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To reset, or not to reset—that is the question
Get PDFWhether to reset qubits, or not, during quantum error correction experiments is a question of both foundational and practical importance for quantum computing. Text-book quantum error correction demands that qubits are reset after measurement. However, fast qubit reset has proven challenging to execute at high fidelity. Consequently, many cutting-edge quantum error correction experiments are opting for the no-reset approach, where physical reset is not performed. It has recently been postulated that no-reset is functionally equivalent to reset procedures, as well as being faster and easier. For memory experiments, we confirm numerically that resetting provides no benefit. On the other hand, we identify a remarkable difference during logical operations. We find that unconditionally resetting qubits can reduce the duration of fault-tolerant logical operation by up to a factor of two as the number of measurement errors that can be tolerated is doubled. We support this with numerical simulations. However, our simulations also reveal that the no-reset performance is superior if the reset duration and infidelity exceed given thresholds. For example, with the noise model we considered, we find the no-reset performance to be superior when the reset duration is greater than approximately 100 ns and the physical error probability is greater than approximately 10−2.5 ≈ 0.003. Lastly, we introduce two novel syndrome extraction circuits that can reduce the time overhead of no-reset approaches. Our findings provide guidance on how experimentalists should design future experiments
Age and Sex Differences in Efficacy of Treatments for Type 2 Diabetes A Network Meta-Analysis
Get PDFIMPORTANCE Sodium-glucose cotransporter 2 (SGLT2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and dipeptidyl peptidase 4 (DPP4) inhibitors improve hyperglycemia, and SGLT2 inhibitors and GLP-1 receptor agonists reduce the risk of major adverse cardiovascular events (MACEs) among individuals with type 2 diabetes. It is not clear whether efficacy varies by age or sex. OBJECTIVE To assess whether age or sex are associated with differences in the efficacy of SGLT2 inhibitors, GLP-1 receptor agonists, and DPP4 inhibitors. DATA SOURCES AND STUDY SELECTION The MEDLINE and Embase databases and US and Chinese clinical trial registries were searched for articles published from inception to November 2022; in August 2024, the search was updated to capture the trial results. Two reviewers screened for randomized clinical trials of SGLT2 inhibitors, GLP-1 receptor agonists, or DPP4 inhibitors vs a placebo or active comparator in adults with type 2 diabetes. DATA EXTRACTION AND SYNTHESIS Individual participant data and aggregate data were used to estimate age × treatment interactions and sex × treatment interactions in multilevel network meta-regression models. MAIN OUTCOME AND MEASURES Hemoglobin A1c (HbA1c) and MACEs. RESULTS Of the 601 eligible trials identified (592 trials with 309 503 participants reported HbA1c; mean age, 58.9 [SD, 10.8] years; 42.3% were female and 23 trials with 168 489 participants reported MACEs; mean age, 64.0 [SD, 8.6] years; 35.3% were female), individual participant data were obtained for 103 trials (103 reported HbA1c and 6 reported MACEs). The use of SGLT2 inhibitors (vs placebo) was associated with less HbA1c lowering with increasing age for monotherapy (absolute reduction [AR], 0.24% [95% credible interval {CrI}, 0.10% to 0.38%] per 30-year increment in age), for dual therapy (AR, 0.17% [95% CrI, 0.10% to 0.24%]), and for triple therapy (AR, 0.25% [95% CrI, 0.20% to 0.30%]). The use of GLP-1 receptor agonists was associated with greater HbA1c lowering with increasing age for monotherapy (AR, −0.18% [95% CrI, −0.31% to −0.05%] per 30-year increment in age) and for dual therapy (AR, −0.24% [95% CrI, −0.40% to −0.07%]), but not for triple therapy (AR, 0.04% [95% CrI, −0.02% to 0.11%]). The use of DPP4 inhibitors was associated with slightly better HbA1c lowering in older people for dual therapy (AR, −0.09% [95% CrI, −0.15% to −0.03%] per 30-year increment in age), but not for monotherapy (AR, −0.08% [95% CrI, −0.18% to 0.01%]) or triple therapy (AR, −0.01% [95% CrI, −0.06% to 0.05%]). The relative reduction in MACEs with use of SGLT2 inhibitors was greater in older vs younger participants per 30-year increment in age (hazard ratio, 0.76 [95% CrI, 0.62 to 0.93]), and the relative reduction in MACEs with use of GLP-1 receptor agonists was less in older vs younger participants (hazard ratio, 1.47 [95% CrI, 1.07 to 2.02]). There was no consistent evidence for sex × treatment interactions with use of SGLT2 inhibitors and GLP-1 receptor agonists. CONCLUSIONS AND RELEVANCE The SGLT2 inhibitors and GLP-1 receptor agonists were associated with lower risk of MACEs. Analysis of age × treatment interactions suggested that SGLT2 inhibitors were more cardioprotective in older than in younger people despite smaller reductions in HbA1c; GLP-1 receptor agonists were more cardioprotective in younger people
