bluuebunny/crossref_metadata_2025 huggingface dataset:
The SIMULATE ureteroscopy training curriculum: educational value and transfer of skills
Authors: Aydın Abdullatif , Ahmed Kamran , Baig Umair , Raison Nicholas , Lantz Powers Andrea G. , Macchione Nicola , Al-Jabir Ahmed , Abe Takashige , Khan Muhammad Shamim , Dasgupta Prokar ,   the SIMULATE Trial Contributors
Published: February 2021

Objective

Different simulation modalities may be utilised in a curricular fashion to benefit from the strengths of each training model. The aim of this study is to evaluate a novel multi-modality ureterorenoscopy (URS) simulation curriculum in terms of educational value, content validity, transfer of skills and inter-rater reliability.

Methods

This international prospective study recruited urology residents (n = 46) with ≤ 10 URS experience and no prior simulation training. Participants were guided through each phase of the expert-developed SIMULATE URS curriculum by trainers and followed-up in the operating room (OR). Video recordings were obtained during training. A post-training evaluation survey was distributed to evaluate content validity and educational value, using descriptive statistics. Performance was evaluated using the objective structured assessment of technical skills (OSATS) scale to measure improvement in scores throughout the curriculum. Pearson’s correlation coefficient and Cohen’s kappa tests were utilised to investigate correlation and agreement between raters.

Results

Participants reported gaining OR-transferrable skills (Mean: 4.33 ± 0.67) and demonstrated marked improvement in throughout the curriculum, transferred to the OR for both semi-rigid URS (p = 0.004) and flexible URS (p = 0.007). 70% of participants were successfully followed-up in the OR (n = 32). No differences were identified with the additional use of fresh frozen cadavers (p = 0.85, p = 0.90) and the URO Mentor VR simulator (p = 0.13, p = 0.22). A moderate level of correlation was noted on the video OSATS assessments, between two expert assessors (r = 0.70), but a poor agreement with the live rating.

Conclusion

The SIMULATE URS training curriculum received high educational value from participants, who demonstrated statistically significant improvement with consecutive cases throughout the curriculum and transferability of skills to the OR in both semi-rigid and flexible URS.
Implementation and training with laparoscopic distal pancreatectomy: 23-year experience from a high-volume center
Authors: Sahakyan Mushegh A. , Røsok Bård I. , Tholfsen Tore , Kleive Dyre , Waage Anne , Ignjatovic Dejan , Buanes Trond , Labori Knut Jørgen , Edwin Bjørn
Published: February 2021

Background

Distal pancreatectomy is the most common procedure in minimally-invasive pancreatic surgery. Data in the literature suggest that the learning curve flattens after performing up to 30 procedures. However, the exact number remains unclear.

Methods

The implementation and training with laparoscopic distal pancreatectomy (LDP) in a high-volume center were studied between 1997 and 2020. Perioperative outcomes and factors related to conversion were assessed. The individual experiences of four different surgeons (pioneer and adopters) performing LDP on a regular basis were examined.

Results

Six hundred forty LDPs were done accounting for 95% of all distal pancreatectomies performed throughout the study period. Conversion was needed in 14 (2.2%) patients due to intraoperative bleeding or tumor adherence to the major vasculature. Overall morbidity and mortality rates were 35 and 0.6%, respectively. Intra- and postoperative outcomes did not change for any of the surgeons within their first 40 cases. Operative time significantly decreased after the first 80 cases for the pioneer surgeon and did not change afterwards although the proportion of ductal adenocarcinoma increased. Tumor size increased after the first 80 cases for the first adopter without affecting the operative time.

Conclusions

In this nearly unselected cohort, no significant changes in surgical outcomes were observed throughout the first 40 LDPs for different surgeons. The exact number of procedures required to overcome the learning curve is difficult to determine as it seems to depend on patient selection policy and specifics of surgical training at the corresponding center.
Sensitivity of anti-SARS-CoV-2 serological assays in a high-prevalence setting
Authors: Müller Lisa , Ostermann Philipp Niklas , Walker Andreas , Wienemann Tobias , Mertens Alexander , Adams Ortwin , Andree Marcel , Hauka Sandra , Lübke Nadine , Keitel Verena , Drexler Ingo , Di Cristanziano Veronica , Hermsen Derik Franz , Kaiser Rolf , Boege Friedrich , Klein Florian , Schaal Heiner , Timm Jörg , Senff Tina
Published: February 2021

Evaluation and power of seroprevalence studies depend on the performed serological assays. The aim of this study was to assess four commercial serological tests from EUROIMMUN, DiaSorin, Abbott, and Roche as well as an in-house immunofluorescence and neutralization test for their capability to identify SARS-CoV-2 seropositive individuals in a high-prevalence setting. Therefore, 42 social and working contacts of a German super-spreader were tested. Consistent with a high-prevalence setting, 26 of 42 were SARS-CoV-2 seropositive by neutralization test (NT), and immunofluorescence test (IFT) confirmed 23 of these 26 positive test results (NT 61.9% and IFT 54.8% seroprevalence). Four commercial assays detected anti-SARS-CoV-2 antibodies in 33.3-40.5% individuals. Besides an overall discrepancy between the NT and the commercial assays regarding their sensitivity, this study revealed that commercial SARS-CoV-2 spike-based assays are better to predict the neutralization titer than nucleoprotein-based assays are.
SARS-CoV-2 is rapidly inactivated at high temperature
Authors: Biryukov Jennifer , Boydston Jeremy A. , Dunning Rebecca A. , Yeager John J. , Wood Stewart , Ferris Allison , Miller David , Weaver Wade , Zeitouni Nathalie E. , Freeburger Denise , Dabisch Paul , Wahl Victoria , Hevey Michael C. , Altamura Louis A.
Published: February 2021

