bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison between Propofol and Total Inhalational Anaesthesia on Cardiovascular Outcomes Following On-pump Cardiac Surgery in Higher-Risk Patients – A Randomised Controlled Pilot and Feasibility Study
Authors: Milne Benjamin , John Martin , Evans Richard , Robertson Steven , Scanaill Pádraig Ó , Murphy Gavin J , Landoni Giovanni , Marber Mike , Clayton Tim , Kunst Gudrun
Published: February 2024

Objectives

Myocardial revascularisation and cardiopulmonary bypass (CPB) can cause ischemia-reperfusion injury, leading to myocardial and other end-organ damage. Volatile anaesthetics protect the myocardium in experimental studies, however there is uncertainty as whether this translates into clinical benefits.

Methods

In this single blinded parallel group randomised controlled feasibility trial higher-risk patients undergoing elective coronary artery bypass graft surgery with an additive European System for Cardiac Operative Risk Evaluation (EuroScore)>5 were randomised to receive either propofol or total inhalational anaesthesia for maintenance of anaesthesia. The primary outcome was the feasibility to recruit and randomise 50 patients across two cardiac surgical centres and secondary outcomes included the feasibility of collecting the planned perioperative data and clinically relevant outcomes and assessments of effective patient identification, screening and recruitment.

Results

All 50 patients were recruited within 11 months in two centres allowing for a 13-month hiatus in recruitment due to the COVID-19 pandemic. Overall, 50/108 (46%) of eligible patients were recruited. One patient withdrew before surgery and one patient did not undergo surgery. All but one completed in-hospital and 30-day follow-up.

Conclusions

It is feasible to recruit and randomise higher-risk patients undergoing CABG surgery to a study comparing total inhalational and propofol anaesthesia in a timely manner and with high acceptance and completion rates.
Prolonged Water-only Fasting is a Safe and Feasible Treatment Option for Managing Stage 1 and 2 Hypertension
Authors: Zeiler Evelyn , Gabriel Sahmla , Ncube Mackson , Thompson Natasha , Scharf Eugene , Goldhamer Alan C. , Myers Toshia R.
Published: February 2024

Prolonged water-only fasting appears to reduce high blood pressure but randomized controlled trials are needed. This single arm pre-post interventional trial (clinicaltrials.gov,NCT04515095) investigates the safety, feasibility, and effectiveness of prolonged water-only fasting in the treatment of stage 1 and 2 hypertension. Twenty-nine participants with stage 1 and 2 hypertension, who were pre-approved to water-only fast for ≥7 days, were enrolled from a residential fasting center. Participants received 24-hour medical supervision, and adverse events were recorded according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Feasibility was assessed based on retention rate, ability to complete minimal fast length, and intervention acceptability. Demographic, anthropometric, medication use, laboratory, and survey data were also collected. Twenty-seven of the 29 enrolled participants attended all study visits through the six-week follow-up visit and completed at least seven consecutive days of water-only fasting. The majority of adverse events were mild and transient and there were no higher-grade or serious adverse events. Overall, the intervention was acceptable. At the six-week follow-up visit, there were sustained reductions in median systolic/diastolic blood pressure (−19.19/-5.13 mmHg), body weight (−6.72 kg), abdominal circumference, −6.55 cm), and anti-hypertensive medication use (−93%), which also persisted at the 12-month follow-up visit. These preliminary data suggest that prolonged water-only fasting is a safe and feasible treatment option for stage 1 and 2 hypertension. The data also suggest that fasting may result in sustainable reductions in high blood pressure and anti-hypertensive medication use.
The risk prediction models of neonatal necrotizing enterocolitis in China: a systematic review
Authors: Wu Jiaming , Du jiajia , Peng Junjie , Guo Xin , Hu Xue , Li Yunchuan , Wu Yuanfang
Published: February 2024

Objective

Systematically evaluate the risk prediction model for neonatal necrotizing enterocolitis (NEC) in China, providing reference for clinical work and future research.

Methods

We searched Chinese and English databases were systematically searched to focus on NEC risk prediction modeling studies.The search time ranged from database establishment to 25 August 2023.Two researchers independently screened the literature and extracted information.Then risk of bias and applicability were assessed by using the Prediction Model Risk of Bias Assessment Tool.

Results

A total of 10 papers involving 12 NEC risk prediction models were included, which is focusing on the populations of preterm infants mostly, building the methods of models diversity, predicting factors discrepancy widely.

conclusion

The existing NEC risk prediction models in China have good predictive performance, while they often lack external validation, resulting in an overall high risk of bias. In the future, clinicians and nurses should learn from the evaluation criterions based on the PROBAST, then to test and verify them. Or machine learning algorithms usage is to construct models with operationalization and better predictive efficacy. [REGISTRATION: PROSPERO ID: CRD42024503844]
Functional Analysis of the Zinc Finger Modules of theS. cerevisiaeSplicing Factor Luc7
Authors: Carrocci Tucker J. , DeMario Samuel , He Kevin , Zeps Natalie J. , Harkner Cade T. , Chanfreau Guillaume , Hoskins Aaron A.
Published: February 2024

