bluuebunny/crossref_metadata_2025 huggingface dataset:
P.121 Ruptured intracranial infectious aneurysms: single Canadian center experience
Authors: Son M , Kiwan R , Mayich M , Boulton M , Pandey S , Sharma M
Published: June 2022

Background: Ruptured Intracranial Infected Aneurysms (IIAs) are relatively rare, but they portend high mortality. To our knowledge, there are no Canadian case-series on IIA, as well there is a relative paucity of international published experiences. Our purpose is to share the experience of a single Canadian tertiary centre in managing ruptured IIA and to conduct a systematic review. Methods: We did a retrospective case review series of adult patients with ruptured IIA treated at our institution. Secondly, we conducted a systematic review of literature on ruptured IIA between 2011-2021 inclusive. Results: At our institution, of a total 8 cases with ruptured IIA, 4 were treated endovascularly and 2 by surgical bypass. For the systematic review, we included 9 non-comparative studies with a total of 509 patients (318 males) and at least 437 ruptured IIA aneurysms. Favourable outcome was specified for 63.3% of patients (n=57). Regarding ruptured IIA, favourable clinical outcome was described in 59.3% (n=16). Conclusions: This study highlights a single Canadian tertiary centre experience in the management of IIA and compares it to the global trends of the last 10 years in a systematic review.
P.129 Radiofrequency rhizotomy for trigeminal neuralgia under general anaesthetic with intraoperative neuromonitoring
Authors: Persad A , Norton JA , Vitali AM
Published: June 2022

Background: Radiofrequency rhizotomy is an efficacious technique for treatment of trigeminal neuralgia that is classically performed with the patient awake. Previous studies have investigated methods for both anatomic and neurophysiologic optimization for nerve targeting. Methods: We performed a retrospective review of prospectively collected data on patients undergoing radiofrequency rhizotomy under a general anesthetic. Electrodes are placed in the temporalis, masseter and one of mylohyoid or anterior belly of digastric muscles. We then localize of the correct subdivision of the trigeminal nerve. The division of the trigeminal nerve with pain shows a muscle response, which is not present in normal subdivisions. Results: A total of 23 radiofrequency rhizotomies were performed under general anesthetic. Abnormal conduction reflexes were present in all cases, and dissipated after lesioning. Pre-operative BNI pain scores were 4.1 ± 0.3, which dropped to 1.8 ± 1.9 post-op (p=0.003). Number of pain medications (2.9 ± 0.6 v. 1.3 ± 1.3, p=0.007) and number of patients with opioid usage (78.7% v. 21.7%, p=0.007) both decreased after rhizotomy. Conclusions: Using a novel conduction pathway, we have successfully been able to monitor radiofrequency rhizotomy in patients operated on under a general anesthetic, with promising preliminary results. Further work is needed to better evaluate this intervention.
P.136 Intraoperative 5-ALA fluorescence-guided resection of high-grade glioma leads to greater extent of resection with better outcomes: a systematic review
Authors: Eatz T , Eichberg DG , Lu VM , Di L , Komotar RJ , Ivan ME
Published: June 2022

Background: 5-aminolevulinic acid (5-ALA) enhances intraoperative high grade glioma (HGG) tissue visualization. Despite promising randomized clinical trial data suggesting survival benefit for 5-ALA-guided HGG surgery, patient outcome efficacy is not universally accepted. Methods: We performed a systematic review of the literature to evaluate whether there is a beneficial effect upon survival and extent of resection from the utilization of 5-ALA in HGG surgery. Literature regarding 5-ALA usage in HGG surgery was reviewed according to PRISMA guidelines. Results: 3,756 published studies were screened, 536 evaluated, and 45 included. Of studies that directly compared the use of 5-ALA to white light (28.9%), 5-ALA lead to a better progression-free survival (PFS) and overall survival (OS) in 88.4 and 67.5% of patients, respectively. 42.2% demonstrated that 5-ALA use was associated with less post-op neurological deficits, whereas 23.3% of studies showed that surgeries using 5-ALA lead to more deficits. 34.5% demonstrated no difference between 5-ALA and without. Conclusions: 5-ALA was found to be associated with a greater extent of resection and longer OS and PFS in HGG surgeries. Postop neurologic deficit rates were inconclusive when comparing 5-ALA groups to white light groups. 5-ALA is a useful surgical adjunct for HGG resection with preserved patient safety.
P.146 Exploring the Canadian management of aSAH and delayed cerebral ischemia
Authors: Eagles ME , MacLean MA , Kameda-Smith M , Duda T , Almojuela A , Bokhari R , Elkaim LM , Iorio-Morin C , Persad AR , Rizzuto M , Lownie SP , Christie SD , Teitelbaum JS
Published: June 2022

