bluuebunny/crossref_metadata_2025 huggingface dataset:
A relaxometry method that emphasizes practicality and availability
Authors: Madore Bruno , Jerosch‐Herold Michael , Chiou Jr‐Yuan George , Cheng Cheng‐Chieh , Guenette Jeffrey P. , Mihai Georgeta
Published: July 2022

Purpose

Although many methods have been proposed to quantitatively map the main MRI parameters (e.g., T1, T2, C × M0), these methods often involve special sequences not readily available on clinical scanners and/or may require long scan times. In contrast, the proposed method can readily run on most scanners, offer flexible tradeoffs between scan time and image quality, and map MRI parameters jointly to ensure spatial alignment.

Methods

The approach is based on the multi‐shot spin‐echo (SE) EPI sequence. The corresponding signal equation was derived and strategies for solving it were developed. As usual with multi‐shot EPI, scan time can readily be traded‐off against image quality by adjusting the echo train length. Validation was performed against reference relaxometry methods, in gel phantoms with varying concentrations of gadobutrol and gadoterate meglumine contrast agents. In vivo examples are further presented, from 3 neuroradiology patients.

Results

Bland–Altman analysis was performed: for T2, as compared to 2D SE, bias was 0.29 ms and the 95% limits of agreement ranged from −1.15 to +1.73 ms. For T1, compared to inversion‐recovery SE (and MOLLI), bias was −20.2 ms (and −14.5 ms) and the limits of agreement ranged from −62.4 to +22.0 ms (and −53.8 to +24.9 ms). The mean relative T1 error between the proposed method and each of the 2 reference methods was similar to that of the reference methods among themselves.

Conclusion

In the constellation of existing relaxometry methods, the proposed method is meant to stand out in terms of its practicality and availability.
Exploring pelvic floor muscle function in men with and without pelvic floor symptoms: A population‐based study
Authors: Notenboom‐Nas Françoise J. M. , Knol‐de Vries Grietje E. , Beijer Lotte , Tolsma Yme , Slieker‐ten Hove Marijke C. Ph. , Dekker Janny H. , van Koeveringe Gommert A. , Blanker Marco H.
Published: July 2022

Background

Pelvic floor symptoms (PFS), such as lower urinary tract symptoms, defecation disorders, sexual problems, and genital‐pelvic pain, are prevalent in men. Thorough physical assessments of the external anal sphincter (EAS) and the puborectal muscle (PRM) are the keys to unraveling the role of muscle dysfunction.

Objectives

To explore associations within and between the EAS and PRM and between muscle (dys‐) function and the number of male PFS.

Methods

This cross‐sectional study purposively enrolled men aged ≥21 years with 0–4 symptoms from a larger study. After extensive external and internal digital pelvic floor assessment, we explored (1) agreement between muscle function of the EAS versus PRM (using cross tabulation), (2) associations within and between the EAS and PRM (using heatmaps), and (3) associations between muscle function and number of PFS (using a visual presentation [heatmaps] and χ2 tests).

Results

Overall, 42 out of 199 men (21%) had completely normal muscle function. Sixty‐six (33.2%) had no symptoms, of which 53 (80%) had some degree of muscle dysfunction. No clear dose–response relationship existed between muscle (dys‐) function and the number of symptoms. The PRM showed both more dysfunction and severer dysfunction than the EAS.

Conclusions

No clear association exists between muscle dysfunction and the number of symptoms, and the absence of PFS does not indicate normal muscle function for all men. Dysfunction levels are highest for the PRM. Further pelvic floor muscle research is warranted in men with PFS.
Improving a constructive heuristic for the general routing problem
Authors: Boyacı Burak , Dang Thu Huong , Letchford Adam N.
Published: July 2022

The general routing problem (GRP) is a fundamental ‐hard vehicle routing problem, first defined by Orloff in 1974. It contains as special cases the Chinese postman problem, the rural postman problem, the graphical TSP, and the Steiner TSP. We examine in detail a known constructive heuristic for the GRP, due to Christofides and others. We show how to speed it up, in both theory and practice, while obtaining solutions that are at least as good. Computational results show that, for large instances, our implementation is faster than the original by several orders of magnitude.
Weak population differentiation and high diversity in Salsola tragus in the inland Pacific Northwest, USA
Authors: Spring John F. , Revolinski Samuel R. , Young Frank L. , Lyon Drew J. , Burke Ian C.
Published: July 2022

BACKGROUND

Salsola tragus is a widespread and problematic weed of semi‐arid wheat production globally, and in the inland Pacific Northwest region of the USA. The species exhibits high levels of phenotypic diversity across its range and, at least in California USA, previous work has described cryptic diversity comprising a multi‐species complex. Such cryptic diversity could suggest the potential for a differential response to management inputs between groups, and have important implications for the spread of herbicide resistance or other adaptive traits within populations. We used a genotyping‐by‐sequencing approach to characterize the population structure of S. tragus in the inland Pacific Northwest.

RESULTS

Our results indicated that the population in this region is comprised of a single, tetraploid species (S. tragus sensu latu) with weak population structure on a regional scale. Isolation‐by‐distance appears to be the primary pattern of structure, but an independent set of weakly differentiated clusters of unknown origin were also apparent, along with a mixed mating system and high levels of largely unstructured genetic diversity.