Identification of splice sites is a critical step in pre-mRNA splicing since definition of the exon/intron boundaries controls what nucleotides are incorporated into mature mRNAs. The intron boundary with the upstream exon is initially identified through interactions with the U1 snRNP. This involves both base pairing between the U1 snRNA and the pre-mRNA as well as snRNP proteins interacting with the 5’ splice site/snRNA duplex. In yeast, this duplex is buttressed by two conserved protein factors, Yhc1 and Luc7. Luc7 has three human paralogs (LUC7L, LUC7L2, and LUC7L3) which play roles in alternative splicing. What domains of these paralogs promote splicing at particular sites is not yet clear. Here, we humanized the zinc finger domains of the yeast Luc7 protein in order to understand their roles in splice site selection using reporter assays, transcriptome analysis, and genetic interactions. While we were unable to determine a function for the first zinc finger domain, humanization of the second zinc finger domain to mirror that found in LUC7L or LUC7L2 resulted in altered usage of nonconsensus 5’ splice sites. In contrast, the corresponding zinc finger domain of LUC7L3 could not support yeast viability. Further, humanization of Luc7 can suppress mutation of the ATPase Prp28, which is involved in U1 release and exchange for U6 at the 5’ splice site. Our work reveals a role for the second zinc finger of Luc7 in splice site selection and suggests that different zinc finger domains may have different ATPase requirements for release by Prp28.
Variant Surface Protein GP60 Contributes to Host Infectivity ofCryptosporidium parvum
Authors: Li Muxiao , Yang Fuxian , Hou Tianyi , Gong Xiaoqing , Li Na , Sibley L. David , Feng Yaoyu , Xiao Lihua , Guo Yaqiong
Published: February 2024

Biological studies of the determinants ofCryptosporidiuminfectivity and virulence are lacking despite the fact that cryptosporidiosis is a major public health problem. Here, we used advanced genetic tools to investigate the processing, fate, and function of the 60-kDa glycoprotein (GP60), an immunodominant variable antigen associated with protection against reinfection. Endogenous gene tagging revealed that GP60 is highly expressed in sporozoites, merozoites and male gametes, suggesting that it may be involved in both invasion and sexual replication. GP60 is translocated to the parasite membrane and cleaved at the furin cleavage site into GP40 and GP15. During invasion, GP40 translocates to the apical end of the zoites and remains detectable at the parasite-host interface. Although GP60 is dispensable, both gene deletion and replacement reduce parasite growth and severity of infection. Depletion of its structural domains, GP40, or GP15 individually affects GP60 translocation but has less effect on its function. These findings suggest that the GP60 protein contributes to host infectivity likely through its multiple functions inC. parvum-host interactions. They further our understanding of the pathogenesis of cryptosporidiosis.
Profiling multi-body interactions of BCL2 with single-molecule co-immunoprecipitation reveals the molecular mechanism of ABT-199 resistance
Authors: Chun Changju , Yoon Tae-Young
Published: February 2024

A capability to characterize protein-protein interactions (PPIs) in a quantitative manner with an increased speed would form a technical basis for accelerating drug discovery targeting the PPI network. We here used the single-molecule pull-down and co-IP platform to examine PPI between BCL2 and BH3-only proteins in crude extract environments. We focused on how the PPI strengths changed with single-point BCL2 mutations found in relapsed chronic lymphocytic leukemia showing ABT-199 resistance, where we took a mix-and-match approach to examine various pairs of baits and preys while titrating their concentrations. This allowed us to examine total 21 PPI reactions and 420 data points, forming a high-resolution large data set of the dissociation constants (Kd) and the drug inhibitory constants (Ki). Our data suggest that the different BCL2 mutants take different routes to acquire resistance to ABT-199, demonstrating how large-scale, quantitative PPI data sets reveal insights into the evolving dynamics of PPI networks.
Functional Modification of Cyanobacterial Phycobiliprotein and Phycobilisomes through Bilin Metabolism Control
Authors: Sato Mizuho , Kawaguchi Takeshi , Maeda Kaisei , Watanabe Mai , Ikeuchi Masahiko , Narikawa Rei , Watanabe Satoru
Published: February 2024

The light-harvesting antenna complexes in cyanobacteria are known as phycobilisomes (PBSs), and they can adapt to a diverse range of light environments owing to the deployment of different phycobiliproteins within the PBS structures. Freshwater cyanobacteria such asSynechococcus elongatusPCC 7942 thrive under red light due to phycocyanin (PC), along with phycocyanobilin (PCB), in PBS. Conversely, cyanobacteria in shorter-wavelength light environments, such as green light, employ phycoerythrin paired with phycoerythrobilin (PEB) alongside PC in PBS. Synthetic biology studies have shown that PEB production can be enhanced by additional expression of the heterologous PEB synthases, namely 15,16-dihydrobiliverdin:ferredoxin oxidoreductase and PEB:ferredoxin oxidoreductase (PebAB), leading to cellular browning due to PEB accumulation. This approach is genetically unstable, and the properties of the resulting PEB-bound PBS complexes remain uncharacterized. Herein, we engineered a novel strain ofSynechococcus7942 PEB1, with finely tuned control of PEB metabolism. PEB1 exhibited a remarkable and reversible color shift from green to brown and pink, based on the PebAB induction levels. High induction led to a complete PCB-to-PEB substitution, causing the disassembly of the PBS rod complex. In contrast, low PebAB levels resulted in the formation of a stable chimeric PBS complex with partial PCB-to-PEB substitution. This adaptation enabled efficient light harvesting in the green spectrum and energy transfer to the photosynthetic reaction center. These findings, which improve our understanding of PBS and highlight the structural importance of the bilin composition, lay the foundation for future PBS adaptation studies in bioengineering, synthetic biology, and renewable energy.
Changes in Gait Asymmetry May Be Caused by Adaptation of Spinal Reflexes
Authors: Refy Omar , Mo Owen , Hsu Jacob , Weber Douglas J. , Geyer Hartmut
Published: February 2024

