bluuebunny/crossref_metadata_2025 huggingface dataset:
Friction Stir-Based Techniques: An Overview
Authors: El-Zathry Noah E. , Akinlabi Stephen , Woo Wai Lok , Patel Vivek , Mahamood Rasheedat M.
Published: October 2024

Friction stir-based techniques (FSTs), originating from friction stir welding (FSW), represent a solid-state processing method catering to the demands of various industrial sectors for lightweight components with exceptional properties. These techniques have gained much more attraction by providing an opportunity to tailor the microstructure and enhance the performance and quality of produced welds and surfaces. While significant attention has historically been directed towards the FSW process, this review delves into the working principles of FSTs, exploring their influence on mechanical properties and microstructural characteristics of various materials. Additionally, emphasis is placed on elucidating the advancement of hybrid FSW processes for both similar and dissimilar metal components, aimed at enhancing welding quality through meticulous control of grain textures, structures, precipitation, and phase transformations. Finally, the review identifies current knowledge gaps and suggests future research directions. This review paper synthesises academic literature sourced from the Web of Science (WoS) and Scopus databases, supplemented by additional sources such as books from the last 15 years.
Gradient-Layered MXene/Hollow Lignin Nanospheres Architecture Design for Flexible and Stretchable Supercapacitors
Authors: Zhang Haonan , Hao Cheng , Fu Tongtong , Yu Dian , Howe Jane , Chen Kaiwen , Yan Ning , Ren Hao , Zhai Huamin
Published: October 2024

With the rapid development of flexible wearable electronics, the demand for stretchable energy storage devices has surged. In this work, a novel gradient-layered architecture was design based on single-pore hollow lignin nanospheres (HLNPs)-intercalated two-dimensional transition metal carbide (Ti3C2Tx MXene) for fabricating highly stretchable and durable supercapacitors. By depositing and inserting HLNPs in the MXene layers with a bottom-up decreasing gradient, a multilayered porous MXene structure with smooth ion channels was constructed by reducing the overstacking of MXene lamella. Moreover, the micro-chamber architecture of thin-walled lignin nanospheres effectively extended the contact area between lignin and MXene to improve ion and electron accessibility, thus better utilizing the pseudocapacitive property of lignin. All these strategies effectively enhanced the capacitive performance of the electrodes. In addition, HLNPs, which acted as a protective phase for MXene layer, enhanced mechanical properties of the wrinkled stretchable electrodes by releasing stress through slip and deformation during the stretch-release cycling and greatly improved the structural integrity and capacitive stability of the electrodes. Flexible electrodes and symmetric flexible all-solid-state supercapacitors capable of enduring 600% uniaxial tensile strain were developed with high specific capacitances of 1273 mF cm−2 (241 F g−1) and 514 mF cm−2 (95 F g−1), respectively. Moreover, their capacitances were well preserved after 1000 times of 600% stretch-release cycling. This study showcased new possibilities of incorporating biobased lignin nanospheres in energy storage devices to fabricate stretchable devices leveraging synergies among various two-dimensional nanomaterials.
The Temporal-Political Dimensions of Green Colonialism through Wind Power Development at Fosen, Norway
Authors: Ellingsen Henrikke Sæthre
Published: October 2024

The 2021 Fosen verdict challenged Norway’s human rights reputation, stating that wind power development in Indigenous South Saami reindeer herding territories violated the Saami herders’ human rights. Previous research has described the development as a form of green colonialism. This article expands our comprehension of some central dynamics of green colonialism in contemporary Norway by exploring the temporal-political dimensions of wind power development. This qualitative study collected data from conversations, semi-structured interviews, and document analysis and applied a decolonial analytical approach. The results showed that the Norwegian government employed different temporal-political strategies before and after the verdict. Initially, urgency was used to justify why the Saami herders had to be forced to give up land for the ‘greater good of society.’ After the verdict stated that Indigenous rights had been violated, the government spent over two years finding ‘good solutions,’ showing how time use changed from urgency to delay. The article’s findings indicate that the Norwegian state’s use of time may be an intrinsic part of how green colonialism plays out in the research context and further suggest that time can be a political tool in asymmetrical colonial relations by connecting the strategies to time ontologies and power.
The Road to Paradox
Authors: Halbach Volker , Leigh Graham E.
Published: October 2024

Truth, provability, necessity, and other concepts are fundamental to many branches of philosophy, mathematics, computer science, and linguistics. Their study has led to some of the most celebrated achievements in logic, such as Gödel's incompleteness theorems, Tarski's theorem on the undefinability of truth, and numerous accounts of the paradoxes associated with these concepts. This book provides a clear and direct introduction to the theory of paradoxes and the Gödel incompleteness theorems. It offers new analyses of the ideas of self-reference, circularity, and the semantic paradoxes, and helps readers to see both how paradoxes arise and what their common features are. It will be valuable for students and researchers with a minimal background in logic and will equip them to understand and discuss a wide variety of topics in philosophical logic.
Physico-chemical properties and microstructure of bentonite in highly alkaline environments
Authors: Harrou Achraf , Lechheb Mahdi , El Ouahabi Meriam , Fagel Nathalie , Gharibi Elkhadir
Published: October 2024

