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Science China. Mathematics 2023Simultaneously investigating multiple treatments in a single study achieves considerable efficiency in contrast to the traditional two-arm trials. Balancing treatment...
Simultaneously investigating multiple treatments in a single study achieves considerable efficiency in contrast to the traditional two-arm trials. Balancing treatment allocation for influential covariates has become increasingly important in today's clinical trials. The multi-arm covariate-adaptive randomized clinical trial is one of the most powerful tools to incorporate covariate information and multiple treatments in a single study. Pocock and Simon's procedure has been extended to the multi-arm case. However, the theoretical properties of multi-arm covariate-adaptive randomization have remained largely elusive for decades. In this paper, we propose a general framework for multi-arm covariate-adaptive designs which also includes the two-arm case, and establish the corresponding theory under widely satisfied conditions. The theoretical results provide new insights into the balance properties of covariate-adaptive randomization procedures and make foundations for most existing statistical inferences under two-arm covariate-adaptive randomization. Furthermore, these open a door to study the theoretical properties of statistical inferences for clinical trials based on multi-arm covariate-adaptive randomization procedures.
PubMed: 35912316
DOI: 10.1007/s11425-020-1954-y -
Molecular Plant Feb 2024The growth-promoting hormones brassinosteroids (BRs) and their key signaling component BZR1 play a vital role in balancing normal growth and defense reactions. Here, we...
The growth-promoting hormones brassinosteroids (BRs) and their key signaling component BZR1 play a vital role in balancing normal growth and defense reactions. Here, we discovered that BRs and OsBZR1 upregulated sakuranetin accumulation and conferred basal defense against Magnaporthe oryzae infection under normal conditions. Resource shortages, including phosphate (Pi) deficiency, potentially disrupt this growth-defense balance. OsSPX1 and OsSPX2 have been reported to sense Pi concentration and interact with the Pi signal mediator OsPHR2, thus regulating Pi starvation responses. In this study, we discovered that OsSPX1/2 interacts with OsBZR1 in both Pi-sufficient and Pi-deficient conditions, inhibiting BR-responsive genes. When Pi is sufficient, OsSPX1/2 is captured by OsPHR2, enabling most of OsBZR1 to promote plant growth and maintain basal resistance. In response to Pi starvation, more OsSPX1/2 is released from OsPHR2 to inhibit OsBZR1 activity, resulting in slower growth. Collectively, our study reveals that the OsBZR1-SPX1/2 module balances the plant growth-immunity trade-off in response to Pi availability.
Topics: Plant Proteins; Oryza; Phosphates; Brassinosteroids; Gene Expression Regulation, Plant
PubMed: 38069474
DOI: 10.1016/j.molp.2023.12.003 -
British Journal of Anaesthesia Nov 2021This editorial highlights the findings of the Balanced Anaesthesia Delirium study, a 515-patient substudy of the 6644 patient Balanced Anaesthesia trial, which found...
This editorial highlights the findings of the Balanced Anaesthesia Delirium study, a 515-patient substudy of the 6644 patient Balanced Anaesthesia trial, which found that targeting deep anaesthesia in patients undergoing major noncardiac surgery was not associated with significantly increased postoperative death or major morbidity. The substudy found that using bispectral index (BIS) guidance with the intention of deliberately achieving deep volatile agent-based anaesthesia (target BIS reading 35 vs 50) significantly increased delirium incidence (28% vs 19%), although not subsyndromal delirium incidence (45% vs 49%). We discuss the implications of these findings for anaesthetic practice, and address whether the BIS should be used as a guide to deliver precision anaesthesia for delirium prevention. We posit that subpopulation-based differences within this multicentre substudy could have affected delirium occurrence, since the findings appeared to rest on outcomes in patients from East Asia. We conclude that questions of whether and for whom deep anaesthesia is deliriogenic remain unanswered.
Topics: Anesthesia, General; Anesthesiology; Anesthetics; Delirium; Humans
PubMed: 34503835
DOI: 10.1016/j.bja.2021.08.003 -
Cellular and Molecular Bioengineering Aug 2022First-generation college students face unique challenges compared to non-first-generation college students, especially in STEM fields. First-generation STEM students...