In a recent human study, we found that adaptive changes in step length asymmetry (SLA) are correlated with similar changes in the H-reflex gains of the leg muscles during split-belt treadmill locomotion. While this observation indicated a closer link between gait asymmetry and spinal reflex adaptation, it did not reveal their causal relationship. To better understand this relationship, here we use a neuromuscular model of human walking whose control relies primarily on spinal reflexes. Subjecting the model to split-belt treadmill locomotion with different combinations of belt speed and reflex gain adaptation patterns, we find that belt speed changes increase the variability in SLA but do not result in consistent SLA patterns as observed in human experiments, whereas reflex gain adaptations do. Furthermore, we find that the model produces SLA patterns similar to healthy adults when its reflex gains are adapted in a way similar to the H-reflex changes we observed in our previous human study. The model also predicts SLA patterns similar to the ones observed for cerebellar degeneration patients when the reflexes do not adapt beyond a sudden dip at the time the ipsilateral belt speed is lowered. Our results suggest that SLA does not arise from imposing belt speed changes but requires the adaptation of the reflex gains, and that the dynamic adaptation of these gains may be an essential part of human gait control when encountering unexpected environment changes such as the uneven speed changes in split-belt treadmill locomotion.
Acquiring social safety engages oxytocin neurons in the supraoptic nucleus – role of Magel2 deficiency
Authors: Chakraborty Prabahan , Lamat Hugo , André Emilie M. , Fontanaud Pierre , Jeanneteau Freddy
Published: February 2024

Introduction

Exposure to social trauma may alter engagement with both fear-related and unrelated social stimuli long after. Intriguingly, how simultaneous discrimination of social fear and safety is affected in neurodevelopmental conditions like autism remains underexplored. The role of the neuropeptide oxytocin is established in social behaviors, and yet unexplored during such a challenge post-social trauma.

Methods

UsingMagel2knockout mice, an animal model of Prader Willi Syndrome (PWS) and autism spectrum disorders, we tested memory of social fear and safety after a modified social fear conditioning task. Additionally, we tracked the activity of oxytocin neurons in the supraoptic (SON) and paraventricular (PVN) nuclei of the hypothalamus by fibre photometry, as animals were simultaneously presented with a choice between a fear and safe social cue during recall.

Results

MaleMagel2KO mice trained to fear females with electrical footshocks avoided both unfamiliar females and males during recalls, lasting even a week post-conditioning. On the contrary, trainedMagel2WT avoided only females during recalls, lasting days rather than a week post-conditioning. Inability to overcome social fear and avoidance of social safety inMagel2KO mice were associated with reduced engagement of oxytocin neurons in the SON, but not the PVN.

Conclusion

In a preclinical model of PWS, we demonstrated region-specific deficit in oxytocin activity associated with behavioral generalization of social fear to social safety. Insights from this study add to our understanding of oxytocin action in the brain at the intersection of social trauma, PWS and related autism spectrum disorders.
Visual stimulation drives retinotopic acetylcholine release in the mouse visual cortex
Authors: Knudstrup Scott G. , Martinez Catalina , Rauscher Bradley C. , Doran Patrick R. , Fomin-Thunemann Natalie , Kilic Kivilcim , Jiang John , Devor Anna , Thunemann Martin , Gavornik Jeffrey P.
Published: February 2024

Cholinergic signaling is involved with a variety of brain functions including learning and memory, attention, and behavioral state modulation. The spatiotemporal characteristics of neocortical acetylcholine (ACh) release in response to sensory inputs are poorly understood, but a lack of intra-region topographic organization of cholinergic projections from the basal forebrain has suggested diffuse release patterns and volume transmission. Here, we use mesoscopic imaging of fluorescent ACh sensors to show that visual stimulation results in ACh release patterns that conform to a retinotopic map of visual space in the mouse primary visual cortex, suggesting new modes of functional cholinergic signaling in cortical circuits.x
Functional variation in human Carbohydrate-Active enZYmes (hCAZymes) in relation to the efficacy of a FODMAP-reducing diet in IBS patients
Authors: Zamfir-Taranu Andreea , Löscher Britt-Sabina , Carbone Florencia , Hoter Abdullah , Blanco Cristina Esteban , Bozzarelli Isotta , Torices Leire , Routhiaux Karen , Van den Houte Karen , Bonfiglio Ferdinando , Mayr Gabriele , Corsetti Maura , Naim Hassan Y , Franke Andre , Tack Jan , D’Amato Mauro
Published: February 2024

Objective

Limiting the dietary intake of carbohydrates poorly absorbed in the small intestine (FODMAPs) has therapeutic effects in some but not all irritable bowel syndrome (IBS) patients. We investigated genetic variation in human Carbohydrate-Active enZYmes (hCAZymes) genes in relation to the response to a FODMAP-lowering diet in the DOMINO study.

