bluuebunny/crossref_metadata_2025 huggingface dataset:
Postero-posterolateral approach in total hip arthroplasty
Authors: Ait Mokhtar Mokrane
Published: July 2020

Introduction

Evolving surgical techniques in total hip arthroplasty (THA) have sought to make the surgical procedures safer. This requires having highly reproducible incision landmarks and simplifying the procedures. The postero-posterolateral approach, a very posterior incision in the hip, meets those requirements. However, this has not helped to reduce the post-operative dislocation rate. The aim of this study was to assess the relevance of combining the postero-posterolateral approach and next-generation dual mobility cups (DMC) in terms of dislocation risk.

Materials and methods

One hundred and fifty-eight THA were performed consecutively using the postero-posterolateral approach on 150 patients, by a single surgeon, over a 49-month period (November 2010 to December 2014). All acetabular implants were impacted.

Results

Average length of the incision was 7 cm (6 to 9 cm). Mean duration of the surgical procedure was 75 minutes (40 to 100). Mean blood loss was estimated at 210 cc (25 to 410 cc). All patients could walk with assistance the day before transferring to a rehabilitation centre. There was one posterior dislocation (0.63%), without recurrence.

Conclusion

The straightforwardness and reproducibility of the anatomical landmarks used for the postero-posterolateral approach, added to the stability of the dual mobility cup, result in a safe combination in the therapeutic THA arsenal.
Neural reflectance transformation imaging
Authors: Dulecha Tinsae G. , Fanni Filippo A. , Ponchio Federico , Pellacini Fabio , Giachetti Andrea
Published: July 2020

Reflectance transformation imaging (RTI) is a computational photography technique widely used in the cultural heritage and material science domains to characterize relieved surfaces. It basically consists of capturing multiple images from a fixed viewpoint with varying lights. Handling the potentially huge amount of information stored in an RTI acquisition that consists typically of 50–100 RGB values per pixel, allowing data exchange, interactive visualization, and material analysis, is not easy. The solution used in practical applications consists of creating “relightable images” by approximating the pixel information with a function of the light direction, encoded with a small number of parameters. This encoding allows the estimation of images relighted from novel, arbitrary lights, with a quality that, however, is not always satisfactory. In this paper, we present NeuralRTI, a framework for pixel-based encoding and relighting of RTI data. Using a simple autoencoder architecture, we show that it is possible to obtain a highly compressed representation that better preserves the original information and provides increased quality of virtual images relighted from novel directions, especially in the case of challenging glossy materials. We also address the problem of validating the relight quality on different surfaces, proposing a specific benchmark, SynthRTI, including image collections synthetically created with physical-based rendering and featuring objects with different materials and geometric complexity. On this dataset and as well on a collection of real acquisitions performed on heterogeneous surfaces, we demonstrate the advantages of the proposed relightable image encoding.
Potential of platinum-resensitization by Wnt signaling modulators as treatment approach for epithelial ovarian cancer
Authors: Kaltofen Till , Preinfalk Valentina , Schwertler Stephanie , Fraungruber Patricia , Heidegger Helene , Vilsmaier Theresa , Vattai Aurelia , Czogalla Bastian , Mayr Doris , Mahner Sven , Jeschke Udo , Trillsch Fabian
Published: July 2020

Purpose

Canonical Wnt/ β-catenin pathway is one mechanism being activated in platinum-resistant epithelial ovarian cancer (EOC). Detecting potential targets for Wnt pathway modulation as a putative future therapeutic approach was the aim of this study.

Methods

Biological effects of different Wnt modulators (SB216763, XAV939 and triptolide) on the EOC cell lines A2780 and its platinum-resistant clone A2780cis were investigated via multiple functional tests. Immunohistochemistry (IHC) was carried out to compare the expression levels of Wnt marker proteins (β-catenin, snail/ slug, E-cadherin) in patient specimens and to correlate them with lifetime data.

Results

We could show that activated Wnt signaling of the platinum-resistant EOC cell line A2780cis can be reversed by Wnt manipulators through SB216763 or XAV939. All Wnt manipulators tested consecutively decreased cell proliferation and cell viability. Apoptosis of A2780 and A2780cis was enhanced by triptolide in a dose-dependent manner, whereas cell migration was inhibited by SB216763 and triptolide. IHC analyses elucidated significantly different expression patterns for Wnt markers in the serous subtype. Herein, higher plasmatic snail/ slug expression is associated with improved progression-free (PFS) and overall survival (OS).

