bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer-assisted open reduction internal fixation of intraarticular radius fractures navigated with patient-specific instrumentation, a prospective case series
Authors: Casari F. A. , Roner S. , Fürnstahl P. , Nagy L. , Schweizer A.
Published: March 2021

Background

Intra-articular fractures are associated with posttraumatic arthritis if inappropriately treated. Exact reduction of the joint congruency is the main factor to avoid the development of arthrosis. Aim of this study was to evaluate feasibility of computer-assisted surgical planning and 3D-printed patient-specific instrumentation (PSI) for treatment of distal intraarticular radius fractures.

Method

7 Patients who suffered a distal intraarticular radius fracture were enrolled in this prospective case series. Preoperative CT-scan was recorded, whereupon a 3D model was computed for surgical planning and design of PSI for surgical navigation. Postoperative accuracy and joint congruency were assessed. Patients were followed-up 3, 6 and 12 months postoperatively.

Results

Mean follow-up was 16 months. Over all range of motion was restored and flexion, extension and pronation showed significant recovery, p < 0.05. Biggest intraarticular joint step-off and gap reduced from average 2.49 (± 1.04) to 0.8 mm (± 0.44), p < 0.05 and 6.12 mm (± 1.04) to 2.21 mm (± 1.16), p < 0.05. Average grip strength restored (3–16 months) from 20.33 kg (± 7.12) to 39.3 kg (± 19.55) p < 0.05, 100% of the healthy contralateral side. 3D-accuracy for guided fragments was 2.07 mm (± 0.64) and 8.59° (± 2.9) and 2.33 mm (± 0.69) and 12.86° (± 7.13), p > 0.05 for fragments reduced with ligamentotaxis.

Conclusion

Computer-assisted and PSI navigated intraarticular radius fracture treatment is feasible, safe and accurate. The benefits of this method, however, do not outstand the additional effort.

Level of evidence

IV.
Effects of sildenafil and tadalafil on skin flap viability
Authors: Souza Rafael A. C. , Martinelli-Kläy Carla Patrícia , d’Acampora Armando J. , Bernardes Geraldo J. S. , Sgrott Sandro M. , Souza Laila A. C. , Lombardi Tommaso , Sudbrack Thaís R.
Published: March 2021

Vascular complication is one of the causes of skin flap healing failure. Sildenafil and tadalafil, a type-5 phosphodiesterase inhibitor, can improve flap viability, however, the action mechanisms involved in this process are still unclear. To assess the effects of orally administered sildenafil and tadalafil on the healing kinetics and skin flap viability, sixty-two Wistar rats were divided into three groups: control (n = 22), sildenafil (n = 20), and tadalafil (n = 20). The solutions were administered orally (dose: 10 mg/kg) immediately after the surgical procedure and then every 24 h. At postoperative days 7 and 14, the skin flap samples were collected, submitted to histological processing and evaluated under optical microscopy. In experimental groups (sildenafil and tadalafil), we found an increased vascularization (p < 0.05) on the 7th and 14th day associated with the ulcer size decrease on the 14th day, although it was not significant. There was a higher influx of neutrophils and a decrease of mononuclear population on the 7th day (p < 0.05). On the 14th day, these differences were observed only in the tadalafil group (p < 0.05). This study suggested positive results with the use of sildenafil and tadalafil as adjuvant drugs in skin flap viability.
Impact of resection margin status on survival in advanced N stage pancreatic cancer – a multi-institutional analysis
Authors: Teske Christian , Stimpel Richard , Distler Marius , Merkel Susanne , Grützmann Robert , Bolm Louisa , Wellner Ulrich , Keck Tobias , Aust Daniela E. , Weitz Jürgen , Welsch Thilo
Published: March 2021

Background

The present study aimed to examine the impact of microscopically tumour-infiltrated resection margins (R1) in pancreatic ductal adenocarcinoma (PDAC) patients with advanced lymphonodular metastasis (pN1–pN2) on overall survival (OS).

Methods

This retrospective, multi-institutional analysis included patients undergoing surgical resection for PDAC at three tertiary university centres between 2005 and 2018. Subcohorts of patients with lymph node status pN0–N2 were stratified according to the histopathological resection status using Kaplan-Meier survival analysis.

Results

The OS of the entire cohort (n = 620) correlated inversely with the pN status (26 [pN0], 18 [pN1], 11.8 [pN2] months, P < 0.001) and R status (21.7 [R0], 12.5 [R1] months, P < 0.001). However, there was no statistically significant OS difference between R0 versus R1 in cases with advanced lymphonodular metastases: 19.6 months (95% CI: 17.4–20.9) versus 13.6 months (95% CI: 10.7–18.0) for pN1 stage and 13.7 months (95% CI: 10.7–18.9) versus 10.1 months (95% CI: 7.9–19.1) for pN2, respectively. Accordingly, N stage–dependent Cox regression analysis revealed that R status was a prognostic factor in pN0 cases only. Furthermore, there was no significant survival disadvantage for patients with R0 resection but circumferential resection margin invasion (≤ 1 mm; CRM+; 10.7 months) versus CRM-negative (13.7 months) cases in pN2 stages (P = 0.5).