Background: Delayed Cerebral Ischemia (DCI) is a complication of aneurysmal subarachnoid hemorrhage (aSAH) and is associated with significant morbidity and mortality. A paucity of high-quality evidence is available to guide the management of DCI. As such, our objective was to evaluate practice patterns of Canadian physicians regarding the management of aSAH and DCI. Methods: The Canadian Neurosurgery Research Collaborative (CNRC) performed a cross-sectional survey of Canadian neurosurgeons, intensivists, and neurologists who manage aSAH. The survey was distributed to members of the Canadian Neurosurgical and Neurocritical Care Societies, respectively. Responses were analyzed using quantitative and qualitative methods. Results: The response rate was 129/340 (38%). Agreement among respondents included the need for intensive care unit admission, use of clinical and radiographic monitoring, and prophylaxis for prevention of DCI. Indications for starting hyperdynamic therapy varied. There was discrepancy in the proportion of patients felt to require intravenous milrinone, intra-arterial vasodilators, or physical angioplasty for treatment of DCI. Most respondents reported their facility does not utilize a standardized definition for DCI. Conclusions: DCI is an important clinical entity for which no consensus exists in management among Canadian practitioners. The CNRC calls for the development of national standards in the diagnosis and management of DCI.
P.150 The Canadian Medical Student Interest Group in Neurosurgery (CaMSIGN) platform: a retrospective study on Canadian medical students
Authors: Arfaie S , Mashayekhi MS , Farimani PL , Hakak-Zargar B , Kawalec P , Saini J , Swan ER , Sonfack DJ , Ahmed A
Published: June 2022

Background: The Canadian Medical Student Interest Group in Neurosurgery (CaMSIGN) is the first neurosurgery platform of its kind in Canada. Methods: In this retrospective study, data from CaMSIGN’s online platforms have been collated from February 2021 to the present and analyzed to show trends in user engagement. Results: CaMSIGN events generated 1,575 views on YouTube (384 from Canada). The total watch time was 170.3 hours, of which 43.9 hours were Canadian (28.5%). The total views normalized by the total number of students interested in neurosurgery was 17.12 hours. The normalized Canadian view was 4.17. 717 people follow the CaMSIGN Facebook account (normalized= 7.79). 152 people follow our Instagram (normalized= 1.65). 338 people follow our Twitter (normalized= 3.67). This number is comparable to that of estimated practicing neurosurgeons in Canada (333). A total of 32,974 people visited the Twitter page, with a monthly average of 2747.8. Lastly, the campaign website has had 5,811 visitors since its launch in June 2021 with a monthly average of 695.57 visitors. The number of website visitors has increased at a rate of 3.1327 visitors/month. Conclusions: Through this initiative, our aim has been to model a pan-Canadian approach to neurosurgery.
P.163 Endoscopic third ventriculostomy for VP shunt malfunction during the third trimester of pregnancy: illustrative case
Authors: Alhaj A , Al-Saadi T , Dudley R
Published: June 2022

Background: Endoscopic third ventriculostomy (ETV) is a successful procedure for treating noncommunicating hydrocephalus as an alternative to initial ventriculoperitoneal (VP) shunt placement and as a salvage procedure when a VP shunt fails. Physiological changes of pregnancy can lead to VP shunt failure and complicate the management of shunt malfunction, particularly in the third trimester. Methods: Case report: ETV was successfully used in the third trimester (31 weeks of gestation) of pregnancy for acute hydrocephalus due to VP shunt malfunction, and the patient went on to deliver a healthy baby at term; the patient remained well in the long-term follow-up. An English-language PubMed literature review revealed four cases of VP shunt failure successfully treated with an ETV in the first or second trimester but no such reports in the third trimester of pregnancy. Results: This case report adds to the sparse literature regarding the use of an ETV to treat VP shunt malfunction in the third trimester of pregnancy. This appears to be a unique first-time report of the use of an ETV during this specific challenging prenatal period. Conclusions: ETV appears to be a safe and effective alternative to VP shunt replacement in the late prenatal period of pregnancy in well-selected candidates.
P.166 Subcutaneous intrathecal catheter and port implants for administration of Nusinersen in patients with Spinal Muscular Atrophy
Authors: Bokeris A , Mcneely D , Sheriko J
Published: June 2022

Background: Until recently, no effective treatment was available for spinal muscular atrophy (SMA). In 2017, Health Canada approved intrathecal Nusinersen a medication that prevents degeneration of the motor neurons in the spinal cord. The administration is intrathecally most commonly via lumbar puncture (LP) to have a direct effect on the motor neurons of the spinal cord.

Many older patients with SMA and concomitant spinal deformities present technical challenges to access the thecal sac. Different routes have been described for delivery of the medication. These techniques may require sedation, are associated with radiation exposure, and demand experience personnel. Methods: A new surgical technique has been proposed to overcome these obstacles by combining two Health Canada approved devices: 1) an intrathecal catheter designed for intrathecal baclofen pumps and 2) an implantable subcutaneous port designed for intravascular medication administration Results: We describe the technical nuances and outline the clinical outcomes of six patients with complex spine deformities who have undergone such an implant for administration of Nusinersen. Conclusions: We discuss the benefits of the procedure which includes: 1) administration in the outpatient setting without sedation, 2) avoidance of costly imaging and experienced personnel, and 3) placement of the catheter in the cervicothoracic junction.
P.174 The nerve root sedimentation sign on MRI is not only correlated with neurogenic claudication: association with leg dominant mechanical pain
Authors: Newton B , Huschi Z , Persad A , Neuburger L , Ahmed U , Cheng Y , Fourney D
Published: June 2022

