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Preoperative Narcotic Use, Impaired Ambulation Status, and Increased Intraoperative Blood Loss Are Independent Risk Factors for Complications Following Posterior Cervical Laminectomy and Fusion Surgery.
ObjectiveThis retrospective cohort study seeks to identify risk factors associated with complications following posterior cervical laminectomy and fusion (PCLF) surgery.MethodsAdults undergoing PCLF from 2012 through 2018 at a single center were identified. Demographic and radiographic data, surgical characteristics, and complication rates were compared. Multivariate logistic regression models identified independent predictors of complications following surgery.ResultsA total of 196 patients met the inclusion criteria and were included in the study. The medical, surgical, and overall complication rates were 10.2%, 23.0%, and 29.1% respectively. Risk factors associated with medical complications in multivariate analysis included impaired ambulation status (odds ratio [OR], 2.27; p=0.02) and estimated blood loss over 500 mL (OR, 3.67; p=0.02). Multivariate analysis revealed preoperative narcotic use (OR, 2.43; p=0.02) and operative time (OR, 1.005; p=0.03) as risk factors for surgical complication, whereas antidepressant use was a protective factor (OR, 0.21; p=0.01). Overall complication was associated with preoperative narcotic use (OR, 1.97; p=0.04) and higher intraoperative blood loss (OR, 1.0007; p=0.03).ConclusionPreoperative narcotic use and estimated blood loss predicted the incidence of complications following PCLF for CSM. Ambulation status was a significant predictor of the development of a medical complication specifically. These results may help surgeons in counseling patients who may be at increased risk of complication following surgery
Pareto-optimal clustering with the primal deterministic information bottleneck
At the heart of both lossy compression and clustering is a trade-off between
the fidelity and size of the learned representation. Our goal is to map out and
study the Pareto frontier that quantifies this trade-off. We focus on the
Deterministic Information Bottleneck (DIB) formulation of lossy compression,
which can be interpreted as a clustering problem. To this end, we introduce the
{\it primal} DIB problem, which we show results in a much richer frontier than
its previously studied dual counterpart. We present an algorithm for mapping
out the Pareto frontier of the primal DIB trade-off that is also applicable to
most other two-objective clustering problems. We study general properties of
the Pareto frontier, and give both analytic and numerical evidence for
logarithmic sparsity of the frontier in general. We provide evidence that our
algorithm has polynomial scaling despite the super-exponential search space;
and additionally propose a modification to the algorithm that can be used where
sampling noise is expected to be significant. Finally, we use our algorithm to
map the DIB frontier of three different tasks: compressing the English
alphabet, extracting informative color classes from natural images, and
compressing a group theory inspired dataset, revealing interesting features of
frontier, and demonstrating how the structure of the frontier can be used for
model selection with a focus on points previously hidden by the cloak of the
convex hull.Comment: 26 pages, 11 figure
On reliable computation over larger alphabets
We present two new positive results for reliable computation using formulas
over physical alphabets of size . First, we show that for logical
alphabets of size the threshold for denoising using gates subject to
-ary symmetric noise with error probability is strictly larger
that possible for Boolean computation and we demonstrate a clone of -ary
functions that can be reliably computed up to this threshold. Secondly, we
provide an example where , showing that reliable Boolean computation
can be performed using -input ternary logic gates subject to symmetric
ternary noise of strength by using the additional alphabet
element for error signalling.Comment: 14 pages, 2 figure
Error Correction of Quantum Algorithms: Arbitrarily Accurate Recovery Of Noisy Quantum Signal Processing
The intrinsic probabilistic nature of quantum systems makes error correction
or mitigation indispensable for quantum computation. While current
error-correcting strategies focus on correcting errors in quantum states or
quantum gates, these fine-grained error-correction methods can incur
significant overhead for quantum algorithms of increasing complexity. We
present a first step in achieving error correction at the level of quantum
algorithms by combining a unified perspective on modern quantum algorithms via
quantum signal processing (QSP). An error model of under- or over-rotation of
the signal processing operator parameterized by is introduced.