Conclusions

An R1 resection is not associated with worse OS in pN2 cases. If there is evidence of advanced lymph node metastasis and a re-resection due to an R1 situation (e.g. at venous or arterial vessels) may substantially increase the perioperative risk, margin clearance in order to reach local control might be avoided with respect to the OS.
Keeping the ageing brain wired: a role for purine signalling in regulating cellular metabolism in oligodendrocyte progenitors
Authors: Rivera Andrea D. , Chacon-De-La-Rocha Irene , Pieropan Francesca , Papanikolau Maria , Azim Kasum , Butt Arthur M.
Published: March 2021

White matter (WM) is a highly prominent feature in the human cerebrum and is comprised of bundles of myelinated axons that form the connectome of the brain. Myelin is formed by oligodendrocytes and is essential for rapid neuronal electrical communication that underlies the massive computing power of the human brain. Oligodendrocytes are generated throughout life by oligodendrocyte precursor cells (OPCs), which are identified by expression of the chondroitin sulphate proteoglycan NG2 (Cspg4), and are often termed NG2-glia. Adult NG2+ OPCs are slowly proliferating cells that have the stem cell–like property of self-renewal and differentiation into a pool of ‘late OPCs’ or ‘differentiation committed’ OPCs(COPs) identified by specific expression of the G-protein-coupled receptor GPR17, which are capable of differentiation into myelinating oligodendrocytes. In the adult brain, these reservoirs of OPCs and COPs ensure rapid myelination of new neuronal connections formed in response to neuronal signalling, which underpins learning and cognitive function. However, there is an age-related decline in myelination that is associated with a loss of neuronal function and cognitive decline. The underlying causes of myelin loss in ageing are manifold, but a key factor is the decay in OPC ‘stemness’ and a decline in their replenishment of COPs, which results in the ultimate failure of myelin regeneration. These changes in ageing OPCs are underpinned by dysregulation of neuronal signalling and OPC metabolic function. Here, we highlight the role of purine signalling in regulating OPC self-renewal and the potential importance of GPR17 and the P2X7 receptor subtype in age-related changes in OPC metabolism. Moreover, age is the main factor in the failure of myelination in chronic multiple sclerosis and myelin loss in Alzheimer’s disease, hence understanding the importance of purine signalling in OPC regeneration and myelination is critical for developing new strategies for promoting repair in age-dependent neuropathology.
Ductal ligation timing and neonatal outcomes: a 12-year bicentric comparison
Authors: Martini Silvia , Galletti Silvia , Kelsall Wilf , Angeli Emanuela , Agulli Marta , Gargiulo Gaetano Domenico , Chen Si Emma , Corvaglia Luigi , Singh Yogen
Published: March 2021

Patent ductus arteriosus (PDA) is common among extremely preterm infants. In selected cases, surgical PDA ligation may be required. The timing for PDA ligation may depend upon a variety of factors, with potential clinical implications. We aimed to investigate the impact of different surgical PDA managements on ligation timing and neonatal outcomes. Inborn infants < 32 weeks of gestation and < 1500 g admitted at two tertiary Neonatal Intensive Care Units that underwent PDA ligation between 2007 and 2018 were enrolled in this retrospective cohort study and split into the following groups based on their surgical management: on-site bedside PDA ligation (ONS) vs. referral to an off-site pediatric cardiac surgery (OFS). Neonatal characteristics, surgical timing, and clinical outcomes of the enrolled infants were compared between the groups. Multivariate analysis was performed to evaluate the impact of PDA ligation timing on significantly different outcomes. Seventy-eight neonates (ONS, n = 39; OFS, n = 39) were included. Infants in the ONS group underwent PDA ligation significantly earlier than those in the OFS group (median age 12 vs. 36 days, p < 0.001) with no increase in postoperative mortality and complications. The multivariate analysis revealed a significant association between PDA ligation timing, late-onset sepsis prevalence (OR 1.045, 0.032), and oxygen need at discharge (OR 1.037, p = 0.025).

Conclusions: Compared with off-site surgery, on-site bedside ligation allows an earlier surgical closure of PDA, with no apparent increase in mortality or complications. Earlier PDA ligation may contribute to reduced rates of late-onset sepsis and post-discharge home oxygen therapy, with possible cost-benefit implications.

What is known:• Ineffective or contraindicated pharmacological closure of a hemodynamically significant PDA may require a surgical ligation.• Available literature comparing the effect of early vs. late PDA ligation on the main neonatal morbidities has yield contrasting results.

What is new:• The availability of a cardiac surgery service performing bedside PDA ligation allows an earlier intervention compared to patient referral to an off-site center, with no difference in postoperative mortality and complications compared to off-site surgery.• Earlier PDA ligation was associated with a lower prevalence of late-onset sepsis and of oxygen need at discharge, with possible cost-benefit implications.
Correlation Clustering in Data Streams
Authors: Ahn Kook Jin , Cormode Graham , Guha Sudipto , McGregor Andrew , Wirth Anthony
Published: March 2021

Clustering is a fundamental tool for analyzing large data sets. A rich body of work has been devoted to designing data-stream algorithms for the relevant optimization problems such as k-center, k-median, and k-means. Such algorithms need to be both time and and space efficient. In this paper, we address the problem of correlation clustering in the dynamic data stream model. The stream consists of updates to the edge weights of a graph on n nodes and the goal is to find a node-partition such that the end-points of negative-weight edges are typically in different clusters whereas the end-points of positive-weight edges are typically in the same cluster. We present polynomial-time, $$O(n\cdot {{\,\mathrm{polylog}\,}}n)$$