Background: A correlation between the nerve root sedimentation sign (SedSign) and neurogenic claudication has been demonstrated; though it did not account for leg-dominant pain. This study analyzed the utility of SedSign to diagnose leg-dominant pain using validated classification systems. Methods: We retrospectively reviewed prospective data from 367 patients with back or leg pain collected between January 1, 2012 to May 31, 2018. Baseline characteristics included SSPc (Saskatchewan Spine Pathway classification), Oswestry disability index (ODI), visual analogue pain scores (VAS), and EuroQol Group 5-Dimension Self-Report (EQ5D). Inter- and intra-rater reliability for SedSign was 73% and 91%. Results: SedSign was positive in 111 (30.2%) and negative in 256 (69.8%) patients. Univariate analysis showed a correlation between SedSign and age, male sex, ODI, EQ5D, cross-sectional area (CSA) of stenosis, antero-posterior diameter of stenosis, and leg-dominant pain; negative SedSign was correlated with back-dominant pain. Multivariate analysis revealed an association between SedSign and age, male sex, CSA stenosis, and ODI walking distance. The sensitivity, specificity, positive and negative predictive values of SedSign for leg-dominant pain were 33.5%, 83.2%, 77.0%, and 57.3%. Conclusions: SedSign has high specificity but low sensitivity for leg-dominant pain. Despite a similar correlation between SedSign and neurogenic claudication or sciatica, significance was lost on multivariate analysis.
P.175 An exploration of the evolving perception of quality of life from the perspective of individuals living with a cervical spinal cord injury in Nova Scotia
Authors: Leck E , Marshall E , Christie S
Published: June 2022

Background: Spinal cord injuries invoke enormous life changes for the individual, with impacts not just on physical functioning, but social and psychological well-being. Individuals learn to deal with these changes, and handle these new stressors in different ways. Extant literature suggest the majority of people eventually attain a quality of life (QoL) simular to able-bodied individuals. We sought to validate these observations in a contemporary cohort and specifically explore how patients’ perceptions evolve over time. Methods: We conducted hour-long semi-structured interviews with 15 individuals living with cervical spinal cord injuries. Interviews took place over the telephone or virtually via MS Teams. Interview transcripts were then analyzed using an iterative coding process and thematic analysis (NVivo). Results: The over-arching journey that most participants described was a continuous evolution in QoL, as they learned to adapt and function with their injury. However, these trajectories were disparate and heavily reliant on personal supports and resources available, their psychosocial enviornment and inherent coping strategies. Conclusions: This study emphasizes the unique nature of each person’s journey, and not all people attain a satisfactory QoL. Our approach needs to be individualized, adjusting to specific circumstances, in order to provide more inclusive and supportive care.
GP.3 Measurement of decremental response is repeatable in amyotrophic lateral sclerosis
Authors: Jewett G , Khayambashi S , Martinez J , Petrillo J , Korngut L
Published: June 2022

Background: Neuromuscular junction transmission impairment has been described in amyotrophic lateral sclerosis (ALS). The degree of repetitive nerve stimulation (RNS) decrement may correlate with disease activity if measurement is repeatable. We determined test-retest correlation of decremental response in patients with ALS. Methods: RNS (3 Hz) was assessed by blinded technician and clinician on median - abductor pollicis brevis (median-APB), ulnar - adductor digiti minimi (ulnar-ADM), and/or accessory - trapezius (accessory-TRAP) nerve-muscle pairs during two evaluations. Repeatability was assessed by measuring the strength of test-retest correlation using the Pearson correlation coefficient (r). Results: 24 patients were included. Decrement was measured for 16 patients on median-APB, 22 on ulnar-ADM, and 24 on accessory-TRAP. Repeated measures of decrement demonstrated strong test-retest correlation for median-APB (r = 0.82, p < 0.001) and accessory-TRAP (r = 0.87, p < 0.001). Correlation was poor in ulnar-ADM (r = −0.01, p = 0.949). Correlation was superior in median-APB muscles with higher Medical Research Council (MRC) grade strength (MRC ≥ 4, r = 0.89, p = 0.001 vs MRC < 4, r = 0.73, p = 0.062). Conclusions: Decremental response in patients with ALS has strong test-retest correlation in median-APB and accessory-TRAP, but not in ulnar-ADM.
B.4 Spatiotemporal mapping and decoding of oculomotion in the pediatric frontal eye field
Authors: Chang S , Singhal A , Tamber M
Published: June 2022

Background: The frontal eye fields (FEFs) are linked to oculomotor control and hypothesized to reside in the prefrontal cortex, where electrical stimulation reportedly evokes contraversive eye movements. The exact location and function of the FEFs in humans is controversial. Stereo-electroencephalography (SEEG) is a minimally invasive technique used to guide epilepsy surgery. It provides a unique opportunity to collect human neurophysiological data outside of the operating room and has been used by other groups to advance our understanding of specific brain functions. Methods: Two pediatric subjects undergoing non-lesional epilepsy workup were enrolled into this prospective, IRB-approved study, and received brain MRI prior to SEEG implantation. SEEG recordings were collected with video of the subjects’ eyes while performing gaze-related tasks. Results: Stimulation testing elicited contraversive head turning with or without eye deviation, and hemifacial spasm, depending on the site of stimulation. Low-threshold sites eliciting these stereotyped movements were located just deep to the inferior precentral gyrus. Stimulation of sites in the posterior middle frontal gyrus did not elicit eye movements. Conclusions: Our findings suggest that the FEFs are located more posteriorly than widely held, involving the motor cortex. Further testing in pediatric and adult subjects is warranted to confirm this hypothesis.
Competing Endogenous RNAs (ceRNAs) in Colorectal Cancer: A Review
Authors: Akhbari Mohammad Hossein , Zafari Zahra , Sheykhhasan Mohsen
Published: June 2022