Design

hCAZy polymorphism was studied in IBS patients from the dietary (FODMAP-lowering; N=196) and medication (otilonium bromide; N=54) arms of the DOMINO trial via targeted sequencing of 6 genes of interest (AMY2B,LCT,MGAM,MGAM2,SIandTREH). hCAZyme defective (hypomorphic) variants were identified via computational annotation using clinical pathogenicity classifiers. Age-and sex-adjusted logistic regression was used to test hCAZyme polymorphisms in cumulative analyses where IBS patients were stratified into carrier and non-carrier groups (collapsing all hCAZyme hypomorphic variants into a single bin). Quantitative analysis of hCAZyme variation was also performed, in which the number of hCAZyme genes affected by a hypomorphic variant was taken into account.

Results

In the dietary arm, the number of hypomorphic hCAZyme genes positively correlated with treatment response rate (P=0.03, OR=1.51 [CI=0.99-2.32]). In the IBS-D group (N=55), hCAZyme carriers were six times more likely to respond to the diet than non-carriers (P=0.002, OR=6.33 [CI=1.83-24.77]). These trends were not observed in the medication arm.

Conclusions

hCAZYme genetic variation may be relevant to the efficacy of a carbohydrate-lowering diet. This warrants additional testing and replication of findings, including mechanistic investigations of this phenomenon.

WHAT IS KNOWN

Carbohydrates are known triggers of IBS symptoms, and limiting their dietary consumption appears to have therapeutic effects

The lowFODMAP diet improves symptoms in some but not all IBS patients

WHAT IS NEW HERE

Carrying hypomorphic hCAZyme gene variants associates with increased efficacy of a FODMAP-lowering diet in IBS, especially in patients with diarrhoea (IBS-D)

hCAZyme genotype information may be relevant to increase therapeutic precision in IBS, contributing to personalising carbohydrate-focused dietary interventions
The natural recovery of visuospatial neglect: a systematic review and meta-analysis
Authors: Overman Margot Juliëtte , Binns Elena , Milosevich Elise T , Demeyere Nele
Published: February 2024

Background

Visuospatial neglect is a common consequence of stroke and is characterised by impaired attention to contralesional space. Currently, the extent and time course of recovery from neglect are not clearly established. This systematic review and meta-analysis aimed to determine the natural recovery trajectory of post-stroke neglect.

Methods

PsycInfo, Embase, and MEDLINE were searched for articles reporting recovery rates of neglect after stroke. Time since stroke was categorised into early (0-3 months), mid (3-6 months), or late (>6 months) recovery phases. Random-effects models for pooled prevalence were generated for each phase, and potential sources of heterogeneity were explored with meta-regressions. Methodological quality of each study was assessed using the Joanna Briggs Institute checklist, with low-quality studies excluded in sensitivity analyses.

Results

A total of 27 studies reporting data from 839 stroke survivors with neglect were included. Meta-analyses indicated a recovery rate of 42% in the early phase, which increased to 53% in the mid-recovery phase. Additional recovery in the late phase was minimal, with an estimated 56% recovery rate. Estimates were robust to sensitivity analyses. Meta-regressions showed significantly greater recovery in studies which included patients with left-hemisphere lesions (ß=0.275,p<0.05).

Conclusions

Most natural recovery from neglect occurs in the first three months, although additional gains can be expected up to 6 months post-stroke. Whilst a large proportion of patients recover from neglect, over 40% show persistent symptoms. Further research is needed on effective rehabilitation interventions, particularly focusing on patients most at risk of chronic visuospatial neglect.
Evolutionary Lags in the Primate Brain Size/Body Size Relationship
Authors: Dunbar Robin
Published: February 2024

INTRODUCTION

The original brain lag hypothesis proposed that primate brain evolution depended on spare energy derivative of savings of scale enabled by increasing body size. Deaner & Nunn [1] concluded that, in fact, there was no evidence for a brain lag. However, their result may have been due to a number of possible confounds in their analysis.

METHODS

I revisit their analysis to test for potential confounds using updated datasets. I also ask how primates paid for the energy costs incurred by changes in brain and body mass, and whether the impetus for these changes was predation risk. Finally, I ask whether the observed patterns explain the brain/body size ratio trajectory observed in fossil hominins.

RESULTS

I show that using statistically more appropriate statistics and updated data yields a significant brain lag effect. However, contrary to the original brain lag hypothesis, the brain/body ratio does not converge back on the allometric regression line, but continues to evolve beyond it. Increases in brain size are correlated with exploiting large group size rather than body size as the principal defence against predation risk, with significant growth in brain size (but not body size) only being possible if species adopted a more frugivorous diet. Finally, I show that hominins followed a similar trajectory from an australopithecine baseline that fell on the relevant allometric regression.