O
(
n
·

polylog

n
)

-space approximation algorithms for natural problems that arise. We first develop data structures based on linear sketches that allow the “quality” of a given node-partition to be measured. We then combine these data structures with convex programming and sampling techniques to solve the relevant approximation problem. Unfortunately, the standard LP and SDP formulations are not obviously solvable in $$O(n\cdot {{\,\mathrm{polylog}\,}}n)$$

O
(
n
·

polylog

n
)

-space. Our work presents space-efficient algorithms for the convex programming required, as well as approaches to reduce the adaptivity of the sampling.
Formulation and experimental validation of space-fractional Timoshenko beam model with functionally graded materials effects
Authors: Stempin Paulina , Sumelka Wojciech
Published: March 2021

In this study, the static bending behaviour of a size-dependent thick beam is considered including FGM (Functionally Graded Materials) effects. The presented theory is a further development and extension of the space-fractional (non-local) Euler–Bernoulli beam model (s-FEBB) to space-fractional Timoshenko beam (s-FTB) one by proper taking into account shear deformation. Furthermore, a detailed parametric study on the influence of length scale and order of fractional continua for different boundary conditions demonstrates, how the non-locality affects the static bending response of the s-FTB model. The differences in results between s-FTB and s-FEBB models are shown as well to indicate when shear deformations need to be considered. Finally, material parameter identification and validation based on the bending of SU-8 polymer microbeams confirm the effectiveness of the presented model.
A hypothesis for the pathogenesis of radiation-induced oral mucositis: when biological challenges exceed physiologic protective mechanisms. Implications for pharmacological prevention and treatment
Authors: Sonis Stephen T.
Published: March 2021

Oral mucositis (OM) remains a significant unmet need for patients being treated with standard concomitant chemoradiation (CRT) regimens for head and neck cancers (HNC). OM’s pathogenesis is complex and includes both direct and indirect damage pathways. In this paper, the field is reviewed with emphasis on the initiating and sustaining role of oxidative stress on OM’s pathobiology. A hypothesis is presented which suggests that based on OM’s clinical and biological trajectory, mucosal damage is largely the consequence of cumulative CRT-induced biological changes overwhelming physiologic self-protective mechanisms. Furthermore, an individual’s ability to mount and maintain a protective response is dependent on interacting pathways which are primarily determined by a multiplex consisting of genomics, epigenomics, and microbiomics. Effective biologic or pharmacologic OM interventions are likely to supplement or stimulate existing physiologic damage-control mechanisms.
Human herpesvirus type 2 infection of primary murine astrocytes causes disruption of the mitochondrial network and remodeling of the actin cytoskeleton: an in vitro morphological study
Authors: Słońska Anna , Cymerys Joanna , Chodkowski Marcin , Bąska Piotr , Krzyżowska Małgorzata , Bańbura Marcin W.
Published: March 2021

Herpesviruses are capable of infecting not only neurons, where they establish latent infection, but also astrocytes. Since astrocytes are important for the functioning of the central nervous system (CNS), their infection may lead to serious neurological disorders. Thus, in the present study we investigated the ability of human herpesvirus type 2 (HHV-2) to infect primary murine astrocytes in vitro and the effect of infection on their mitochondrial network and actin cytoskeleton. In immunofluorescence assays, antibodies against HHV-2 antigens and glial fibrillary acidic protein (GFAP) were used to confirm that the infected cells are indeed astrocytes. Real-time PCR analysis showed a high level of HHV-2 replication in astrocytes, particularly at 168 h postinfection, confirming that a productive infection had occurred. Analysis of mitochondrial morphology showed that, starting from the first stage of infection, HHV-2 caused fragmentation of the mitochondrial network and formation of punctate and tubular structures that colocalized with virus particles. Furthermore, during the late stages of infection, the infection affected the actin cytoskeleton and induced formation of actin-based cellular projections, which were probably associated with enhanced intracellular spread of the virus. These results suggest that the observed changes in the mitochondrial network and actin cytoskeleton in productively infected astrocytes are required for effective replication and viral spread in a primary culture of astrocytes. Moreover, we speculate that, in response to injury such as HHV-2 infection, murine astrocytes cultured in vitro undergo transformation, defined in vivo as reactive astrocytosis.
When is it biological control? A framework of definitions, mechanisms, and classifications
Authors: Stenberg Johan A. , Sundh Ingvar , Becher Paul G. , Björkman Christer , Dubey Mukesh , Egan Paul A. , Friberg Hanna , Gil José F. , Jensen Dan F. , Jonsson Mattias , Karlsson Magnus , Khalil Sammar , Ninkovic Velemir , Rehermann Guillermo , Vetukuri Ramesh R. , Viketoft Maria
Published: March 2021