Cementitious materials and their alkaline pore fluids can change the structure of bentonite used as a raw material for road embankments or concrete storage of garbage cans. This study investigated the alteration of montmorillonite-rich bentonite from northeast Morocco (Trebia deposit, Nador) in alkaline media rich in Ca2+, Mg2+, Na+, or K+. Specimens based on raw bentonite mixed with variable proportions of oxides (CaO, MgO) or hydroxides (NaOH, KOH) and water were prepared and aged for 28 days. Mineralogical composition by X-ray diffraction (XRD) was determined on raw bentonite and specimens to follow phase changes. Chemical composition and thermal characteristics were determined for raw bentonite and specimens by Fourier-transform infrared spectroscopy (FT-IR) and thermogravimetric/differential thermal analysis (TGA/DTA). Microstructural evolution and alteration of the external surface of bentonite were evaluated using scanning electron microscopy coupled with energy dispersive X-ray (SEM/EDX) analysis. XRD results of bentonite-CaO mixture demonstrated the formation of gels (e.g. C-S-H) and calcite. When the amount of CaO added increased, excess portlandite and the precipitation of calcite in the outer surface of bentonite occurred, stopping pozzolanic reaction and consequently decreasing the compressive strength of specimens. On the other hand, the addition of MgO allowed the formation of brucite. Sodalite and cancrinite were neoformed with the addition of 32 wt.% NaOH after 28 days of hydration. The addition of hydroxides (NaOH or KOH) to bentonite did not reveal any setting due to the absence of the formation of cementitious phases.
Oscillation migration of a neutrally buoyant oblate spheroid in the elasto-inertial duct flow
Authors: Li Yansong , Xu Chunxiao , Zhao Lihao
Published: October 2024

The peculiar migration and rotational dynamics of non-spherical particles in non-Newtonian flows stem from the interplay between fluid rheology and fluid inertial effects. In this paper, the cross-flow migration of a neutrally buoyant oblate spheroid (aspect ratio

$AR = 0.5$

) immersed in the elasto-inertial duct flow is investigated by particle-resolved simulations with the immersed boundary method. Different from spherical particles, due to the orientation-dependent lift force, the oblate spheroid migrates in an oscillating manner in the duct. The travelling period for particles reaching the duct centreline undergoes a non-monotonic change with elastic number, revealing the existence of a critical elastic number governing the migrating efficiency of oblate particles within the present flow system. For the particle rotation and orientation, the present results indicate that the particle rotation rate and orbit drifting rate are both hindered by the fluid elasticity. With increasing the fluid elasticity, three different orientation modes – log-rolling mode, kayaking-like mode and longside-flow alignment mode – are observed successively during the elasto-inertial migration of the oblate spheroid. Potentially, the present results could be used to design the rheology-based controlling strategy for guiding particles to achieve optimal focusing and orientation in microfluidic applications without the need for external forcing fields.
A reciprocal theorem for biphasic poro-viscoelastic materials
Authors: Moradi Moslem , Shi Wenzheng , Nazockdast Ehssan
Published: October 2024

In studying the transport of inclusions in multiphase systems we are often interested in integrated quantities such as the net force and the net velocity of the inclusions. In the reciprocal theorem the known solution to the first and typically easier boundary value problem is used to compute the integrated quantities, such as the net force, in the second problem without the need to solve that problem. Here, we derive a reciprocal theorem for poro-viscoelastic (or biphasic) materials that are composed of a linear compressible solid phase, permeated by a viscous fluid. As an example, we analytically calculate the time-dependent net force on a rigid sphere in response to point forces applied to the elastic network and the Newtonian fluid phases of the biphasic material. We show that when the point force is applied to the fluid phase, the net force on the sphere evolves over time scales that are independent of the distance between the point force and the sphere; in comparison, when the point force is applied to the elastic phase, the time scale for force development increases quadratically with the distance, in line with the scaling of poroelastic relaxation time. Finally, we formulate and discuss how the reciprocal theorem can be applied to other areas, including (i) calculating the network slip on the sphere's surface, (ii) computing the leading-order effects of nonlinearities in the fluid and network forces and stresses, and (iii) calculating self-propulsion in biphasic systems.
The effects of stratification on the near wake of 6 : 1 prolate spheroid
Authors: Ohh Chan-Ye , Spedding Geoffrey R.
Published: October 2024

An experimental study has been conducted on the near wake of a 6 : 1 spheroid, in both uniform and stratified backgrounds. The pitch angle,

$\theta$

, was varied from

$0^\circ \text { to }20^\circ$

. When

$\theta = 0^\circ$

, stratification decreases the characteristic wake element spacing so a characteristic Strouhal number (

$St$

) increases from 0.32 to 0.4. However, a similar measure scaled on wake momentum thickness shows the wake spacing to converge on those measured for other bluff and streamlined bodies. There is an apparent effect of Reynolds number, which changes the location of separation lines and hence the initial wake thickness. When

$\theta > 0^\circ$

, the wake is a combination of the usual drag wake together with a collection of streamwise vortices that have separated from the body, and this wake geometry can evolve in ways that are measurably different from the zero incidence case. These differences may be limited to the near wake, as the later evolution appears to converge with previous bluff- and streamlined bodies, with normalised wake height,