CONCLUSIONS

Despite considerable phenotypic variability within S. tragus in the region, agronomic weed managers can likely consider it as a single entity across the region, rather than a collection of cryptic subgroups with possible differential responses to management inputs or agroecosystem conditions. A lack of strong barriers to migration and gene flow mean that adaptive traits, such as herbicide resistance, can be expected to spread rapidly through populations across the region. © 2022 Society of Chemical Industry.
Efficient and multifidelity terrain modeling for 3D large‐scale and unstructured environments
Authors: Liu Xu , Li Decai , He Yuqing , Gu Feng
Published: July 2022

The vast amount of data captured by robots in large‐scale unstructured environments brings computation and storage problems to terrain modeling methods. Considering the practical terrain geometry structures, we design a large‐scale terrain modeling framework for efficiently generating the compact and accurate terrain models from incomplete and uncertain measurements. The multiresolution elevation filtering is developed to generate terrain surfaces that preserve terrain details in the bumpy areas while achieving a sparse representation over the flat areas, which simultaneously reduces the computation time, storage space, and inference error. To further reduce the high computational complexity, we propose a computation decomposition strategy by adopting the Gaussian mixture model to partition the whole terrain surface into several subsurfaces, enabling the method to scale to much larger environments. For each subsurface, we train a Gaussian process model using the local data to adapt to the local terrain structure, concurrently resolving the data incompleteness and uncertainty. Furthermore, to provide a more informative terrain model, we efficiently derive terrain gradient through a closed‐form solution by treating the generated terrain models as continuous functions, enabling more robotics applications, such as the path planning. We perform extensive experiments to evaluate our framework, including the use of two medium‐sized terrain data sets to evaluate the overall and local performance, and two large‐scale glacier terrain and mountain terrain in the area of up to 9 km2 to validate the practical applications.
Heilbronn triangle‐type problems in the unit square [0,1]2
Authors: Benevides Fabricio S. , Hoppen Carlos , Lefmann Hanno , Odermann Knut
Published: July 2022

The Heilbronn triangle problem is a classical geometrical problem that asks for a placement of points in the unit square that maximizes the smallest area of a triangle formed by three of those points. This problem has natural generalizations. For an integer and a set of points in , let be the minimum area of the convex hull of points in . Here, instead of considering the supremum of over all such choices of , we consider its average value, , when the points in are chosen independently and uniformly at random in . We prove that , for every fixed .
Equity and justice in science education: Toward a pluriverse of multiple identities and onto‐epistemologies
Authors: Kayumova Shakhnoza , Dou Remy
Published: July 2022

Concepts in science education such as “science identity” and “science capital” are informed by dominant epistemological and ontological positions, which translate into assumptions about what counts as science and whose science counts. In this theoretical paper we draw on decolonial and antiracist perspectives to examine these assumptions in light of the heterogeneous onto‐epistemological and axiological values, cultural perspectives, and contributions of nondominant groups, and specifically of those who have been historically marginalized based on their gender, race, ethnic, age, and/or social class identity. Building on these arguments, we critique deficit‐based approaches to science teaching, learning, and research, including those that focus on systemic injustice, yet leave intact dominant framings of the scientific enterprise, which are exclusionary and meritocratic. As an alternative, we offer a design of science teaching and learning for the pluriverse—“a world where many worlds fit”. This alternative allows us to reconstruct science and science‐related “outcomes,” such as identity, in the service of cultural, epistemic, and linguistic pluralism. We close the paper with the idea that because mainstream theories reproduce deficit framings and educational injustices, we must engage with decolonial1theories of pluriversality and discuss different onto‐epistemologies to be able to grapple with existing social, racial, environmental injustices, and land‐based devastations.
Bayesian criterion‐based assessments of recurrent event models with applications to commercial truck driver behavior studies
Authors: Zhang Yiming , Chen Ming‐Hui , Guo Feng
Published: July 2022

Multitype recurrent events are commonly observed in transportation studies, since commercial truck drivers may encounter different types of safety critical events (SCEs) and take different lengths of on‐duty breaks in a driving shift. Bayesian nonhomogeneous Poisson process models are a flexible approach to jointly model the intensity functions of the multitype recurrent events. For evaluating and comparing these models, the deviance information criterion (DIC) and the logarithm of the pseudo‐marginal likelihood (LPML) are studied and Monte Carlo methods are developed for computing these model assessment measures. We also propose a set of new concordance indices (C‐indices) to evaluate various discrimination abilities of a Bayesian multitype recurrent event model. Specifically, the within‐event C‐index quantifies adequacy of a given model in fitting the recurrent event data for each type, the between‐event C‐index provides an assessment of the model fit between two types of recurrent events, and the overall C‐index measures the model's discrimination ability among multiple types of recurrent events simultaneously. Moreover, we jointly model the incidence of SCEs and on‐duty breaks with driving behaviors using a Bayesian Poisson process model with time‐varying coefficients and time‐dependent covariates. An in‐depth analysis of a real dataset from the commercial truck driver naturalistic driving study is carried out to demonstrate the usefulness and applicability of the proposed methodology.
A Miopetaurista (Rodentia, Sciuridae) cranium from the Middle Miocene of Bavaria (Germany) and brain evolution in flying squirrels
Authors: Grau‐Camats Montserrat , Bertrand Ornella C. , Prieto Jérôme , López‐Torres Sergi , Silcox Mary T. , Casanovas‐Vilar Isaac
Published: July 2022