First-generation college students face unique challenges compared to non-first-generation college students, especially in STEM fields. First-generation STEM students drop out of their major at higher rates than non-first-generation students. This may be due to a lack of role models or mentorship in the college environment or in the field, a challenging curriculum, and difficulty balancing personal and academic commitments. There has been a lack of significant attention given to studying first-generation college students in undergraduate engineering, and therefore, there is limited understanding of how to navigate post-secondary education as a first-generation college student to succeed in undergraduate engineering. Here, I lay out tips for success based on my own experience as a first-generation student in engineering. This includes how to find the right major for you, adjust to college, have a solid support system, seek out research opportunities, become involved in outreach, experience inclusivity, balance courses with other commitments, and apply for scholarships. This article also discusses considerations in pursuing graduate education. With more support, mentoring and guidance, a greater percentage of first-generation students will succeed in pursuing undergraduate engineering degrees.
PubMed: 36119133
DOI: 10.1007/s12195-022-00736-w -
Biometrika Sep 2018The seminal work of Morgan & Rubin (2012) considers rerandomization for all the units at one time.In practice, however, experimenters may have to rerandomize units...
The seminal work of Morgan & Rubin (2012) considers rerandomization for all the units at one time.In practice, however, experimenters may have to rerandomize units sequentially. For example, a clinician studying a rare disease may be unable to wait to perform an experiment until all the experimental units are recruited. Our work offers a mathematical framework for sequential rerandomization designs, where the experimental units are enrolled in groups. We formulate an adaptive rerandomization procedure for balancing treatment/control assignments over some continuous or binary covariates, using Mahalanobis distance as the imbalance measure. We prove in our key result that given the same number of rerandomizations, in expected value, under certain mild assumptions, sequential rerandomization achieves better covariate balance than rerandomization at one time.
PubMed: 30174335
DOI: 10.1093/biomet/asy031 -
Neuron Nov 2021Many studies have shown that the excitation and inhibition received by cortical neurons remain roughly balanced across many conditions. A key question for understanding... (Review)
Review
Many studies have shown that the excitation and inhibition received by cortical neurons remain roughly balanced across many conditions. A key question for understanding the dynamical regime of cortex is the nature of this balancing. Theorists have shown that network dynamics can yield systematic cancellation of most of a neuron's excitatory input by inhibition. We review a wide range of evidence pointing to this cancellation occurring in a regime in which the balance is loose, meaning that the net input remaining after cancellation of excitation and inhibition is comparable in size with the factors that cancel, rather than tight, meaning that the net input is very small relative to the canceling factors. This choice of regime has important implications for cortical functional responses, as we describe: loose balance, but not tight balance, can yield many nonlinear population behaviors seen in sensory cortical neurons, allow the presence of correlated variability, and yield decrease of that variability with increasing external stimulus drive as observed across multiple cortical areas.
Topics: Cerebral Cortex; Models, Neurological; Neurons
PubMed: 34464597
DOI: 10.1016/j.neuron.2021.07.031 -
BMC Medical Research Methodology Jun 2023In the causal analysis of observational studies, covariates should be carefully balanced to approximate a randomized experiment. Numerous covariate balancing methods...
BACKGROUND
In the causal analysis of observational studies, covariates should be carefully balanced to approximate a randomized experiment. Numerous covariate balancing methods have been proposed for this purpose. However, it is often unclear what type of randomized experiments the balancing approaches aim to approximate; and this may cause ambiguity and hamper the synthesis of balancing characteristics within randomized experiments.
METHODS
Randomized experiments based on rerandomization, known for significant improvement on covariate balance, have recently gained attention in the literature, but no attempt has been made to integrate this scheme into observational studies for improving covariate balance. Motivated by the above concerns, we propose quasi-rerandomization, a novel reweighting method, where observational covariates are rerandomized to be the anchor for reweighting such that the balanced covariates obtained from rerandomization can be reconstructed by the weighted data.
RESULTS
Through extensive numerical studies, not only does our approach demonstrate similar covariate balance and comparable estimation precision of treatment effect to rerandomization in many situations, but it also exhibits advantages over other balancing techniques in inferring the treatment effect.
CONCLUSION
Our quasi-rerandomization method can approximate the rerandomized experiments well in terms of improving the covariate balance and the precision of treatment effect estimation. Furthermore, our approach shows competitive performance compared with other weighting and matching methods. The codes for the numerical studies are available at https://github.com/BobZhangHT/QReR .