$L_V = 0.5$

and centreline velocity,

$\bar {u}_0 = 0.3$

at

$Nt = 10$

, as the early wake enters the non-equilibrium regime with similar values to previously studied stratified wakes. In the presence of density stratification, the inclined wake itself generates large-scale internal wave undulations with time scale

$2{\rm \pi} /N$

, even when the background stratification is not strong and a body-based Froude number is

$O(10)$

. The geometry and strengths of the primary streamwise vortices are not symmetric, mirroring previous results from experiments and computations in the literature.
Exploring cultural, social, and biological factors influencing obesity onset in two racial-ethnic groups in Quibdó, Colombia
Authors: Castro-Prieto Paula Andrea , Molano-Moreno Daniela , Lucumí Diego I.
Published: October 2024

Obesity rates in Colombia are increasing, with variations among racial and ethnic groups. Studies on adult obesity often address socio-economic status, gender, and education but neglect racial-ethnic influences, notably in areas like Quibdó. Therefore, based on the theory of triadic influence, we conducted a qualitative study to identify biobehavioural, social, and cultural phenomena that, from the perspectives of the participants, influence the onset of obesity in Afro-Colombian and indigenous in Quibdó in 2022. The stratification variables were race, ethnicity (Afro-Colombian and Indigenous), and educational level (secondary or higher). Based on a literature review of qualitative studies that commonly explored food culture, nutritional status, and physical activity in analysing obesity within racial and ethnic populations, we incorporated these categories into our research methodology through semi-structured interviews. A framework analysis was used as a qualitative methodology to organise and analyse the collected data. We conducted 21 semi-structured interviews, 13 with the Afro-Colombian population and eight with indigenous inhabitants. The results indicate that cultural beliefs, forced displacement/migration, and alterations in public order have resulted in changes in food security, food culture, and physical activity practices, affecting the onset of obesity. Notably, distinctions in cultural beliefs regarding food culture and health as factors influencing obesity were observed between Afro-Colombians and the Indigenous populations; however, educational differences within the same racial ethnic group were not predominant. Findings indicate obesity is influenced by cultural, social, and biobehavioural factors, especially in regions with racial-ethnic communities facing complex conditions, necessitating targeted racial-ethnic public health policies.
A double-blind, placebo-controlled, randomised withdrawal study of adjunctive brexpiprazole maintenance treatment for major depressive disorder
Authors: McIntyre Roger S. , Sundararajan Kripa , Behl Saloni , Hefting Nanco , Jin Na , Brewer Claudette , Hobart Mary , Thase Michael E.
Published: October 2024

Objective:

To compare time to relapse in patients with major depressive disorder (MDD) stabilised on antidepressant treatment (ADT) + brexpiprazole who were randomised to continued adjunctive brexpiprazole or brexpiprazole withdrawal (switch to placebo).

Methods:

This Phase 3, multicentre, double-blind, placebo-controlled, parallel-arm, randomised withdrawal study enrolled adults with MDD and inadequate response to 2–3 ADTs. All patients started on adjunctive brexpiprazole 2–3 mg/day (Phase A, 6–8 weeks). Patients whose symptoms stabilised (Phase B, 12 weeks) were randomised 1:1 to adjunctive brexpiprazole or adjunctive placebo (Phase C, 26 weeks). The primary endpoint was time to relapse in Phase C. Depression rating scale score changes were secondary endpoints.

Results:

1149 patients were enrolled and 489 patients were randomised (ADT + brexpiprazole n = 240; ADT + placebo n = 249). Median time to relapse was 63 days from randomisation in both treatment groups for patients who received ≥1 dose. Relapse criteria were met by 22.5% of patients (54/240) on ADT + brexpiprazole and 20.6% (51/248) on ADT + placebo (hazard ratio, 1.14; 95% confidence interval, 0.78–1.67; p = 0.51, log-rank test). Depression scale scores improved during Phases A–B and were maintained in Phase C. Mean weight increased by 2.2 kg in Phases A–B and stabilised in Phase C.

Conclusion:

Time to relapse was similar between continued adjunctive brexpiprazole and brexpiprazole withdrawal; in both groups, ∼80% of stabilised patients remained relapse free at their last visit. Adjunctive brexpiprazole therapy was generally well tolerated over up to 46 weeks, with minimal adverse effects following brexpiprazole withdrawal.

ClinicalTrials.gov identifier: NCT03538691. Funding: Otsuka, Lundbeck.
2023 CUMES Undergraduate Research Workshop and Poster Presentation
Authors: Eljamal Mekarem
Published: October 2024

For ten years, the Committee for Undergraduate Middle East Studies (CUMES) has organized the Undergraduate Research Workshop and Poster Session, creating a space where undergraduate students can present their work, receive feedback, and learn more about career paths related to Middle East studies. In 2016, I was fortunate enough to participate in the session, an experience that not only marked my entry into MESA but also showed me what generative scholarly engagement can look like. From the care that faculty participants took in their comments to the engagement during the poster presentations, my experience with the workshop has guided my own approach to providing student feedback, and it is an honor to have the space to reflect on this past experience and engage with the work of current undergraduates at the 2023 workshop.
Renal expression of calcium and phosphorus transporters: contrasting responses to dietary calcium and microbial phytase in broilers and growing pigs
Authors: Hu Yixin , Bikker Paul , Hendriks Wouter H. , van Krimpen Marinus M. , van Baal Jürgen
Published: October 2024