Conclusion

According to the described effects on EOC biology, all three Wnt manipulators seem to have the potential to augment the impact of a platinum-based chemotherapy in EOC. This is promising as a dominance of this pathway was confirmed in serous histology.
Summer UTCI variability in Poland in the twenty-first century
Authors: Krzyżewska Agnieszka , Wereski Sylwester , Dobek Mateusz
Published: July 2020

The paper analyses the temporal and spatial variability of the Universal Thermal Climate Index (UTCI) in Poland in summer. Summer is the season with the highest intensity of tourism traffic that is why it is important to determine biometeorological conditions, especially in popular tourist destinations such as coastal, mountain and urban areas, in the times of climate changes. The analysis was based on data from 18 stations of IMGW-PIB (Institute of Meteorology and Water Management—National Research Institute), distributed evenly in the territory of the country, and representing all eight bioclimatic regions. The data include air temperature, relative humidity, wind velocity and cloudiness at 12 UTC from summer months: June, July and August from the years 2001–2018. Thermoneutral zone was the most frequently occurring UTCI class in Poland. It was recorded during 56–75% of summer days (with the exception of mountain stations, where it occurred on 30–35% of days). Moderate heat stress is the second most frequently occurring category with a frequency from 18 to 29% with the exception of mountain and coastal areas. Extreme and very strong cold stress occurred particularly in high mountain stations, and was sporadically observed at the coast of the Baltic Sea; however, the occurrence of such conditions decreases, which if favourable for beach tourism. No cases of extreme heat stress were recorded in any of the stations. The most unfavourable bioclimatic conditions were characteristic of the Upland Region (IV), represented by Kraków and Sandomierz, where very strong heat stress occurred with a 10% frequency. This is a limitation for urban tourism in those regions. The highest UTCI values were recorded in Kraków on 17 July 2007 and 29 July 2005. The highest number of cases with strong and very strong heat stress was recorded in 2015 as a consequence of the heat wave observed in Poland in the first half of August. In the majority of the analysed stations, in the second half of the analysed period (2010–2018), an increase in the number of days with strong and very strong heat stress was observed in comparison with the first half of period (2001–2009). The highest frequency of such days was observed in July. Based on the data, there are 4 potential periods of occurrence of such days, with two most intense being 26. July–13 August and 14–22 July.
Who turns to the human? Companion pigs’ and dogs’ behaviour in the unsolvable task paradigm
Authors: Pérez Fraga Paula , Gerencsér Linda , Lovas Melinda , Újváry Dóra , Andics Attila
Published: July 2020

When facing an unsolvable problem, dogs exhibit spontaneous human-oriented behaviours (e.g. looking at the human partner, gaze alternations between the human and the target) sooner and for longer than domestic cats and hand-raised wolves. These behaviours have been interpreted as interspecific communicative acts aimed to initiate interaction. Here, we compare the emergence of human-oriented behaviours (e.g. orientation towards humans, orientation alternations, vocalizations) in similarly raised family dogs and miniature pigs utilising an unsolvable task paradigm which consists of Baseline (no task), Solvable and Unsolvable phases. Relative to the Baseline phase in which both species showed human-oriented behaviours to a similar extent, during the Unsolvable phase dogs showed more and pigs showed less such behaviours. Species-predispositions in communicative behaviour may explain why dogs have a higher inclination than pigs to initiate interspecific interactions with humans in problem-solving contexts.
Survival rates on pre-weaning European hares (Lepus europaeus) in an intensively used agricultural area
Authors: Voigt Ulrich , Siebert Ursula
Published: July 2020

The primary cause of the long-term decline in European hares’ (Lepus europaeus) population throughout Europe is widely assumed to be the intensification of agriculture. A critical component in this population dynamics is seen in the survival of leverets from birth to reproductive age. In European hares, the first stage of life until weaning has been sparsely studied, in particular habitat selection, movements and survival rate, as juveniles’ precocial lifestyle is dominated by any kind of anti-predation behaviour. In the present study, free-living and pre-weaning European hares were detected systematically by thermography (n = 394), being radio-tagged or marked (n = 229) from birth until the fifth week of life to research the early juvenile survival and proximate causes of mortality. Kaplan-Meier survival curves were computed overall and in relation to the strata of season, sex and type of daytime resting place. The survival rate of radio-tagged leverets was 0.35 in the first month of life, and 0.63, 0.52 and 0.44 for the first, second and third week of life, respectively. Approximately 21.6% and 50% of all confirmed deaths occurred during the first 7 and 13 days after birth. By the end of the 4th week of life, the mortality rate caused by predation, suspected predation, agricultural practices and unexplained cases was 41.7%, 36.7%, 11.7% and 10.0%, respectively. There was no significant difference in survival between the sexes and seasons. In contrast, young hares died more frequently as a consequence of choosing a hiding place without shelter during the daytime.
The Potential of Albuminuria as a Biomarker of Diabetic Complications
Authors: Raja Pappitha , Maxwell Alexander P. , Brazil Derek P.
Published: July 2020

Diabetes mellitus is a disease of dysregulated blood glucose homeostasis. The current pandemic of diabetes is a significant driver of patient morbidity and mortality, as well as a major challenge to healthcare systems worldwide. The global increase in the incidence of diabetes has prompted researchers to focus on the different pathogenic processes responsible for type 1 and type 2 diabetes. Similarly, increased morbidity due to diabetic complications has accelerated research to uncover pathological changes causing these secondary complications. Albuminuria, or protein in the urine, is a well-recognised biomarker and risk factor for renal and cardiovascular disease. Albuminuria is a mediator of pathological abnormalities in diabetes-associated conditions such as nephropathy and atherosclerosis. Clinical screening and diagnosis of diabetic nephropathy is chiefly based on the presence of albuminuria. Given the ease in measuring albuminuria, the potential of using albuminuria as a biomarker of cardiovascular diseases is gaining widespread interest. To assess the benefits of albuminuria as a biomarker, it is important to understand the association between albuminuria and cardiovascular disease. This review examines our current understanding of the pathophysiological mechanisms involved in both forms of diabetes, with specific focus on the link between albuminuria and specific vascular complications of diabetes.
First report of pharmaceuticals and personal care products in two tropical rivers of southwestern India
Authors: Joshua Derrick Ian , Praveenkumarreddy Yerabham , Prabhasankar Valiparambil Prabhakaranunni , D’Souza Andrea Petula , Yamashita Nobuyoshi , Balakrishna Keshava
Published: July 2020