Colorectal cancer (CRC) is a common type of cancer and the second leading cause of cancer-related deaths worldwide. Competing endogenous RNAs (ceRNAs) that contain microRNA response elements (MREs) are involved in CRC progression. They can compete with microRNAs (miRNAs) via their MREs, which can combine non-coding and coding RNAs via complex ceRNA networks. This molecular interaction has the potential to affect a wide variety of biological processes, and many cancers can occur as a result of an imbalanced ceRNA network. Recent research indicates that numerous dysregulated RNAs in CRC may function as ceRNAs, regulating multiple biological functions of the tumour, including proliferation, apoptosis, metastasis, invasion and migration. In this review, we discuss the role of protein-coding and non-coding RNAs, such as long non-coding RNAs, circular RNAs and pseudogenes, in the occurrence of ceRNA networks in CRC, and their function in cancer-related pathways, such as Wnt/β-catenin, mitogen-activated protein kinase and transforming growth factor-β signalling pathways. Additionally, we discuss validated ceRNAs associated with CRC biological functions and their potential role as novel prognostic and diagnostic biomarkers. Examining the role of ceRNAs in CRC sheds new light on cancer treatment and pathogenesis.
Output characteristics of high-power stimulated Brillouin scattering pulse compression enhanced by thermal effects based on HT270
Authors: Wang Hongli , Cha Seongwoo , Kong Hong Jin , Wang Yulei , Lv Zhiwei
Published: June 2022

Thermal effects are typically considered as obstacles to high-repetition-rate stimulated Brillouin scattering (SBS) pulse compression. In this paper, a novel method is proposed for improving the SBS output characteristics by exploiting thermal effects on the liquid medium. Using HT270, the SBS output parameters with the medium purification and rotating off-centered lens methods are studied at different repetition rates. The results indicate that these two methods can alleviate thermal effects and improve the energy efficiency, but the rotating method reduces the energy stability because of the aggravated optical breakdown at the kilohertz-level repetition rate. For a 35-mJ pump energy, the energy efficiency at 2 kHz without the rotating method is 30% higher than that at 100 Hz and 70% higher than that at 500 Hz. The enhancement of the SBS output characteristics by thermal effects is demonstrated theoretically and experimentally, and 2-kHz high-power SBS pulse compression is achieved with HT270.
Income inequality in authoritarian regimes: the role of political institutions and state capacity
Authors: Panaro Angelo Vito , Vaccaro Andrea
Published: June 2022

In recent decades, there has been an institutional shift in the literature on authoritarian regimes, with scholars investigating the role of political institutions, such as elections and political parties, in shaping regime stability and economic performance. However, scant attention has been devoted to the effect of political institutions on policy outcomes, and more specifically, on income inequality. This paper adds to this debate and sheds light on the role of formal and informal institutions, on the one hand, and state capacity, on the other, in influencing levels of income inequality in autocracies. We argue that, while the presence of elections and multiparty competition creates more favourable conditions for the adoption of redistributive policies, state capacity increases the likelihood of successfully implemented policy decisions aimed at reducing the level of inequality. Our empirical analysis rests on a time-series cross-sectional dataset, which includes around 100 countries from 1972 to 2014. The findings indicate that both political institutions and a higher level of state capacity lead to lower levels of income inequality in authoritarian contexts.
Gravity effects in two-dimensional and axisymmetric water impact models
Authors: Hulin F. , Del Buono A. , Tassin A. , Bernardini G. , Iafrati A.
Published: June 2022

The effect of gravity during the water entry of two-dimensional and axisymmetric bodies is investigated analytically and numerically. An extension to the Wagner model of water impact is proposed in order to take into account the effect of gravity. For this purpose, the free-surface condition is modified. The pressure is computed using the modified Logvinovich model of Korobkin (Eur. J. Appl. Maths, vol. 6, 2004, pp. 821–838). The model has been implemented and validated through comparisons with fully nonlinear potential flow simulations of different two-dimensional and axisymmetric water entry problems. Our investigation shows that it is equally important to account for gravity when computing the pressure distribution and to account for gravity when computing the size of the wetted surface in order to obtain accurate force results with the Wagner model. Simulations of wedges and cones with different values of deadrise angle (

$\beta$

) entering water at constant speed (

$V$

) demonstrate the accuracy of the semi-analytical model and show that the effect of gravity in such water impacts is governed by the effective Froude number defined as

$Fr^*=V/(\sqrt {gh}\sqrt {\tan \beta })$

, with

$g$

the acceleration due to gravity and

$h$

the penetration depth. The accuracy of the semi-analytical model for decelerated water entries is also demonstrated by investigating the water entry of a wedge and a cone with a

$15^\circ$

deadrise angle with deceleration until full stop. The semi-analytical model is able to accurately predict the effect of gravity during both two-dimensional and axisymmetric water entry problems with deceleration.
Attenuation of the unsteady loading on a high-rise building using feedback control
Authors: Hu Xiao , Morgans Aimee S.
Published: June 2022