PubMed: 37391690
DOI: 10.1186/s12874-023-01977-7 -
The Journal of Rheumatology Mar 2021Observational studies allow researchers to understand the natural history of rheumatic conditions, risk factors for disease development, and factors affecting important... (Review)
Review
Observational studies allow researchers to understand the natural history of rheumatic conditions, risk factors for disease development, and factors affecting important disease-related outcomes, and to estimate treatment effect from real-world data. However, this design carries a risk of confounding bias. A propensity score (PS) is a balancing score that aims to minimize the difference between study groups and consequently potential confounding effects. The score can be applied in 1 of 4 methods in observational research: matching, stratification, adjustment, and inverse probability weighting. Systemic lupus erythematosus (SLE) is a rare disease characterized by a relatively small sample size and/or low event rates. In this article, we review the PS methods. We demonstrate application of the PS methods to achieve study group balance in a rare disease using an example of risk of infection in SLE patients with hypogammaglobulinemia.
Topics: Bias; Humans; Lupus Erythematosus, Systemic; Observational Studies as Topic; Propensity Score; Rare Diseases; Risk Factors
PubMed: 32611674
DOI: 10.3899/jrheum.200254 -
International Journal of Environmental... Nov 2022Burnout syndrome is officially classified in the International Classification of Diseases as an occupational phenomenon resulting from chronic workplace stress. Each...
Burnout syndrome is officially classified in the International Classification of Diseases as an occupational phenomenon resulting from chronic workplace stress. Each year it is having an increasingly negative impact on the mental and physical health of employees, as well as on health costs and business performance. With this study, we aim at verifying whether there is a greater propensity for burnout depending on an individual's time perspective, based on the framework of Christina Maslach's burnout syndrome theory (consisting of three burnout dimensions), and Phillip Zimbardo's Time Perspective (consisting of five distinct temporal profiles). Within the time perspective construct, we focused on an indicator of temporal adaptation, referred to as a Balanced Time Perspective (BTP). We used the Maslach Burnout Inventory and the Zimbardo Time Perspective Inventory on a sample of 129 Polish corporate employees. We found that two dimensions of burnout (emotional exhaustion and feelings of personal achievement) were significantly correlated to a balanced time perspective, while the third (depersonalization) did not pose a significant correlation. This underlines the interrelationships between personality and burnout, which gives way to one possible solution towards the danger of burnout syndrome-balancing an individuals' time perspective through measures such as Time Perspective Therapy. We believe that the awareness of one's temporal profile gives way to supplement gaps in one time perspective, while deterring the excessive effects of another, resulting in a more balanced time perspective, greater mental health and protection from burnout syndrome.
Topics: Humans; Depersonalization; Burnout, Psychological; Burnout, Professional; Occupational Stress; Achievement; Surveys and Questionnaires
PubMed: 36361358
DOI: 10.3390/ijerph192114466 -
Journal of Public Health in Africa Apr 2023This study's background was inspired by the current COVID-19 handling policy, which focuses on the balance of public health and social economy. However, there is a...
BACKGROUND
This study's background was inspired by the current COVID-19 handling policy, which focuses on the balance of public health and social economy. However, there is a knowledge gap on the dynamic complexity of balancing public health and social economy during the new normal period of COVID-19 handling policy. A system dynamics simulation of the COVID-19 handling policy could be used to understand that gap.
OBJECTIVE
This study aims to uncover the simulation of the COVID-19 handling policy in Indonesia.
METHODS
This study combined quantitative and qualitative modeling methods with a system dynamics tool.
RESULTS
This study revealed 3 elements in the dynamic balance of public health and social economy in the COVID handling policy system: i) COVID-19 and social-economic control; ii) COVID-19 escalation and de-escalation; iii) people's immunity enhancement. Such a mix of COVID-19-controlling policy instruments has maintained a dynamic equilibrium between easing economic suppression at the expense of worsening COVID-19 and tightening public health resolution at the expense of more economic suppression.
CONCLUSIONS
The study conclusions are as follows: i) the COVID-19 handling policy worked as a leverage factor in balancing public health resolution and economic interest during the new normal period in Indonesia; ii) experiential creativity to respond to the newly serious public health problems triggered by COVID-19 implies adding public health knowledge; iii) the study's outcomes imply re-examining the strengths and deficiencies of the entire health system for a better health system.
PubMed: 37404333
DOI: 10.4081/jphia.2023.2233