The occurrence of selected pharmaceuticals (trimethoprim, sulfamethoxazole, chloramphenicol, bezafibrate, ceftriaxone, and naproxen) in two west-flowing tropical rivers (Swarna and Nethravati) of southwestern India is reported for the first time. Water samples were collected during the monsoon and post-monsoon seasons from river water end members and further downstream up to their confluence with the adjacent Arabian Sea. Samples were analyzed using HPLC–MS/MS. Results revealed that there were no significant seasonal variations in concentrations of target analytes in both the rivers. Of the total number of samples analyzed (n = 24), trimethoprim was detected in 100% of the samples, whereas sulfamethoxazole (SMX), chloramphenicol (CAP), ceftriaxone (CTX), and naproxen (NPX) were detected in between 91 and 58% of the samples. Bezafibrate (BZF) was not detected in the samples. Nethravathi river showed higher concentrations of pharmaceuticals than the Swarna river which may be attributed to comparatively larger human population in the basin. Possible impacts of PPCPs on aquatic life offer further scope for study.
Note on “Oligopoly with Hyperbolic Demand: A Differential Game Approach”
Authors: Hoof Simon
Published: July 2020

We correct the local stability analysis of the two-player case of Lambertini (J Optim Theory Appl 145(1):108–119, 2010). Due to a sign error, the steady state was mischaracterized as being stable, while it is unstable.
Spatially Resolved Velocity Mapping of the Melt Plume During High-Pressure Gas Atomization of Liquid Metals
Authors: Bigg T. D. , Mullis A. M.
Published: July 2020

We present details of an image analysis algorithm designed specifically to determine the velocity of material in the melt plume during high-pressure, close-coupled gas atomization. Following high-speed filming (16,000 fps) pairs of images are used to identify and track dominant features within the plume. Due to the complexity of the atomization plume, relatively few features are tracked between any given pair of images, but by averaging over the many thousands of frames obtained during high-speed filming a spatially resolved map of the average velocity of material in the plume can be built up. Velocities in the plume are typically very low compared to that of the supersonic gas, being around 30 m s−1 on the margins of the plume where the melt interacts strongly with the gas and dropping to < 10 m s−1 in the center of the melt plume. Consequently, the efficiency of the atomizer in transferring kinetic energy from the gas to the melt is correspondingly very low, with this being estimated as being no more than 0.1 pct.
Relationship between contact size and static friction: An approach for rigid crystalline surfaces
Authors: Chen Hao , Gao Xinlei
Published: July 2020

Relationship between contact size (A) and static friction (f) has been studied for rigid crystalline systems. We built a series of systems with two identical surfaces but different orientations and investigated the effects of the size and shape of the contact area on static friction. In these systems, there are numerous nontrivial commensurate contacts. Our results confirmed that the relationship between A and f was determined by both commensurability and shape of the contact. For commensurate contacts, f ∝ A independent of the shape. For incommensurate contacts, generally f ∝ A0 for regular shapes or f ∝ A1/4 for irregular shapes; however, in very few cases of regular shapes, f ∝ A1/2. Moreover, in above systems, commensurability of a contact can be easily changed by a perturbation of the misfit angle. Therefore, if the perturbation caused by the lateral force and the deformation of the surface are considered (as is the case in real systems), further research is necessary.
Candida auris Infection and Biofilm Formation: Going Beyond the Surface
Authors: Horton Mark V. , Nett Jeniel E.
Published: July 2020

Purpose of Review

Emergent fungal pathogen C. auris is spreading in hospitals throughout the world and mortality rates for patients with invasive disease approach 60%. This species exhibits a heightened capacity to colonize skin, persist on hospital surfaces, rapidly disseminate in healthcare settings, and resist antifungal therapy.

Recent Findings

Current investigations show that C. auris produces biofilms, surface-adherent communities that resist antifungals and withstand desiccation. These biofilms form when C. auris is growing on skin or in conditions expected in the hospital environment and on implanted medical devices.