CONCLUSION

The brain lag effect is much more complicated than the original hypothesis proposed, with a distinctive switch from body to brain over evolutionary time.
Multiplexedin situhybridization reveals distinct lineage identities for major and minor vein initiation during maize leaf development
Authors: Perico Chiara , Zaidem Maricris , Sedelnikova Olga , Bhattacharya Samik , Korfhage Christian , Langdale Jane A.
Published: February 2024

Leaves of flowering plants are characterised by diverse venation patterns. Patterning begins with the selection of vein-forming procambial initial cells from within the ground meristem of a developing leaf, a process which is considered to be auxin-dependent, and continues until veins are anatomically differentiated with functional xylem and phloem. At present, the mechanisms responsible for leaf venation patterning are primarily characterized in the model eudicotArabidopsis thalianawhich displays a reticulate venation network. However, evidence suggests that vein development may proceed via a different mechanism in monocot leaves where venation patterning is parallel. Here, we employed Molecular Cartography, a multiplexedin situhybridization technique, to analyse the spatiotemporal localisation of a subset of auxin related genes and candidate regulators of vein patterning in maize leaves. We show how different combinations of auxin influx and efflux transporters are recruited during leaf and vein specification, and how major and minor vein ranks develop with distinct identities. The localisation of the procambial markerPIN1aand the spatial arrangement of procambial initial cells that give rise to major and minor vein ranks further suggests that vein spacing is pre-patterned across the medio-lateral leaf axis prior to accumulation of the PIN1a auxin transporter. In contrast, patterning in the adaxial-abaxial axis occurs progressively, with markers of xylem and phloem gradually becoming polarised as differentiation proceeds. Collectively our data suggest that both lineage- and position-based mechanisms may underpin vein patterning in maize leaves.

SIGNIFICANCE STATEMENT

During the development of multicellular organisms specialized cell-types differentiate from pluripotent stem cells, with cell identity acquired via lineage- or position-based mechanisms. In plants, most organs develop post-embryogenesis and as such developmental processes are influenced by the external environment. To adapt to different environmental contexts and yet still form recognizable structures, position-based differentiation mechanisms are deployed in which cells adopt a certain fate depending on the activity of neighbouring cells. Such is the prevalence of position-based mechanisms in plant development that a role for lineage is rarely contemplated. Here we show that stem cells which give rise to different vein types in maize leaves are transcriptionally distinct, possibly reflecting a role for lineage-based mechanisms in the differentiation of leaf veins.
OsNF-YB7 inactivates OsGLK1 to inhibit chlorophyll biosynthesis in rice embryo
Authors: Yang Zongju , Bai Tianqi , E. Zhiguo , Niu Baixiao , Chen Chen
Published: February 2024

As a master regulator of seed development, Leafy Cotyledon 1 (LEC1) promotes chlorophyll (Chl) biosynthesis inArabidopsis, but the mechanism underlying this remains poorly understood. Here, we found that loss of function ofOsNF-YB7, aLEC1homolog of rice, leads to chlorophyllous embryo, indicating thatOsNF-YB7plays an opposite role in Chl biosynthesis in rice compared with that inArabidopsis. OsNF-YB7 regulates the expression of a group of genes responsible for Chl biosynthesis and photosynthesis by directly binding to their promoters. In addition, OsNF-YB7 interacts with Golden 2-Like 1 (OsGLK1) to inhibit the transactivation activity of OsGLK1, a key regulator of Chl biosynthesis. Moreover, OsNF-YB7 can directly repressOsGLK1expression by recognizing its promoterin vivo, indicating the involvement of OsNF-YB7 in multiple regulatory layers of Chl biosynthesis in rice embryo. We propose that OsNF-YB7 functions as a transcriptional repressor to regulate Chl biosynthesis in rice embryo.
Geometry and cell wall mechanics guide early pollen tube growth inArabidopsis thaliana
Authors: Riglet Lucie , Quilliet Catherine , Godin Christophe , John Karin , Fobis-Loisy Isabelle
Published: February 2024

InArabidopsis thaliana, successful fertilization relies on the precise guidance of the pollen tube tip as it navigates through the female pistil tissues to deliver non-motile sperm cells to ovules. While prior studies have unveiled the role of the pistil in directing pollen tubes to ovules, growth guidance mechanisms within the stigmatic epidermis during the initial phase of the pollen tube’s journey remains elusive. A recent analysis comparing wild-type (WT) pollen tube paths in WT andktn1-5stigmatic cells revealed a tight connection between directed pollen tube growth and the mechanical properties of the invaded stigmatic cell. Building upon these observations, we constructed here a mathematical model to explore the mechanisms guiding early pollen tube growth through the papilla cell wall (CW). We found that inktn1-5, the pollen tube moves freely on the curved papilla surface, following geodesics, while the WT papilla exerts directional guidance on the pollen tube. An order of magnitude analysis of the mechanical forces involved in pollen tube growth in papillae suggests a guidance mechanism, where the elongated papilla geometry and the CW elasticity combine to efficiently direct pollen tube growth towards the papilla base.
High-gradient performance of a prototype accelerator cavity for a 3 GeV proton radiography booster
Authors: Zuboraj Muhammed , Batygin Yuri K. , Kurennoy Sergey S. , Olivas Eric R. , Simakov Evgenya I. , Xu Haoran
Published: February 2024