In the absence of a vaccine, preventing the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the primary means to reduce the impact of the 2019 coronavirus disease (COVID-19). Multiple studies have reported the presence of SARS-CoV-2 genetic material on surfaces suggesting that fomite transmission of SARS-CoV-2 is feasible. High temperature inactivation of virus has been previously suggested, but not shown. In the present study, we investigated the environmental stability of SARS-CoV-2 in a clinically relevant matrix dried onto stainless steel at a high temperature. The results show that at 54.5 °C, the virus half-life was 10.8 ± 3.0 min and the time for a 90% decrease in infectivity was 35.4 ± 9.0 min. These findings suggest that in instances where the environment can reach temperatures of at least 54.5 °C, such as in vehicle interior cabins when parked in warmer ambient air, that the potential for exposure to infectious virus on surfaces could be decreased substantially in under an hour.
Surfactants: physicochemical interactions with biological macromolecules
Authors: Aguirre-Ramírez M. , Silva-Jiménez H. , Banat I. M. , Díaz De Rienzo M. A.
Published: February 2021

Macromolecules are essential cellular components in biological systems responsible for performing a large number of functions that are necessary for growth and perseverance of living organisms. Proteins, lipids and carbohydrates are three major classes of biological macromolecules. To predict the structure, function, and behaviour of any cluster of macromolecules, it is necessary to understand the interaction between them and other components through basic principles of chemistry and physics. An important number of macromolecules are present in mixtures with surfactants, where a combination of hydrophobic and electrostatic interactions is responsible for the specific properties of any solution. It has been demonstrated that surfactants can help the formation of helices in some proteins thereby promoting protein structure formation. On the other hand, there is extensive research towards the use of surfactants to solubilize drugs and pharmaceuticals; therefore, it is evident that the interaction between surfactants with macromolecules is important for many applications which includes environmental processes and the pharmaceutical industry. In this review, we describe the properties of different types of surfactants that are relevant for their physicochemical interactions with biological macromolecules, from macromolecules–surfactant complexes to hydrophobic and electrostatic interactions.
Unaided dispersal risk of Magallana gigas into and around the UK: combining particle tracking modelling and environmental suitability scoring
Authors: Wood Louisa E. , Silva Tiago A. M. , Heal Richard , Kennerley Adam , Stebbing Paul , Fernand Liam , Tidbury Hannah J.
Published: February 2021

Marine non-indigenous species are a significant threat to marine ecosystems with prevention of introduction and early detection considered to be the only effective management strategy. Knowledge of the unaided pathway has received relatively little attention, despite being integral to the implementation of robust monitoring and surveillance. Here, particle tracking modelling is combined with spatial analysis of environmental suitability, to highlight UK coastal areas at risk of introduction and spread of Magallana gigas by the unaided pathway. ‘Introduction into UK’ scenarios were based on spawning from the continental coast, Republic of Ireland, Channel Islands and Isle of Man and ‘spread within UK’ scenarios were based on spawning from known UK wild populations and aquaculture sites. Artificial structures were included as spawning sites in an introduction scenario. The UK coast was scored, based on parameters influencing larval settlement, to reflect environmental suitability. Risk maps were produced to highlight areas of the UK coast at elevated risk of introduction and spread of M. gigas by the unaided pathway. This study highlights that introduction of M. gigas into UK waters via the unaided pathway is possible, with offshore structures increasing the potential geographical extent of introduction. Further, there is potential for substantial secondary spread from aquaculture sites and wild populations in the UK. The results of the study are considered in the context of national M. gigas management, whilst the approach is contextualised more broadly as a tool to further understanding of a little-known, yet significant pathway.
Theoretical and Methodological Approaches to Ecological Changes, Social Behaviour and Human Intergroup Tolerance 300,000 to 30,000 BP
Authors: Spikins Penny , French Jennifer C. , John-Wood Seren , Dytham Calvin
Published: February 2021