Here, we will highlight the topic of biofilm formation by C. auris. We illustrate how this process influences resistance to antimicrobials and promotes nosocomial transmission.
A study of sequence stratigraphy of the Early Cretaceous coal-bearing series in the southeastern Songliao Basin, NE China
Authors: Shao Kai , Shao Longyi , Ma Dongmin , Wang Dongdong , Wang Shuai , Gao Di
Published: July 2020

The Early Cretaceous is an important coal accumulation period in China. Abundant coal resources were formed in the southeastern margin of Songliao Basin. Sequence stratigraphy and coal accumulation of the Early Cretaceous in the southeastern margin of Songliao Basin have been studied on the basis of extensive outcrop and borehole data. Based on regional unconformity, basal erosional surfaces of incised valley fills, and abrupt depositional facies-reversal surface, six sequence boundaries have been identified, which subdivide the Early Cretaceous coal-bearing series into 5 third-order sequences. Sequence I corresponds to Huoshiling Formation, sequences II and III correspond to member I and member II of Shahezi Formation. Sequences IV and V correspond to member I and member II of Yingcheng Formation. Sequence I developed at the initial subsiding stage, sequence II and III developed during the stable subsiding stage, while sequence IV and V developed during the basin shrinkage stage. The major coal seams were developed in the sequence II and III, which ensured the relative balance between the increase rate of the accommodation space and the rate of peat accumulation for a longer period, thus forming a thick coal seam.
Providing a ‘point of entry’: Approaches to framing sustainability in curriculum design in Higher Education
Authors: Sandri Orana
Published: July 2020

The rationale for including sustainability in Higher Education curriculum has been made clear, yet how to facilitate effective learning in this field has received less research attention. This article focuses on approaches to the ‘framing’ of sustainability in curriculum design as a tool for educators to contextualise sustainability concepts and practices to engage learners within traditional disciplines where sustainability studies are still relatively novel, and therefore, not embedded within existing disciplinary ‘frames’. The article draws together findings from a qualitative study of four undergraduate sustainability courses to provide initial insight into different framings of sustainability and student experiences within the courses. Drawing on an analysis of empirical data and theory, this article argues that the way sustainability is framed may assist in addressing barriers in the uptake of sustainability by teachers and students in Higher Education. Framing has the potential to support student engagement with sustainability courses and the integration of sustainability within degree programs and professional practices. The findings also indicate that framing, and its effect on learning, are shaped by both the presentation of content and also, more importantly for transformative learning, the pedagogy underpinning the curriculum design.
Deutsche Bahn AG v. Regione Stereá Ellada
Authors: Mariottini Cristina M.
Published: July 2020

With Judgment No. 21995/2019 (the Judgment), the Italian Court of Cassation (Court of Cassation) once again tackled the limits of sovereign immunity with regard to crimes against humanity (para. 7). The Judgment is part of litigation originating in Greece with the Leivadia Tribunal's 1997 Distomo decision, confirmed in 2000 by the Areopago (Hellenic Supreme Court), which ordered Germany to pay compensation and legal costs of approximately 50 million euros to the relatives of 218 victims of the Distomo massacre committed by the German military in 1944. In this Judgment, the Court of Cassation addressed whether sovereign immunity blocked the seizure of German assets located in Italy as part of that compensation order. The Court of Cassation's decision is noteworthy because it takes the discussion on sovereign immunity from jurisdiction and crimes against humanity one step further by addressing, in particular, the question of compensation and attachment of claims and rights held by the debtor against third parties.
Just the Facts: Risk stratifying non-traumatic back pain for spinal epidural abscess in the emergency department
Authors: Polsky Zoe , Dowling Shawn K. , Jacobs W. Bradley
Published: July 2020

A 65-year-old male with a history of hypertension presents to the emergency department (ED) with new onset of non-traumatic back pain. The patient is investigated for life-threatening diagnoses and screened for “red flag symptoms,” including fever, neurologic abnormalities, bowel/bladder symptoms, and a history of injectiondrug use (IVDU). The patient is treated symptomatically and discharged home but represents to the ED three additional times, each time with new and progressive symptoms. At the time of admission, he is unable to ambulate, has perineal anesthesia, and 500 cc of urinary retention. Whole spine magnetic resonance imaging (MRI) confirms a thoracic spinal epidural abscess. This case, and many like it, prompts the questions: when should emergency physicians consider the diagnosis of a spinal epidural abscess, and what is the appropriate evaluation of these patients in the ED? (Figure 1).
Women’s Representation and the Gendered Pipeline to Power
Authors: THOMSEN DANIELLE M. , KING AARON S.
Published: July 2020

The leading explanation for the underrepresentation of women in American politics is that women are less likely to run for office than men, but scholars have given less attention in recent years to the gender makeup of the pipeline to elected office. We examine the gendered pipeline to power across three potential candidate pools: lower-level officeholders, those named in newspapers as likely candidates, and lawyers who made political contributions. We find some evidence that women are less likely to seek elected office; however, the dearth of women in the pipeline plays a much greater role in the lack of women candidates. For the gender disparity in candidates to close, women have to be far more likely to run for office than men, particularly on the Republican side. Our results highlight the need to consider the gendered pipeline to power alongside rates of entry in studies of women’s underrepresentation.
Addressing reproductive health knowledge, infertility and coping strategies among rural women in India
Authors: Patra Shraboni , Unisa Sayeed
Published: July 2020

