bluuebunny/crossref_metadata_2025 huggingface dataset:
Laboratory testing and model calibration of a crushed stone backfill in a geosynthetic reinforced soil wall
Authors: Okafor Chukwuma , Dunlop Sam , Anderson Brian , Montgomery Jack
Published: July 2024

The objective of this study was to understand the effect of the choice of backfill constitutive models on the numerical simulation of a geosynthetic reinforced soil-integrated bridge system (GRS-IBS). The #89 material, a crushed angular granite stone, characterized by maximum particle sizes of 9 mm, was used for the reinforced backfill for the retaining wall. Consolidated drained triaxial tests were conducted at confining stresses of 48 kPa, 83 kPa, and 117 kPa. The average friction angle was 42 degrees. Two soil models (the linear-elastic perfectly-plastic and the Hardening Soil) were calibrated using the laboratory test results. The calibrated soil models were then used to model the reinforced backfill material in finite element simulations of the abutment. Results of the calculated vertical stresses at the instrument position showed reasonable agreement with the field measurement. The non-linear model predicted about twice the deformation (lateral displacement and bridge seat settlement) compared to the linear-elastic perfectly plastic model. Settlement results showed maximum values corresponding to 0.22% and 0.45% of the abutment height for linear-elastic perfectly-plastic model and Hardening-Soil model, respectively, which are less than 0.5% limit recommended by US FHWA, while the lateral displacements were 0.22% and 0.44% of the abutment height for linear-elastic perfectly-plastic model and Hardening Soil model, respectively, both less than the 1% limit recommended by the US FHWA.
Subsoil stiffness effects on the bridge-abutment dynamic behaviour
Authors: Asia Yazan B. , Madabhushi Gopal S.P.
Published: July 2024

Integral abutment bridges (IABs) are robust structures that avoid the use of bearings and expansion joints and are relatively maintenance-free compared to conventional bridges. The seismic design code of IABs is not fully developed, and the complex soil-abutment interaction is not well understood. Therefore, research was carried out at the Schofield centre, the University of Cambridge, to understand the backfill-abutment interaction under earthquake loading, aimed at developing design guidelines for the industry. Understanding the mechanics by which the foundation soil stiffness and strength govern the abutment deformation and, thus, the earth pressures generated behind the abutment is essential. Two centrifuge tests have been conducted simulating an abutment with the conventional abutment-deck connection (or semi-integral abutment bridge), where moment restraint is released. In this paper, the dynamic response of the abutment founded on dry and liquefiable sandy soil is compared. Different deformation modes have been observed depending on the relative abutmentsoil stiffness. The abutment experienced minimal base displacement in dry sands. Conversely, the abutment witnessed cyclic rotational ratcheting about the deck level in liquefiable soil. The dry soil test helped identify the zones where soil stiffness and strength loss can be critical. In the case of the saturated test, the water table level was up to one-third of the abutment height, fully saturating the foundation soil while the backfill height was dry. The comparative results highlight the vulnerability of semi-integral abutment walls to liquefaction-induced failure, as witnessed in the 2011 Christchurch earthquakes.
Rheological behavior of granular materials under different relative densities
Authors: Kumar Jithin S. , Kandasami Ramesh Kannan
Published: July 2024

Granular materials typically exhibit complex behaviour especially during shearing under different states. The material behaviour transitions from fluid-like to unfluid-like primarily due to various fundamental mechanisms involved during the shearing process such as momentum transport, compaction, and jamming. Describing this transition is particularly relevant in a variety of natural phenomena like landslides, debris flow, mudflow, and liquefaction. The mechanism involved in the transitional response is predominantly governed by the initial packing of granular medium, shear rate and boundary stresses. In this study, the influence of relative densities (20% to 74%) on the rheological behaviour of sand is studied using a vane-shear apparatus. The variation of critical shear strength (during jamming), yield strength, apparent viscosity, and the maximum shear rate with relative density is determined from this experimental program. Further, the characterization of the flow behaviour of sand revealed the existence of pre-jamming and post-jamming regimes. The post-jamming response is evaluated by using slope parameters (m and ξ) which predicted an increasing trend with increase in relative density and overburden pressure.
Determination of hypoplastic parameters for a typical gravel backfill material of railway bridges
Authors: Stastny Alexander , Knittel Lukas , Meier Thomas , Tschuchnigg Franz
Published: July 2024

Laboratory test programs on gravel are rare due to the maximum grain size of the material. In this paper an experimental program with triaxial tests under cyclic loading and oedometric tests on highly compacted gravel specimens, representative for bridge backfills materials, is summarized. It is used to calibrate a hypoplastic constitutive model, which includes an extension for intergranular strain to account for the cyclic loading behaviour. So far calibrated parameter sets of this soil model are scarce in literature, especially for coarse grained materials. The calibrated parameter set can be used in numerical studies, e. g. on the cyclic soil structure interaction of integral railway bridges.
Laboratory investigation of the cyclic loading behaviour of intact and de-structured chalk
Authors: Liu Tingfa , Ahmadi-Naghadeh Reza , Vinck Ken , Jardine Richard J. , Kontoe Stavroula , Buckley Roisin M. , Byrne Byron W. , McAdam Ross A.
Published: July 2024

