitor cases as they enter this window has considerable predictive value, with practical consequences for cancer treatment.
Abstract
We report the discovery of seven new Galactic pulsars with the Canadian Hydrogen Intensity Mapping Experiment’s Fast Radio Burst (CHIME/FRB) backend. These sources were first identified via ...single pulses in CHIME/FRB, then followed up with CHIME/Pulsar. Four sources appear to be rotating radio transients, pulsar-like sources with occasional single-pulse emission with an underlying periodicity. Of those four sources, three have detected periods ranging from 220 ms to 2.726 s. Three sources have more persistent but still intermittent emission and are likely intermittent or nulling pulsars. We have determined phase-coherent timing solutions for the latter two. These seven sources are the first discovery of previously unknown Galactic sources with CHIME/FRB and highlight the potential of fast radio burst detection instruments to search for intermittent Galactic radio sources.
•Specific HSP-90 inhibitors block CHIKV replication in vitro and in vivo.•CHIKV proteins nsP3 and nsP4 interact with HSP-90β or HSP-90α.•HSP-90 inhibitors reduced CHIKV induced inflammation in the ...limbs of mice.•HSP-90 may be a potential target to block CHIKV infection.
The global emergence of Chikungunya virus (CHIKV) infection is alarming and currently there is no licensed vaccine or antiviral treatment available to mitigate this disease. CHIKV infection typically results in high viral load with an outcome of high fever, skin rashes, muscle pain, and sequelae of prolonged arthritis, which occurs in >90% of the infected cases. In this study, using biochemical pull-downs, mass-spectrometry, and microscopic imaging techniques, we have identified novel interactions between CHIKV nsP3 or nsP4 proteins with the host stress-pathway chaperone HSP-90 protein. Indeed, silencing of HSP-90 transcripts using siRNA disrupts CHIKV replication in cultured cells. Furthermore, drugs targeting HSP-90, such as commercially available geldanamycin, as well as other specific HSP-90 inhibitor drugs that had been obtained from a purinome mining approach (HS-10 and SNX-2112) showed dramatic reduction in viral titers and reduced inflammation in a CHIKV mouse model of severe infection and musculopathy. The detailed study of the underlying molecular mechanism of these viral and host protein interactions may provide a platform to develop novel therapeutics against CHIKV infection.
Aims/hypothesis
Few large-scale prospective studies have investigated associations between relative leucocyte telomere length (rLTL) and kidney dysfunction in individuals with type 2 diabetes. We ...examined relationships between rLTL and incident end-stage kidney disease (ESKD) and the slope of eGFR decline in Chinese individuals with type 2 diabetes.
Methods
We studied 4085 Chinese individuals with type 2 diabetes observed between 1995 and 2007 in the Hong Kong Diabetes Register with stored baseline DNA and available follow-up data. rLTL was measured using quantitative PCR. ESKD was diagnosed based on the ICD-9 code and eGFR.
Results
In this cohort (mean ± SD age 54.3 ± 12.6 years) followed up for 14.1 ± 5.3 years, 564 individuals developed incident ESKD and had shorter rLTL at baseline (4.2 ± 1.2 vs 4.7 ± 1.2,
p
< 0.001) than the non-progressors (
n
= 3521). On Cox regression analysis, each ∆∆C
t
decrease in rLTL was associated with an increased risk of incident ESKD (HR 1.21 95% CI 1.13, 1.30,
p
< 0.001); the association remained significant after adjusting for baseline age, sex, HbA
1c
, lipids, renal function and other risk factors (HR 1.11 95% CI 1.03, 1.19,
p
= 0.007). Shorter rLTL at baseline was associated with rapid decline in eGFR (>4% per year) during follow-up (unadjusted OR 1.22 95% CI 1.15, 1.30,
p
< 0.001; adjusted OR 1.09 95% CI 1.01, 1.17,
p
= 0.024).
Conclusions/interpretation
rLTL is independently associated with incident ESKD and rapid eGFR loss in individuals with type 2 diabetes. Telomere length may be a useful biomarker for the progression of kidney function and ESKD in type 2 diabetes.