Enhanced dietary Ca intake linearly increases intestinal Ca absorption in pigs, but not in broilers, suggesting potential differences in whole body Ca homeostasis. To determine the role of kidney in Ca homeostasis in these species, we varied in growing pigs in experiment (Exp) 1, the dietary Ca content 2·0 v. 9·6 g/kg and phytase 0 v. 500 FTU/kg, in broilers, in Exp 2 the dietary Ca/retainable P from 1·3 to 2·8 and phytase 0 v. 1000 FTU/kg, and in Exp 3 dietary Ca/P from 0·50 to 1·75. Increasing dietary Ca reduced renal mRNA expression of Ca-related transporters (TRPV5, TRPV6, CaBP-D28k and NCX1) and tight junctions (CLDN-12 and −16) in pigs, indicating Ca reabsorption was reduced to maintain Ca homeostasis. In broilers (Exp 2), high dietary Ca increased renal TRPV6, CaBP-D28k and CLDN-2 mRNA, indicating an increased capacity for Ca reabsorption. Moreover, the effect of dietary Ca was enhanced by inclusion of dietary phytase in pigs but reduced in broilers. Furthermore, increasing dietary Ca upregulated inorganic phosphate transporter 1 (PiT-1), while phytase downregulated xenotropic and polytropic retrovirus receptor 1 (XPR1) mRNA expression in pigs; in broilers, dietary Ca downregulated renal mRNA expression of Na-dependent phosphate transporter IIa (NaPi-IIa), PiT-1, PiT-2 and XPR1, while phytase downregulated NaPi-IIa but upregulated PiT-2 and XPR1 mRNA expression. In Exp 3, Ca/P effect on transporter mRNA expression was largely consistent with Exp 2. In conclusion of this study, together with previously measured data about Ca and P homeostasis, in pigs the kidneys play a more regulatory role in Ca homeostasis than in broilers where the intestine is more important for regulation.
“Child of Koevoet”: Counterinsurgency, Crisis, and the Rise of Private Security in South Africa
Authors: Clarke Paul T.
Published: October 2024

Scholars of various backgrounds have noted how societies across the globe have come to rely on more and more policing and incarceration since the late 1970s. To date, however, detailed analyses of the causes and consequences of this “punitive turn” have been limited to the Global North, with the vast majority of studies focused on the expansion of states’ capacity for violence. This article offers a corrective to the global study of the punitive turn by tracing the rise of South Africa’s private security industry from its inception in the late apartheid period to its current position as one of the largest of its kind in the world. Using newspaper reports, archival material from the apartheid state’s security apparatus, and ethnographic interviews of former and current members of the security industry, it shows how counterinsurgency doctrine, civil war, and deindustrialization shaped South Africa’s punitive turn, precipitating a process where violence was devolved from the state to private actors, including local militias, vigilante groups, and private security firms. This process, it is argued, is far from anomalous, and should be seen as a paradigm for the way the post-1970s punitive turn has unfolded in the majority of the world.
Syntactic priming as implicit learning in German child language
Authors: Tafuri Michelle , Messenger Katherine
Published: October 2024

We investigated syntactic priming in German children to explore crosslinguistic evidence for implicit learning accounts of language production and acquisition. Adult descriptions confirmed that German speakers (N=27) preferred to spontaneously produce active versus passive transitive and DO versus PO dative forms. We tested whether German-speaking children (N=29, M
age
=5.3, 15 girls/14 boys) could be primed to produce these dispreferred forms and whether such priming effects would persist across a target phase. Children first heard a block of priming sentences and then described a block of target pictures. They demonstrated significant priming effects for passive and PO dative structures, and these priming effects did not differ between the first and second halves of the block of target trials. These patterns of German child language production are consistent with implicit learning accounts of syntactic priming.
The spatial–temporal variations and influencing factors of COVID-19 case fatality rate: a worldwide study in 30 countries from February 2021 to May 2022
Authors: Zhao Jing , Huang Xing , Li Xing , Li Bing , Rong Zuhua , Huang Xu , Ren Ruiqi , Li Dan , Li Chao , Li Qun , Xiao Jianpeng , Shi Guoqing
Published: October 2024

To evaluate the variations in COVID-19 case fatality rates (CFRs) across different regions and waves, and the impact of public health interventions, social and economic characteristics, and demographic factors on COVID-19 CFRs, we collected data from 30 countries with the highest incidence rate in three waves. We summarized the CFRs of different countries and continents in each wave through meta-analysis. Spearman’s correlation and multiple linear regression were employed to estimate the correlation between influencing factors and reduction rates of CFRs. Significant differences in CFRs were observed among different regions during the three waves (P < 0.001). An association was found between the changes in fully vaccinated rates (r
s
 = 0.41), population density (r
s
 = 0.43), the proportion of individuals over 65 years old (r
s
 = 0.43), and the reduction rates of case fatality rate. Compared to Wave 1, the reduction rates in Wave 2 were associated with population density (β = 0.19, 95%CI: 0.05–0.33) and smoking rates (β = −4.66, 95%CI: −8.98 – −0.33), while in Wave 3 it was associated with booster vaccine rates (β = 0.60, 95%CI: 0.11–1.09) and hospital beds per thousand people (β = 4.15, 95%CI: 1.41–6.89). These findings suggest that the COVID-19 CFRs varied across different countries and waves, and promoting booster vaccinations, increasing hospital bed capacity, and implementing tobacco control measures can help reduce CFRs.
A systematic review and meta-analysis of bovine tuberculosis occurrence and burden in Bangladesh, 1970–2023
Authors: Islam Sk Shaheenur , Pateras Konstantinos , Kabir S. M. Lutful , Kostoulas Polychronis , Ward Michael P. , Rahman A. K. M. Anisur
Published: October 2024