Archaeological evidence suggests that important shifts were taking place in the character of human social behaviours 300,000 to 30,000 years ago. New artefact types appear and are disseminated with greater frequency. Transfers of both raw materials and finished artefacts take place over increasing distances, implying larger scales of regional mobility and more frequent and friendlier interactions between different communities. Whilst these changes occur during a period of increasing environmental variability, the relationship between ecological changes and transformations in social behaviours is elusive. Here, we explore a possible theoretical approach and methodology for understanding how ecological contexts can influence selection pressures acting on intergroup social behaviours. We focus on the relative advantages and disadvantages of intergroup tolerance in different ecological contexts using agent-based modelling (ABM). We assess the relative costs and benefits of different ‘tolerance’ levels in between-group interactions on survival and resource exploitation in different environments. The results enable us to infer a potential relationship between ecological changes and proposed changes in between-group behavioural dynamics. We conclude that increasingly harsh environments may have driven changes in hormonal and emotional responses in humans leading to increasing intergroup tolerance, i.e. transformations in social behaviour associated with ‘self-domestication’. We argue that changes in intergroup tolerance is a more parsimonious explanation for the emergence of what has been seen as ‘modern human behaviour’ than changes in hard aspects of cognition or other factors such as cognitive adaptability or population size.
Edoxaban, a direct oral factor Xa inhibitor, ameliorates coagulation, microvascular thrombus formation, and acute liver injury in a lipopolysaccharide-induced coagulopathy model in rats
Authors: Morishima Yoshiyuki , Shibutani Tomoko , Noguchi Kengo , Ito Yusuke , Honda Yuko
Published: February 2021

Infection increases the risk of thrombosis through the activation of inflammation and coagulation. Edoxaban, a direct oral factor Xa inhibitor, is used for the prevention and treatment of thrombotic diseases. The aim of this study was to determine the effects of edoxaban on microvascular thrombus formation in a rat model of lipopolysaccharide (LPS)-induced coagulopathy. Rats were intravenously injected with 7.5 mg/kg of LPS (Escherichia coli055:B5). Immediately after LPS injection, the rats were treated with subcutaneous injection of edoxaban. At 2 and 6 h after the injection of LPS, biomarkers of coagulation and organ damages and inflammatory cytokines were measured. Microvascular thrombus formation in organs was evaluated using125I-fibrinogen (human) or by the pathological analysis. Mortality was examined 24 h after LPS injection. After the injection of LPS, D-dimer and thrombin-antithrombin complex increased and platelet numbers decreased, indicating the activation of coagulation. Microvascular thrombi were found in the liver. Markers of liver injury (aspartate aminotransferase and alanine aminotransferase) also increased. Treatment with edoxaban attenuated the changes in the coagulation markers and microvascular thrombus formation in the liver. Edoxaban suppressed the increase in the liver injury markers and reduced the mortality. Edoxaban did not affect the levels of inflammatory cytokines. In conclusions, edoxaban significantly inhibited the activation of coagulation, the formation of microvascular thrombus in the liver and the liver damage, and reduced mortality in rats injected with LPS. These results suggest that the FXa inhibition by edoxaban might be a beneficial therapy for the management of infection-associated thrombosis.
Filling the Disaster Data Gap: Lessons from Cataloging Singapore’s Past Disasters
Authors: Lin Yolanda C. , Khan Feroz , Jenkins Susanna F. , Lallemant David
Published: February 2021

International disaster databases and catalogs provide a baseline for researchers, governments, communities, and organizations to understand the risk of a particular place, analyze broader trends in disaster risk, and justify investments in mitigation. Perhaps because Singapore is routinely identified as one of the safest countries in the world, Singapore’s past disasters have not been studied extensively with few events captured in major global databases such as EM-DAT. In this article, we fill the disaster data gap for postwar Singapore (1950–2020) using specified metrics through an archival search, review of literature, and analysis of secondary sources. We present four key lessons from cataloging these events. First, we expand Singapore’s disaster catalog to 39 events in this time period and quantify the extent of this data gap. Second, we identify the mitigating actions that have followed past events that contribute to Singapore’s present-day safety. Third, we discuss how these past events uncover continuities among vulnerability bearers in Singapore. Last, we identify limitations of a disaster catalog when considering future risks. In expanding the disaster catalog, this case study of Singapore supports the need for comprehensive understanding of past disasters in order to examine current and future disaster resilience.
Physics of kinetic Alfvén waves: a gyrokinetic theory approach
Authors: Chen Liu , Zonca Fulvio , Lin Yu
Published: February 2021

The transverse shear Alfvén wave (SAW) is a fundamental anisotropic electromagnetic oscillation in plasmas with a finite background magnetic field. In realistic plasmas with spatial inhomogeneities, SAW exhibits the interesting spectral feature of a continuous spectrum. That is, the SAW oscillation frequency varies in the non-uniform (radial) direction. This continuum spectral feature then naturally leads to the phase-mixing process; i.e., time asymptotically, the effective radial wave-number increases with time. Any initial perturbation of SAW structures will, thus, evolve eventually into short-wavelength structures; termed as kinetic Alfvén wave (KAW). Obviously, one needs to employ kinetic theory approach to properly describe the dynamics of KAW; including effects such as finite ion-Larmor radius (FILR) and/or wave–particle interactions. When KAW was first discovered and discussed in 1975–1976, it was before the introduction of the linear electromagnetic gyrokinetic theory (1978) and nonlinear electromagnetic gyrokinetic theory (1982). Kinetic treatments then often involved the complicated procedures of taking the low-frequency limit of the Vlasov kinetic theory and/or employing the drift-kinetic theory approach; forsaking, thus, the FILR effects. In recent years, the powerful nonlinear gyrokinetic theory has been employed to re-examine both the linear and nonlinear physics of KAWs. This brief review will cover results of linear and nonlinear analytical theories, simulations, as well as observational evidences. We emphasize, in particular, that due to the enhanced electron–ion de-coupling in the short-wavelength regime, KAWs possess significantly enhanced nonlinear coupling coefficients and, thereby, play important roles in the heating, acceleration, and transport processes of charged particles in magnetized plasmas.
Perspectives on the antibiotic contamination, resistance, metabolomics, and systemic remediation
Authors: Sodhi Kushneet Kaur , Kumar Mohit , Balan Biji , Dhaulaniya Amit Singh , Shree Pallee , Sharma Nitika , Singh Dileep Kumar
Published: February 2021