Flying squirrels (Sciurinae, Pteromyini) are the most successful group of gliding mammals. However, their fossil record mostly consists of isolated dental remains that provide very limited insights into their palaeobiology and evolution. The first skeleton of a fossil flying squirrel, belonging to the species Miopetaurista neogrivensis, has been described only recently. It presents all the diagnostic gliding‐related postcranial features of its extant relatives and shows that this group has undergone very little morphological change for almost 12 myr. However, the associated cranium is badly crushed, and particular details of the cranial morphology cannot be described. Here, we describe a well‐preserved cranium of the closely related Miopetaurista crusafonti from 12.5–12.0 Ma from Bavaria (Germany). Its cranial morphology is found to be almost identical to extant large flying squirrels, even in details such as the position of the foramina. The virtual endocast also shows close affinities to living large flying squirrels in morphology and in the relative volume of different brain regions, showing diagnostic features such as the size reduction of petrosal lobules and olfactory bulbs. However, the encephalization quotient (EQ) and neocortical ratio are lower than observed in extant flying squirrels. EQ is known to increase through time in squirrels, but might also be related to locomotion, given that arboreal and gliding squirrels display higher EQs than terrestrial ones. Because Miopetaurista was certainly a glider, its comparatively lower EQ and neocortical size support the existence of an independent trend of increasing EQ and neocortical complexity in this flying squirrel subclade.
Descriptive analysis of national bovine viral diarrhoea test data in England (2016–2020)
Authors: Prosser Naomi S. , Hill Edward M. , Armstrong Derek , Gow Lorna , Tildesley Michael J. , Keeling Matt J. , Kaler Jasmeet , Ferguson Eamonn , Green Martin J.
Published: July 2022

Background

Bovine viral diarrhoea virus (BVDV) causes substantial economic losses to the cattle industry; however, control and eradication can be achieved by identifying and removing persistently infected cattle from the herd. Each UK nation has separate control programmes. The English scheme, BVDFree, started in 2016 and is voluntary.

Methods

We analysed the test results submitted to BVDFree from 5847 herds between 2016 and 2020.

Results

In 2020, 13.5% of beef breeders and 20.0% of dairy herds that submitted tests had at least one positive (virus/antibody) test result. Although lower than in previous years, there was no clear trend in the proportion of positive tests over time. In virus testing herds, 0.4% of individual tests were positive in 2020, and 1.5% of individual tests were positive in BVDV‐positive virus testing herds. Dairy herds and larger herds were more likely to join BVDFree, and dairy herds were also more likely to virus test than beef breeder herds. Larger herds, herds that used virus testing and herds that had BVDV‐positive test results were more likely to continue submitting tests to BVDFree.

Conclusions

The findings provide a benchmark for the status of BVDV control in England; continued analysis of test results will be important to assess progress towards eradication.
Aggressive piecemeal excision and cervical bridging fixation for cervical vertebral osteosarcoma in two dogs and two cats
Authors: Kouno Shigenori , Tanoue Hirofumi , Shimada Masakazu , Hara Yasushi
Published: July 2022

Two dogs and two cats were referred for primary osteosarcoma of the cervical vertebrae. Each case was treated surgically with a combination of aggressive tumour resection and bridging fixation of the vertebrae, which was performed cranial and caudal to the affected site, using metal implants and polymethylmethacrylate. The cervical spines were stabilised by spinal reconstruction, and the tumours were extensively removed. Aggressive resection and spinal reconstruction prevented pathological fractures, contributed to spinal cord injury recovery, improved clinical symptoms and prolonged life expectancy.
Electrochemical Behavior of Mono‐Substituted [FeFe]‐Hydrogenase H‐Cluster Mimic Mediated by Stannylated Dithiolato Ligand
Authors: Abaalkhail Sara J. , Abul‐Futouh Hassan , Görls Helmar , Weigand Wolfgang
Published: July 2022

In this research work we present the synthesis and characterization of asymmetrical [FeFe]‐hydrogenase mimic, [Fe2(CO)5P(OMe)3{μ‐(SCH2)2SnPh2}] (2), obtained from replacing one of the CO ligands of the parent hexacarbonyl complex [Fe2(CO)6{μ‐(SCH2)2SnPh2}] (1) with the monodentate phosphite P(OMe)3. The molecular structure of complex2was confirmed by X‐ray diffraction analysis. Moreover, the electrochemistry of complexes1and2was investigated to explore the influence of the steric bulk of the Ph‐ring at the bridgehead Sn atom with the nearby P(OMe)3ligand. In addition, both complexes show their potentials toward hydrogen formation in the presence of weak acid, such as acetic acid (AcOH), suggesting an ECEC (E=electron transfer, C=chemical process) mechanism for hydrogen production.
Providing Agile Faculty Development in Times of Uncertainty: Case of the American University in Cairo
Authors: Bali Maha
Published: July 2022