An awareness of fertility and the factors affecting it is crucial to dealing with infertility, though little research has been conducted in the context of rural India. This study assessed Indian women’s perceived causes of, and strategies for coping with, infertility and the associations with levels of reproductive health knowledge in rural areas. Primary data were collected through mapping and listing in high infertility prevalence districts of West Bengal in 2014–15. A total of 159 women aged 20–49 years who had ever experienced infertility were interviewed. A Reproductive Health Knowledge Index (RHKI) was computed to indicate respondent’s level of reproductive health knowledge, and to show its association with perceived causes of infertility and coping with infertility. The highest mean RHKI score was observed among women in the lowest age group (RHKI=5.75, p<0.001), those with a higher level of education (RHKI=9.39, p<0.001) and those who had exposure to any media (RHKI=5.88, p<0.001). Women with a poor wealth index (RHKI=2.11, p<0.01) and those from Scheduled Caste, Scheduled Tribe and Other Backward Class communities (RHKI=4.20, p<0.05) had lower RHKI scores than richer women and those from General Caste communities. Women with a higher RHKI score were more likely to give biology (98.0%, p<0.001), old age (94.1%, p<0.01) and repeated abortions/accident/injury (92.2%, p<0.001) as reasons for infertility, whereas women with a low RHKI were more likely to give religious (73.2%, p<0.001) and old-age-related causes (75.0%, p<0.01) of infertility. Women with a high RHKI score were more likely to opt for modern allopathic treatments (RHKI=7.04, p<0.001), whereas those with a low RHKI score were more likely to seek treatment from religious and superstitious practitioners, use home remedies or receive no treatment at all (RHKI=1.66, p<0.001). Appropriate reproductive health knowledge is crucial if rural Indian women are to correctly assess their infertility problems and choose effective coping strategies.
Emergent STEM lecturer identities: The shaping effects of EMI in action in an internationalised and Englishised HE context
Authors: Block David
Published: July 2020

This paper examines the emergent identities of three STEM (science, technology, engineering and mathematics) lecturers, focusing especially on how they construct themselves with regard to their disciplines and how researchers construct them as potential English language teachers. It begins with essential background information before discussing identity as a key construct. The paper then moves to the presentation of a Foucauldian-inflected version of positioning theory which is employed as a means of understanding the construction of English-medium instruction (EMI) STEM lecturer identities. In the second half of the paper, there is a discussion of three case-studies of EMI STEM lecturers, which shows how each orientates to his or her subject discipline, and the prospect of acting, on occasion, as an English language teacher. Specifically, there is a detailed consideration of how EMI lecturers position themselves in their contacts with researchers and in their teaching; how their self-positionings are consistent or not with how researchers position them; and how self-positionings are similar or different across EMI lecturers. The paper ends with a discussion of what conclusions can be drawn from the research findings.
Experimental Validation of an Adaptive Controller for Manipulators on a Dynamic Platform
Authors: Rodriguez Reina Andres , Nguyen Kim-Doang , Dankowicz Harry
Published: July 2020

This paper reports on laboratory and field experimental results for controlled robotic manipulators operating on moving platforms with unmodeled dynamics. The aim is to validate theoretical predictions for the dependence on control parameters of an adaptive control strategy. In addition, the results provide insight into different discretizations of the continuous-time formulation, suggesting the most suitable discretization scheme for hardware implementation. The second set of experimental results, obtained from an implementation of the control framework for synchronization and consensus in networks of robotic manipulators, similarly validate theoretical predictions on the sensitivity to network communication delays.
Trajectories of co-occurring psychopathology symptoms in autism from late childhood to adulthood
Authors: McCauley James B. , Elias Rebecca , Lord Catherine
Published: July 2020

Given high rates of co-occurring conditions in youth and adults with autism spectrum disorder (ASD), it is critical to examine the developmental trajectories of these symptoms of psychopathology. Using data from a cohort of participants (n= 194), most of whom were first assessed for ASD in very early childhood, we investigated the trajectories of co-occurring depressive, anxiety, and attention-deficit hyperactivity disorder (ADHD) symptoms from late childhood to adulthood. Additionally, childhood predictors and adult outcomes associated with these symptom trajectories were examined. Using group-based trajectory modeling, we found two distinct classes of individuals exhibiting each of these co-occurring symptom patterns: one class exhibited fairly low symptoms across time, and one class with elevated symptoms with varied fluctuation across time (ADHD symptoms starting high but decreasing, anxiety symptoms high and stable, and depressive symptoms fluctuating but peaking at clinically significant levels in young adulthood). All high trajectory classes were associated with age 9 adaptive skills; verbal IQ predicted higher anxiety and depressive symptom classes. After accounting for verbal IQ, all high symptom trajectory classes were negative predictors of objective adult outcomes. These findings call for wide-ranging considerations of the needs of individuals across ability levels, autism symptoms, and behavioral and emotional challenges.
Does indirectness of signal production reduce the explosion-supporting potential in chemotaxis–haptotaxis systems? Global classical solvability in a class of models for cancer invasion (and more)
Authors: SURULESCU CHRISTINA , WINKLER MICHAEL
Published: July 2020