Biological control, or biocontrol, is the exploitation of living agents (incl. viruses) to combat pestilential organisms (incl. pathogens, pests, and weeds) for diverse purposes to provide human benefits. Thus, during the last century the practices and concepts involved have evolved in separate streams associated with distinct scientific and taxonomic disciplines. In parallel developments, there have been increasing references to biological control in industrial contexts and legislation, resulting in conceptual and terminological disintegration. The aim of this paper is to provide a global conceptual and terminological platform that facilitates future development of the field. We review use of previously suggested terms in key fields (e.g., phytopathology, entomology, and weed science), eliminate redundant terminology, identify three principles that should underpin the concept, and then present a new framework for biological control, rooted in seminal publications. The three principles establish that (1) only living agents can mediate biological control, (2) biological control always targets a pest, directly or indirectly, and (3) all biocontrol methods can be classified in four main categories depending on whether resident agents are utilized, with or without targeted human intervention (conservation biological control and natural biological control, respectively) or agents are added for permanent or temporary establishment (classical biological control and augmentative biological control, respectively). Correct identification of what is, and is not, biological control can help efforts to understand and optimize biological pest control for human and environmental benefits. The new conceptual framework may contribute to more uniform and appropriate regulatory approaches to biological control, and more efficient authorization and application of biocontrol products.
Acceptability of the Dapivirine Vaginal Ring for HIV-1 Prevention and Association with Adherence in a Phase III Trial
Authors: Mayo Ashley J. , Browne Erica N. , Montgomery Elizabeth T. , Torjesen Kristine , Palanee-Phillips Thesla , Jeenarain Nitesha , Seyama Linly , Woeber Kubashni , Harkoo Ishana , Reddy Krishnaveni , Tembo Tchangani , Mutero Prisca , Tauya Thelma , Chitukuta Miria , Gati Mirembe Brenda , Soto-Torres Lydia , Brown Elizabeth R. , Baeten Jared M. , van der Straten Ariane ,   for the MTN-020/ASPIRE study team, Baeten Jared , Palanee-Phillips Thesla , Brown Elizabeth , Soto-Torres Lydia , Schwartz Katie , Makanani Bonus , Martinson Francis , Bekker Linda-Gail , Govender Vaneshree , Siva Samantha , Gaffoor Zakir , Naidoo Logashvari , Pather Arendevi , Jeenarain Nitesha , Nair Gonasagrie , Matovu Flavia , Mgodi Nyaradzo , Mhlanga Felix
Published: March 2021

We evaluated the acceptability of the 25 mg dapivirine vaginal ring (DVR) as an HIV prevention intervention and its influence on DVR adherence in the MTN-020/ASPIRE phase III trial. Acceptability measures were captured using ACASI at month 3 and end of product use (median 24 months, IQR 15–30). Monthly returned rings were classified as nonadherent if dapivirine release rate was ≤ 0.9 mg/month. Associations between acceptability measures and nonadherence were estimated using Poisson regression models with robust standard errors. At month 3 (N = 2334), 88% reported DVR was comfortable, 80% were unaware of it during daily activities, and 74% never felt it during sex. At exit, 66% were ‘very likely’ to use DVR in the future. Acceptability was found to differ significantly by country across several measures including wearing the ring during sex, during menses, partner acceptability, impact on sexual pleasure and willingness to use the ring in the future. Risk of nonadherence at month 12 was elevated if DVR was felt during sex at month 3 (aRR 1.67, 95% CI 1.26, 2.23). Risk of nonadherence in the last year of study participation was elevated if, at exit, participants minded wearing during sex (aRR 2.08, 95% CI 1.52, 2.85), during menses (aRR 1.57, 95% CI 1.06, 2.32), reported a problematic change to the vaginal environment (aRR 1.57, 95% CI 1.12, 2.21), and were not “very likely” to use DVR in the future (aRR 1.31, 95% CI 1.02, 1.68). DVR acceptability was overall high yet varied by country. Addressing perceived ring interference with sex, menses, or problematic changes to the vaginal environment in future interventions could help improve adherence, as could embracing sex-positive messaging related to ring use and increased pleasure.

Trial Registration ClinicalTrials.gov Identifier: NCT01617096.
Stagnant peaked free surface released at a sloping beach
Authors: Tyvand Peder A. , Nøland Jonas Kristiansen
Published: March 2021

A stagnant free-surface flow is an instantaneous flow field of pure acceleration with zero velocity and a deformed surface. There exists a potential-flow acceleration field. With zero velocity and the acceleration field given, there is a limiting free-surface position which possesses one peak at its point of highest elevation. By complex analysis, it can be shown that the surface peak has a right angle. We elaborate on an elementary model of two-dimensional stagnant free-surface flow with a peak. Our model may serve to describe a situation of maximal single-wave run-up with a given energy at a uniformly sloping beach. The highest possible run-up of an incoming solitary wave corresponds to zero kinetic energy. It encompasses an idealized situation where the kinetic wave energy is converted into potential energy in a water mass piling up along the slope to become stagnant at one single moment. Multipoles with singularities outside the fluid domain may give rise to a smooth and gradual deceleration needed for a non-breaking run-up process. A pair of dipoles with an orientation perpendicular to a given slope represents the stagnant acceleration fields with the highest surface peak spatially concentrated along the slope. Thereby, a one-parameter family of surface shapes is constituted, only dependent on the slope angle. The initial flow field, the initial free surface, the initial isobars and the geometric parameters are all calculated for different slope angles.
Identification of a novel sex determining chromosome in cichlid fishes that acts as XY or ZW in different lineages
Authors: Feller Anna F. , Ogi Vera , Seehausen Ole , Meier Joana I.
Published: March 2021