The move toward emergency remote teaching meant educational development centers suddenly had to train and support all who teach at their institutions simultaneously. This article will focus on the agile, responsive and value-centric faculty development done locally via the American University in Cairo’s Center for Learning & Teaching, the “glocal” opportunities offered via DigPINS (see Bali and Caines, Int J Educ Technol High Educ 15(46):1–24, 2018), and the curation of openly available community-building resources available to educators worldwide. Central to all of these initiatives is that centering equity and care in how we support faculty (Czerniewicz, Agherdien, Badenhorst, Postdigit Sci Educ 2:946–967, 2020) will trickle down to the ways faculty treat their students during the trauma of the pandemic. We conclude that the pandemic has taught us the importance of centering values of equity and care while supporting faculty during a time of uncertainty and trauma (Imad, TIA 39, 2021), that fostering agency and imagination is more valuable than offering one-size-fits all standard solutions, and that faculty developers need to model adaptability and good pedagogy. Moreover, it is important to nurture and leverage learning communities, take advantage of “glocal” and “open” learning opportunities, and to build capability long-term via developing digital literacies and creativity.
Reflecting on a Year of Emergency Remote Teaching
Authors: Lee Jeonghyun , Soleimani Farahnaz , Harmon Stephen W.
Published: July 2022

This chapter reflects on lessons learned from a year of emergency remote teaching at a technology-focused university since the pandemic outbreak in March 2020. We focus on practical implications for supporting faculty in future emergency remote teaching situations based on an understanding of how faculty adapted to this novel phenomenon and the challenges they encountered during the rapid transition. Specifically, we examine faculty members’ perceptions and attitudes toward emergency remote teaching by taking a mixed-methods approach. We conducted a study using data collected from two anonymous online surveys administered in April 2020 and December 2020 as well as case study interviews conducted in May 2020. Our findings suggest that engaging students in interactive discussions or collaborative activities and assessing students’ learning were the areas in which faculty struggled the most persistently across both semesters. Yet, we observed between the two semesters an increasing trend in the proportion of faculty who felt their course was suitable for online instruction. We also observed a similar uptick in faculty who sought instructional resources from within their department and technology experts on campus. Our study findings capture creative and flexible strategies that our instructors have used to overcome these instructional challenges (e.g., re-configuring projects to handle logistical difficulties). We also identify varying needs and other important individual factors that might explain different transitioning experiences among faculty. The chapter concludes by discussing next steps to effectively support faculty members’ instructional practices and rebuild “the hybrid model” of education for the post-pandemic era.
Chilean Perspectives on Educational Experiences and Innovations in Emergency Contexts
Authors: Sánchez Jaime , Reyes-Rojas José
Published: July 2022

Emergency remote teaching began suddenly and widely by March 2020 after the World Health Organization declared the coronavirus pandemics Chilean education, as many other countries around the globe, adopted the methodology of remote teaching with little no previous experience and a lack of adequate and pertinent administrator, teacher, student, and parent preparation. This chapter presents, analyzes, and discusses the Chilean higher education experiences and innovations in emergency contexts during the COVID-19 pandemic. Actual and future perspectives are discussed on the basis of education in a country with frequent emergency contexts such as earthquakes, tsunamis, floods, fires and now a pandemic. We applied a systematic review research method to the higher education data and information that emerged during the coronavirus pandemic in Chile during the last year. As a result, we ended up drawing some trends, issues, and perspectives on Chilean higher education teaching and learning activities and innovation in emergency contexts. Finally, considering the results obtained, we discuss the main themes that emerged, and some lessons learned by Chilean education in times of pandemic, in order to be better prepared and equipped to face emergency situations with less disruption and detriment to teaching and learning in the future.
Online Learning Environments and Student Engagement: Meeting the Psychological Needs of Learners during the COVID-19 Pandemic
Authors: Hoi Vo Ngoc
Published: July 2022

This chapter reports the results of a qualitative study on students’ perception of the characteristics of the online learning environment and on how those characteristics affect their basic psychological needs and engagement during the emergency transition to online learning due to the Covid-19 pandemic. Semi-structured interviews with 24 students from a higher education institution in Vietnam revealed three main factors, including the instructor, peer groups, and technologies that either undermined or satisfied students’ basic psychological needs and affect students’ engagement in online learning. The findings shed light on the contextual factors that fulfill students’ needs for competence, autonomy, and relatedness, thus the findings provide instructors, course designers, and institutional leaders with useful information for the manipulation of instructional strategies and online learning conditions that promote student engagement in online learning in time of crisis.
Simulated Teaching: An Exploration of Virtual Classroom Simulation for Pre-service Teachers During the COVID-19 Pandemic
Authors: Azukas M. Elizabeth , Kluk Jason R.
Published: July 2022