The unsteady wind loading on high-rise buildings has the potential to influence strongly their structural performance in terms of serviceability, habitability and occupant comfort. This paper investigates numerically the flow structures around a canonical high-rise building immersed in an atmospheric boundary layer, using wall-resolved large eddy simulations. The switching between two vortex shedding modes is explored, and the influence of the atmospheric boundary layer on suppressing symmetric vortex shedding is identified. It is shown that the antisymmetric vortex shedding mode is prevalent in the near wake behind the building, with strong coherence between the periodic fluctuations of the building side force and the antisymmetric vortex shedding mode demonstrated. Two feedback control strategies, exploiting this idea, are designed to alleviate the aerodynamic side-force fluctuations, using pressure sensing on just a single building wall. The sensor response to synthetic jet actuation along the two ‘leading edges’ of the building is characterised using system identification. Both the designed linear controller and the least mean square adaptive controller attenuate successfully the side-force fluctuations when implemented in simulations. The linear controller exhibits a better performance, and its effect on the flow field is to delay the formation of dominant vortices and increase the extent of the recirculation region. Feedback control that requires a smaller sensing area is then explored, with a comparable control effect achieved in the attenuation of the unsteady loading. This study could motivate future attempts to understand and control the unsteady loading of a high-rise building exposed to oncoming wind variations.
Spontaneous and explicit symmetry breaking of thermoacoustic eigenmodes in imperfect annular geometries
Authors: Indlekofer Thomas , Faure-Beaulieu Abel , Dawson James R. , Noiray Nicolas
Published: June 2022

This article deals with the symmetry breaking of azimuthal thermoacoustic modes in annular combustors. Using a nominally symmetric annular combustor, we present experimental evidence of a predicted spontaneous reflectional symmetry breaking, and also an unexpected explicit rotational symmetry breaking in the neighbourhood of the Hopf bifurcation which separates linearly stable azimuthal thermoacoustic modes from self-oscillating modes. We derive and solve a multidimensional Fokker–Planck equation to unravel a unified picture of the phase space topology. We demonstrate that symmetric probability density functions of the thermoacoustic state vector are elusive, because the effect of asymmetries, even imperceptible ones, is magnified close to the bifurcation. This conclusion implies that the thermoacoustic oscillations of azimuthal modes in real combustors will systematically exhibit a statistically dominant orientation of the mode in the vicinity of the Hopf bifurcation.
Emergent rheotaxis of shape-changing swimmers in Poiseuille flow
Authors: Walker B.J. , Ishimoto K. , Moreau C. , Gaffney E.A. , Dalwadi M.P.
Published: June 2022

A simple model for the motion of shape-changing swimmers in Poiseuille flow was recently proposed and numerically explored by Omori et al. (J. Fluid Mech., vol. 930, 2022, A30). These explorations hinted that a small number of interacting mechanics can drive long-time behaviours in this model, cast in the context of the well-studied alga Chlamydomonas and its rheotactic behaviours in such flows. Here, we explore this model analytically via a multiple-scale asymptotic analysis, seeking to formally identify the causal factors that shape the behaviour of these swimmers in Poiseuille flow. By capturing the evolution of a Hamiltonian-like quantity, we reveal the origins of the long-term drift in a single swimmer-dependent constant, whose sign determines the eventual behaviour of the swimmer. This constant captures the nonlinear interaction between the oscillatory speed and effective hydrodynamic shape of deforming swimmers, driving drift either towards or away from rheotaxis.
Never Again
Authors: Wayne Carly , Zhukov Yuri M.
Published: June 2022

Do individuals previously targeted by genocide become more supportive of other victimized groups? How are these political lessons internalized and passed down across generations? To answer these questions, the authors leverage original survey data collected among Holocaust survivors in the United States and their descendants, Jews with no immediate family connection to the Holocaust, and non-Jewish Americans. They find that historical victimization is associated with increased support for vulnerable out-groups, generating stable political attitudes that endure across generations. Holocaust survivors are most supportive of aiding refugees, followed by descendants, especially those who grew up discussing the Holocaust with their survivor relatives. An embedded experiment demonstrates the steadfastness of these attitudes: unlike non-Jews or Jews without survivor relatives, survivors’ and descendants’ views toward refugees do not change after reading an in-group versus out-group–protective interpretation of the “never again” imperative. Histories of victimization can play an ameliorative role in intergroup relations.
Immunological differences between heart- and kidney-transplanted children: a cross-sectional study
Authors: Ekman-Joelsson Britt-Marie , Brandström Per , Allén Maria , Andersson Bengt , Wåhlander Håkan , Mellgren Karin , Ekwall Olov
Published: June 2022

Post-transplantation lymphoproliferative disorder is a potentially mortal complication after heart transplantation in children. As the immune system plays a crucial role in the development of lymphoma, we explored the influence of thymus function in relation to immunosuppressive treatment in organ-transplanted children and healthy control subjects. A prospective case–control study was performed at a single centre, in which 36 children who had undergone heart transplantation were compared to two control groups: 34 kidney-transplanted children and 33 healthy age- and sex-matched children. T- and B-lymphocyte subtypes and monocytes were analysed by flow cytometry, and T-cell receptor excision circles were assessed using quantitative polymerase chain reaction. Heart-transplanted children had a lymphocyte profile characterised by reduced or absent thymic function with low numbers of T-cell receptor excision circles and total and naïve T cells, together with immune activation against the allograft. Despite similar immunosuppressive treatment, the kidney-transplanted group showed an activated T-lymphocyte compartment.
A Three-Dimensional Reconstruction Algorithm for Scanning Transmission Electron Microscopy Data from a Single Sample Orientation
Authors: Brown Hamish G , Pelz Philipp M , Hsu Shang-Lin , Zhang Zimeng , Ramesh Ramamoorthy , Inzani Katherine , Sheridan Evan , Griffin Sinéad M , Schloz Marcel , Pekin Thomas C , Koch Christoph T , Findlay Scott D , Allen Leslie J , Scott Mary C , Ophus Colin , Ciston Jim
Published: June 2022