Antibiotics have been regarded as the emerging contaminants because of their massive use in humans and veterinary medicines and their persistence in the environment. The global concern of antibiotic contamination to different environmental matrices and the emergence of antibiotic resistance has posed a severe impact on the environment. Different mass-spectrometry-based techniques confirm their presence in the environment. Antibiotics are released into the environment through the wastewater steams and runoff from land application of manure. The microorganisms get exposed to the antibiotics resulting in the development of antimicrobial resistance. Consistent release of the antibiotics, even in trace amount into the soil and water ecosystem, is the major concern because the antibiotics can lead to multi-resistance in bacteria which can cause hazardous effects on agriculture, aquaculture, human, and livestock. A better understanding of the correlation between the antibiotic use and occurrence of antibiotic resistance can help in the development of policies to promote the judicious use of antibiotics. The present review puts a light on the remediation, transportation, uptake, and antibiotic resistance in the environment along with a novel approach of creating a database for systemic remediation, and metabolomics for the cleaner and safer environment.
Numerical simulation of periodic MHD casson nanofluid flow through porous stretching sheet
Authors: Al-Mamun Abdullah , Arifuzzaman S. M. , Reza-E-Rabbi Sk. , Alam Umme Sara , Islam Saiful , Khan Md. Shakhaoath
Published: February 2021

The perspective of this paper is to characterize a Casson type of Non-Newtonian fluid flow through heat as well as mass conduction towards a stretching surface with thermophoresis and radiation absorption impacts in association with periodic hydromagnetic effect. Here heat absorption is also integrated with the heat absorbing parameter. A time dependent fundamental set of equations, i.e. momentum, energy and concentration have been established to discuss the fluid flow system. Explicit finite difference technique is occupied here by executing a procedure in Compaq Visual Fortran 6.6a to elucidate the mathematical model of liquid flow. The stability and convergence inspection has been accomplished. It has observed that the present work converged at, Pr ≥ 0.447 indicates the value of Prandtl number and Le ≥ 0.163 indicates the value of Lewis number. Impact of useful physical parameters has been illustrated graphically on various flow fields. It has inspected that the periodic magnetic field has helped to increase the interaction of the nanoparticles in the velocity field significantly. The field has been depicted in a vibrating form which is also done newly in this work. Subsequently, the Lorentz force has also represented a great impact in the updated visualization (streamlines and isotherms) of the flow field. The respective fields appeared with more wave for the larger values of magnetic parameter. These results help to visualize a theoretical idea of the effect of modern electromagnetic induction use in industry instead of traditional energy sources. Moreover, it has a great application in lung and prostate cancer therapy.
Comparison of feature importance measures as explanations for classification models
Authors: Saarela Mirka , Jauhiainen Susanne
Published: February 2021

Explainable artificial intelligence is an emerging research direction helping the user or developer of machine learning models understand why models behave the way they do. The most popular explanation technique is feature importance. However, there are several different approaches how feature importances are being measured, most notably global and local. In this study we compare different feature importance measures using both linear (logistic regression with L1 penalization) and non-linear (random forest) methods and local interpretable model-agnostic explanations on top of them. These methods are applied to two datasets from the medical domain, the openly available breast cancer data from the UCI Archive and a recently collected running injury data. Our results show that the most important features differ depending on the technique. We argue that a combination of several explanation techniques could provide more reliable and trustworthy results. In particular, local explanations should be used in the most critical cases such as false negatives.
Numerical simulation for the steady nanofluid boundary layer flow over a moving plate with suction and heat generation
Authors: Ferdows M. , Shamshuddin MD. , Salawu S. O. , Zaimi K.
Published: February 2021

In the study, the steady, laminar, incompressible, convective flow of a viscous fluid over a moving plate is investigated theoretically by adopting different types of nanoparticles. Radiation, internal heat generation and viscous dissipation effects are considered in the energy modeled equation. The governing flow equations for the momentum and temperature are reduced to dimensionless form via similarity transformations. The solutions to the resultant equations alongside with the transformed boundary conditions are numerically obtained using MATLAB package bvp4c. Validation with earlier studies are done for the non-internal heat generation case for two distinct nanoparticles of type Cu-water and Al-water. Extensive visualization of flow rate and heat distributions for various emerging parameters are examined. Temperature is consistently enhanced with a rising Eckert number of both types of nanofluids, whereas it is strongly reduced with rising values of radiation term. Heat transfer coefficient is consistently increased with a nanoparticle volume fraction of high convective heat in the medium.
Assessment of mosquito larvae (Diptera: Culicidae) productivity in urban cemeteries in Wroclaw (SW Poland)
Authors: Rydzanicz Katarzyna , Czułowska Aleksandra , Dyczko Dagmara , Kiewra Dorota
Published: February 2021