The COVID-19 pandemic complicated the field experience component of teacher preparation because of K-12 school closures. To address these challenges, South Mountain University adopted a virtual classroom simulation, simSchool, in which students take on the role of teachers and interact with virtual students. The purpose of this self-study was to explore both the teacher and student perspectives in the initial implementation of simSchool in a secondary education methods course. Data collected for the study include simSchool performance reports, professor and student journals, student reflections, and student focus groups. Findings indicated that students required a more comprehensive introduction to and rationale for the use of the virtual simulation, more chunking of the training materials, and additional debriefing time after each of the modules. Students needed perseverance and resilience to make the sim work meaningful and had to be open to receiving feedback. Technology was initially a barrier but became less so as students spent more time in the sim. Ultimately the students perceived the sim as beneficial to their growth and development as teachers.
Population pharmacokinetic model to generate mechanistic insights in bile acid homeostasis and drug-induced cholestasis
Authors: de Bruijn Véronique M. P. , Rietjens Ivonne M. C. M. , Bouwmeester Hans
Published: July 2022

Bile acids (BA) fulfill a wide range of physiological functions, but are also involved in pathologies, such as cholestasis. Cholestasis is characterized by an intrahepatic accumulation of BAs and subsequent spillage to the systemic circulation. The aim of the present study was to develop physiologically based kinetic (PBK) models that would provide a tool to predict dose-dependent BA accumulation in humans upon treatment with a Bile Salt Export Pump (BSEP) inhibitor. We developed a PBK model describing the BA homeostasis using glycochenodeoxycholic acid as an exemplary BA. Population wide distributions of BSEP abundances were incorporated in the PBK model using Markov Chain Monte Carlo simulations, and alternatively the total amount of BAs was scaled empirically to describe interindividual differences in plasma BA levels. Next, the effects of the BSEP inhibitor bosentan on the BA levels were simulated. The PBK model developed adequately predicted the in vivo BA dynamics. Both the Markov Chain Monte Carlo simulations based on a distribution of BSEP abundances and empirical scaling of the total BA pool readily described the variations within and between data in human volunteers. Bosentan treatment disproportionally increased the maximum BA concentration in individuals with a large total BA pool or low BSEP abundance. Especially individuals having a large total BA pool size and a low BSEP abundance were predicted to be at risk for rapid saturation of BSEP and subsequent intrahepatic BA accumulation. This model provides a first estimate of personalized safe therapeutic external dose levels of compounds with BSEP-inhibitory properties.
A parabolic approach to the Calabi–Yau problem in HKT geometry
Authors: Bedulli Lucio , Gentili Giovanni , Vezzoni Luigi
Published: July 2022

We consider the natural generalization of the parabolic Monge–Ampère equation to HKT geometry. We prove that in the compact case the equation has always a short-time solution and when the hypercomplex structure is locally flat and admits a compatible hyperkähler metric, then the equation has a long-time solution whose normalization converges to a solution of the quaternionic Monge–Ampère equation first introduced in Alekser and Verbitsky (Isr J Math 176:109–138, 2010). The result gives an alternative proof of a theorem of Alesker (Adv Math 241:192–219, 2013).
Chemical Distance in Geometric Random Graphs with Long Edges and Scale-Free Degree Distribution
Authors: Gracar Peter , Grauer Arne , Mörters Peter
Published: July 2022

We study geometric random graphs defined on the points of a Poisson process ind-dimensional space, which additionally carry independent random marks. Edges are established at random using the marks of the endpoints and the distance between points in a flexible way. Our framework includes the soft Boolean model (where marks play the role of radii of balls centered in the vertices), a version of spatial preferential attachment (where marks play the role of birth times), and a whole range of other graph models with scale-free degree distributions and edges spanning large distances. In this versatile framework we give sharp criteria for absence of ultrasmallness of the graphs and in the ultrasmall regime establish a limit theorem for the chemical distance of two points. Other than in the mean-field scale-free network models the boundary of the ultrasmall regime depends not only on the power-law exponent of the degree distribution but also on the spatial embedding of the graph, quantified by the rate of decay of the probability of an edge connecting typical points in terms of their spatial distance.
QCNet: query context network for salient object detection of automatic surface inspection
Authors: Sun Jie , Yan Senbo , Song Xiaowen
Published: July 2022

Building upon fully convolutional networks (FCNs), deep learning-based salient object detection (SOD) methods achieve gratifying performance in many vision tasks, including surface defect detection. However, most existing FCN-based methods still suffer from the coarse object edge predictions. The state-of-the-art methods employ intricate feature aggregation techniques to refine boundaries, but they are often too computational cost to deploy in the real application. This paper proposes a semantics guided detection paradigm for salient object detection. Guided atrous pyramid module is first applied on the top feature to segment complete salient semantics. Query context modules are further used to build relation maps between saliency and structural information from the top-down pathway. These two modules allow the semantic features to flow throughout the decoder phase, yielding detail enriched saliency predictions. Experimental results demonstrate that the proposed method performs favorably against the state-of-the-art methods on surface defect detection and SOD benchmarks. In addition, this method can detect at 27 FPS in a fully convolutional fashion without any post-processing, which has the potential for real-time detection.
Acetyl-dl-leucine in cerebellar ataxia ([18F]-FDG-PET study): how does a cerebellar disorder influence cortical sensorimotor networks?
Authors: Becker-Bense Sandra , Kaiser Lena , Becker Regina , Feil Katharina , Muth Carolin , Albert Nathalie L. , Unterrainer Marcus , Bartenstein Peter , Strupp Michael , Dieterich Marianne
Published: July 2022

Objective

The aim of the study was to deepen our insights into central compensatory processes of brain networks in patients with cerebellar ataxia (CA) before and with treatment with acetyl-dl-leucine (AL) by means of resting-state [18F]-FDG-PET brain imaging.