Increasing interest in three-dimensional nanostructures adds impetus to electron microscopy techniques capable of imaging at or below the nanoscale in three dimensions. We present a reconstruction algorithm that takes as input a focal series of four-dimensional scanning transmission electron microscopy (4D-STEM) data. We apply the approach to a lead iridate, PbIrO, and yttrium-stabilized zirconia, YZrO, heterostructure from data acquired with the specimen in a single plan-view orientation, with the epitaxial layers stacked along the beam direction. We demonstrate that Pb–Ir atomic columns are visible in the uppermost layers of the reconstructed volume. We compare this approach to the alternative techniques of depth sectioning using differential phase contrast scanning transmission electron microscopy (DPC-STEM) and multislice ptychographic reconstruction.
Hype, skin in the game, and the stability of cooperative science
Authors: Lenardic Adrian , Seales Johnny , Covington Anthony
Published: June 2022

We address a recently posed question: ‘Why Do So Many Astronomy (and Astrobiology) Discoveries Fail to Live Up to the Hype?’ We expand it to cover hype within science in general. Our answer relies on working definitions of hype and skin in the game, as applied to research science, and a game theory model for the stability of cooperative science. Low skin in the game allows internal feedbacks, within the research science community, to initiate increased hype and a drift toward structural instability. The instability leads to the deterioration of cooperative equilibria, which further enhances hype. Along the drift, the number of results hyped as breakthroughs will increase and more claims will fail to live up to the hype. This can lead to the public perception that science is moving backwards and a shift in the perception of what scientists, and science, values. Although a hype instability can be initiated by external nudges, a bigger role is played by the internal dynamics of the system, i.e. the collective of working scientists. Corrections for a drift toward instability should, likewise, focus on internal structure. Proposed external shifts on how research is disseminated will add restrictions to a system that can do more harm than good.
Preeclampsia-induced alterations in brain and liver gene expression and DNA methylation patterns in fetal mice
Authors: Hofsink Naomi , Dijkstra Dorieke J. , Stojanovska Violeta , Scherjon Sicco A. , Plösch Torsten
Published: June 2022

Exposure to pregnancy complications, including preeclampsia (PE), has lifelong influences on offspring’s health. We have previously reported that experimental PE, induced in mice by administration of adenoviral sFlt1 at gestational day 8.5 combined with LPS at day 10.5, results in symmetrical growth restriction in female and asymmetrical growth restriction in male offspring. Here, we characterize the molecular phenotype of the fetal brain and liver with respect to gene transcription and DNA methylation at the end of gestation.

In fetal brain and liver, expression and DNA methylation of several key regulatory genes is altered by PE exposure, mostly independent of fetal sex. These alterations point toward a decreased gluconeogenesis in the liver and stimulated neurogenesis in the brain, potentially affecting long-term brain and liver function. The observed sex-specific growth restriction pattern is not reflected in the molecular data, showing that PE, rather than tissue growth, drives the molecular phenotype of PE-exposed offspring.
Distinctive germination attributes of feather fingergrass (Chloris virgata) biotypes in response to different thermal conditions
Authors: Desai Het Samir , Chauhan Bhagirath Singh
Published: June 2022

An in-depth understanding of the germination response of troublesome weed species, such as feather fingergrass (Chloris virgata Sw.), to environmental factors (temperature, soil moisture, etc.) could play an essential role in the development of sustainable site-specific weed control programs. A laboratory experiment was conducted to understand the germination response of 10 different biotypes of C. virgata to five temperature regimes (ranging from 15/5 to 35/25 C) under a 12/12-h (light/dark) photoperiod. No consistent germination behavior was observed between biotypes, as some biotypes demonstrated high final cumulative germination (FCG) at low alternating temperature regimes (15/5 and 20/10 C) and some biotypes exhibited high FCG at a high alternating temperature regime (30/20 C). All biotypes revealed late germination initiation (T10, time taken to reach 10% germination) at the lowest temperature range (15/5 C), ranging from 171 to 173 h. However, less time was required to reach 90% germination (T90), ranging from 202 to 756 h. At higher alternating temperature regimes (30/20 and 35/25 C), all biotypes initiated germination (T10) within 40 h, and a wide range of hours was required to reach 90% germination (T90), ranging from 284 to 1,445 h. Differences in FCG of all the biotypes at all the temperature ranges showcased the differential germination nature among biotypes of C. virgata. The cool temperatures delayed germination initiation compared with warmer temperatures, even though FCGs were similar across a wide range of thermal conditions, indicating that this species will be problematic throughout the calendar year in different agronomic environments. The data from this study have direct implications on scheduling herbicide protocols, tillage timing, and planting time. Therefore, data generated from this study can aid in the development of area- and species-specific weed control protocols to achieve satisfactory control of this weed species.
Stationäre Schematherapie bei Schulvermeidung – ein Fallbeispiel
Authors: Neumann Ursula , Knollmann Martin , Hebebrand Johannes
Published: June 2022