Sex determination systems are highly conserved among most vertebrates with genetic sex determination, but can be variable and evolve rapidly in some. Here, we study sex determination in a clade with exceptionally high sex chromosome turnover rates. We identify the sex determining chromosomes in three interspecific crosses of haplochromine cichlid fishes from Lakes Victoria and Malawi. We find evidence for different sex determiners in each cross. In the Malawi cross and one Victoria cross the same chromosome is sex-linked but while females are the heterogametic sex in the Malawi species, males are the heterogametic sex in the Victoria species. This chromosome has not previously been reported to be sex determining in cichlids, increasing the number of different chromosomes shown to be sex determining in cichlids to 12. All Lake Victoria species of our crosses are less than 15,000 years divergent, and we identified different sex determiners among them. Our study provides further evidence for the diversity and evolutionary flexibility of sex determination in cichlids, factors which might contribute to their rapid adaptive radiations.
Multiple steady statehood: the roles of productive and extractive capacities
Authors: Lagerlöf Nils-Petter
Published: March 2021

This paper proposes a model of statehood, defined as elite extraction of resources from a subject population. Different from most of the existing literature, the size of the subject population evolves endogenously in a Malthusian fashion, and the elite take into account the effects on future population levels when taxing the current population. The elite can spend extracted resources by investing in productive and extractive capacities. Productive capacity increases the size of the pie, while extractive capacity makes it easier for the elite to tax it. Together—but not each on its own—these two types of investment can give rise to multiple steady-state equilibria, such that one steady state has both a higher rate of extraction, and higher population density and output, than the other steady state. The model can also account for a positive empirical relationship between land productivity and state antiquity among countries with relatively late state development.
A review of modelling methodologies for flood source area (FSA) identification
Authors: Singh Amrie , Dawson David , Trigg Mark , Wright Nigel
Published: March 2021

Flooding is an important global hazard that causes an average annual loss of over 40 billion USD and affects a population of over 250 million globally. The complex process of flooding depends on spatial and temporal factors such as weather patterns, topography, and geomorphology. In urban environments where the landscape is ever-changing, spatial factors such as ground cover, green spaces, and drainage systems have a significant impact. Understanding source areas that have a major impact on flooding is, therefore, crucial for strategic flood risk management (FRM). Although flood source area (FSA) identification is not a new concept, its application is only recently being applied in flood modelling research. Continuous improvements in the technology and methodology related to flood models have enabled this research to move beyond traditional methods, such that, in recent years, modelling projects have looked beyond affected areas and recognised the need to address flooding at its source, to study its influence on overall flood risk. These modelling approaches are emerging in the field of FRM and propose innovative methodologies for flood risk mitigation and design implementation; however, they are relatively under-examined. In this paper, we present a review of the modelling approaches currently used to identify FSAs, i.e. unit flood response (UFR) and adaptation-driven approaches (ADA). We highlight their potential for use in adaptive decision making and outline the key challenges for the adoption of such approaches in FRM practises.
Fundamentality from grounding trees
Authors: Correia Fabrice
Published: March 2021

I provide and defend two natural accounts of (both relative and absolute) fundamentality for facts that do justice to the idea that the “degree of fundamentality” enjoyed by a fact is a matter of how far, from a ground-theoretic perspective, the fact is from the ungrounded facts.
CycleGAN for interpretable online EMT compensation
Authors: Krumb Henry , Das Dhritimaan , Chadda Romol , Mukhopadhyay Anirban
Published: March 2021

Purpose

Electromagnetic tracking (EMT) can partially replace X-ray guidance in minimally invasive procedures, reducing radiation in the OR. However, in this hybrid setting, EMT is disturbed by metallic distortion caused by the X-ray device. We plan to make hybrid navigation clinical reality to reduce radiation exposure for patients and surgeons, by compensating EMT error.

Methods

Our online compensation strategy exploits cycle-consistent generative adversarial neural networks (CycleGAN). Positions are translated from various bedside environments to their bench equivalents, by adjusting their z-component. Domain-translated points are fine-tuned on the x–y plane to reduce error in the bench domain. We evaluate our compensation approach in a phantom experiment.

Results

Since the domain-translation approach maps distorted points to their laboratory equivalents, predictions are consistent among different C-arm environments. Error is successfully reduced in all evaluation environments. Our qualitative phantom experiment demonstrates that our approach generalizes well to an unseen C-arm environment.

Conclusion

Adversarial, cycle-consistent training is an explicable, consistent and thus interpretable approach for online error compensation. Qualitative assessment of EMT error compensation gives a glimpse to the potential of our method for rotational error compensation.
Application of a Lumped Multi-Section Model for Analyzing the Thermal Performance of a Small-Scale Biomass Boiler
Authors: Polesek-Karczewska Sylwia , Wardach-Święcicka Izabela , Kardaś Dariusz , Turzyński Tomasz
Published: March 2021

The stationary lumped-cell model was developed and used to simulate the thermal characteristics of domestic biomass boiler with helically coiled tube heat exchanger (HCHE). The device serves as the heat source for ORC (Organic Rankine Cycle) unit and utilizes the thermal oil as the medium transferring the heat to the unit. Most of studies available in the literature refer to the CFD simulations for water flow in tube coils or in one- or two-turn coil elements. These investigations are basically focused on the determination of Nusselt number. The proposed herein model aims at determining the thermal performance of flue gas-oil HCHE while providing low CPU time. To demonstrate the model possibilities, it was used to predict the flue gas temperatures at the inlet and outlet from the heat exchange zone, based on measurement data regarding the outlet temperature of thermal oil. Six test series were considered. The computation results appeared to be in satisfactory agreement with experimental results (the discrepancies do not exceed 12%). The investigations showed that the used approach may be recommended as an alternative method that allows for fast prediction of thermal parameters for units of complex geometries, in particular the multi-coil heat exchangers.
FunQ: Measuring the fun experience of a learning activity with adolescents
Authors: Tisza Gabriella , Markopoulos Panos
Published: March 2021