Chalk is a soft biomicrite composed of silt-sized crushable CaCO3 aggregates. Chalk’s response to cyclic loading depends critically on its sensitive micro fabric and state, which may be altered significantly by high-pressure compression, dynamic impact or prior large-strain repetitive shearing. This paper reports high-resolution undrained cyclic triaxial experiments on low- to medium-density intact chalk and chalk de-structured by dynamic compaction to model the effects of percussive pile driving. The intact chalk manifested stable and nearly linear visco-elastic response under a wide range of the one-way, stress-controlled cyclic loading conditions imposed. However, high level cycling led to sudden failures that resembled the fatigue response of metals, concretes and rocks, with little sign of cyclic damage before sharp pore pressure reductions, non-uniform displacements and finally brittle collapses. However, the de-structured chalk’s response to high-level undrained cycling resembles that of silts, developing both contractive and dilative phases that led to pore pressure build-up, leftward effective stress-path drift, permanent strain accumulation, cyclic stiffness losses and increasing damping ratios. Results from exemplar tests are presented to illustrate these key features and demonstrate how chalk’s undrained cyclic shearing characteristics depend also on effective stress level. The experimental outcomes provide significant scope for developing constitutive and empirical relationships or predictive tools to enable the interpretation and design of driven pile foundations in chalk and other chalk-structure interaction related problems under cyclic loading.
The monotonic behaviour of a low- to medium-density chalk through in-situ and laboratory characterisation
Authors: Vinck Ken , Liu Tingfa , Jardine Richard , Kontoe Stavroula , Buckley Róisín , Byrne Byron , McAdam Ross , Ferreira Pedro , Coop Matthew
Published: July 2024

Chalk is a highly variable cemented biomicrite limestone that can show widely different rock strengths and patterns of micro to macro fissuring and jointing, due to variations in depositional environments and local geological histories. This paper describes the characterisation of a very weak to weak, low- to medium-density chalk through in situ profiling and laboratory testing, which provided new insights into the geomaterial’s mechanical behaviour. The chalk de-structures when taken to large strains, leading to remarkably high pore pressures beneath penetrating cones and degraded responses in full-displacement pressuremeter tests. Laboratory tests on carefully formed specimens explored the chalk’s unstable structure and marked time-, rate- and pressure dependency. A clear hierarchy was found between profiles of peak strength with depth from Brazilian tension, drained and undrained triaxial and direct simple shear tests conducted from in-situ stress conditions. Highly instrumented triaxial tests sheared from low confining stresses indicated stiffness anisotropy and showed very brittle failure behaviour from small strains. Progressively more ductile behaviour was seen as confining pressures were raised, with failures being delayed until increasingly large strains and finally stable critical states were attained. The chalk’s mainly sub-vertical jointing and micro-fissuring led to properties depending on specimen scale, with high-quality laboratory stiffness measurements significantly exceeding those obtained from in-situ geophysical testing, which far exceed the operational stiffnesses of the chalk mass. While compressive strength and stiffness appear relatively insensitive to effective stress levels, consolidation to higher pressures closes micro-fissures and reduces anisotropy. The results provided the basis for numerical analysis with advanced constitutive models that inform the interpretation of axial and lateral tests on driven piles and inform the development of new practical design methods.
Freezing-thawing response of sand-kaolin mixtures in oedometric conditions
Authors: Viglianti Andrea , Guida Giulia , Casini Francesca
Published: July 2024

The freezing and thawing cycles applied to soils can often be causes of irreversible instabilities, uplift, or subsidence. These phenomena can be both natural (e.g. permafrost regions) or artificially induced (e.g. artificial ground freezing (AGF), as an excavation earth support technique for tunnelling). When the soil temperature falls below 0°C, the liquid water changes phase turning into ice. The freezing process generally implies an expansion of the soil element due to (i) the lower density of the migration of the ice and (ii) the pore water toward the frozen front. The complex interaction between the solid grains, the water and the ice formation during freezing determines the soil’s overall thermo-hydromechanical (THM) behaviour. Sandy mixtures with different percentages of kaolin were tested on an oedometer developed at the Geotechnical Laboratory of Universita degli Studi di Roma Tor Vergata, working at temperatures below zero. The samples were compressed under five different vertical stresses (50, 100, 200, 400 and 800 kPa, respectively), and then a freezing and thawing cycle was applied by steps to a minimum temperature of -20°C. The experimental results regarding temperature evolution, vertical displacements, and liquid water amount monitored are discussed and interpreted through a micro-to-macro approach. The data analysis revealed interesting outcomes that characterise mechanical and hydraulic hysteresis during freezing and thawing processes. A deeper understanding of the coupled phenomena that occur during the freezing and thawing cycles is supposed to contribute to developing a constitutive model that can reproduce the irreversible volumetric response of frozen soils.
Some practical applications of shear wave velocity measurements in dense sand
Authors: Long Michael , Trafford Andrew , Judge Maria , Donohue Shane
Published: July 2024