In many European countries, cemeteries are found to be suitable habitats for the proliferation of native and invasive mosquito species. The study aimed to assess for the first time in Poland the suitability of urban cemeteries for mosquito larvae development in water supply wells. From May to September 2019 in three urban cemeteries in Wroclaw (SW Poland), a total of 757 inspection of water supply wells were carried out. The mosquito larvae development, expressed as the general container index (GCI), differed between the examined areas and months of the study. The highest GCI value was calculated for Grabiszyński and Bujwida cemeteries (72.0 % and 59.3 % respectively). Larvae of three native mosquito species were identified in all inspected breeding places during the survey: Culex pipiens s.l. Linnaeus (95 %), Cx. torrentium Martini (4 %), Anopheles maculipennis s.l. Meigen (less than 1 %). No larvae of invasive Aedes mosquito species were found. In the inspected water supply wells larval productivity peaked in June, when the average temperature reached 22.7 °C. Due to the likelihood of the establishment and adaptation of invasive aedine mosquito species in Poland, constant analysis of the larvae composition in cemeteries should be continued.
Bibliotherapy for Sexual Dysfunctions: A Systematic Review and Meta-Analysis
Authors: van Lankveld Jacques J.D.M. , van de Wetering Fleur T. , Wylie Kevan , Scholten Rob J.P.M.
Published: February 2021

Aim

The objective of this study was to assess the efficacy of bibliotherapy for sexual dysfunctions, when compared with no treatment and compared with other interventions.

Methods

MEDLINE, EMBASE, and PsycINFO were searched from 1970 to January 2020. Selection criteria were randomized controlled trials evaluating assisted or unassisted bibliotherapy for all types of sexual dysfunctions compared with no treatment (wait list or placebo) or with other psychological interventions. Bibliotherapy is defined as psychological treatment using printed instruction to be used by the individual or couple suffering from sexual dysfunction. Primary outcome measures were male and female sexual functioning level and continuation/remission of sexual dysfunction. Secondary outcomes were sexual satisfaction and dropout rate. Sexual functioning and sexual satisfaction were self-reported by participants using validated questionnaires.

RESULTS

Fifteen randomized controlled trials with a total of 1,113 participants (781 women; 332 men) met inclusion criteria. Compared with no treatment, unassisted bibliotherapy resulted in larger proportions of female participants reporting remission of sexual dysfunction, and sexual satisfaction was higher in treated participants, both female and male participants. Compared with no treatment, assisted bibliotherapy had significant positive effects on female sexual functioning; no effects on male sexual functioning were found. Results of unassisted and assisted bibliotherapy did not differ from those of other intervention types on any outcome. Throughout, no differences between study conditions were found regarding dropout rates. The certainty of the evidence for all outcomes was rated as very low.

CONCLUSION

We found indications of positive effects of bibliotherapy for sexual dysfunctions. Across studies, more significant effects were found for women than for men. However, owing to limitations in the study designs and imprecision of the findings, we were unable to draw firm conclusions about the use of bibliotherapy for sexual dysfunction. More high quality and larger trials are needed. Relevant outcome measures for future studies should be defined as well as unified grading systems to measure these endpoints. In addition, future studies should report on treatment acceptability and adherence.
Square Pegs and Round Holes (Continued): Financial Market Surveillance Authorities and Internal Market Association
Authors: BAUR GEORGES S
Published: February 2021

After the financial crisis of 2008, the European Union (‘EU’) not only increased its substantial legislation regarding financial services, but also built up a strong and unified system of financial market supervision. In particular, central surveillance authorities were created. These were given far-reaching competences with regard to substituting dysfunctional national authorities or players in the financial services sector. The three European Economic Area (‘EEA’) and European Free Trade Association (‘EFTA’) States—Iceland, Liechtenstein, and Norway—participate in the EU's internal market through their membership of the EEA. In order to continue participating on an equal footing in the internal market for financial services and to honour their duty to maintain homogeneity, the EEA EFTA States also had to incorporate the new institutional setup regarding financial services supervision. This obligation, however, in particular relating to certain intrusive powers of the new surveillance authorities, collided with some constitutional reservations, above all of the two Nordic EEA EFTA States. This article will show how these conflicting aims could be merged into a system that on the one hand guarantees the unified overall approach needed for strengthened surveillance of the internal market for financial services, and on the other hand safeguards certain constitutional reservations of the EEA EFTA States. It also looks at how third countries that do not (fully) participate in the internal market, such as the United Kingdom and Switzerland, are likely to be treated in this context by the EU.
Rival principals and shrewd agents: Military assistance and the diffusion of warfare
Authors: Neads Alex
Published: February 2021