Researchers and practitioners in learning sciences, educational technology and child-computer interaction often argue that fun is an essential element of learning. Therefore, researchers in the above fields aim to explore how learning activities could be made more enjoyable in order to facilitate engagement in the learning process and to improve the learning outcomes. Despite such wide interest, there has been little systematic effort to define and measure fun. The herein introduced research aims to (a) define the term “fun” and (b) to create a tool for the reliable measurement of it. In the first study testing the initial item pool 75 students (μage = 11.78); in the think-aloud study testing the comprehensibility of the items six 11-year-old children and in the final validation study, 128 students (μage = 12.15) participated. We applied a deductive scale development approach. For the model testing, CFA was used and second-order latent variable models were fitted. In this paper, we conceptualize the term of fun and introduce the final 18-item version of the FunQ that consists of six dimensions (Autonomy, Challenge, Delight, Immersion, Loss of Social Barriers and Stress) and bears with the appropriate validity and reliability measures (ωoverall = 0.875 and ωpartial = 0.864; RMSEA = 0.052 and SRMR = 0.072). We contribute with (a) a review of the literature regarding the concept of fun, (b) a conception of fun as a multidimensional theoretically motivated concept, (c) a multidimensional instrument for assessing experienced fun—the FunQ—and (d) a psychometric evaluation of the proposed instrument. FunQ is put forward as a reliable and much-needed addition to the current palette of instruments.
Our future in the Anthropocene biosphere
Authors: Folke Carl , Polasky Stephen , Rockström Johan , Galaz Victor , Westley Frances , Lamont Michèle , Scheffer Marten , Österblom Henrik , Carpenter Stephen R. , Chapin F. Stuart , Seto Karen C. , Weber Elke U. , Crona Beatrice I. , Daily Gretchen C. , Dasgupta Partha , Gaffney Owen , Gordon Line J. , Hoff Holger , Levin Simon A. , Lubchenco Jane , Steffen Will , Walker Brian H.
Published: March 2021

The COVID-19 pandemic has exposed an interconnected and tightly coupled globalized world in rapid change. This article sets the scientific stage for understanding and responding to such change for global sustainability and resilient societies. We provide a systemic overview of the current situation where people and nature are dynamically intertwined and embedded in the biosphere, placing shocks and extreme events as part of this dynamic; humanity has become the major force in shaping the future of the Earth system as a whole; and the scale and pace of the human dimension have caused climate change, rapid loss of biodiversity, growing inequalities, and loss of resilience to deal with uncertainty and surprise. Taken together, human actions are challenging the biosphere foundation for a prosperous development of civilizations. The Anthropocene reality—of rising system-wide turbulence—calls for transformative change towards sustainable futures. Emerging technologies, social innovations, broader shifts in cultural repertoires, as well as a diverse portfolio of active stewardship of human actions in support of a resilient biosphere are highlighted as essential parts of such transformations.
A numerical scheme for the solution of neutral integro-differential equations including variable delay
Authors: Gürbüz Burcu
Published: March 2021

In this study, an effective numerical technique has been introduced for finding the solutions of the first-order integro-differential equations including neutral terms with variable delays. The problem has been defined by using the neutral integro-differential equations with initial value. Then, an alternative numerical method has been introduced for solving these type of problems. The method is expressed by fundamental matrices, Laguerre polynomials with their matrix forms. Besides, the solution has been obtained by using the collocation points with regard to the reduced system of algebraic equations and Laguerre series.
Empirical investigation of the relationship between bilingualism and social flexibility
Authors: Champoux-Larsson Marie-France , Dylman Alexandra S. , Esteves Francisco
Published: March 2021

Recently, a relationship between bilingualism and enhanced social flexibility has been suggested. However, research on the subject is scarce and what little exists is limited by several conceptual and methodological concerns. In the current study, we attempted to (a) replicate the findings from a study by Ikizer and Ramírez-Esparza (Bilingualism: Language and Cognition 21:957–969, 2018) by using the scales that the authors developed, and (b) test the concept of social flexibility experimentally with a switch-task using socially relevant stimuli. In the first part, participants (n = 194) filled out the scales developed by Ikizer and Ramírez-Esparza. We could not find that bilingualism leads to enhanced social flexibility. We did, however, find that higher level of education led to higher scores on the social flexibility scale. In the second part, a subsample (n = 74) from Part 1 completed a task where they were asked to identify the congruency between a face and a voice based on either gender or emotion, and to switch between these two tasks. The experimental task did not show an advantage for the bilingual participants. On the contrary, higher proficiency in a second language led to lower accuracy in the congruent emotion condition, while level of education led to higher accuracy in that same condition. We suggest that factors other than bilingualism, such as level of education and biculturalism, most likely drove the effect found both in the current study and originally by Ikizer and Ramírez-Esparza.
Research trends of microplastics in the soil environment: Comprehensive screening of effects
Authors: Kim Shin Woong , Rillig Matthias C.
Published: March 2021