Shear wave velocity (Vs) profiles were obtained using two techniques at a dense sand site in Blessington near Dublin, Ireland. It was shown that both the multichannel analysis of surface waves (MASW) and seismic CPT (SCPTU) techniques provided reliable data. Use was made of a novel approach involving a Monte Carlo inversion of the MASW output to assess the fit between the measured and theoretical surface wave data. Differences between the SCPTU and MASW data are likely to be due to a combination of natural anisotropy in the sand and to uncertainty in the two methods involved. Previous published correlations between CPTU data and Vs also work well for this site. The Vs data was also used to accurately predict (Class 3 prediction) measured settlement data from shallow footing tests at the site.
Population genetic structure ofSchistosoma bovisandS. curassonicollected from cattle in Mali
Authors: Diakité Assitan , Agniwo Privat , Dabo Abdoulaye , Sidibé Bakary , Savassi Boris A.E.S. , Akplogan Ahristode , Guindo Hassim , Dembélé Laurent , Ibikounlé Moudachirou , Niaré Safiatou Doumbo , Tembely Saidou , Boissier Jérôme
Published: July 2024

Schistosomiasis is of medical and veterinary importance. Despite the critical situation of schistosomiasis in sub-Saharan Africa, few molecular epidemiological studies have been carried out to determine the role of animals in its transmission. In Mali, it has been over three decades since the last molecular study of animal schistosomes was carried out. It is now urgent to identify circulating strains of the parasite because of potential interactions with other schistosome species, which could complicate disease control. The aim of our work was to study the composition and genetic structure of schistosome populations collected from cattle. The prevalence of schistosome was 23.9%, with the prevalences ofSchistosoma bovis (Sb)andS. curassoni (Sc)estimated at 12.6% and 9.8%, respectively. No hybrid strains orS. haematobiumwere found. The parasites displayed distinct geographical distribution withSbdominant in Bamako (78.8% and 98% in Central Bamako Slaughterhouse and Sabalibougou Slaughterhouses, respectively) andScdominant in Kayes (95.3%). Of the 476 parasites with a complete genetic profile, 60.4% were pureSc, and were mainly from Kayes. We identified two clusters at the site level (Fst of 0.057 and 0.042 forSbandSc, respectively). Cluster 1 was predominantly composed of pureSbparasites and cluster 2 was mainly composed of pureScparasites, from Bamako and Kayes, respectively. Our study shows that cattle schistosomiasis remains endemic in Mali withS. bovisandS. curassoni. A robust genetic structure between the different schistosome populations was identified, which included two clusters based on the geographical distribution of the parasites.
Akute Immunneuropathie und Optikusneuritis – Übersicht und
Fallbericht eines seltenen Überlappungssyndroms
Authors: Jüchtern Marvin , Nebelo Frederik Maximilian , Mull Michael , Dafotakis Manuel , Brunkhorst Robert , Matz Oliver
Published: July 2024

Die vorliegende Arbeit gibt einen Überblick über nosologische,
pathomechanistische und therapeutische Aspekte von kranialen
Überlappungssyndromen akuter Immunneuropathien. Eine 18-jährige Patientin
entwickelte eine bilaterale faziale Parese, akrodistale Parästhesien und
Sehstörungen nach einem gastrointestinalen Infekt. Kraft, Koordination und
Muskeleigenreflexe der Extremitäten waren regelrecht. Bei Kontrastmittelaufnahme
mehrerer Hirnnerven sowie von Konus- und Kaudafasern, zytoalbuminärer
Dissoziation im Liquor und Demyelinisierungszeichen in der Elektroneurographie
diagnostizierten wir eine akut-inflammatorische demyelinisierende
Polyradikuloneuritis mit Neuritis nervi optici. Die Beschwerden der Patientin
sprachen gut auf eine Plasmapherese an. Auch bei Patienten mit Hirnnervenparesen
und Parästhesien ohne Hyporeflexie oder Extremitätenschwäche sollte an eine
akute Immunneuropathie gedacht werden. Kombinationen mit zentraler Affektion wie
der Optikusneuritis sind dabei möglich.
Elektrophysiologische Aspekte in der Diagnostik und Pathophysiologie
der Critical Illness Polyneuromyopathie (CIPNM)
Authors: Sekhniashvili Madona , Toyka Klaus Viktor , Baum Petra
Published: July 2024

Critical Illness Neuromyopathie (CIPNM) ist eine Sepsis-Komplikation mit noch
immer ungeklärter Pathophysiologie. Die motorische und sensible
Elektroneurographie zeigen eine Minderung der Amplituden von Muskel- und
Nervensummenaktionspotentialen (MSAP/NSAP). Veränderungen im EMG finden sich in
der Frühphase der Erkrankung nicht. Mit einer aufwändigen elektrophysiologischen
Technik wurden Veränderungen der Nerven- und Muskelfaser-Erregbarkeit
beschrieben, die als Zeichen einer Fehlfunktion von Na-Kanälen interpretiert
wurden. Eine neue, auf jedem EMG-Gerät durchführbare 0,2–0,5 Hz Serienreizung
der motorischen Nerven oder direkt des Muskels führt bei CIPNM zu einer starken
Fazilitierung der MSAP und eignet sich als diagnostisches Kriterium. Die
hochgradige Variabilität der Fazilitierung spricht für eine fluktuierende,
dysfunktionelle Neuromyopathie. Sensible Nerven zeigten nur selten eine geringe
Fazilitierung. Als pathogene Faktoren wurden fokale Ischämie mit Hypoxie und
toxische Entzündungs-Botenstoffe vermutet, die ein Energiedefizit erzeugen und
neben anderem Na-Kanäle funktionell beeinträchtigen könnten.
Therapeutische Neurostimulation bei Epilepsien
Authors: Schulze-Bonhage Andreas
Published: July 2024