Graphical abstract
Policies like the carbon tax and tightened building regulations have been advocated as the effective drivers of carbon reduction strategy adoption. Few however, have acknowledged that project ...environment strategy adoption is a matter of organisational culture (OC). This paper reports a study that aims to examine the effect of some key drivers on the contractors' adoption of carbon reduction strategies in OC perspective. A conceptual model which depicts the hypothesised relationship among OC, carbon reduction drivers and strategy adoption is presented. The model is tested with data collected by a survey conducted in New South Wales, Australia. To test the conceptual model, Pearson correlation analysis and multiple moderated regression (MMR) analysis were employed. The results suggest that the respondents may not adjust their attitudes in carbon reduction strategy adoption for the sake of avoiding ‘penalty’. The findings may be thought provoking for those who believe that levies on carbon emissions would lead to a behavioural drift.
► The role of organizational culture (OC) on carbon reduction behaviours is studied. ► Levies on carbon emissions may not lead to contractors' behavioural change. ► Stringent standards and Rewards are more effective drivers of carbon reduction. ► OC is conducive to contractor's behavioural change in carbon reduction in projects.
Silver diamine fluoride (SDF) is a dental biomaterial used to arrest dental caries. To better understand SDF’s mechanism of action, we examined the localization of silver within the tissues of ...SDF-treated teeth. Carious primary teeth fixed within 2 min of SDF application (SDF-minutes, n = 3), at 3 wk after SDF application in vivo (SDF-weeks, n = 4), and at 2 y after multiple SDF applications in vivo (SDF-multiple, n = 1) were investigated in this study. Carious primary teeth without SDF application (no-SDF, n = 3) served as controls. Mineral density and structural analyses were performed via micro–X-ray computed tomography and scanning electron microscopy. Elemental analyses were performed through X-ray fluorescence microprobe and energy-dispersive X-ray spectroscopic techniques. SDF-treated teeth revealed higher X-ray–attenuated surface and subsurface regions within carious lesions, and similar regions were not present in no-SDF teeth. Regions of higher mineral density correlated with regions of silver abundance in SDF-treated teeth. The SDF penetration depth was approximated to 0.5 ± 0.02 mm and 0.6 ± 0.05 mm (mean ± SD) for SDF-minutes and SDF-weeks specimens, respectively. A higher percentage of dentin tubular occlusion by silver or calcium phosphate particles was observed in primary teeth treated with SDF-weeks as compared with SDF-minutes. Elemental analysis also revealed zinc abundance in carious lesions and around the pulp chamber. SDF-weeks teeth had significantly increased tertiary dentin than SDF-minutes and no-SDF teeth. These results suggest that SDF treatment on primary teeth affected by caries promotes pathologic biomineralization by altering their physicochemical properties, occluding dentin tubules, and increasing tertiary dentin volume. These seemingly serendipitous effects collectively contribute to the cariostatic activity of SDF.
The global emergence of carbapenem-resistant
Enterobacteriaceae
(CRE) presents a significant clinical concern, prompting the WHO to prioritize CRE as a top priority pathogen in their 2017 global ...antibiotic-resistant bacteria priority list. Due to the fast-depleting antibiotic arsenal, clinicians are now resorting to using once-abandoned, highly toxic antibiotics such as the polymyxins and aminoglycosides, creating an urgent need for new antibiotics. Drug repurposing, the application of an approved drug for a new therapeutic indication, is deemed a plausible solution to this problem. A total of 1,163 FDA-approved drugs were screened for activity against a clinical carbapenem- and multidrug-resistant
E. coli
isolate using a single-point 10 μM assay. Hit compounds were then assessed for their suitability for repurposing. The lead candidate was then tested against a panel of clinical CREs, a bactericidal/static determination assay, a time-kill assay and a checkerboard assay to evaluate its suitability for use in combination with Tigecycline against CRE infections. Three drugs were identified. The lead candidate was determined to be Zidovudine (azidothymidine/AZT), an oral anti-viral drug used for HIV treatment. Zidovudine was shown to be the most promising candidate for use in combination with Tigecycline to treat systemic CRE infections. Further experiments should involve the use of animal infection models.
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