Avoidable visits to UK emergency departments from the patient perspective: A recursive bivariate probit approach
Get PDFUnsustainably high numbers of patients attending emergency departments (ED) is a serious issue worldwide, with consequences for the quality and timeliness of emergency care. Avoidable visits, i.e. unnecessary or that should be dealt with elsewhere, exacerbate this issue. Most studies focussed on avoidable attendances use clinical data collected by hospital staff, while this study relies on survey data collected from patients asked to recall their last ED attendance and reflect on its necessity. We apply a Recursive Bivariate Probit model to quantify the factors affecting patients' perception of an ED visit being avoidable (or not), unveiling how it relates to socio-demographic and contextual factors. We find that patients who do not trust their General Practitioner (GP) are less likely to think their ED visit was avoidable. The perception of whether an ED visit was avoidable is also associated with symptoms experienced, patients’ ethnicity and waiting time for a GP appointment
Improved De-Orientation Processing for Polarimetric SAR Data Using a Phenomenological Approach
Get PDFPolarimetric synthetic aperture radar data can be used to retrieve structural and textural information of the surface and is widely used in land cover classification. To extract relevant parameters, the data must first be compensated for the orientation of the polarimetric scattering targets. However, existing methods for de-orientation processing are not able achieve this robustly and the data still suffer from orientation-induced scattering mechanism ambiguity. Here, we present a new approach to de-orientation that greatly improves on existing methods. Our algorithm innovatively employs phenomenological target decomposition theory and the concept of polarization nulls to extract and de-orient orientation-perturbed components of the target. The objective is to manipulate coherency matrix elements of a distributed target to obtain more descriptive target parameters, which are of critical importance in its de-orientation. We applied our approach to C-, L-, and P-band datasets containing built-up areas with different orientations. In contrast to existing methods, our de-orientation algorithm led to targets of all orientations being identified as having similar scattering characteristics. We also demonstrated that, an improved polarimetric target decomposition performance is achieved when the proposed de-orientation processing is incorporated into model-based decompositions
Constraints on optical and near-infrared variability in the localization of the long-period radio transient GLEAM-X J1627−52
Get PDFGLEAM-X J1627−52 was discovered as a periodic (∼18 min) radio signal over a duration of three months in 2018. It is an
enigmatic example of a growing population of ‘long-period radio transients’ consistent with Galactic origins. Their nature is
uncertain, and leading models invoke magnetic neutron stars or white dwarfs, potentially in close binary systems, to power
them. GLEAM-X J1627−52 resides in the Galactic plane with a comparatively coarse localization (2 arcsec). Here, we study
the localization region to search for spectrophotometric signatures of a counterpart using time-domain searches in optical and
near-infrared imaging, and MUSE integral field spectroscopy. No sources in the localization display clear white dwarf spectral
signatures, although at the expected distance we can only provide modest limits on their presence directly. We rule out the
presence of hot subdwarfs in the vicinity. We found no candidate within our search for variability or periodic behaviour in the
light curves. Radial velocity curves additionally show only weak evidence of variation, requiring any realistic underlying system
to have very low orbital inclination (i 5 deg). Two Balmer emission line sources are reminiscent of white dwarf pulsar systems,
but their characteristics fall within expected M-dwarf chromospheric activity with no signs of being in a close binary. Currently the white dwarf pulsar scenario is not supported, although longer baseline data and data contemporaneous with a radio active epoch are required before stronger statements. Isolated magnetars, or compact binaries remain viable. Our limits highlight the difficulty of these searches in dense environments at the limits of ground-based data
Molecular clock complexities of Clostridioides difficile
Get PDFObjectives
Reconstruct the phylogenetic status of a collection of historical Clostridioides difficile isolates and evaluate the congruence of their evolutionary trajectories with established molecular clock models.