We aimed to estimate the overall apparent prevalence, true prevalence, and the spatial, temporal, and test-specific burden of bovine tuberculosis in Bangladesh. PubMed, Web of Science, Scopus, Google Scholar, and BanglaJOL were searched for bovine tuberculosis publications in Bangladesh from 1 January 1970 to 23 June 2023. Of 142 articles screened, systematic review and meta-analysis were performed on 22 (15.5%) articles. The apparent estimated bovine tuberculosis prevalence was 7%. The apparent Bayesian pooled mean bovine tuberculosis prevalences based on caudal fold test and single intradermal comparative tuberculin test were 7.83% and 9.89%, respectively, and the true pooled mean prevalences were 10.39% and 10.48%, respectively. Targeted interventions are recommended for districts with higher prevalence to effectively reduce the bovine tuberculosis burden in those areas. Current diagnostic practices employed in Bangladesh may not accurately reflect the bovine tuberculosis burden. Our findings highlight the need for better diagnostic tools and supplemental testing methods to ensure accurate diagnosis and surveillance. Efforts should prioritize obtaining ‘true’ prevalence estimates corrected for misclassification bias, rather than relying solely on apparent prevalence. Underestimating the bovine tuberculosis burden could result in inadequate resource allocation and hinder the implementation of effective control measures.
Intrauterine administration of paternal and maternal peripheral blood mononuclear cells mix as solution for repeated implantation failure
Authors: Elloumi Hanen , Ben Khelifa Mariem , Mnallah Sonia , Khrouf Mohamed , Rekik Sabrine , Zhioua Fethi , Ben khalifa Moncef , Braham Marouen , Jemaà Mohamed , Mahmoud Khaled
Published: October 2024

To date, implantation is the rate-limiting step for the success of in vitro fertilization (IVF) treatment. Accumulating evidence suggests that immune cells contribute to embryo implantation, and several therapeutic approaches have been proposed for the treatment of recurrent implantation failure (RIF). Endometrial immune modulation with autologous activated peripheral blood mononuclear cells (PBMCs) is one of the most widely used protocols. However, the effect of intrauterine insemination of mixed paternal and maternal-activated PBMCs has not yet been attempted and studied. The aim of our study is to test the effect of the addition of paternal lymphocytes on the implantation rate in RIF patients. Mononuclear cells were isolated from the peripheral blood of 98 RIF patients and cultured for 72 h before insemination into the endometrial cavity 48 h before embryo transfer. Our patients were divided into 4 groups according to the type and number of PBMCs inseminations. Our study shows that activated PBMCs promoted clinical pregnancy rates (CPR) in all groups. Moreover, we found that the groups injected with more than 2 million cells showed a better clinical outcome and, more interestingly, patients inseminated with both paternal and maternal activated PBMCs showed the highest CPR, reaching 47.2%, in addition to the highest implantation rate 31. 2% and the live birth rate 41.39%. Our work demonstrates the importance of administering a large number of activated PBMCs with the addition of paternal activated PBMCs to immunomodulate the endometrium for the success of in vitro fertilization in RIF patients.
Frequency, characteristics, antithrombotic therapies, and outcomes of thromboembolism in paediatric patients with CHD undergoing cardiac surgery: a single centre retrospective study
Authors: Kiskaddon Amy L. , Stock Arabela C. , Betensky Marisol , Ignjatovic Vera , Fierstein Jamie L. , Frank Shannon , Quintessenza James A. , Goldenberg Neil A.
Published: October 2024

Introduction:

Thromboembolism is a complication in paediatric patients with CHD requiring cardiac surgery. Previous research has focused on post-operative thromboembolism. This study aimed to describe thromboembolism frequency before or after cardiac surgery in children with CHD.

Methods:

We performed a single-centre retrospective study from October 2020 to June 2023 (inclusive). Patients were eligible for inclusion if they were <21 years of age and underwent cardiac surgery. Outcomes of interest included the occurrence and characteristics of thromboembolism in the 12 months before and after surgery, antithrombotic therapies, recurrent thromboembolism, and clinically significant bleeding.