This paper reports the design, fabrication, and results of the high-gradient conditioning and testing for a two-cell, π-mode, standing wave normal-conducting prototype booster cavity for the proposed 3 GeV proton linac upgrade at Los Alamos Neutron Science Center. Increasing the energy of proton beam from the existing 800 MeV to 3 GeV will improve resolution of the proton radiography by up to 10 times. The proposed energy boost can be achieved with a compact normal-conducting high-gradient radio-frequency (rf) linac section. The C-band section of the booster linac was designed with optimized-shaped copper accelerator cavities with distributed rf coupling. A short two-cell test prototype structure was designed for the frequency of 5.712 GHz, fabricated, and tested at the C-band Engineering Research Test Facility in New Mexico (CERF-NM) at Los Alamos National Laboratory. The maximum klystron power coupled into the test structure was 8.3 MW with 1  μs pulse length and 100 Hz repetition rate. The breakdown probabilities were recorded as functions of the accelerating gradient and peak surface fields. Operation of the test cavity at accelerating gradients of up to 100  MV/m was demonstrated.

Published by the American Physical Society
2024
Linear coupling of transverse betatron oscillations: Dynamic stability and invariants of motion
Authors: Tzenov Stephan I. , Chen Zhichu , Wu Hailong
Published: February 2024

Based on the technique of the discrete one-turn transfer maps, the problem of linear coupling between horizontal and vertical betatron oscillations in an accelerator has been treated exactly and entirely in explicit form. The stability region in the fractional part of the horizontal and the vertical betatron tune space as a function of the linear coupling strength has been obtained, and the increment/decrement of the horizontal and the vertical betatron oscillations in the case of the linear sum resonance has been shown to be approximately equal to the half of the coupling strength. The normal form parameterization of the one-turn linear map with horizontal-to-vertical coupling has been developed in detail in the spirit of Edwards and Teng formalism. The motion in the normal mode in the new normal form coordinates is decoupled by implying that two independent Courant-Snyder invariants exist, which have been found explicitly.

Published by the American Physical Society
2024
Self-consistent optimization of the
z
expansion for
B
-meson decays
Authors: Simons Daniel , Gustafson Erik , Meurice Yannick
Published: February 2024

We discuss the self-consistency imposed by the analyticity of regular parts of form factors, appearing in the z expansion for semileptonic B-meson decays, when fitted in different kinematic regions. Relying on the uniqueness of functions defined by analytic continuation, we propose four metrics which measure the departure from the ideal analytic self-consistency. We illustrate the process using Belle data for B→Dℓνℓ with the two kinematic regions chosen as the five low-z and the five high-z bins. For this specific example, the metrics provide consistent indications that some choices (order of truncation, Boyd-Grinstein-Lebed or Bourrely-Caprini-Lellouch) made in the form of the z expansion can be optimized. However, other choices (z origin, location of isolated poles and threshold constraints) appear to have very little effect on these metrics. On the other hand, changing the kinetic regions affects the results and should also be considered in the optimization process. We briefly discuss the implication for optimization of the

z

expansion for nucleon form factors relevant for neutrino oscillation experiments.

Published by the American Physical Society
2024
Form factors of
B(s)
to light scalar mesons with the
B
-meson light-cone sum rules
Authors: Khosravi R.
Published: February 2024

In this work, the transition form factors of the semileptonic decays of B(s) to the light scalar mesons with masses close to 1.5 GeV such as K0*(1430),a0(1450), and f0(1500) are calculated in the framework of the light-cone sum rules. For this purpose, the two- and three-particle B-meson distribution amplitudes (DAs) are used. Note that it is possible to use the B-meson DAs for the Bs meson in the SU(3)F symmetry limit. The transition form factors are obtained in terms of the two-particle DAs up to twist-five accuracy, and the three-particle up to twist-six level. We apply two classes of the phenomenological models for the DAs of the B meson. The longitudinal lepton polarization asymmetries and branching fractions for the semileptonic decays of B(s) to the light scalar mesons are estimated with the help of these form factors.