Military assistance is a perennial feature of international relations. Such programmes typically aim to improve the effectiveness of local partners, exporting the donor's way of war through the provision of training and equipment. By remaking indigenous armies in their own image, donors likewise hope to mitigate the profound agency costs associated with the transfer of military capability. But, while technical and organisational transformations can provide notable battlefield advantages, the philosophies underlying such innovations are not so easily propagated. Instead, new tactics, structures, and technologies typically intersect with pre-existing local schemata of war, producing novel if sometimes dysfunctional hybrid praxes. According to principal-agent theory, the application of greater conditionality in the provision of military assistance should improve the fidelity of military diffusion, aligning agents’ divergent interests with their principals’ goals. In practice, however, principal-agent exchanges rarely exist in isolation. Examining the modernisation of nineteenth-century Japan as a case study in military diffusion, this article argues that competition between rival patrons allows recipient states to play would-be principals off against each other, bypassing conditionality by replicating a marketplace for military assistance. In so doing, however, agents trade functionality for sovereignty in their military diffusion.
Imagining (in)security: NATO's collective self-defence and post-9/11 military policing in the Mediterranean Sea
Authors: Pomarède Julien
Published: February 2021

How do scenarios of dangerous futures imagined in the framework of the post-9/11 counterterrorism shape security institutions? Critical Security Studies (CSS)'s dominant answer is that state apparatus are significantly transformed by the use of new technologies of prediction that are very prolific in imagining potential risks. The present article questions this technologically determinist thesis. Introducing the notion of weak field in the study of pre-emption, it argues that the political sociology of transnational fields of power can help us in historicise and assess more precisely the impact of imagination over power and control in the pre-emptive era. The article analyses NATO's reaction to 9/11 as a case study. It shows how the fabrication of potential terrorist threats by NATO's practitioners, that served to justify the pre-emptive use of the collective self-defence clause of the Washington Treaty (Article 5), evolved into an ambiguous support for NATO's military policing of the Mediterranean basin and into its involvement in migration control.
An Identification-Based Method Improving the Transparency of a Robotic Upper Limb Exoskeleton
Authors: Verdel Dorian , Bastide Simon , Vignais Nicolas , Bruneau Olivier , Berret Bastien
Published: February 2021

Over the past decade, research on human–robot collaboration has grown exponentially, motivated by appealing applications to improve the daily life of patients/operators. A primary requirement in many applications is to implement highly “transparent” control laws to reduce the robot impact on human movement. This impact may be quantified through relevant motor control indices. In this paper, we show that control laws based on careful identification procedures improve transparency compared to classical closed-loop position control laws. A new performance index based on the ratio between electromyographic activity and limb acceleration is also introduced to assess the quality of human exoskeleton interaction.
Quantification of Nonlinear Multiphase Flow in Porous Media
Authors: Zhang Yihuai , Bijeljic Branko , Gao Ying , Lin Qingyang , Blunt Martin J.
Published: February 2021

We measure the pressure difference during two‐phase flow across a sandstone sample for a range of injection rates and fractional flows of water, the wetting phase, during an imbibition experiment. We quantify the onset of a transition from a linear relationship between flow rate and pressure gradient to a nonlinear power‐law dependence. We show that the transition from linear (Darcy) to nonlinear flow and the exponent in the power‐law is a function of fractional flow. We use energy balance to accurately predict the onset of intermittency for a range of fractional flows, fluid viscosities, and different rock types.
An Integrated Late Pleistocene to Holocene Tephrostratigraphic Framework for South‐East and East Asia
Authors: Sun Chunqing , Wang Luo , Plunkett Gill , Zhang Enlou , Liu Jiaqi
Published: February 2021

Volcanic ash has been widely used as unique independent marker horizons for dating and synchronizing paleoenvironments and archeological records. Here, we report a series of key widespread late Pleistocene to Holocene tephras horizons from a lake sequence in southern China that have significant potential for dating and synchronizing paleoenvironmental records from East Asia. Translatitudinal paleoclimatological, paleoenvironmental, and archeological correlations from the tropical Philippines, mainland China, and midlatitude Japan are achievable through these extensively distributed tephras, including synthetic studies of the Younger Dryas and mid‐Holocene climate events. Additionally, we establish refined ages for four pre‐1991 Pinatubo eruptions and date three late Pleistocene Luzon eruptions based on the lake sequence age model, which will facilitate future studies of tropical volcanic eruptions’ forcing of climate change. Our results highlight the volcanic hazards around densely populated East Asia, and bring solutions to resolving dating uncertainty in the synchronization of rapid climate events across the region.
Seismic Evidence of Bottom‐Up Crustal Control on Volcanism and Magma Storage Near Mount St. Helens
Authors: Kiser Eric , Levander Alan , Schmandt Brandon , Hansen Steven
Published: February 2021

The lower crust has long been recognized as a place where significant chemical evolution of magma occurs. Understanding the conditions that lead to long‐term storage in or rapid transport through these lower crustal systems has remained a challenge. In this study, active‐source seismic data are processed to image prominent reflectors in the lower crust and upper mantle near Mount St. Helens. Results show strong and weak near‐Moho reflectivity located near previously inferred regions of magma storage and high‐density bodies underlying volcanic centers, respectively. To explain these observations, we hypothesize that magmas intersecting the high‐density lower crustal bodies experience enhanced vertical buoyancy forces/transport due to the increased density contrast between melt and host rock. The reduced reflectivity near high‐density bodies is therefore a result of both decreased impedance contrasts between crust and mantle host rocks and diminished lower crust magma accumulation, which ultimately causes focusing of volcanism above these features.
Geophysical Monitoring Shows that Spatial Heterogeneity in Thermohydrological Dynamics Reshapes a Transitional Permafrost System
Authors: Uhlemann S. , Dafflon B. , Peterson J. , Ulrich C. , Shirley I. , Michail S. , Hubbard S. S.
Published: February 2021