We propose and study a class of parabolic-ordinary differential equation models involving chemotaxis and haptotaxis of a species following signals indirectly produced by another, non-motile one. The setting is motivated by cancer invasion mediated by interactions with the tumour microenvironment, but has much wider applicability, being able to comprise descriptions of biologically quite different problems. As a main mathematical feature constituting a core difference to both classical Keller–Segel chemotaxis systems and Chaplain–Lolas type chemotaxis–haptotaxis systems, the considered model accounts for certain types of indirect signal production mechanisms. The main results assert unique global classical solvability under suitably mild assumptions on the system parameter functions in associated spatially two-dimensional initial-boundary value problems. In particular, this rigorously confirms that at least in two-dimensional settings, the considered indirectness in signal production induces a significant blow-up suppressing tendency also in taxis systems substantially more general than some particular examples for which corresponding effects have recently been observed.
Average Ionospheric Middle and Low Latitudes Nighttime Zonal Currents Deduced From CHAMP
Authors: Zhou Yun‐Liang , Lühr Hermann , Alken Patrick
Published: July 2020

By utilizing magnetic field measurements collected by CHAMP during the years 2001–2009, average characteristics of nighttime ionospheric zonal currents at middle and low latitudes are investigated. We provide for the first time the detailed dependencies of these currents on location, local time, season, and the level of solar activity. The main results obtained are (1) the nighttime zonal ionospheric currents at F‐region altitude, derived from the vertical magnetic component, exhibit on average height‐integrated current densities up to 10 mA/m. The amplitude varies quasi‐linearly with F10.7 flux level. (2) During equinoxes symmetric current systems at F‐region altitude are found in the two hemispheres. After sunset, eastward currents dominate at low latitudes, fading away toward midnight. After midnight regions of eastward currents are observed at midlatitude. During solstice seasons, eastward currents are enhanced in the summer hemisphere; westward currents are stronger in local winter. (3) Longitudinal variations of F‐region currents show clear wave‐1 patterns. This is related to the effect of the stationary planetary wave‐1 and the diurnal nonmigrating tide, D0. This dominant tidal signal, enhancing eastward currents over the Pacific region, appears at middle and low latitudes and during all seasons. (4) At the magnetic equator, signs of the equatorial electrojet (EEJ) are evident after 02:30 MLT. Intensity of westward currents in the narrow band increases toward sunrise. Longitudinal variations of the EEJ show a similar wave‐1 pattern as F‐region currents. Here the westward current density is enhanced over Africa/India. The EEJ wave‐1 modulation is strongest around June solstice.
Precision Measurements of Radar Transverse Scattering Speeds From Meteor Phase Characteristics
Authors: Mazur Michael , Pokorný Petr , Brown Peter , Weryk Robert J. , Vida Denis , Schult Carsten , Stober Gunter , Agrawal Anamika
Published: July 2020

In this paper, we describe an improved technique for using the backscattered phase from meteor radar echo measurements just prior to the specular point (t0) to calculate meteor speeds and their uncertainty. Our method, which builds on earlier work of Cervera et al. (1997, https://doi.org/10.1029/96RS03638), scans possible speeds in the Fresnel distance‐time domain with a dynamic, sliding window and derives a best‐speed estimate from the resultant speed distribution. We test the performance of our method, called pre‐t0 speeds by sliding‐slopes technique (PSSST), on transverse scattered meteor echoes observed by the Middle Atmosphere Alomar Radar System (MAARSY) and the Canadian Meteor Orbit Radar (CMOR) and compare the results to time‐of‐flight and Fresnel transform speed estimates. Our novel technique is shown to produce good results when compared to both model and speed measurements using other techniques. We show that our speed precision is ±5% at speeds less than 40 km/s, and we find that more than 90% of all CMOR multistation echoes have PSSST solutions. For CMOR data, PSSST is robust against the selection of critical phase value and poor phase unwrapping. Pick errors of up to ±6 pulses for meteor speeds less than about 50 km/s produce errors of less than ±5% of the meteoroid speed. In addition, the width of the PSSST speed Kernel density estimate (KDE) is used as a natural measure of uncertainty that captures both noise and t0 pick uncertainties.
Experimental Investigation on the Movability of Water in Shale Nanopores: A Case Study of Carboniferous Shale From the Qaidam Basin, China
Authors: Yang Shugang , Yu Qingchun
Published: July 2020

The movability of water in shale nanopores intensely affects the transport and storage of other fluids and plays an important role in the geological water cycle. To investigate the movability of water, three shale samples were used to conduct flow experiments using the steady state and step‐by‐step depressurization method. The experimental results show that the movability of water strongly depends on the pressure gradient. Two water‐related mechanisms, shear fluidity and electroviscous effect, are primarily responsible for the difference in movability between free water and bound water. The flow of water in these samples deviates from Darcy's law, and the threshold pressure gradient (TPG) is observed. When the pressure gradient is higher than the TPG, water starts to flow, and the permeability increases with increasing pressure gradient. Based on the analysis of the solid‐liquid interfacial forces, the water in the shale was quantitatively classified into four types (L1, L2, L3, and L4) according to its movability. The calculation results indicate that most of the water, which could be up to 74.46–89.73%, is immovable under the experimental conditions. The proportion of movable water increases with increasing pressure gradient, and the relation can be expressed by a quadratic function. The moving ratio was defined as the ratio of the volume of water involved in flow to the total pore volume. The correlation between the moving ratio and permeability is a power function with exponents ranging from 1.16 to 1.43, indicating that water permeability is sensitive to the moving ratio.
Turbulence‐Based Model for Subthreshold Aeolian Saltation
Authors: Rana Santosh , Anderson William , Day Mackenzie
Published: July 2020