Das Spektrum möglicher Neurostimulationsbehandlungen von Epilepsien hat sich in
den letzten Jahren deutlich erweitert. Nach Einführung der Vagusnervstimulation
1994 haben sich mit der Stimulation der anterioren Thalamuskerne, in den USA der
responsiven intrakranielle Fokusstimulation und zuletzt in Europa der
epicraniellen Fokalen Cortexstimulation neue klinische Behandlungsansätze
entwickelt. In dieser Übersichtsarbeit werden die den Stimulationsbehandlungen
zugrunde liegenden Prinzipien dargestellt, klinische Aspekte und Ergebnisse der
einzelnen Methoden dargestellt und abschließend eine Übersicht zu
Indikationsstellungen gegeben.
“Just Got Diagnosed; What Worked for You?”: A Mixed-Methods Analysis of Treatment Experiences in the Prolactinoma Subreddit
Authors: Dimitroyannis Rose , Fenton David , Thodupunoori Sharanya , Cho Stella , Nordgren Rachel , Polster Sean P. , Horowitz Peleg M. , Das Paramita , Roxbury Christopher R.
Published: July 2024

Introduction With improvement in complication and remission rates, recent studies have suggested the viability of transsphenoidal surgery as first-line management for prolactinomas. Reddit, an online forum, allows posters to interact with one another, and discuss symptoms, treatments, and disease courses through specialized forums known as “subreddits.” Given the lack of research comparing patient experience on pharmacotherapy versus surgery, we sought to assess the sentiment of treatment within the “r/Prolactinoma subreddit” community.

Methods A search was done by filtering the r/Prolactinoma subreddit. Posts were sorted by “top” of “all time,” meaning entries with the most engagement throughout the site's history. Welch's t-test was used to analyze treatment type, while sentiment regarding treatment was analyzed using grounded theory qualitative methods.

Results From 189 total entries, 82 were included; 33% (n = 27/82) were posts. Of posters disclosing their treatment, 11% underwent surgery (n = 9/79), while 76% received medication (n = 60/79). The proportion of positive:negative sentiment and level of engagement on posts regarding pharmacotherapy versus surgical treatments were not significantly different (p > 0.05). Qualitative analysis showed themes of changes after medical treatment, immediate changes postsurgery, and online community.

Conclusion Our mixed-methods study found statistically nonsignificant differences in sentiment when comparing Reddit posts from patients who underwent medical and surgical management. Qualitative analysis revealed several themes regarding patients' perceptions of medical and surgical management and the benefits of an online community. The qualitative themes brought to light by this study may serve to inform future studies examining the patient experience with prolactinoma care.
Are Neonatal Birth Weights Reduced in Low-Risk Patients Diagnosed with COVID-19 during Pregnancy?
Authors: Foster Hannah S. , Forkpa Markolline , Van Tienhoven Ximena A. , Schwartz Nadav , Srinivas Sindhu , Parry Samuel , Mccabe Meaghan G.
Published: July 2024

Objective Studies have shown that the 2019 novel coronavirus disease (COVID-19) may be associated with an increased risk of adverse pregnancy outcomes including preeclampsia, preterm birth, and stillbirth. However, the relationship between COVID-19 and abnormal fetal growth (i.e., low neonatal birth weight) has not been elucidated. Because other viruses affect fetal growth, obstetrical providers began to recommend ultrasound studies during the third trimester to assess fetal growth in patients with COVID-19 during pregnancy. The aim of this study was to determine if neonatal birth weight was different between low-risk patients diagnosed with COVID-19 during pregnancy and low-risk patients without COVID-19 in pregnancy, to ascertain if third trimester growth ultrasound is warranted in this patient population.

Study Design We performed a retrospective cohort study of low-risk pregnant patients (who had no other indications for sonographic fetal surveillance during the third trimester) with and without COVID-19 during pregnancy. Patient demographics, gestational dating, neonatal birth weights, and corresponding Alexander growth curve birth weight percentiles were collected. The primary outcome was small-for-gestational age (SGA) neonates, defined as birth weight < 10th percentile for gestational age at delivery (SGA10).

Results Our cohort (N = 513) included 248 COVID-19-exposed patients and 265 patients who did not have COVID-19 during pregnancy. Gestational age at delivery and average neonatal birth weights were similar in COVID-19-exposed (38 weeks 5 days, 3,266 g) and unexposed patients (38 weeks 4 days, 3,224 g; p = 0.434, 0.358). Rates of SGA10 neonates were similar in the COVID-19-exposed (22/248, 8.9%) and -unexposed (23/265, 8.7%, p = 0.939) groups. Timing and severity of COVID-19 during pregnancy also were not associated with rates of SGA neonates.

Conclusion In a cohort of low-risk patients, rates of SGA neonates were similar in patients with and without COVID-19 during pregnancy. These findings suggest that ultrasound surveillance to detect fetal growth restriction in low-risk patients with COVID-19 during pregnancy is not warranted.