Climate change is causing rapid changes of Arctic ecosystems. Yet, data needed to unravel complex subsurface processes are very rare. Using geophysical and in situ sensing, this study closes an observational gap associated with thermohydrological dynamics in discontinuous permafrost systems. It highlights the impact of vegetation and snow thickness distribution on subsurface thermohydrological properties and processes. Large snow accumulation near tall shrubs insulates the ground and allows for rapid and downward heat flow. Thinner snow pack above graminoid results in surficial freezing and prevents water from infiltrating into the subsurface. Analyzing short‐term disturbances, we found that lateral flow could be a driving factor in talik formation. Interannual measurements show that deep permafrost temperatures increased by about 0.2°C over 2 years. The results, which suggest that snow‐vegetation‐subsurface processes are tightly coupled, will be useful for improving predictions of Arctic feedback to climate change, including how subsurface thermohydrology influences CO2 and CH4 fluxes.
Paleomagnetic and Chronologic Data Bearing on the Permian/Triassic Boundary Position of Qamdo in the Eastern Qiantang Terrane: Implications for the Closure of the Paleo‐Tethys
Authors: Guan Chong , Yan Maodu , Zhang Weilin , Zhang Dawen , Fu Qiang , Yu Liang , Xu Wanlong , Zan Jinbo , Li Bingshuai , Zhang Tao , Shen Miaomiao
Published: February 2021

The tectonic evolution of the eastern Paleo‐Tethys in the Three‐Rivers headwater region remains uncertain, especially because of the lack of quality paleomagnetic data from the east Eastern Qiangtang Terrane (EQT). Here, we present an integrated paleomagnetic and zircon U‐Pb geochronologic study of the Gadikao Formation (Fm.) volcanic rocks in the EQT. This previously assumed Carboniferous or Permian rock unit is now zircon U‐Pb dated to ∼254–248 Ma. Our new high quality (29 sites and 257 samples) inferred primary paleomagnetic results yield a robust Permo‐Triassic boundary paleopole of 59.7°N and 228.2°E (A95 = 3.3°), with a paleolatitude of 10.0 ± 3.3°N for the study area. Integrated with other reliable Permo‐Triassic paleomagnetic data of the EQT and the Tarim Block and other lines of geologic evidence, we propose that the EQT drifted continuously northward during 300–200 Ma and the Paleo‐Tethys Ocean probably closed at ∼232–220 Ma around the Qamdo region, most likely at 230 Ma.
Fluid‐Earthquake and Earthquake‐Earthquake Interactions in Southern Kansas, USA
Authors: Verdecchia Alessandro , Cochran Elizabeth S. , Harrington Rebecca M.
Published: February 2021

An increase in injection activity associated with energy production in southern Kansas starting in 2013 has been linked to the occurrence of more than 130,000 earthquakes (M −1.5 to 4.9) between 2014 and 2017. Studies suggest that the dramatic increase in seismicity rate is related to wastewater injection into the highly permeable Arbuckle formation. Most of the seismicity is located in the underlying crystalline basement, for which hydrological properties and specific fault geometries are unknown. Additionally, some earthquake clusters occurred relatively far (tens of kilometers) from the main injection wells. Therefore, the effect of pore pressure diffusion may be insufficient to explain the relation between the volume of injected fluids and the spatiotemporal evolution of seismicity. Combining physical models (static stress and poroelasticity) and a statistical cluster analysis applied to a high‐resolution relocated catalog, we analyze the evolution of seismicity in southern Kansas. We find that pore pressure changes (Δp) and Coulomb stress changes (ΔCFS) due to fluid diffusion smaller than 0.1 MPa are enough to initiate seismic sequences, which then evolve depending on their distance from the major injection wells. However, we find that earthquake sequences have different seismogenic responses to Δpand ΔCFS in terms of triggering threshold. In regions located close to disposal wells (Harper area) our cluster analysis suggests that both earthquake interactions and fluid diffusion control the evolution of seismicity. On the other hand, at greater distances (Milan area), where clustering behavior suggests greater earthquake interactions, we find that coseismic ΔCFS are larger than Δp.
The California Undercurrent as a Source of Upwelled Waters in a Coastal Filament
Authors: Zaba Katherine D. , Franks Peter J. S. , Ohman Mark D.
Published: February 2021