Sand transport initiation and cessation occurs when the surface shear velocity exceeds a fluid threshold and falls below an impact threshold, respectively. Even when average shear velocity is below fluid threshold, turbulent fluctuations can initiate saltation, leading to turbulence‐driven transport intermittency. We leveraged the dynamic properties of large‐eddy simulation to recover a shear velocity time series due to atmospheric turbulence and recover a probability density function for saltation based on the frequency of events where wind has previously exceeded fluid threshold but not yet dropped below impact threshold. By conditionally sampling, we can quantitatively predict the frequency of intermediate saltation. Results show that a compensated, subthreshold shear velocity exhibits linear dependence upon the actual shear velocity. This compensated shear velocity compares favorably against field data. Model performance under terrestrial and Mars conditions is also shown.
Ocean Tide Loading Effects on InSAR Observations Over Wide Regions
Authors: Yu Chen , Penna Nigel T. , Li Zhenhong
Published: July 2020

Recent and future Interferometric Synthetic Aperture Radar (InSAR) missions provide spatially wide and temporally continuous observations capturing relative ground motions over great distances which enable nationwide or continent‐wide deformation mapping. To achieve this, long wavelength errors, which increase with distance and are coupled with geophysical deformation, must be corrected. We predict the ocean tide loading (OTL) effect on Sentinel‐1 interferograms globally for all ascending and descending acquisitions, and they are largest in coastal regions. Then, interferograms over southwest Britain are investigated, with the OTL correction having a similar noise reduction effect as when correcting for tropospheric delay (27% standard deviation reduction for tropospheric delay and 46% for combined tropospheric delay and OTL). OTL corrections contribute considerably to the noise reduction of the InSAR time series, with the time series standard deviation reducing by 33% after correcting tropospheric errors and 52% after also applying OTL corrections.
A Closure of the Mongol‐Okhotsk Ocean by the Middle Jurassic: Reconciliation of Paleomagnetic and Geological Evidence
Authors: Yi Zhiyu , Meert Joseph G.
Published: July 2020

The late Mesozoic closure of the Mongol‐Okhotsk Ocean (MOO) is critical for understanding the tectonics of East Asia. There is a considerable mismatch (~40 million years) between the timing of MOO closure based on paleomagnetic data and geological evidence. We review paleomagnetic data from Mongolia, Siberia, and North China and argue that previously published apparent polar wander paths (APWPs) for North China and Siberia are insufficient to constrain the timing of MOO closure. Our new analysis incorporates newly published paleomagnetic data from North China and a refined geochronology for the key Siberian poles. We combine this with an updated global APWP incorporating large‐scale Jurassic true polar wander and argue that the MOO was closed by the Middle Jurassic. This temporal shift is compatible with geology‐based models. The Middle Jurassic reconstruction of Eurasia suggests that the East Asian blocks had become a quasi‐rigid part of Pangea prior to breakup.
Triggering the Indian Ocean Dipole From the Southern Hemisphere
Authors: Zhang Lian‐Yi , Du Yan , Cai Wenju , Chen Zesheng , Tozuka Tomoki , Yu Jin‐Yi
Published: July 2020

This study identifies a new triggering mechanism of the Indian Ocean Dipole (IOD) from the Southern Hemisphere. This mechanism is independent from the El Niño‐Southern Oscillation (ENSO) and tends to induce the IOD before its canonical peak season. The joint effects of this mechanism and ENSO may explain different lifetimes and strengths of the IOD. During its positive phase, development of sea surface temperature cold anomalies commences in the southern Indian Ocean, accompanied by an anomalous subtropical high system and anomalous southeasterly winds. The eastward movement of these anomalies enhances the monsoon off Sumatra‐Java during May–August, leading to an early positive IOD onset. The pressure variability in the subtropical area is related with the Southern Annular Mode, suggesting a teleconnection between high‐latitude and midlatitude climate that can further affect the tropics. To include the subtropical signals may help model prediction of the IOD event.
Development of Hierarchical Ensemble Model and Estimates of Soil Water Retention With Global Coverage
Authors: Zhang Yonggen , Schaap Marcel G. , Wei Zhongwang
Published: July 2020

Correct quantification of mass and energy exchange processes between land surface and atmosphere requires an accurate description of unsaturated soil hydraulic properties. Soil pedotransfer functions (PTFs) have been widely used to predict soil hydraulic parameters. Here, 13 PTFs were grouped according to input data requirements and evaluated against a well‐documented database (National Cooperative Soil Survey Characterization [NCSS]) covering the continental United States (87.7% of data) and other regions of the globe (12.3% of data). Weighted ensembles were shown to have improved performance over individual PTFs in terms of evaluation criteria. Validation of moisture content estimated from the ensemble models against observations showed promising results. Global maps of soil water retention data from the ensemble models as well as their uncertainty were provided. Our full 13‐member ensemble model provides more accurate estimates than PTFs that are currently being used in Earth system models, which may, therefore, provide improved water fluxes and reduce uncertainty of the estimations.
The Modulation of Plasma and Waves by Background Electron Density Irregularities in the Inner Magnetosphere
Authors: Yue Chao , Ma Qianli , Jun Chae‐Woo , Bortnik Jacob , Zong Qiugang , Zhou Xuzhi , Jang Eunjin , Reeves Geoffrey D. , Spence Harlan E. , Wygant John R.
Published: July 2020