Key Points
Evaluation of Volumetric Changes between Pediatric Rotary Files and Manual Files during Canal Preparation of Primary Mandibular Canine: A Nano-CT Analysis
Authors: Suresh Balaji , Jeevanandan Ganesh , Ravindran Vignesh , Vishwanathaiah Satish , Panda Suman , Syed Ather Ahmed , Altowairqi Sultan , AlShehri Aram , Alaqla Ali , Khanagar Sanjeev , Maganur Prabhadevi
Published: July 2024

Objective Pediatric endodontics has become popular due to advancements in cleaning, shaping, and irrigation systems, resulting in faster and effective removal of infected pulp, saving time, and creating a pathogen-free environment. The patented rotary file system, Kedo S, designed for primary teeth, introduced a single file generation for efficient pulp therapy. However, there are currently no studies assessing canal preparation in primary mandibular canine using nano-computed tomography (nano-CT). This study aims to evaluate the efficacy of rotary file systems (Kedo S plus, Kedo SG blue) against traditional hand files in root canal preparation of primary mandibular canines using nano-CT.

Materials and Methods This in vitro study was performed in extracted primary mandibular canine based on certain inclusion and exclusion criteria. Samples were prepared and working length was determined before the preoperative scan using a high-resolution nano-CT device (SkyScan 2214, Bruker, Kontich, Belgium). A single well-experienced pediatric dentist prepared the canals using three file systems: Kedo S plus, Kedo SG blue, and hand K-files. A postoperative scan was performed similar to preoperative scan. Image reconstruction was performed with NRecon software for three-dimensional volumetric visualization and analysis of the root canals.

Results Kedo S plus displayed significant alterations in volumetric, surface area, and instrumented areas postpreparation compared with Kedo SG blue and hand files. Statistical analysis revealed significant differences in volumetric and surface changes between Kedo S plus and hand files.

Conclusion Rotary file systems, especially Kedo S plus, resulted in increased canal volume and surface area with minimal uninstrumented areas, showing promise for primary dentition root canal preparations. Further clinical assessments are warranted to validate these findings.
Pathways to Neuropalliative Care Practice
Authors: Harrigan Eileen , Kirsch Hannah L. , Adjepong Kwame , Crooms Rita Caroline
Published: July 2024

As neuropalliative care is better recognized and more widely utilized, there is as great a need for clinicians trained in the field as there is for disease-specific symptom management, advance care planning, and end-of-life care. In this manuscript, we describe potential career trajectories in neuropalliative care. For clinicians, this includes educational and training opportunities within primary neuropalliative care (integrating palliative care principles into usual neurology practice), specialty neuropalliative care (completing a hospice and palliative medicine fellowship), and hospice. We also describe considerations for establishing new clinical neuropalliative practices and highlight neuropalliative education and research as key areas for advancing the field.
The Young: Early-Onset Colon Cancer
Authors: Cohen David , Rogers Caitlin , Gabre Joel , Dionigi Beatrice
Published: July 2024

Early-onset colorectal cancer (EO-CRC), characterized by diagnosis before the age of 50 years, has emerged as a significant healthcare challenge with increasing global incidence. While traditional risk factors such as family history and inherited syndromes contribute to EO-CRC, a substantial proportion of cases remain sporadic, necessitating further investigation into additional etiological factors. Molecular studies reveal heterogeneity in EO-CRC, with distinct mutational profiles compared to late-onset CRC. Clinical management presents unique considerations, including challenges in early detection and treatment strategies tailored to younger patients. Addressing EO-CRC requires a multidisciplinary approach integrating epidemiological, molecular, and clinical insights to improve prevention, diagnosis, and therapeutic outcomes. Emerging research avenues explore novel biomarkers and therapeutic targets, offering promise for advancing understanding and management of this disease in contemporary oncology practice.
Coordinative Europeanization and Russia’s war of aggression: how crises shape Europeanization dynamics in EU foreign policy
Authors: Juncos Ana E. , Lovato Marianna , Pomorska Karolina
Published: July 2024

The European Union’s response to Russia’s war of aggression has run contrary to expectations of EU foreign policy inaction and incoherence as well as warnings of de-Europeanization and renationalization of foreign policy. Drawing on the concept of coordinative Europeanization, we argue that the response to the war has allowed for a more horizontal, cooperative decision-making process involving both member states and EU institutions, as well as a reversal of traditionally Western European-centric dynamics of horizontal Europeanization. With the aim of investigating these changes further, this paper relies on the 2022 Russian invasion of Ukraine as a case study to explore how crises shape Europeanization dynamics in EU foreign and security policy. Relying on primary and secondary sources as well as interviews with EU and national officials, we show how the coordinative Europeanization we have witnessed since the start of the war can be attributed to the characteristics of the crisis itself. In so doing, the paper contributes to the literature on Europeanization of foreign policy as well as to studies focusing on the effect of crises on the process of European integration.
A method to prevent clogging and clustering in microfluidic systems using microbubble streaming
Authors: Bakhtiari Amirabas , Kähler Christian J.
Published: July 2024

This paper presents an innovative strategy to address the issues of clogging and cluster-related challenges in microchannels within microfluidic devices. Leveraging three-dimensional (3D) microbubble streaming as a dynamic solution, our approach involves the controlled activation of microbubbles near channel constrictions, inducing microstreaming with distinctive features. This microstreaming, characterized by a high non-uniform 3D gradient and significant shear stress, effectively inhibits arch formation at constrictions and disintegrates particle clusters, demonstrating real-time prevention of clogging incidents and blockages. This study includes experimental validation of the anti-clogging technique, a detailed examination of microstreaming phenomena, and their effects on clogging and clustering issues. It also incorporates statistical analyses performed in various scenarios to verify the method’s effectiveness and adaptability. Moreover, a versatile control system has been designed that operates in event-triggered, continuous, or periodic modes, which suits different lab-on-a-chip applications and improves the overall functionality of microfluidic systems.
Monitoring tropical freshwater fish with underwater videography and deep learning
Authors: Jansen Andrew , van Bodegraven Steve , Esparon Andrew , Gadhiraju Varma , Walker Samantha , Buccella Constanza , Bock Kris , Loewensteiner David , Mooney Thomas J. , Harford Andrew J. , Bartolo Renee E. , Humphrey Chris L.
Published: July 2024