In the California Current System, cross‐shore transport of upwelled, nutrient‐rich waters from the coastal margin to the open ocean can occur within intermittent, submesoscale‐to‐mesoscale features such as filaments. Time‐varying spatial gradients within filaments affect net cross‐shore fluxes of physical, biological, and chemical tracers but require high‐resolution measurements to accurately estimate. In June 2017, the California Current Ecosystem Long Term Ecological Research program process cruise (P1706) conducted repeat sections by an autonomous Spray glider and a towed SeaSoar to investigate the role of one such coastal upwelling feature, the Morro Bay filament, which was characterized by enhanced cross‐filament gradients (both physical and biological) and an along‐filament jet. Within the jet, speeds were up to 0.78 m/s and the offshore transport was 1.5 Sverdrups (3.8 Sverdrups) in the upper 100 m (500 m). A climatological data product from the sustained California Underwater Glider Network provided necessary information for water mass differentiation. The analysis revealed that the cold, salty side of the filament carried recently upwelled California Undercurrent water and corresponded to higher chlorophyll‐a fluorescence than the warm, fresh side, which carried California Current water. Thus, there was a convergence of heterogeneous water masses within the core of the filament’s offshore‐flowing jet. These water masses have different geographic origins and thermohaline characteristics, which has implications for filament‐related cross‐shore fluxes and submesoscale‐to‐mesoscale biological community structure gradients.
The Impact of Föhn Conditions Across the Antarctic Peninsula on Local Meteorology Based on AWS Measurements
Authors: Kirchgaessner Amélie , King John C. , Anderson Philip S.
Published: February 2021

Föhn winds are warm, strong, downslope winds on the lee side of mountains, which can last from several hours to a few days. Recently Föhn conditions over the ice shelves on the eastern side of the Antarctic Peninsula (AP) mountains have attracted particular interest in the polar science community. Here, on the Larsen ice shelves (LIS) they provide atmospheric conditions for significant warming over the ice shelf which are thought to have clearly contributed to the collapse of Larsen A and B ice shelves in 1995 and 2002, respectively. We examine the representation of Föhn conditions as observed by measurements at an Automatic Weather Station (AWS) located on Cole Peninsula (CP) on the east of the AP mountain range in 2011. We introduce criteria to identify Föhn conditions and analyze the meteorological conditions at the AWS location with regard to the influence of Föhn overall, and on a seasonal and monthly basis. We consult two cases to highlight the seasonally different effects Föhn can have. We also compare our findings with data obtained in other studies, e.g., an AWS in a comparable location at Flask Glacier (FG). Measurements obtained at a crest AWS on the Avery Plateau (AV), and the analysis of conditions upstream using the Froude number help to put observations at CP into a wider context. Most importantly our data show that Föhn conditions can raise the air temperature to above freezing, and thus trigger melt/sublimation even in winter.
Machine Learning the Warm Rain Process
Authors: Gettelman A. , Gagne D. J. , Chen C.‐C. , Christensen M. W. , Lebo Z. J. , Morrison H. , Gantos G.
Published: February 2021

Clouds are critical for weather and climate prediction. The multiple scales of cloud processes make simulation difficult. Often models and measurements are used to develop empirical relationships for large‐scale models to be computationally efficient. Machine learning provides another potential tool to improve our empirical parameterizations of clouds. To explore these opportunities, we replace the warm rain formation process in a General Circulation Model (GCM) with a detailed treatment from a bin microphysical model that causes a 400% slowdown in the GCM. We analyze the changes in climate that result from the use of the bin microphysical calculation and find improvements in the rain onset and frequency of light rain compared to high resolution process models and observations. We also find a resulting change in the cloud feedback response of the model to warming, which will significantly impact the climate sensitivity. We then replace the bin microphysical model with several neural networks designed to emulate the autoconversion and accretion rates produced by the bin microphysical model. The neural networks are organized into two stages: the first stage identifies where tendencies will be nonzero (and the sign of the tendency), and the second stage predicts the magnitude of the autoconversion and accretion rates. We describe the risks of overfitting, extrapolation, and linearization by using perfect model experiments with and without the emulator. We can recover the solutions with the emulators in almost all respects, and get simulations that perform as the detailed model, but with the computational cost of the control simulation.
Genome evolution and the emergence of pathogenicity in avian Escherichia coli
Authors: Mageiros Leonardos , Méric Guillaume , Bayliss Sion C. , Pensar Johan , Pascoe Ben , Mourkas Evangelos , Calland Jessica K. , Yahara Koji , Murray Susan , Wilkinson Thomas S. , Williams Lisa K. , Hitchings Matthew D. , Porter Jonathan , Kemmett Kirsty , Feil Edward J. , Jolley Keith A. , Williams Nicola J. , Corander Jukka , Sheppard Samuel K.
Published: February 2021

Chickens are the most common birds on Earth and colibacillosis is among the most common diseases affecting them. This major threat to animal welfare and safe sustainable food production is difficult to combat because the etiological agent, avian pathogenic Escherichia coli (APEC), emerges from ubiquitous commensal gut bacteria, with no single virulence gene present in all disease-causing isolates. Here, we address the underlying evolutionary mechanisms of extraintestinal spread and systemic infection in poultry. Combining population scale comparative genomics and pangenome-wide association studies, we compare E. coli from commensal carriage and systemic infections. We identify phylogroup-specific and species-wide genetic elements that are enriched in APEC, including pathogenicity-associated variation in 143 genes that have diverse functions, including genes involved in metabolism, lipopolysaccharide synthesis, heat shock response, antimicrobial resistance and toxicity. We find that horizontal gene transfer spreads pathogenicity elements, allowing divergent clones to cause infection. Finally, a Random Forest model prediction of disease status (carriage vs. disease) identifies pathogenic strains in the emergent ST-117 poultry-associated lineage with 73% accuracy, demonstrating the potential for early identification of emergent APEC in healthy flocks.