It is shown that while Pauli -errors are not recoverable without additional
resources, Pauli and errors can be arbitrarily suppressed by coherently
appending a noisy `recovery QSP.' Furthermore, it is found that a recovery QSP
of length is sufficient to correct any length- QSP with
unique phases to -order in error . Allowing an additional
assumption, a lower bound of is shown, which is tight for ,
on the length of the recovery sequence. Our algorithmic-level error correction
method is applied to Grover's fixed-point search algorithm as a demonstration
A Grand Unification of Quantum Algorithms
Quantum algorithms offer significant speedups over their classical
counterparts for a variety of problems. The strongest arguments for this
advantage are borne by algorithms for quantum search, quantum phase estimation,
and Hamiltonian simulation, which appear as subroutines for large families of
composite quantum algorithms. A number of these quantum algorithms were
recently tied together by a novel technique known as the quantum singular value
transformation (QSVT), which enables one to perform a polynomial transformation
of the singular values of a linear operator embedded in a unitary matrix. In
the seminal GSLW'19 paper on QSVT [Gily\'en, Su, Low, and Wiebe, ACM STOC
2019], many algorithms are encompassed, including amplitude amplification,
methods for the quantum linear systems problem, and quantum simulation. Here,
we provide a pedagogical tutorial through these developments, first
illustrating how quantum signal processing may be generalized to the quantum
eigenvalue transform, from which QSVT naturally emerges. Paralleling GSLW'19,
we then employ QSVT to construct intuitive quantum algorithms for search, phase
estimation, and Hamiltonian simulation, and also showcase algorithms for the
eigenvalue threshold problem and matrix inversion. This overview illustrates
how QSVT is a single framework comprising the three major quantum algorithms,
thus suggesting a grand unification of quantum algorithms
International TV series distribution on Chinese digital platforms: marketing strategies and audience engagement
The relationship between online media platforms in China and fan groups is a dynamic one when it comes to the distribution of international TV series and other media content, as media platforms incorporate user-generated content to encourage or foster audience engagement. Through a series of case studies, this article investigates how international TV series are acquired, distributed, marketed and curated on Chinese online video platforms. This helps to identify specific strategies and themes used by these platforms to promote international content and engage users. These marketing techniques, however, are not always as successful as expected, suggesting the need for a closer examination of the types of engagement sought by media platforms, and the ways in which Chinese audiences have responded within their cultural context
HLA class I-redirected anti-tumour CD4+T-cells require a higher TCR binding affinity for optimal activity than CD8+T-cells
CD4+ T helper cells are a valuable component of the immune response towards cancer. Unfortunately, natural tumour-specific CD4+ T-cells occur in low frequency, express relatively low affinity T-cell receptors (TCRs) and show poor reactivity towards cognate antigen. In addition, the lack of human leukocyte antigen (HLA) class II expression on most cancers dictates that these cells are often unable to respond to tumour cells directly. These deficiencies can be overcome by transducing primary CD4+ T-cells with tumour-specific HLA class I-restricted TCRs prior to adoptive transfer. The lack of help from the coreceptor CD8 glycoprotein in CD4+ cells might result in these cells requiring a different optimal TCR binding affinity. Here we compared primary CD4+ and CD8+ T-cells expressing wildtype and a range of affinity-enhanced TCRs specific for the HLA A*0201-restricted NY-ESO-1- and gp100 tumour antigens. Our major findings are: (i) redirected primary CD4+ T-cells expressing TCRs of sufficiently high affinity exhibit a wide range of effector functions, including cytotoxicity, in response to cognate peptide; and, (ii) optimal TCR binding affinity is higher in CD4+ T-cells than CD8+ T-cells. These results indicate that the CD4+ T-cell component of current adoptive therapies using TCRs optimised for CD8+ T-cells is below par and that there is room for substantial improvement. This article is protected by copyright. All rights reserved
Determinants of library use amongst university students
ABSTRACT The purpose of the study is to examine the factors affecting library use amongst university students. Logistic regression analysis is applied on data collected using stratified random questionnaire-based interviews of 388 students of a public university in Malaysia. Results of the marginal effects indicate that students of Indian and other descent are more likely to use the library than their Malay cohorts. In addition, those who have attended library induction sessions, those who believe that the library provides a useful avenue for them to achieve their academic goals, and frequent online users are more likely to utilize the library than their cohorts, all else equal. Students in their third/fourth/final year of studies have a lower propensity for library visits than their second year counterparts, ceteris paribus. Meanwhile, factors such as gender, parental education, campus residence, field of study, and job status do not affect library utilization in a statistically significant manner. Based on these results, several observations are noted vis-Ã -vis the determinants of library use amongst university students
Prevalence and correlates of mental health difficulties amongst LGBTQ people in Southeast Asia: A systematic review
No study to date has reviewed the evidence base concerning prevalence and correlates of depression, anxiety, non-suicidal self-injury, and suicidality amongst LGBTQ people in Southeast Asia. We carried out a systematic review of quantitative articles (n = 25) identified through electronic databases. Heightened prevalence of mental health difficulties and minority stressors were found amongst Southeast Asian LGBTQ people which included significant effect size differences relative to cisgender and heterosexual people. This review underscores the need for a more nuanced understanding of minority stressors and protective factors to inform mental health prevention efforts
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