Context The application of deep learning to monitor tropical freshwater fish assemblages and detect potential anthropogenic impacts is poorly understood. Aims This study aimed to compare the results between trained human observers and deep learning, using the fish monitoring program for impact detection at Ranger Uranium Mine as a case study. Methods Fish abundance (MaxN) was measured by trained observers and deep learning. Microsoft’s Azure Custom Vision was used to annotate, label and train deep learning models with fish imagery. PERMANOVA was used to compare method, year and billabong. Key results Deep learning model training on 23 fish taxa resulted in mean average precision, precision and recall of 83.6, 81.3 and 89.1%, respectively. PERMANOVA revealed significant differences between the two methods, but no significant interaction was observed in method, billabong and year. Conclusions These results suggest that the distribution of fish taxa and their relative abundances determined by deep learning and trained observers reflect similar changes between control and exposed billabongs over a 3-year period. Implications The implications of these method-related differences should be carefully considered in the context of impact detection, and further research is required to more accurately characterise small-growing schooling fish species, which were found to contribute significantly to the observed differences.
Evaluation of genetic markers for the metabarcoding of Australian marsupials from predator scats
Authors: Campbell Catriona D. , MacDonald Anna J. , Sarre Stephen D.
Published: July 2024

Context DNA recovered from predator faeces (scats) can be used to determine the presence of fauna and shed light on their life histories and inter-species interactions. DNA metabarcoding, which involves concurrent amplification and sequencing of DNA from multiple taxa, represents an important advance by enabling the simultaneous detection of multiple species from such samples. Although an attractive proposition, metabarcoding requires ‘universally’ applicable genetic markers that can discriminate among a broad range of taxa, while also targeting sequences that are sufficiently short to be amplified from degraded DNA. Aims To identify, evaluate, and test metabarcoding DNA markers suitable for the detection of marsupials and other Australian fauna from terrestrial predator scats found in nature. Methods We apply a bioinformatic approach using publicly available DNA databases and a locally derived and marker-specific reference-DNA database to evaluate the diagnostic ability and likelihood of amplification of candidate metabarcoding markers for marsupials and other taxa that may be consumed by predators. Key results We identify two markers (12SV5 and 16SMam) that are suitable for use and successfully identify marsupial sequences at a high level of resolution. These markers work best in combination because they bring complementary levels of primer specificity and diagnostic ability in detecting multiple prey species as well as the predator. We also show that these samples work well in predator scats sampled from the wild in Tasmania. Conclusions These markers provide a useful tool for surveying mammalian predators and their prey and could also be applied to eDNA analyses from other sample types. Improvements to the reference database and further development of markers targeting different taxonomic groups will improve the resolution and usefulness of this approach. Implications Metabarcoding of predator scats provides a potent approach to non-invasive wildlife survey that offers the opportunity for the detection of multiple species across all vertebrates.
Data-driven inverse design of flexible pressure sensors
Authors: Liu Zhiguang , Cai Minkun , Hong Shenda , Shi Junli , Xie Sai , Liu Chang , Du Huifeng , Morin James D. , Li Gang , Wang Liu , Wang Hong , Tang Ke , Fang Nicholas X. , Guo Chuan Fei
Published: July 2024

Artificial skins or flexible pressure sensors that mimic human cutaneous mechanoreceptors transduce tactile stimuli to quantitative electrical signals. Conventional trial-and-error designs for such devices follow a forward structure-to-property routine, which is usually time-consuming and determines one possible solution in one run. Data-driven inverse design can precisely target desired functions while showing far higher productivity, however, it is still absent for flexible pressure sensors because of the difficulties in acquiring a large amount of data. Here, we report a property-to-structure inverse design of flexible pressure sensors, exhibiting a significantly greater efficiency than the conventional routine. We use a reduced-order model that analytically constrains the design scope and an iterative “jumping-selection” method together with a surrogate model that enhances data screening. As an exemplary scenario, hundreds of solutions that overcome the intrinsic signal saturation have been predicted by the inverse method, validating for a variety of material systems. The success in property design on multiple indicators demonstrates that the proposed inverse design is an efficient and powerful tool to target multifarious applications of flexible pressure sensors, which can potentially advance the fields of intelligent robots, advanced healthcare, and human–machine interfaces.
Reassessing the exon–foldon correspondence using frustration analysis
Authors: Galpern Ezequiel A. , Jaafari Hana , Bueno Carlos , Wolynes Peter G. , Ferreiro Diego U.
Published: July 2024