Results:

Among 260 patients included, 35 (13.5%) developed an index thromboembolism. Twelve (34.3%) patients had an index thromboembolism <12 months before surgery and 23 (65.7%) had an index thromboembolism <12 months after surgery, including 8 (22.9%) patients who had thromboembolism during both exposure periods. The median interquartile range (IQR) time of thromboembolism relative to cardiac surgery was –26 (–4 to –140) days and 15 (4 to 41) days, respectively. Seven (20%) patients had arterial, 18 (51.4%) venous, and 3 (8.6%) had both arterial and venous thromboembolism. Median (IQR) antithrombotic therapy duration was 49 (24–84) days. Nine (25.7%) patients developed recurrent thromboembolism and five (14.3%) patients experienced clinically significant bleeding.

Conclusions:

The risk of thromboembolism and recurrence is high both before and after cardiac surgery among paediatric patients with CHD. Prospective multi-centre studies should seek to identify risk factors for preoperative and postoperative thromboembolism to inform the design of future risk-stratified thromboembolism prevention trials in children with CHD.
A tale of two tails: 130 years of growth at risk
Authors: Gächter Martin , Hasler Elias , Huber Florian
Published: October 2024

We extend the growth-at-risk (GaR) literature by examining US growth risks over 130 years using a time-varying parameter stochastic volatility regression model. This model effectively captures the distribution of GDP growth over long samples, accommodating changing relationships across variables and structural breaks. Our analysis offers several key insights for policymakers. We identify significant temporal variation in both the level and determinants of GaR. The stability of upside risks to GDP growth, as seen in previous research, is largely confined to the Great Moderation period, with a more balanced risk distribution prior to the 1970s. Additionally, the distribution of GDP growth has narrowed significantly since the end of the Bretton Woods system. Financial stress is consistently associated with higher downside risks, without affecting upside risks. Moreover, indicators such as credit growth and house prices influence both downside and upside risks during economic booms. Our findings also contribute to the financial cycle literature by providing a comprehensive view of the drivers and risks associated with economic booms and recessions over time.
Correlation of thickness changes and daily dose detection of delivery analysis (DA) software in helical tomotherapy
Authors: Wijarn Nattawut , Watcharawipha Anirut , Nobnop Wannapha
Published: October 2024

Purpose:

To assess the correlation between the dose distribution provided by the delivery analysis (DA) software and the measured dose distribution using an ArcCHECK (AC) phantom in the presence of thickness variation.

Materials and Methods:

Two sets of targets were established within the phantom. Target A was placed on the detector areas, whereas Target B was positioned at the centre of the phantom. Bolus was applied to the surface of the phantom at different thicknesses ranging from 0 to 2 cm to verify the dose distribution in both TomoHelical (HT) and TomoDirect (TD) techniques. The gamma passing rate (GPRs) were evaluated against predefined thresholds of 3%/3 mm and 3%/2 mm. Correlation study evaluated the level of agreement between DA and AC values.

Results:

Both AC and DA exhibited a decline in GPRs as the bolus thickness decreased. Significant correlations were observed between AC and DA for both HT and TD techniques, with a p value of less than 0.001.

Conclusion:

The results indicate that DA software has the capability to detect anatomical changes during tomotherapy treatments. This is substantiated by the statistical association found between DA and the standard AC phantom system for dose distributions in both HT and TD methods.
Electronic referral system policy analysis: a qualitative study in the context of Iran
Authors: Kabir Mohammad Javad , Heidari Alireza , Honarvar Mohammad Reza , Khatirnamani Zahra
Published: October 2024

Background:

Referral system is among the key elements of primary health care that leads to enhanced efficiency, reduced costs, reduced waiting time, and patients’ enhanced access to more specialized services. The present study was aimed at analysing the policies of the electronic referral (e-Referral) system in Iran.

Methods:

This qualitative study was conducted based on Walt and Gilson’s policy triangle and Kingdon’s models. Data were collected through document analysis and 51 semi-structured interviews with managers at various levels, experts, family physicians, specialist physicians, and patients. Document analysis was performed by content analysis method, and interview analysis was performed through framework analysis method in Atlas.ti 8.

Results:

The e-Referral system was launched with the aim of equitable access to services and to benefit from better management of health resources. Valid scientific evidences were used to formulate policies. Numerous meetings were held with domestic and foreign stakeholders at the provincial, city, and rural levels. The implementation of the programme followed a bottom-up approach, and the main obstacles to the implementation of the programme included the change of senior managers of the health system and their not being fully aware of the importance of the programme, inadequate allocation of financial resources, and unwillingness of some patients to follow the referral system.

Conclusions:

The policy triangle framework, while explaining the components of the e-Referral system programme, revealed the obstacles to the proper implementation of the programme. In order to ensure that the programme goes on continuously and successfully, it is essential to create the necessary determination and commitment on the part of the minister of health and medical education and senior managers of the health system, earmark resources for the programme, improve resource allocation with insurance management, reform the payment system, plan to raise public awareness, and attract community participation.
Exploring health worker absenteeism at public healthcare facilities in Chhattisgarh, India
Authors: Kerketta Priyanka , Maniyara Karthika , Palle Edukondal , Kodali Prakash Babu
Published: October 2024

Aim:

This study aims to assess the health worker absenteeism and factors associated with it in a high-focus district in Chhattisgarh, India.

Background:

Human resources for health are among the key foundations to build resilient healthcare systems. Chhattisgarh is a high-focus Indian state with a severe shortage of health care workers, and absenteeism further aggravates the shortage.