Published by the American Physical Society
2024
Energy Principles of Scientific Breakeven in an Inertial Fusion Experiment
Authors: Hurricane O. A. , Callahan D. A. , Casey D. T. , Christopherson A. R. , Kritcher A. L. , Landen O. L. , Maclaren S. A. , Nora R. , Patel P. K. , Ralph J. , Schlossberg D. , Springer P. T. , Young C. V. , Zylstra A. B.
Published: February 2024

Fusion “scientific breakeven” (i.e., unity target gain Gtarget, total fusion energy out > laser energy input) has been achieved for the first time (here, Gtarget∼1.5). This Letter reports on the physics principles of the design changes that led to the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce target gain greater than unity and exceeded the previously obtained conditions needed for ignition by the Lawson criterion. Key elements of the success came from reducing “coast time” (the time duration between the end of the laser pulse and implosion peak compression) and maximizing the internal energy delivered to the “hot spot” (the yield producing part of the fusion fuel). The link between coast time and maximally efficient conversion of kinetic energy into internal energy is explained. The energetics consequences of asymmetry and hydrodynamic-induced mixing were part of high-yield big radius implosion design experimental and design strategy. Herein, it is shown how asymmetry and mixing consolidate into one key relationship. It is shown that mixing distills into a kinetic energy cost similar to the impact of implosion asymmetry, shifting the threshold for ignition to higher implosion kinetic energy—a factor not normally included in most statements of the generalized Lawson criterion, but the key needed modifications clearly emerge.

Published by the American Physical Society
2024
Mitigating crosstalk errors by randomized compiling: Simulation of the BCS model on a superconducting quantum computer
Authors: Perrin Hugo , Scoquart Thibault , Shnirman Alexander , Schmalian Jörg , Snizhko Kyrylo
Published: February 2024

We develop and apply an extension of the randomized compiling (RC) protocol that includes a special treatment of neighboring qubits and dramatically reduces crosstalk effects caused by the application of faulty gates on superconducting qubits in IBMQ quantum computers ( and ). Crosstalk errors, stemming from controlled- () two-qubit gates, are a crucial source of errors on numerous quantum computing platforms. For the IBMQ machines, their effect on the performance of a given quantum computation is often overlooked. Our RC protocol turns coherent noise due to crosstalk into a depolarizing noise channel that can then be treated using established error mitigation schemes, such as noise estimation circuits. We apply our approach to the quantum simulation of the nonequilibrium dynamics of the Bardeen-Cooper-Schrieffer (BCS) Hamiltonian for superconductivity, a particularly challenging model to simulate on quantum hardware because of the long-range interaction of Cooper pairs. With 135 gates, we work in a regime where crosstalk, as opposed to either Trotterization or qubit decoherence, dominates the error. Our twirling of neighboring qubits is shown to dramatically improve the noise estimation protocol without the need to add new qubits or circuits and allows for a quantitative simulation of the BCS model.

Published by the American Physical Society
2024
Robustness and Eventual Slow Decay of Bound States of Interacting Microwave Photons in the Google Quantum AI Experiment
Authors: Surace Federica Maria , Motrunich Olexei
Published: February 2024

Integrable models are characterized by the existence of stable excitations that can propagate indefinitely without decaying. This includes multimagnon bound states in the celebrated XXZ spin-chain model and its integrable Floquet counterpart. A recent Google Quantum AI experiment [A. Morvan , Nature , 240 (2022)] realizing the Floquet model has demonstrated the persistence of such collective excitations even when the integrability is broken: this observation is at odds with the expectation of ergodic dynamics in generic nonintegrable systems. Here, we study the spectrum of the model realized in the experiment using exact diagonalization and physical arguments. We find that isolated bands corresponding to the descendants of the exact bound states of the integrable model are clearly observable in the spectrum for a large range of system sizes. However, our numerical analysis of the localization properties of the eigenstates suggests that the bound states become unstable in the thermodynamic limit. A perturbative estimate of the decay rate agrees with the prediction of an eventual instability for large system sizes.

Published by the American Physical Society
2024
Impact of IT governance mechanisms on IT-enabled dynamic capabilities to achieve firm performance: role of moderators
Authors: Ilmudeen Aboobucker , Qaffas Alaa A.
Published: February 2024

Purpose

Although information technology (IT) governance and IT capability have been extensively examined, the impact of IT governance mechanisms on IT-enabled dynamic capability (ITDC) with moderators has received less attention. This study investigates how the impact of IT governance mechanisms on firm performance is achieved through an ITDC through the moderating role of IT governance decentralization and a turbulent environment.

Design/methodology/approach

This study extends from the traditional view of IT capabilities and integrates dynamic capability theory to propose that IT governance is vital for the ITDC. Path analysis, hierarchical regression analysis and moderation analysis were performed using partial least squares (Smart PLS 3.0) as the data analysis methods. This study empirically tests the proposed mediated moderation model by using data collected from 254 firms in China to test the hypotheses.

Findings

Significant and impactful relationships are found in the model that includes turbulent environment moderating effects. Contrary to expectations, IT governance decentralization is also significant but not very strong.

Research limitations/implications

This study’s findings have implications for investigating IT governance, IT-enabled capabilities and moderators. Accordingly, this study has implications for board and executive management to capitalize on dynamic IT capability, to keep pace with the challenges and turbulent conditions associated with business needs and for the productivity paradox in the context of Chinese firms.

Originality/value

This country-specific research study theoretically contributes to the IT governance, dynamic capabilities and turbulent environment in the information systems literature and proposes many practical guides to the board and executive management of companies in the Chinese context.
Identifying and prioritizing factors influencing the social insurance contribution of unorganized workers
Authors: Dash Mohapatra Bighnesh , Sahoo Chandan Kumar , Chopra Avinash
Published: February 2024

Purpose

The purpose of this study is to explore and prioritize the factors that determine the social insurance contribution of unorganized workers.