Methods

Retrospective analyses of [18F]-FDG-PET data in 22 patients with CA (with vestibular and ocular motor disturbances) of different etiologies who were scanned before (PET A) and on AL treatment (PET B). Group subtraction analyses, e.g., for responders and non-responders, comparisons with healthy controls and correlation analyses of regional cerebral glucose metabolism (rCGM) with symptom duration, ataxia (SARA) and quality of life (QoL) scores were calculated.

Results

Prior to treatment rCGM was consistently downregulated at the cerebellar level and increased in multisensory cortical areas, e.g., somatosensory, primary and secondary visual (including V5, precuneus), secondary vestibular (temporal gyrus, anterior insula), and premotor/supplementary motor areas. With AL (PET B vs. A) cerebellar hypometabolism was deepened and sensorimotor hypermetabolism increased only in responders with clinical benefit, but not for the non-responders and the whole CA group. A positive correlation of ataxia improvement with rCGM was found in visual and vestibular cortices, a negative correlation in cerebellar and brainstem areas. QoL showed a positive correlation with rCGM in the cerebellum and symptom duration in premotor and somatosensory areas.

Conclusions

Central compensatory processes in CA mainly involve multisensory visual, vestibular, and somatosensory networks as well as premotor/primary motor areas at the cortical level. The enhanced divergence of cortical sensorimotor up- and cerebellar downregulation with AL in responders could reflect amplification of inhibitory cerebellar mechanisms.
QoS-aware and multi-objective virtual machine dynamic scheduling for big data centers in clouds
Authors: Li Jirui , Zhang Rui , Zheng Yafeng
Published: July 2022

Efficient resource scheduling is one of the most critical issues for big data centers in clouds to provide continuous services for users. Many existing scheduling schemes based on tasks on virtual machine (VM), pursued either load balancing or migration cost under certain response time or energy efficiency, which cannot meet the true balance of the supply and demand between users and cloud providers. The paper focuses on the following multi-objective optimization problem: how to pay little migration cost as much as possible to keep system load balancing under meeting certain quality of service (QoS) via dynamic VM scheduling between limited physical nodes in a heterogeneous cloud cluster. To make these conflicting objectives coexist, a joint optimization function is designed for an overall evaluation on the basis of a load balancing estimation method, a migration cost estimation method and a QoS estimation method. To optimize the consolidation score, an array mapping and a tree crossover model are introduced, and an improved genetic algorithm (GA) based on them is proposed. Finally, empirical results based on Eucalyptus platform demonstrate the proposed scheme outperforms exiting VM scheduling models.
Ecosystem transformation following the mid-nineteenth century cessation of Aboriginal fire management in Cape Pillar, Tasmania
Authors: Adeleye Matthew Adesanya , Haberle Simon Graeme , Ondei Stefania , Bowman David M. J. S.
Published: July 2022

Ongoing European suppression of Aboriginal cultural land management since early-nineteenth century colonisation is widely thought to have caused major transformations across all Australian landscapes, including vegetation thickening, severe fires and biodiversity declines. However, these effects are often confounded in the densely settled southern Australia due to European land transformation. Landscapes currently under conservation and national park management in Tasmania are generally less disturbed, providing an opportunity to track ecosystem changes caused by the removal of Aboriginal peoples following colonisation in southern Australia. We use a multi-proxy palaeoecological technique and the analysis of historical aerial photography to investigate these changes in Cape Pillar, southeast Tasmania. Results reveal a major ecological shift following European colonisation, with the replacement of stable, open wet heathland characterised by minor fires (active cultural land use) with dense dry scrub characterised by major fires (cessation of cultural land use). We also discuss potential background role of regional climatic shifts in the observed ecological changes. Management programmes designed to restore open heathland pre-colonial cultural ecosystem would help reduce the risk of large fires in Cape Pillar.
Devonian to Carboniferous continental-scale carbonate turnover in Western Laurentia (North America): upwelling or climate cooling?
Authors: Hedhli Makram , Dewing Keith , Beauchamp Benoit , Grasby Stephen E. , Meyer Rudi
Published: July 2022