Methods:

This study was conducted as a mixed-methods study employing sequential explanatory design. Absenteeism was defined as the absence of health worker in the designated position without a formal leave or official reason in two different unannounced visits. A facility survey across all the public healthcare facilities in Jashpur district, Chhattisgarh, was conducted through random, unannounced visits employing a checklist developed based on Indian Public Health Standards. Twelve participants were purposively sampled and interviewed from healthcare facilities to explore factors associated with absenteeism. Survey data were analysed descriptively, and thematic analysis was employed to analyse qualitative interviews.

Findings:

Among all the positions filled at primary health centre level (n = 339), close to 8% (n = 27) were absent, whereas among the positions filled at community health centre level (n = 285), only 1.14% (n = 4) were absent. Absenteeism was not found in the district hospital. Qualitative interviews reveal that macro-level (geographical location and lack of connectivity), meso-level (lack of equipment and amenities, makeshift health facilities, doctor shortage, and poor patient turnover), and micro-level (unmet expectations) factors contribute to health worker absenteeism.

Conclusion:

Health worker absenteeism was more at PHC level. Systemic challenges, human resource shortages, and infrastructural shortcomings contributed to health worker absenteeism.
Evaluating physical activities in clinical diabetes: lifestyle scores hypothesis
Authors: Bwititi Phillip , Egwuenu Solomon , Oshionwu Echinei , Okuzor John , Odufu Alex , Ofili Charles , Nwose Ezekiel Uba
Published: October 2024

Background:

The concept of lifestyle-based risk scores is known but not evaluated in most rural communities of low- to mid-income countries. This study investigated the correlation of lifestyle scores with health indices.

Methods:

This was a descriptive cross-sectional investigation. A total of 203 participants (141 females and 62 males), 18–90 years, had anthropometric assessments and lifestyle scores determined from a 12-item framework. Data analysis included average age in different health conditions, lifestyle scores in age groups, and correlations with age.

Results:

Average age of healthy subpopulation was 39 years while diabetes, hypertension, and obesity subpopulations were 58, 64, and 56 years, respectively. The percentage of participants whose activities of daily living (ADL) were unaffected by ill-health decreased with age (P < 0.0001), and lifestyle scores also decreased with age (P < 0.01) and negatively correlated with physical activities.

Conclusion:

This report contributes to diabetes cardiovascular complications management. Sedentary ADL factors need integration in healthy lifestyle education especially among the elderly.
Fossil and present-day stromatolite ooids contain a meteoritic polymer of glycine and iron
Authors: McGeoch Julie E.M. , Frommelt Anton J. , Owen Robin L. , Cinque Gianfelice , McClelland Arthur , Lageson David , McGeoch Malcolm W.
Published: October 2024

Hemoglycin, a space polymer of glycine and iron, has been identified in the carbonaceous chondritic meteorites Allende, Acfer 086, Kaba, Sutter's Mill and Orgueil. Its core form has a mass of 1494 Da and is basically an antiparallel pair of polyglycine strands linked at each end by an iron atom. The polymer forms two- and three- dimensional lattices with an inter-vertex distance of 4.9 nm. Here the extraction technique for meteorites is applied to a 2.1 Gya fossil stromatolite to reveal the presence of hemoglycin by mass spectrometry. Intact ooids from a recent (3000 Ya) stromatolite exhibited the same visible hemoglycin fluorescence in response to x-rays as an intact crystal from the Orgueil meteorite. X-ray analysis confirmed the existence in ooids of an internal three-dimensional lattice of 4.9 nm inter-vertex spacing, matching the spacing of lattices in meteoritic crystals. FTIR measurements of acid-treated ooid and a Sutter's Mill meteoritic crystal both show the presence, via the splitting of the Amide I band, of an extended anti-parallel beta sheet structure. It seems probable that the copious in-fall of carbonaceous meteoritic material, from Archaean times onward, has left traces of hemoglycin in sedimentary carbonates and potentially has influenced ooid formation.
Religious citizens, secular states: why do states in sub-Saharan Africa provide minimal support to religion?
Authors: Jeffery-Schwikkard David
Published: October 2024

Although most people in sub-Saharan Africa are very religious, state support for religion (such as through policies legislating religious values and supporting religious institutions) is very low in the region. Why is this? This paper explores this phenomenon using data from Pew Research Centre and Religion and State Project. While population religiosity is ordinarily correlated with state support for religion elsewhere in the world, sub-Saharan Africa is indeed anomalous. Yet contrary to popular explanations, this is not explained by limited state capacity, weak democracies, religious and ethnic pluralism, or majority religion. Using case studies of Rwanda and Mozambique, the paper considers whether challenges to the moral authority of religious actors as leaders of “the nation” may help explain why state support for religion is so low in sub-Saharan Africa. Taken together, these findings challenge assumptions that high religiosity in sub-Saharan Africa is a threat to secular governance.
Benefits and Pitfalls of GRACE and Streamflow Assimilation for Improving the Streamflow Simulations of the WaterGAP Global Hydrology Model
Authors: Schulze K. , Kusche J. , Gerdener H. , Döll P. , Müller Schmied H.
Published: October 2024