Methods
Phylogenetic analysis was performed on Illumina sequence reads from previously analysed historic C. difficile isolates (1980–86; n = 75) demonstrating multiple antimicrobial resistances. Data was grouped by ribotype (RT), including comparators from European surveillance (2012–13) and phylogenetic studies (1985–2010). Reads were mapped to CD630/CD196 reference genomes and compared using recombination-adjusted maximum likelihood trees. Prediction intervals for expected SNP differences by age were calculated using a Poisson distribution and molecular clock estimates (0.74 SNPs per genome/per year). Root-to-tip analysis was performed to determine the date of most common recent ancestor of genomes sharing a ribotype.
Results
Moxifloxacin-resistant (>16 mg/L) RT027 isolate JV67 (1986) was two SNPs distinct from a 2006 genome, fewer than the expected lower estimate (4.4 SNPs) under current molecular clock calculations; (p = 3.93x10−5). For isolate JV02 (1981), the 13 SNP divergence from a 2008 isolate was consistent with expectations (5.9 SNPs; p = 0.07). JV73 (1983) demonstrated an 8 SNP difference, which although above the expected lower limit (5.5 SNPs), was outside the 95 % prediction interval; (p = 4.51x10−3). Only sixty-nine percent of historical genomes fit within the prediction interval for the number of SNPs expected compared to recent isolates, with fewer SNPs observed more frequently than expected. Root-to-tip analysis demonstrated a weak linear correlation.
Conclusions
C. difficile molecular clock estimations may be more complex than previously considered, with periods of spore quiescence potentially complicating analyses
Computer Vision in Clinical Neurology
No full textImportance
Neurological examinations traditionally rely on visual analysis of physical clinical signs, such as tremor, ataxia, or nystagmus. Contemporary score-based assessments aim to standardize and quantify these observations, but these tools suffer from clinimetric limitations and often fail to capture subtle yet important aspects of human movement. This poses a significant roadblock to more precise and personalized neurological care, which increasingly focuses on early stages of disease. Computer vision, a branch of artificial intelligence, has the potential to address these challenges by providing objective measures of neurological signs based solely on video footage.
Observations
Recent studies highlight the potential of computer vision to measure disease severity, discover novel biomarkers, and characterize therapeutic outcomes in neurology with high accuracy and granularity. Computer vision may enable sensitive detection of subtle movement patterns that escape the human eye, aligning with an emerging research focus on early disease stages. However, challenges in accessibility, ethics, and validation need to be addressed for widespread adoption. In particular, improvements in clinical usability and algorithmic robustness are key priorities for future developments.
Conclusions and Relevance
Computer vision technologies have the potential to revolutionize neurological practice by providing objective, quantitative measures of neurological signs. These tools could enhance diagnostic accuracy, improve treatment monitoring, and democratize specialized neurological care. Clinicians should be aware of these emerging technologies and their potential to complement traditional assessment methods. However, further research focusing on clinical validation, ethical considerations, and practical implementation is necessary to fully realize the potential of computer vision in clinical neurology
Dual Influence of Credit Management on Consumer Behavior: An Empirical Analysis Based on the Driving License Score System of Hello Bike
No full textSystematicity over the course of early development:an analysis of phonological networks
Get PDFThis paper explores the early lexicons of nine infants acquiring English or French to determine the extent of systematicity in the early vocabulary, and how this changes over time. Network graphs are generated from the point of first word production in the data set until age 30 months. Two measures of systematicity - mean path length and clustering coefficient - are analysed to establish the extent to which the early productive lexicon consists of closely-connected clusters of similar-sounding forms. Results show that early production is highly systematic when compared to random networks, but that the network becomes more dispersed as it increases in size. Connectivity within the network is consistently higher for infants’ actual productions when compared with the adult target forms, and this effect increases over time. This suggests a systematic approach to production over the course of early development
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