Zusammenfassung. Nach einer kurzen Erläuterung der Grundbegriffe der Schematherapie wird an einem Fallbeispiel eine stationäre Therapie bei chronifizierter Schulvermeidung veranschaulicht. Die Schwerpunkte liegen hierbei auf der multiprofessionellen Umsetzung schematherapeutischer Konzepte sowie der Kombination und Adaption schematherapeutischer Techniken mit klassischen kognitiv-verhaltenstherapeutischen Interventionen. Abschließend werden die Befunde der Veränderungsmessungen und die Möglichkeiten und Grenzen einer multiprofessionellen schematherapeutischen Behandlung von Schulvermeidung im stationären Setting diskutiert. Es wird aufgezeigt, dass die Schematherapie eine besonders gut geeignete Therapieform für Jugendliche mit Schulvermeidung sein kann.
Effect of Nitrate on the Photochemical Production of Carbonyl Sulfide From Surface Seawater
Authors: Li Jian‐Long , Zhai Xing , Du Lin
Published: June 2022

Carbonyl sulfide (COS) plays an important role in the sulfur cycle and climate change. Yet, much remains unknown about the photochemical mechanisms of COS in nutrient‐rich seawater. We measured the photochemical production rates of COS in the surface seawater of the Indian Ocean under sunlight irradiation. The photochemical production of COS was mainly initiated by ultraviolet (UV) radiation with UVA contributing approximately 68% to the total COS production. Using cysteine, a typical proxy of dissolved organic sulfur, the effect of enhanced nitrate concentration on COS formation was conducted in authentic seawater during simulated sunlight irradiation, indicating the enhancement of the COS formation with increasing nitrate concentrations. This result revealed that the generation of hydroxyl radical with nitrate photolysis plays a key role in the COS formation process. These findings improve our understanding of the marine COS photoproduction cycle and the impact of nitrate on the COS photochemical production in surface seawater.
Influence of Kelp Forest Biomass on Nearshore Currents
Authors: Monismith Stephen G. , Alnajjar Maha W. , Woodson C. Brock , Boch Charles A. , Hernandez Arturo , Vazquez‐Vera Leonardo , Bell Tom W. , Micheli Fiorenza
Published: June 2022

As part of a project focused on the coastal fisheries of Isla Natividad, an island on the Pacific coast of Baja California, Mexico, we conducted a 2‐1/2 year study of flows at two sites within the island's kelp forests. At one site (Punta Prieta), currents are tidal, whereas at the other site (Morro Prieto), currents are weaker and may be more strongly influenced by wind forcing. Satellite estimates of the biomass of the giant kelp (Macrocystis pyrifera) for this period varied between 0 (no kelp) and 3 kg/m2 (dense kelp forest), including a period in which kelp entirely was absent as a result of the 2014–2015 “Warm Blob” in the Eastern Pacific. During this natural “deforestation experiment”, alongshore velocities at both sites when kelp was present were substantially weaker than when kelp was absent, with low‐frequency alongshore currents attenuated more than higher frequency ones, behavior that was the same at both sites despite differences in forcing. The attenuation of cross‐shore flows by kelp was less than alongshore flows; thus, residence times for water inside the kelp forest, which are primarily determined by cross‐shore velocities, were only weakly affected by the presence or absence of kelp. The flow changes we observed in response to changes in kelp density are important to the biogeochemical functioning of the kelp forest in that slower flows imply longer residence times, and, are also ecologically relevant in that reduced tidal excursions may lead to more localized recruitment of planktonic larvae.
The Direct Effect of Medium Energy Electron Precipitation on Mesospheric Dynamics During a Sudden Stratospheric Warming Event in 2010
Authors: Zúñiga López Héctor Daniel , Tyssøy Hilde Nesse , Smith‐Johnsen Christine , Maliniemi Ville
Published: June 2022

Medium energy electron (MEE) (30–1,000 keV) precipitation enhances the production of nitric (NOx) and hydrogen oxides (HOx) throughout the mesosphere, which can destroy ozone (O3) in catalytic reactions. The dynamical effect of the direct mesospheric O3 reduction has long been an outstanding question, partly due to the concurrent feedback from the stratospheric O3 reduction. To overcome this challenge, the Whole Atmosphere Community Climate Model version 6 is applied in the specified dynamics mode for the year 2010, with and without MEE ionization rates. The results demonstrate that MEE ionization rates can modulate temperature, zonal wind and the residual circulation affecting NOx transport. The required fluxes of MEE to impose dynamical changes depend on the dynamical preconditions. During the Northern Hemispheric winter, even weak ionization rates can modulate the mesospheric signal of a sudden stratospheric warming event. The result provides a first step in a paradigm shift for the understanding of the MEE direct effect.
A Probabilistic View on Rupture Predictability: All Earthquakes Evolve Similarly
Authors: Münchmeyer Jannes , Leser Ulf , Tilmann Frederik
Published: June 2022