The Devonian to Carboniferous (DC) transition coincided with a green-to-ice house climatic shift, anoxia, disappearance of lower latitude carbonate banks, and turnover from warm-to-cool water carbonate factories. In western Laurentia, the switch to carbonate factories dominated by cool-water biota was contemporaneous with a tectonically driven palaeogeographic change. To investigate this depositional shift and infer the relative impact of climate vs tectonics, a continental-scale sedimentological and geochemical study was conducted on twelve stratigraphic sections of DC strata from western Canada to southern Nevada (USA). The spatial–temporal distribution of microfacies records the turnover from [i] a Famennian lime mud-rich, shallow warm-water carbonate ramp with low sedimentation rates, mesotrophic conditions and tabular geometry to [ii] Tournaisian to Viséan lime mud-depleted and grainstone dominated cool-water carbonate ramp with anomalous high sedimentation rates, oligotrophic conditions and a pronounced slope. Positive excursions of δ18Ocarb (+ 2‰ V-PDB) and δ13Ccarb (+ 4‰ V-PDB) of Lower Mississippian carbonates likely correspond to the first cooling peak of the Carboniferous-Permian icehouse climate, following carbon withdrawal during black shale deposition during the late Famennian and early Tournaisian. However, late Tournaisian return of photozoan elements and their persistence throughout the Viséan suggests that warmer surface water existed, revealing a decoupling of the lower latitude ocean and the atmosphere. Shoaling of the thermocline was likely a result of cold-water upwelling along an open coast, as the Antler orogen no longer provided an oceanic obstruction to the west. This study shows that carbonate platforms are more susceptible to regional changes than global shifts.
Definitions of intent suitable for algorithms
Authors: Ashton Hal
Published: July 2022

This article introduces definitions for direct, means-end, oblique (or indirect) and ulterior intent which can be used to test for intent in an algorithmic actor. These definitions of intent are informed by legal theory from common law jurisdictions. Certain crimes exist where the harm caused is dependent on the reason it was done so. Here the actus reus or performative element of the crime is dependent on the mental state or mens rea of the actor. The ability to prosecute these crimes is dependent on the ability to identify and diagnose intentional states in the accused. A certain class of auto didactic algorithmic actor can be given broad objectives without being told how to meet them. Without a definition of intent, they cannot be told not to engage in certain law breaking behaviour nor can they ever be identified as having done it. This ambiguity is neither positive for the owner of the algorithm or for society. The problem exists over and above more familiar debates concerning the eligibility of algorithms for culpability judgements that mens rea is usually associated with. Aside from inchoate offences, many economic crimes with elements of fraud or deceit fall into this category of crime. Algorithms operate in areas where these crimes could be plausibly undertaken depending on whether the intent existed in the algorithm or not.
Analytical design models for geotechnical seismic isolation systems
Authors: Tsang Hing-Ho
Published: July 2022

Geotechnical Seismic Isolation (GSI) can be defined as a new category of seismic isolation techniques that involve the dynamic interaction between the structural system and geo-materials. Whilst the mechanism of various GSI systems and their performance have already been demonstrated through different research methods, there is a missing link between fundamental research and engineering practice. This paper aims to initiate the development in this direction. A new suite of equivalent-linear foundation stiffness and damping models under the same framework is proposed for four GSI configurations, one of which is a novel combination of two existing ones. The exact solutions for the equivalent dynamic properties of flexible-base systems have also been derived that explicitly include the foundation inertia and the strain-dependent equivalent damping of foundation materials, which are both significant for GSI systems. The application of the proposed analytical design models has been illustrated through response history analyses and a detailed hand-calculation design procedure has also been outlined and demonstrated.
Natural and Anthropogenic Sources of Seismic, Hydroacoustic, and Infrasonic Waves: Waveforms and Spectral Characteristics (and Their Applicability for Sensor Calibration)
Authors: Schwardt Michaela , Pilger Christoph , Gaebler Peter , Hupe Patrick , Ceranna Lars
Published: July 2022

The record of seismic, hydroacoustic, and infrasonic waves is essential to detect, identify, and localize sources of both natural and anthropogenic origin. To guarantee traceability and inter-station comparability, as well as an estimation of the measurement uncertainties leading to a better monitoring of natural disasters and environmental aspects, suitable measurement standards and reliable calibration procedures of sensors, especially in the low-frequency range down to 0.01 Hz, are required. Most of all with regard to the design goal of the Comprehensive Nuclear-Test-Ban Treaty Organisation’s International Monitoring System, which requires the stations to be operational nearly 100% of the time, the on-site calibration during operation is of special importance. The purpose of this paper is to identify suitable excitation sources and elaborate necessary requirements for on-site calibrations. We give an extensive literature review of a large variety of anthropogenic and natural sources of seismic, hydroacoustic, and infrasonic waves, describe their most prominent features regarding signal and spectral characteristics, explicitly highlight some source examples, and evaluate the reviewed sources with respect to requirements for on-site calibrations such as frequency bandwidth, signal properties as well as the applicability in terms of cost–benefit. According to our assessment, earthquakes stand out across all three waveform technologies as a good natural excitation signal meeting the majority of the requirements. Furthermore, microseisms and microbaroms allow a calibration at very low frequencies. We also find that in each waveform technique man-made controlled sources such as drop weights or air guns are in good agreement with the required properties, although limitations may arise regarding the practicability. Using these sources, procedures will be established allowing calibration without record interrupting, thereby improving data quality and the identification of treaty-related events.
Interfacing PDM MEMS Microphones with PFM Spiking Systems: Application for Neuromorphic Auditory Sensors
Authors: Gutierrez-Galan Daniel , Rios-Navarro Antonio , Dominguez-Morales Juan Pedro , Duran-Lopez Lourdes , Jimenez-Moreno Gabriel , Jimenez-Fernandez Angel
Published: July 2022