We collated and synthesized previous studies that reported the impacts of microplastics on soil parameters. The data were classified and integrated to screen for the proportion of significant effects, then we suggest several directions to alleviate the current data limitation in future experiments. We compiled 106 datasets capturing significant effects, which were analyzed in detail. We found that polyethylene and pellets (or powders) were the most frequently used microplastic composition and shape for soil experiments. The significant effects mainly occurred in broad size ranges (0.1–1 mm) at test concentrations of 0.1%–10% based on soil dry weight. Polyvinyl chloride and film induced significant effects at lower concentrations compared to other compositions and shapes, respectively. We adopted a species sensitivity distribution (SSD) and soil property effect distribution (SPED) method using available data from soil biota, and for soil properties and enzymes deemed relevant for microplastic management. The predicted-no-effect-concentration (PNEC)-like values needed to protect 95% of soil biota and soil properties was estimated to be between 520 and 655 mg kg−1. This study was the first to screen microplastic levels with a view toward protecting the soil system. Our results should be regularly updated (e.g., quarterly) with additional data as they become available.
Individual, Relational, and Sociocultural Determinants of Sexual Function and Sexual Satisfaction in Ecuador
Authors: Hidalgo Daniela Arcos , Dewitte Marieke
Published: March 2021

Aim

Various individual, relational, and sociocultural variables have been identified as determinants of sexual responding, but these have rarely been investigated in non-Western cultures that are characterized by sexual conservatism. We aimed to explore the role of socioeconomic status and religion, sexual double standards, erotophobia-erotophilia, sexual dysfunctional beliefs, and relationship satisfaction to explain sexual function and satisfaction in Ecuador.

Method

599 participants (431 women and 159 men) completed an online survey.

Main Outcomes Measures

The Female sexual function was predicted by sexual satisfaction, relationship satisfaction, sexual dysfunctional beliefs, and sexual double standards, while the male sexual function was predicted solely by sexual satisfaction. Additionally, female sexual satisfaction was predicted by sexual function, relationship satisfaction, and sexual dysfunctional beliefs, while male sexual satisfaction was predicted by sexual function and relationship satisfaction.

Results

Female Sexual Function Index, International Index of Erectile Function, Brief Sexual Opinion Survey, Sexual Double Standards Scale, Sexual Dysfunctional Beliefs Questionnaire, New Sexual Satisfaction Scale, and Couple Satisfaction Index.

Conclusion

This study provided novel information on the determinants of sexual function and satisfaction within a culture in which conservative religious beliefs still prevail. Results should be interpreted with caution given the unequal distribution of men and women, social desirability and volunteer biases, and the specific COVID-19 pandemic context during which the survey took place. Markers of sexual conservatism were inversely related to sexual function and satisfaction, mainly in women, and may, therefore, be important targets of treatment. Female sexuality seemed more context-dependent than male sexuality, although enhancing the general climate of the relationship may benefit feeling sexually satisfied in both men and women.
Identifying a Safe and Just Corridor for People and the Planet
Authors: Rockström Johan , Gupta Joyeeta , Lenton Timothy M. , Qin Dahe , Lade Steven J. , Abrams Jesse F. , Jacobson Lisa , Rocha Juan C. , Zimm Caroline , Bai Xuemei , Bala Govindasamy , Bringezu Stefan , Broadgate Wendy , Bunn Stuart E. , DeClerck Fabrice , Ebi Kristie L. , Gong Peng , Gordon Chris , Kanie Norichika , Liverman Diana M. , Nakicenovic Nebojsa , Obura David , Ramanathan Veerabhadran , Verburg Peter H. , van Vuuren Detlef P. , Winkelmann Ricarda
Published: March 2021

Keeping the Earth system in a stable and resilient state, to safeguard Earth's life support systems while ensuring that Earth's benefits, risks, and related responsibilities are equitably shared, constitutes the grand challenge for human development in the Anthropocene. Here, we describe a framework that the recently formed Earth Commission will use to define and quantify target ranges for a “safe and just corridor” that meets these goals. Although “safe” and “just” Earth system targets are interrelated, we see safe as primarily referring to a stable Earth system and just targets as being associated with meeting human needs and reducing exposure to risks. To align safe and just dimensions, we propose to address the equity dimensions of each safe target for Earth system regulating systems and processes. The more stringent of the safe or just target ranges then defines the corridor. Identifying levers of social transformation aimed at meeting the safe and just targets and challenges associated with translating the corridor to actors at multiple scales present scope for future work.
Amplification and Tuning of Ground Motion at the Outer Cascadia Accretionary Prism
Authors: Davis Earl E. , Farrugia Joseph J.
Published: March 2021