Protein folding and evolution are intimately linked phenomena. Here, we revisit the concept of exons as potential protein folding modules across a set of 38 abundant and conserved protein families. Taking advantage of genomic exon–intron organization and extensive protein sequence data, we explore exon boundary conservation and assess the foldon-like behavior of exons using energy landscape theoretic measurements. We found deviations in the exon size distribution from exponential decay indicating selection in evolution. We show that when taken together there is a pronounced tendency to independent foldability for segments corresponding to the more conserved exons, supporting the idea of exon–foldon correspondence. While 45% of the families follow this general trend when analyzed individually, there are some families for which other stronger functional determinants, such as preserving frustrated active sites, may be acting. We further develop a systematic partitioning of protein domains using exon boundary hotspots, showing that minimal common exons correspond with uninterrupted alpha and/or beta elements for the majority of the families but not for all of them.
Motorized chain models of the ideal chromosome
Authors: Cao Zhiyu , Wolynes Peter G.
Published: July 2024

An array of motor proteins consumes chemical energy in setting up the architectures of chromosomes. Here, we explore how the structure of ideal polymer chains is influenced by two classes of motors. The first class which we call “swimming motors” acts to propel the chromatin fiber through three-dimensional space. They represent a caricature of motors such as RNA polymerases. Previously, they have often been described by adding a persistent flow onto Brownian diffusion of the chain. The second class of motors, which we call “grappling motors” caricatures the loop extrusion processes in which segments of chromatin fibers some distance apart are brought together. We analyze these models using a self-consistent variational phonon approximation to a many-body Master equation incorporating motor activities. We show that whether the swimming motors lead to contraction or expansion depends on the susceptibility of the motors, that is, how their activity depends on the forces they must exert. Grappling motors in contrast to swimming motors lead to long-ranged correlations that resemble those first suggested for fractal globules and that are consistent with the effective interactions inferred by energy landscape analyses of Hi-C data on the interphase chromosome.
甘青語言區域漢語副動詞附綴「是」
Authors: Shao Mingyuan , Lin Xuna
Published: July 2024

抽象的

副動詞作為甘青語言區域的重要特徵之一，廣泛分佈在甘青漢語中。雖然學者對它的語義、形態和句法特徵進行了描寫，以及確認此現象並非漢語內部創新，乃經由接觸而來，但對它的語法性質卻定性不準，且未描寫它在限定性、指稱轉換和預指照應等方面的特徵。本文以副動詞「是」為例，基於類型學視角，探討它的形態句法特徵，並詳細考察它的語法化過程，認為它兼有接觸引發的語法演變中「語法借用」和「語法複製」兩種類型特質。本文否定副動詞「是」的藏語拷貝說，而支持它來自阿勒泰類型語言。在區域特徵推移上，副動詞和連動結構在亞洲大陸上呈現明顯的地理互補分佈格局。
Atomic thermal fluctuation reduction method for robust local lattice structure identification in finite-temperature molecular dynamics
Authors: Hirano Atsuo , Tsunemoto Yosuke , Takahashi Akiyuki
Published: July 2024

Classical molecular dynamics (MD) is extensively employed to explore the properties, deformations, and fractures of materials at the atomic scale. Identifying local structures is crucial for understanding the mechanisms behind material deformation and fracture. Nevertheless, analyzing the local lattice structure at high temperatures poses challenges due to atomic thermal fluctuations, which act as noise and potentially lead to misjudgment of the local lattice structure. To date, various strategies have been implemented to circumvent this issue. However, they cannot be a solution because it is unable to reproduce phenomena unique to high temperatures, whereas others require significant computational resources. This paper introduces an innovative method to reduce atomic thermal fluctuations using a straightforward algorithm, thereby facilitating accurate identification of local lattice structures even at high temperatures. Our approach incorporates novel degrees of freedom, termed ‘Markers,’ that are linked to atoms. By reducing the thermal fluctuation of these Markers, precise analysis of the local lattice structure becomes feasible. The efficacy of this method is validated through its thermal reducibility and Markers trackabilities to atoms. Utilizing common neighbor analysis, the error rate for structure identification with our method is nearly 0% at temperatures up to 1200 K in Fe, in contrast to approximately 5% without it. Furthermore, the average distance between atoms and Markers remains below 0.1 Å. Applying our method to phase transformations, we successfully observed the transition from face-centered cubic to body-centered cubic structure in Fe at 1200 K. This method holds promise for expanding the capabilities of MD simulations at high temperatures.
Hawking for everyone: commemorating half a century of an unfinished scientific revolution
Authors: Pinochet Jorge
Published: July 2024

This year marks half a century since Stephen Hawking made his greatest scientific discovery by theoretically proving that ‘black holes ain’t so black’, as they behave like hot bodies with an absolute temperature that depends inversely on their mass. This discovery is expressed by a simple and elegant equation known as the Hawking temperature. The best way to commemorate this great scientific event is by bringing it to a wide audience. The simplest and most transparent and intuitive tool to achieve this goal is dimensional analysis. The objective of this work is to use this tool to derive the Hawking equation, reveal its meaning, and explore its main physical consequences.
Temperature gradient for improving the output non-linearity in shape memory alloy actuators
Authors: Osorio Salazar Andres , Sugahara Yusuke
Published: July 2024