Design/methodology/approach

A two-stage procedure was adopted to recognize and prioritize factors influencing the social insurance participation of unorganized workers: first, crucial factors influencing unorganized workers’ contribution towards social insurance were identified by employing exploratory factor analysis, and in the second phase, the fuzzy analytical hierarchal process was applied to rank the specified criteria and then sub-criteria by assigning weights.

Findings

Four broad factors were identified, namely, economic, political, operational and socio-psychological, that significantly influence unorganized workers’ contribution towards social insurance. Later findings revealed that the prime influencer of unorganized workers’ contribution is employment contracts followed by average earnings, delivery of quality services, eligibility and accessibility.

Practical implications

The research findings are feasible as the basic propositions are based on real-world scenario. The identification and ranking of factors have the potential to be used as a checklist for policymakers when designing pension and social insurance for unorganized workers. If it is not possible to consider all, the criteria and sub-criteria assigned upper rank can be given priority to extend pension coverage for a large group of working poor.

Social implications

The key factors driving social insurance contributions have been highlighted by studying the stakeholders’ perceptions at a micro level. By comprehending the challenges, there is a possibility of covering a large section of the working poor into social insurance coverage.

Originality/value

This paper is believed to be one of its kinds to acknowledge a combination of factors that determine the contribution of unorganized workers to social insurance. This study is an empirical investigation to prioritize the essential drivers of social insurance participation by low-income cohorts in the context of emerging countries. The present approach of employing fuzzy logic has also very limited use in social insurance literature yet.
A systematic review of the literature on lesson study in Germany: a professional development approach under the radar of research?
Authors: Bucher Julian , Kager Klara , Vock Miriam
Published: February 2024

Purpose

The purpose of this paper is to systematically review the history and current state of lesson study (LS) in Germany. In particular, this paper describes the development of LS over time and its stakeholders.

Design/methodology/approach

Conducting a systematic literature review, we searched three scientific databases and Google Scholar, examined 806 results and included 50 articles in our final sample, which we analyzed systematically.

Findings

The spread of LS in Germany can be divided into three phases, characterized by their own LS projects as well as their own ways of understanding LS. Although interest in LS has increased significantly in recent years, it is only present at a small number of schools and universities in Germany if compared internationally. Furthermore, this paper identifies the so-called learning activity curves as a tool frequently used for observation and reflection that appears to be unknown outside German-speaking countries.

Originality/value

This paper may act as an outline for countries without large-scale LS projects and with limited support from policymakers. The experience from Germany demonstrates the outcomes and challenges that can arise in such a situation and shows how unique LS features and proceedings have emerged.
Categorizing behavioral and formed concepts in sports marketing research
Authors: Müller Tobias , Schuberth Florian , Henseler Jörg
Published: February 2024

Purpose

Sports marketing and sponsorship research is located at the intersection of behavioral and design research, which means that it analyzes the current world and shapes a future world. This dual focus poses challenges for formulating and testing theories of sports marketing.

Design/methodology/approach

This article develops criteria for categorizing theoretical concepts as either behavioral or formed as different ways of expressing ideas of sports marketing research. It emphasizes the need for clear concept categorization for proper operationalization and applies these criteria to selected theoretical concepts of sports marketing and sponsorship research.

Findings

The study defines three criteria to categorize theoretical concepts, namely (1) the guiding idea of research, (2) the role of observed variables, and (3) the relationship among observed variables. Applying these criteria to concepts of sports marketing research manifests the relevance of categorizing theoretical concepts as either behavioral or formed to operationalize concepts correctly.

Originality/value

This study is the first in sports marketing to clearly categorize theoretical concepts as either behavioral or formed, and to formulate guidelines on how to differentiate behavioral concepts from formed concepts.
Beyond taste: examining sustainable value, perceived CSR and consumer behaviour in the restaurant industry
Authors: Mou Wanyu , Rasoolimanesh S. Mostafa , Chuah Stephanie Hui-Wen
Published: February 2024

Purpose

As perceived corporate social responsibility (CSR) has become one of the long-term sustainable development strategies for many companies, this paper investigates the interrelationships between sustainable values (SVs), perceived CSR and customer behaviour in the restaurant industry.

Design/methodology/approach

To gather data needed to meet the study aims, we conducted an online survey of restaurant patrons in China, and used partial least squares structural equation modelling (PLS-SEM) to analyse the proposed models and test the hypotheses.

Findings

The obtained findings confirm that the three studied SV dimensions (equality, respect for nature and shared responsibility) have positive effects on perceived CSR, which in turn significantly affects word of mouth (WOM). Moreover, perceived CSR mediates the relationship between the three SVs and WOM but has no impact on the relationship between SVs and revisit intention.

Practical implications

The results of this study have practical implications for managers in the restaurant industry. Restaurant managers can prioritize their CSR efforts based on the relative importance of SV dimensions, which is useful in generating positive WOM.

Originality/value

Even though the importance of CSR is widely recognised, it is insufficiently studied from the perspective of restaurant customers. This research not only addresses this gap, but also expands the current understanding of SVs and their impact on CSR.