Ground‐motion amplification in the outer Cascadia subduction zone accretionary prism has been documented previously by comparing earthquake and microseismic vertical ground‐motion and pressure records from an ONC/NEPTUNE Canada cabled observatory site on the outer prism to those from a site on the flank of the Juan de Fuca Ridge. Since then, four additional instruments became operational, and data, now spanning 10 years, include more than 100 large (Mw > 7) distant earthquakes. Well‐tuned response at the outer prism sites is observed in both vertical and horizontal components, with peaks in the spectral ratio of vertical velocity relative to nearby ocean crustal and continental bedrock sites (V/Vref) at 9 s, and in the intra‐site horizontal to vertical spectral ratio horizontal‐to‐vertical spectral ratio at 14 s, both with band widths of ±10% to 15% at half amplitude. The vertical response is consistent with ¼ wavelength compressional wave reinforcement, while the horizontal motion tuning most likely reflects the effects of the low velocity prism sediments on surface‐wave propagation. At the periods of maximum relative motion, outer prism surface‐wave vertical and horizontal accelerations are enhanced by factors of up to 15 and 25, respectively. Similar behaviour is seen in microseismic records from these sites, and, to a lesser extent, in earthquake records from temporarily deployed Cascadia Initiative seismometers along the outer Cascadia prism to the south. Such tuning and amplification must be accounted for when assessing the dynamic behavior of the prism and its basal fault at the time of large local earthquakes.
Tropical Cyclone Wind Speed Estimation From Satellite Altimeter‐Derived Ocean Parameters
Authors: Sharoni Syarawi M. H. , Md Reba Mohd Nadzri , Hossain Mohammad Shawkat
Published: March 2021

This study investigates the satellite altimeter‐derived ocean parameters from Joint Altimetry Satellite Oceanography Network (Jason)‐2 and Jason‐3 response to the coincident wind speed at 10 m from sea surface (U10) from Meteorological Operational (MetOp)‐A and MetOp‐B satellite scatterometers inside the tropical cyclone environment. The high wind speed regime and rainy condition inside the tropical cyclone have reduced the U10 accuracy and thus, would benefit from more ocean related parameters to be considered. The altimeter Ku‐band backscatter and significant wave height are commonly used to estimate extreme U10 but still show significant error in rainy tropical cyclone. New U10 models incorporating several Jasons derived ocean parameters (including brightness temperatures and water content) were designed by the multiple linear regression and artificial neural network techniques. Parameter analysis indicated that the C‐band backscatter outperforms the Ku‐band counterpart in relation to U10 inside the tropical cyclone. The proposed models show U10 estimation up to 35 ms−1 with 1 ms−1 accuracy and major improvement inside the tropical cyclone rain and at the high wind speed regime. This too shows the ability of satellite altimeter in estimating U10 in extreme environment with great accuracy.
Archetypes and Controls of Riverine Nutrient Export Across German Catchments
Authors: Ebeling Pia , Kumar Rohini , Weber Michael , Knoll Lukas , Fleckenstein Jan H. , Musolff Andreas
Published: March 2021

Elevated nutrient inputs challenge the health and functioning of aquatic ecosystems. To improve riverine water quality management, it is necessary to understand the underlying biogeochemical and physical processes, anthropogenic drivers and their interactions at catchment scale. We hypothesize that the spatial heterogeneity of nutrient sources dominantly controls the variability of in‐stream concentration dynamics among catchments. We investigated controls of mean nitrate (NO3−), phosphate (PO43−), and total organic carbon (TOC) concentrations and concentration‐discharge (C‐Q) relationships in 787 German catchments of a newly assembled data base, covering a wide range of physiographic and anthropogenic settings. We linked water quality metrics to catchment characteristics using partial least squares regressions and random forests. We found archetypalC‐Qpatterns with enrichment dominating NO3−and TOC, and dilution dominating PO43−export. Both the mean NO3−concentrations and their variance among sites increased with agricultural land use. We argue that subsurface denitrification can buffer high nitrogen inputs and cause a decline in concentration with depth, resulting in chemodynamic, strongly positiveC‐Qpatterns. Mean PO43−concentrations were related to point sources, though the low predictive power suggests effects of unaccounted in‐stream processes. In contrast, high diffuse agricultural inputs explained observed positive PO43−C‐Qpatterns. TOC levels were positively linked to the abundance of riparian wetlands, while hydrological descriptors were important for explaining TOC dynamics. Our study shows a strong modulation of anthropogenic inputs by natural controls for NO3−and PO43−concentrations and dynamics, while for TOC only natural controls dominate observed patterns across Germany.
The Space Dust That Causes Zodiacal Light Might Come from Mars
Authors: Stanley Sarah
Published: March 2021

Serendipitous observations by the Juno spacecraft while it was en route to Jupiter suggest a Martian source for the dust, but how the dust escapes Mars or its moons remains unknown.
New Funding Fortifies Africa’s Great Green Wall
Authors: Hornyak Tim
Published: March 2021

With increased investment and renewed interest, a project to halt land degradation across the Sahel aims to transform the landscape—and people’s lives.
The Evolution of Water Resources Research
Authors: Clark Martyn
Published: March 2021

The outgoing Editor in Chief of Water Resources Research reflects on his tenure and expresses appreciation to all those who contributed to the success of the journal.
Introducing the New Editor in Chief of Water Resources Research
Authors: Destouni Georgia
Published: March 2021

Find out about the person taking the helm of Water Resources Research and her vision for the coming years.
The New River Gorge: Ancient River, Old Mines, New National Park
Authors: Morton Mary
Published: March 2021

Living in Geologic Time: Regrowth and resiliency bring new accolades to one of the world’s oldest rivers.
Superlasers Shed Light on Super-Earth Mantles
Authors: Cartier Kimberly
Published: March 2021

By compressing iron oxide to pressures expected inside a large and rocky exoplanet, scientists discovered that such mantles could layer, mix, and flow in ways very different from those inside our planet.