The non-linearity of shape memory alloy’s (SMA) input vs. output relationship has been a significant barrier to their broader application for actuators. In this article, we introduce a novel activation approach with the objective of improving the output nonlinearity in SMA actuators by using a liquid temperature gradient for activation. This gradient, with a narrow inflection point, selectively activates and deactivates different portions of the SMA, allowing control of the overall actuator’s output by adjusting the inflection point’s position. Two prototypes with the proposed concept were constructed and tested for force and displacement output. Their inner shape design facilitates the creation of a temperature gradient, whose inflection point is adjusted by varying the mix ratio of the inlet of hot and cold water. The performance of the prototypes was evaluated, including their ability to generate a temperature gradient, output linearity, activation dead time and time constant, and compatibility with a linear controller. The output linearity, activation dead time, and time constant were also compared with traditional wet activation. Our findings suggest that this technique significantly enhances the performance and predictability of SMA-based actuators and is compatible with PID controllers without additional feedforward or modeling techniques, offering a practical solution to a long-standing challenge in the field.
Adsorption performance and its mechanism of uranium using rod-like hydroxyapatite by one-step hydrothermal method
Authors: Li Longxiang , Zhou Zhongkui , Wang Guanghui , Guo Yadan , Zhang Yishuo , Xin Yan
Published: July 2024

Rod-like Hydroxyapatite (HAP) was synthesized using a one-step hydrothermal method. The successful synthesis of HAP has been confirmed based on the results of XRD and EDS. TEM images show that the HAP synthesized through the one-step hydrothermal method exhibits a rod-like morphology with good dispersion and minimal stacking. There was no significant aggregation observed and the diameter is about 25 nm. Both single-factor experiments and orthogonal experiments were conducted to determine the optimal conditions for adsorbing uranium from wastewater with an initial concentration of 10 mg·l−1. The optimized parameters included a pH of 5.0, a HAP dosage of m = 0.01 g, a reaction time of t = 30 min, a temperature at room temperature, and an agitation speed of R = 120 r·min−1. Under these conditions, the uranium removal efficiency exceeded 98%. The impact of anions and cations in the solution on uranium adsorption by HAP was investigated, revealing that cations with higher valence and anions with higher charge density had a more pronounced effect on the adsorption process. The fitting results obtained using adsorption isotherm and kinetic models indicated that the primary mechanism of uranium adsorption was surface monolayer chemical adsorption. Thermodynamic parameters suggested that the adsorption of uranium onto HAP was a spontaneous, endothermic process driven by entropy. Characterization results from EDS, XRD, FTIR, and XPS techniques indicated that the mechanism of uranium adsorption by HAP involved electrostatic adsorption, dissolution–precipitation, and ion exchange processes.
Quantum fluctuation in the segregation phase of two-component weakly interacting Bose–Einstein condensates
Authors: Ng Dung L , Th Lam L , Tien L V , Song P Th
Published: July 2024

Our investigation focuses on the condensate density, excited and condensed fractions of bosons in a mixture of two-component segregated weakly interacting Bose–Einstein condensates (BECs) at zero temperature based on the Gross–Pitaevskii (GP) and Cornwall-Jackiw-Tomboulis (CJT) theories. We find that the repulsive interaction among interspecies of bosons is the origin of the local behavior and the decline of quantum fluctuation. These features are disparate to the single BEC or miscible BECs. The numerical evaluation of the condensed fraction is provided to support the experimental observation.
First-principles study of metal Li adsorption on RE-MoSe2 surface
Authors: Yuan Yue , Shen Tao , Feng Yue , Liu Chi , Liu Xin
Published: July 2024

This study focuses on the modification of the intrinsic MoSe2 using rare earth (RE) elements and investigates its structure, adsorption energy, magnetic properties and work function. Modification studies show that all doping models exhibit metallic properties and all introduce varying degrees of magnetism. In order to investigate the effect of modification means on the adsorption effect, the adsorption of Li on RE-MoSe2 at different sites was investigated by using first-principles density functional theory. It is found that although the doping of La element produces the strongest magnetism. However, its magnetism is significantly weakened or even disappears when Li is adsorbed on the Mo top site of the La-MoSe2 system. The adsorption energy of Li for the La-MoSe2 system is the opposite of what was concluded for the Ce-MoSe2 and Eu-MoSe2 systems. The adsorption stability of the Se top site of the La-MoSe2 system is the poorest, whereas it is the strongest in the other two systems. Research has shown that RE-MoSe2 could be a potential candidate for Li-absorbing materials.
High-temperature erosion behavior of Al2O3 reinforced Inconel625 high velocity oxy-fuel sprayed and direct-aged composite coatings
Authors: Prashar Gaurav , Vasudev Hitesh
Published: July 2024

In this study, Inconel625+30%Al2O3 (IN30AL) blended powders were sprayed on a commercially used boiler steel ASTM SA210 GrA1 using high-velocity oxy-fuel approach (HVOF). The microstructure, mechanical properties and elevated temperature erosion behavior of post-processed coatings and as-sprayed IN30ALcoatings were investigated. The elevated temperature erosion studies on IN30AL coatings both as-sprayed and post-processed were investigated at 900 °C temperature at two impact angles 30° and 90° using standard high temperature erosion test rig. Phase composition, interface of substrate/coating, and morphologies of eroded coatings were examined using x-ray diffraction, x-ray maps, scanning electron microscope, & energy dispersive spectrometer techniques. Compared with the as-sprayed IN30AL coatings, the heat-treated coatings have refined microstructure, better mechanical properties which improve the elevated temperature erosion resistance of IN30ALcoatings.