Distribution and change of freshwater resources is often simulated with global hydrological models. However, owing to process representation limitations and forcing data uncertainties, these model simulations have shortcomings. Combining them with observations via data assimilation, for example, with data from the Gravity Recovery and Climate Experiment (GRACE) mission or streamflow measured at in situ stations is considered to improve the realism of the simulations. We assimilate gridded total water storage anomaly (TWSA) from GRACE into the WaterGAP Global Hydrology Model (WGHM) over the Mississippi River basin via an Ensemble Kalman Filter. Our results agree with previous studies where assimilating GRACE observations nudges TWSA simulations closer to the observations, reducing the root mean square error (RMSE) by 21% compared to an uncalibrated model. However, simulations of streamflow show degeneration at more than 90% of all gauge stations for metrics such as RMSE and correlations; only the annual phase of simulated streamflow improves at half the stations. Therefore, for the first time, we instead assimilated streamflow observations into the WGHM, which improved simulated streamflow at up to nearly 80% of the stations, with normalized RMSE showing improvements of up to 0.1, while TWSA was well‐simulated in all metrics. Combining both approaches, that is, jointly assimilating GRACE‐derived TWSA and streamflow observations, leads to a trade‐off between a good fit of both variables albeit skewed to the GRACE observations. Overall, we speculate that our findings point to limitations of process representation in WGHM hindering consistent flux simulation from the storage history, especially in dry regions.
High Frequency Monitoring and Nitrate Sourcing Reveals Baseflow and Stormflow Controls on Total Dissolved Nitrogen and Carbon Export Along a Rural‐Urban Gradient
Authors: Delesantro Joseph M. , Duncan Jonathan M. , Riveros‐Iregui Diego , Whitmore Keridwen M. , Band Lawrence E.
Published: October 2024

Efforts to reduce nitrogen and carbon loading from developed watersheds typically target specific flows or sources, but across gradients in development intensity there is no consensus on the contribution of different flows to total loading or sources of nitrogen export. This information is vital to optimize management strategies leveraging source reductions, stormwater controls, and restorations. We investigate how solute loading and sources vary across flows and land‐use using high frequency monitoring and stable nitrate isotope analysis from five catchments with different sanitary infrastructure, along a gradient in development intensity. High frequency monitoring allowed estimation of annual loading and attribution to storm versus baseflows. Nitrate loads were 16 kg/km2/yr. from the forested catchment and ranged from 68 to 119 kg/km2/yr., across developed catchments, highest for the septic served site. Across developed catchments, baseflow contributions ranged from 40% of N loading to 75% from the septic served catchment, and the contribution from high stormflows increased with development intensity. Stormflows mobilized and mixed many surface and subsurface nitrate sources while baseflow nitrate was dominated by fewer sources which varied by catchment (soil, wastewater, or fertilizer). To help inform future sampling designs, we demonstrate that grab sampling and targeted storm sampling would likely fail to accurately predict annual loadings within the study period. The dominant baseflow loads and subsurface stormflows are not treated by surface water management practices primarily targeted to surface stormflows. Using a balance of green and gray infrastructure and stream/riparian restoration may target specific flow paths and improve management.
Here’s Why Resolution Copper Wants to Mine Oak Flat
Authors: van Deelen Grace
Published: October 2024

Southeastern Arizona’s “Copper Triangle” is a hot spot for high-grade deposits, thanks to ancient magmatic activity.
What’s On the Horizon for Open Access Geoscience Books?
Authors: Boyt David , Lunn Jenny
Published: October 2024

On the first anniversary of their partnership, AGU and the Geological Society of London reflect on the GeoHorizons series and why open access books are valuable for the geoscience community.
Seismo‐Acoustic Characterization of the 2018 Sierra Negra Caldera Resurgence and Fissure Eruption in the Galápagos Islands
Authors: Ortiz Hugo D. , Matoza Robin S. , Bernard Benjamin , De Negri Rodrigo , Ruiz Mario C.
Published: October 2024

The 2018 eruption of Sierra Negra volcano, Galápagos, Ecuador has provided new insights into the mechanisms of caldera resurgence, subsidence, and fissuring at basaltic shield volcanoes. Here, we integrate local (∼0.4 km) seismo‐acoustic records and regional (∼85 km) infrasound array data to present new observations of the 2018 Sierra Negra eruption with improved time and spatial resolutions. These observations include: air‐to‐ground coupling ∼2 hr before the time of the eruption onset, migration of the infrasound tremor from 22:54 June 26 to 12:31 June 27 UT (all times in UT), and persistent infrasound detections during the weeks between 5 July and 18 August from an area that does not coincide with the previously documented eruptive fissures. We interpret air‐to‐ground coupling as infrasound tremor generated in the nearby fissures before the main eruptive phase started, although ambiguity remains in interpreting a single seismic‐infrasonic sensor pair. The progressive location change of the infrasound tremor agrees with the migration of the eruption down the north flank of Sierra Negra at a rate of ∼0.15 ± 0.04 m/s. The weeks‐long persistent detections coincide with a region that has thermal anomalies, co‐eruptive deformation, lava fields, and geological features that could be interpreted as multiple lava tube skylights. Our observations and interpretations provide constraints on the mechanisms underlying fissure formation and magma emplacement at Sierra Negra.