The background cold electron density plays an important role in plasma and wave dynamics. Here, we investigate an event with clear modulation of the particle fluxes and wave intensities by background electron density irregularities based on Van Allen Probes observations. The energies at the peak fluxes of protons and Helium ions of 100 eV to several keV are well correlated with the total electron density variation. Intense electromagnetic ion cyclotron (EMIC) and magnetosonic (MS) waves are simultaneously observed in the high‐density regions and disappear in low‐density regions. Based on the linear theory of wave growth, the EMIC waves are generated by the ~10 keV protons, while most MS waves are generated by the positive gradient of proton phase space density at several hundred eV in the high‐density regions. Our results indicate the importance of background plasma density structures in generation of plasma waves by unstable ion distributions.
Impact of Eurasian Ice Sheet and North Atlantic Climate Dynamics on Black Sea Temperature Variability During the Penultimate Glacial (MIS 6, 130–184 ka BP)
Authors: Wegwerth Antje , Kaiser Jérôme , Dellwig Olaf , Arz Helge W.
Published: July 2020

Understanding hemisphere‐wide millennial‐scale temperature variability during past glacials in response to ice sheet dynamics and orbital forcing is one of the key targets for Quaternary climate research. While an inland propagation of abrupt temperature changes into Eurasia from the North Atlantic realm during the last glacial (Weichselian) receives increasingly broad support, much less is known regarding the penultimate glacial (Saalian) temperature variability, especially from a continental interior perspective. Here, we present a TEX86‐derived lake surface temperature (LST) record from the former Black Sea “Lake” covering nearly the entire Marine Isotope Stage (MIS) 6. While orbital‐scale LST cooling likely relates to meltwater discharge from the retreating Eurasian Ice Sheet during insolation maxima, millennial‐scale LST variability suggests interstadial warming in phase with Greenland and northern Mediterranean Sea temperature records during the first half of MIS 6. Although summer insolation reached an interglacial‐like level during this period, we propose that the reduced extent of the Eurasian Ice Sheet associated with northward shifted atmospheric fronts was ultimately responsible for the inland propagation of Dansgaard‐Oeschger‐like temperature variability. During the second half of MIS 6, temperature patterns across the North Atlantic‐Eurasian corridor were more variable and less comparable with each other, likely because of the larger continental ice sheet weakening northern hemisphere atmospheric teleconnections. Temperature records across the North Atlantic‐Eurasian realm suggest a weaker atmospheric teleconnection during MIS 6 compared to MIS 3, likely related to a stronger imprint of the Eurasian Ice Sheet on the continental and regional climate.
Improved Characterization of DNAPL Source Zones via Sequential Hydrogeophysical Inversion of Hydraulic‐Head, Self‐Potential and Partitioning Tracer Data
Authors: Kang Xueyuan , Kokkinaki Amalia , Kitanidis Peter K. , Shi Xiaoqing , Revil André , Lee Jonghyun , Soueid Ahmed Abdellahi , Wu Jichun
Published: July 2020

High‐resolution characterization of hydraulic properties and dense nonaqueous phase liquid (DNAPL) contaminant source is crucial to develop efficient remediation strategies. However, DNAPL characterization suffers from a limited number of borehole data in the field, resulting in a low‐resolution estimation. Moreover, high‐resolution DNAPL characterization requires a large number of unknowns to be estimated, presenting a computational bottleneck. In this paper, a low‐cost geophysical approach, the self‐potential method, is used as additional information for hydraulic properties characterization. Joint inversion of hydraulic head and self‐potential measurements is proposed to improve hydraulic conductivity estimation, which is then used to characterize the DNAPL saturation distribution by inverting partitioning tracer measurements. The computational barrier is overcome by (a) solving the inversion by the principal component geostatistical approach, in which the covariance matrix is replaced by a low‐rank approximation, thus reducing the number of forward model runs; (b) using temporal moments of concentrations instead of individual concentration data points for faster forward simulations. To assess the ability of the proposed approach, numerical experiments are conducted in a 3‐D aquifer with 104 unknown hydraulic conductivities and DNAPL saturations. Results show that with realistic DNAPL sources and a limited number of hydraulic heads, the traditional hydraulic/partitioning tracer tomography roughly reconstructs subsurface heterogeneity but fails to resolve the DNAPL distribution. By adding self‐potential data, the error is reduced by 24% in hydraulic conductivity estimation and 68% in DNAPL saturation characterization. The proposed sequential inversion framework utilizes the complementary information from multi‐source hydrogeophysical data sets, and can provide high‐resolution characterizations for realistic DNAPL sources.