Ruptures of the largest earthquakes can last between a few seconds and several minutes. An early assessment of the final earthquake size is essential for early warning systems. However, it is still unclear when in the rupture history this final size can be predicted. Here we introduce a probabilistic view of rupture evolution ‐ how likely is the event to become large ‐ allowing for a clear and well‐founded answer with implications for earthquake physics and early warning. We apply our approach to real time magnitude estimation based on either moment rate functions or broadband teleseismic P arrivals. In both cases, we find strong and principled evidence against early rupture predictability because differentiation between differently sized ruptures only occurs once half of the rupture has been observed. Even then, it is impossible to foresee future asperities. Our results hint toward a universal initiation behavior for small and large ruptures.
Surface Ozone‐Temperature Relationship: The Meridional Gradient Ratio Approximation
Authors: Zhang Xiyue , Waugh Darryn W. , Kerr Gaige Hunter , Miller Scot M.
Published: June 2022

The daily variation of ground‐level ozone (O3), a harmful pollutant, is positively correlated with air temperature (T) in many midlatitude land regions in the summer. The observed temporal regression slope between O3 and T (dO3/dT) is referred to as the “ozone‐climate change penalty” and has been proposed as a way to predict the impact of future climate warming on O3 from observations. Here, we use two chemical transport models to show that the spatial variation of dO3/dT is primarily determined by simultaneous meridional advection of O3 and T. Furthermore, the sign and magnitude of dO3/dT can be approximated by their climatological meridional gradient ratio (O3 gradient divided by T gradient). Consideration of expected changes in the meridional gradients of T and O3 due to climate change indicates that dO3/dT will likely change. Caution is needed when using the observed climate penalty to predict O3 changes.
Rapid Growth of Outer Size of Tropical Cyclones: A New Perspective on Their Destructive Potential
Authors: Li Yi , Tang Youmin , Wang Shuai
Published: June 2022

The destructive potential of a tropical cyclone (TC) is primarily determined by its intensity and outer size. Although TC intensification has been researched extensively, the growth rate of its outer size remains obscure. This prompts us to develop the concept of rapid growth of outer size (RG) of TCs. RG is defined as an increase of at least 75 km in the gale‐force wind radius within 24 hr using an objective anomaly detection algorithm. RG is intrinsically linked to the life cycle of the outer size and comprises most of the peak for large TCs (>300 km) in the distribution of lifetime maximum size. Compared with rapid intensification, RG is a more dangerous change in the TC structure, leveling up the destructive potential more rapidly. This is the first attempt to reveal the importance of RG to the outer size climatology, life cycle, and destructive potential of TCs.
Recent Increase in the Occurrence of Snow Droughts Followed by Extreme Heatwaves in a Warmer World
Authors: Li Xiangfei , Wang Shuo
Published: June 2022

The compound of late winter snow droughts and early spring heatwaves (compound snow drought and heatwave (CSDHW)) could dramatically affect ecosystems and water availability, but has not been systematically investigated. Here we present a comprehensive assessment of CSDHW events and possible driving mechanisms. We find that 7% of the snow‐covered area experiences significant (p < 0.05) CSDHW events, and an average of 35% of snow droughts are followed by heatwaves during 1981–2020. The spatial extent of CSDHW is asymmetrically enlarging, with a significant increase in Eurasia and a relatively high fluctuation in North America. Specifically, the warm‐type CSDHW (i.e., snow drought with normal or above‐average precipitation followed by heatwave) occurs more frequently, with spatial coverage increasing faster than the dry‐type CSDHW (i.e., snow drought with below‐average precipitation followed by heatwave). In comparison, dry snow drought is more likely to be followed by heatwave due to intensified soil drought and atmospheric aridity.
Associations between the home environment and childhood weight change: a cross-lagged panel analysis
Authors: Kininmonth Alice R. , Schrempft Stephanie , Smith Andrea , Dye Louise , Lawton Clare , Fisher Abigail , Llewellyn Clare H. , Fildes Alison
Published: June 2022

Background

The obesogenic quality of the home environment is hypothesised to play an important role in children’s weight development but few prospective studies have investigated relationships between the home environment and adiposity across childhood.

Objective

To investigate the continuity and stability of the home environment from ages 4 to 12, and bi-directional relationships between the home environment and BMI-SDS from ages 4 to 12.

Methods

Parents from the Gemini cohort completed the Home Environment Interview (HEI), a comprehensive measure of the obesogenic home environment, when their children were aged 4 and 12 (n = 149 families, n = 298 children). The obesogenic home environment was measured using four composite scores capturing the food, activity, media environments, and the overall home environment. Child weights and heights were used to calculate BMI-SDS. Continuity was assessed with Pearson’s correlations between scores at each time point, and stability by changes in mean scores over time. Cross-lagged analyses were performed (HEI composites at age 4 to BMI-SDS at age 12 and the reverse) to measure the magnitude and direction of associations.

Results

The home environment showed moderate-to-high continuity from ages 4 to 12 (r = 0.30–0.64). The overall home environment (r = 0.21, p < 0.01) and media composites (r = 0.23, p < 0.01) were cross-sectionally associated with child BMI-SDS at age 12, but not at age 4. Longitudinally, the home media environment at age 4 predicted increases in child BMI-SDS at age 12 (β; 95% CI = 0.18; 0.08,0.28, p < 0.01). No associations were observed for the reverse path, or the remaining composites (the overall, food and activity) in either direction.

Conclusion

This study provides evidence that the obesogenic home environment tracks across childhood and highlights the importance of the early home media environment for child weight development. The findings provide insight into key aspects of the home environment that could be targeted when developing obesity treatment or prevention strategies.