Neuromorphic computation processes sensors output in the spiking domain, which presents constraints in many cases when converting information to spikes, loosing, as example, temporal accuracy. This paper presents a spike-based system to adapt audio information from low-power pulse-density modulation (PDM) microelectromechanical systems microphones into rate coded spike frequencies. These spikes could be directly used by the neuromorphic auditory sensor (NAS) for frequency decomposition in different bands, avoiding the analog or digital conversion to spike streams. This improves the time response of the NAS, allowing its use in more time restrictive applications. This adaptation was conducted in VHDL as an interface for PDM microphones, converting their pulses into temporal distributed spikes following a pulse-frequency modulation scheme with an accurate inter-spike-interval, known as PDM to spikes interface (PSI). We introduce a new architecture of spike-based band-pass filter to reject DC components and distribute spikes in time. This was tested in two scenarios, first as a stand-alone circuit for its characterization, and then integrated with a NAS for verification. The PSI achieves a total harmonic distortion of$$-$$-46.18 dB and a signal-to-noise ratio of 63.47 dB, demands less than 1% of the resources of a Spartan-6 FPGA and its power consumption is around 7 mW.
A method of sequential log-convex programming for engineering design
Authors: Karcher Cody , Haimes Robert
Published: July 2022

A method of Sequential Log-Convex Programming (SLCP) is constructed that exploits the log-convex structure present in many engineering design problems. The mathematical structure of Geometric Programming (GP) is combined with the ability of Sequential Quadratic Program (SQP) to accommodate a wide range of objective and constraint functions, resulting in a practical algorithm that can be adopted with little to no modification of existing design practices. Three test problems are considered to demonstrate the SLCP algorithm, comparing it with SQP and the modified Logspace Sequential Quadratic Programming (LSQP). In these cases, SLCP shows up to a 77% reduction in number of iterations compared to SQP, and an 11% reduction compared to LSQP. The airfoil analysis code XFOIL is integrated into one of the case studies to show how SLCP can be used to evolve the fidelity of design problems that have initially been modeled as GP compatible. Finally, a methodology for design based on GP and SLCP is briefly discussed.
Enhancing the information of nonlinear SU(1, 1) quantum systems interacting with a two-level atom
Authors: Abd-Rabbou M. Y. , Ali S. I. , Ahmed M. M. A.
Published: July 2022

The effect of nonlinearity, initial atomic state, and different resonance cases on the interaction between nonlinear SU (1, 1) quantum states and a two-level atom is discussed. The optimal behaviours of decoherence, entanglement and quantum coherence are predicted via using the skew information, tomographic entropy, and the relative entropy of coherence, respectively. It is shown that the detuning parameter has a destructive effect on the coherence and consequently on the entanglement if the quantum system is regulated in the ideal SU (1, 1) quantum systems. For the nonlinear SU (1, 1) quantum systems, the ability to suppress the decay of entanglement induced by the detuning may be increased by preparing the initial atomic state in its excited state.
COVID-19 and renal involvement: a prospective cohort study assessing the impact of mild SARS-CoV-2 infection on the kidney function of young healthy males
Authors: Al Rumaihi Khalid , Khalafalla Kareim , Arafa Mohamed , Nair Arun , Al Bishawi Ahmad , Fino Areen , Sirtaj Faheem , Ella Mohamed Khair , ElBardisi Haitham , Khattab Muhammad Abu , Majzoub Ahmad
Published: July 2022

Purpose

COVID-19 frequently affects the kidneys with symptoms ranging from mild proteinuria to progressive acute kidney injury. This prospective study aimed to assess the short- and long-term impact of asymptomatic and mild COVID-19 on the renal function of healthy young adults, and to determine the correlation between viral load and kidney function among these patients.

Methods

This was a prospective cohort study conducted over a period of 6 months. Patients were followed-up at baseline, and then after 3 and 6 months, respectively. Real-time PCR cycle threshold (CT) was used to determine the viral load and disease activity. Patients were classified into two groups with either asymptomatic COVID-19 or mild pneumonia. The assessment parameters were variables that could directly or indirectly relate to the renal function.

Results

A total of 48 patients were included and evaluated. The majority of patients (62.5%) had asymptomatic COVID-19 disease. Patients with mild pneumonia had significantly higher serum creatinine (SCr) at the time of COVID-19 diagnosis (beta = 12.836, 95% CI = 2.405–23.268, P = 0.019), after 3 months (beta = 14.345, 95% CI = 1.149–27.542, P = 0.035), and after 6 months (beta = 14.100, 95% CI = 0.730–27.470, P = 0.040) compared to asymptomatic patients. Mild pneumonia was also significantly associated with lower serum albumin level at the time of COVID-19 diagnosis (beta = – 6.317, 95% CI = – 9.448–− 3.185, P < 0.001).

Conclusion

Mild COVID-19 is associated with mild renal involvement without AKI. Changes in the renal function appear to be related to reduced creatinine clearance and possible albumin leakage in the acute phase of the disease. The reduction in creatinine clearance is not predicted by viral load, and it appears to be a long-term effect of the disease that can last for at least 6 months.