bluuebunny/crossref_metadata_2025 huggingface dataset:
Minimum‐series twist distributions for yawing‐moment control during pure roll*
Authors: Hunsaker Douglas F. , Moorthamers Bruno , Joo James J.
Published: May 2021

The main wings of most aircraft produce adverse yaw during roll. In order to control the lateral direction of the aircraft during the roll, the rudder is often mixed with the aileron. Lifting‐line theory is used here to develop spanwise lift distributions that require the minimum number of terms in the Fourier‐series solution for controlling the yawing moment during pure rolling motion using only the main wing. It is shown that the yawing moment can be controlled for arbitrary rolling moments and/or rolling rates by adding symmetric twist in the main wing. The induced‐drag penalty for using this method to control the yawing moment is significant and discussed in detail. For example, it is shown that if zero yawing moment is prescribed, the induced drag can increase by 108% for a prescribed rolling moment or by 300% during a steady rolling rate relative to the induced drag in steady level flight. Because this is the minimum‐series solution, it does not represent the solution for yaw control with minimum induced drag, since more terms could be used in the Fourier series describing the lift distribution to control yaw with less induced drag. However, the solutions presented here can be useful for aircraft with continuous trailing‐edge technologies that are limited in spanwise deflection gradients, and provide a theoretical upper bound on the minimum induced‐drag that can be expected if the main wing is used for yawing‐moment control during pure roll.
A derived dryolestid mammal indicates possible insular endemism in the Late Jurassic of Germany
Authors: Martin Thomas , Averianov Alexander O. , Schultz Julia A. , Schwermann Achim H. , Wings Oliver
Published: May 2021

The Langenberg Quarry near Bad Harzburg has yielded the first Jurassic stem therian mammal of Germany, recovered from Kimmeridgian (Late Jurassic) near shore deposits of a palaeo-island within the Lower Saxony Basin of the European archipelago. The new stem therian is represented by one lower and three upper molars.Hercynodon germanicusgen. et sp. nov. is attributed to the Dryolestidae, a group of pretribosphenic crown mammals that was common in western Laurasia from the Middle Jurassic to the Early Cretaceous. The new taxon is characterised by small size, a reduced cusp pattern in the upper molars lacking a metacone, and enhancement of the shearing crests paracrista and metacrista. Phylogenetic analysis identifiedHercynodongen. nov. as sister taxon ofCrusafontiafrom the Lower Cretaceous (Barremian) of Spain. Both taxa belong to an endemic European clade of dryolestids, including alsoAchyrodonandPhascolestesfrom the earliest Cretaceous (Berriasian) of England. Despite its greater geological age,Hercynodongen. nov. is the most derived representative of that clade, indicated by the complete reduction of the metacone. The discrepancy between derived morphology and geological age may be explained by an increased rate of character evolution in insular isolation. Other insular phenomena have earlier been observed in vertebrates from the Langenberg Quarry, such as dwarfism in the small sauropodEuropasaurus, and possible gigantism in the morganucodontan mammaliaformStorchodonand the pinheirodontid multituberculate mammalTeutonodonwhich grew unusually large.
Evaluating class and school effects on the joint student achievements in different subjects: a bivariate semiparametric model with random coefficients
Authors: Masci Chiara , Ieva Francesca , Agasisti Tommaso , Paganoni Anna Maria
Published: May 2021

This paper proposes an innovative statistical method to measure the impact of the class/school on student achievements in multiple subjects. We propose a semiparametric model for a bivariate response variable with random coefficients, that are assumed to follow a discrete distribution with an unknown number of support points, together with an Expectation-Maximization algorithm—called BSPEM algorithm—to estimate its parameters. In the case study, we apply the BSPEM algorithm to data about Italian middle schools, considering students nested within classes, and we identify subpopulations of classes, standing on their effects on student achievements in reading and mathematics. The proposed model is extremely informative in exploring the correlation between multiple class effects, which are typical of the educational production function. The estimated class effects on reading and mathematics student achievements are then explained in terms of various class and school level characteristics selected by means of a LASSO regression.
The relationship between subjectivity in managerial performance evaluation and the three dimensions of justice perception
Authors: Tran Thuy-Van , Lepistö Sinikka , Järvinen Janne
Published: May 2021

This paper examines the relationship between subjectivity in performance evaluation and the three dimensions of justice perceptions in an emerging economy; prior research on this topic has primarily focused solely on the advanced capitalist economies of Western nations. The paper also aims to expand on existing research by focusing on the role of interactional justice perceptions in relation to subjective evaluation (Byrne et al. in Hum Resour Manag J 22(2):129–147; Folger and Cropanzano, in Organizational justice and human resource management, Sage, Thousand Oaks, 1998). Results from a survey of 160 middle managers in Vietnam indicate that subjective evaluation is associated predominantly with negative effects. We found that, in an emerging economy like that of Vietnam, subjective evaluation reduces interactional justice perception, which in turn decreases the perception of procedural and distributive justice. The mediating effects suggest that the reason subjective evaluation influences employee procedural/distributive justice perceptions lies in the interactional justice perceived from supervisors. This research clarifies the effects of subjective evaluation on the dimensions of justice perception and contributes to the literature on performance evaluation and organizational justice in a non-Western context. It also highlights the importance of respect and communication for fairness perception in both theory and practice.
Robot-assisted laparoscopic surgery for treatment of urinary tract stones in children: report of a multicenter international experience
Authors: Esposito Ciro , Masieri Lorenzo , Blanc Thomas , Lendvay Thomas , Escolino Maria
Published: May 2021

This study aimed to report a multi-institutional experience with robot-assisted laparoscopic surgery (RALS) for treatment of urinary tract stones in children. The medical records of 15 patients (12 boys), who underwent RALS for urolithiasis in 4 international centers of pediatric urology over a 5-year period, were retrospectively collected. The median patient age was 8.5 years (range 4–15). Eleven/fifteen patients (73.3%) had concurrent uretero–pelvic junction obstruction (UPJO) and 2/15 patients (13.3%) had neurogenic bladder. Stones were in the renal pelvis in 8/15 (53.3%), in the lower pole in 3/15 (20%), in the bladder in 2/15 (13.3%), and in multiple locations in 2/15 (13.3%). One patient (6.6%) had bilateral multiple kidney stones. The median stone size was 10.8 mm (range 2–30) in upper tract location and 27 mm (range 21–33) into the bladder. Eleven patients with concomitant UPJO underwent simultaneous robot-assisted pyelolithotomy and pyeloplasty in 12 kidney units. Two patients with isolated staghorn stones received robot-assisted pyelolithotomy. Robot-assisted cystolithotomy was performed in two patients with bladder stones. The median operative time was 131.8 min (range 60–240). The stone-free rate was 80% following initial surgery and 100% after secondary treatment. Clavien 2 complications (hematuria, infections) were recorded in 5/15 patients (33.3%). Three/fifteen patients (20%) with residual renal stones were successfully treated using ureterorenoscopy (Clavien 3b). RALS was a feasible, safe and effective treatment option for pediatric urolithiasis in selected cases such as large bladder stones, bilateral kidney stones, staghorn stones or concomitant anomalies such as UPJO requiring simultaneous pyeloplasty.
Spectral analysis of transient amplifiers for death–birth updating constructed from regular graphs
Authors: Richter Hendrik
Published: May 2021

A central question of evolutionary dynamics on graphs is whether or not a mutation introduced in a population of residents survives and eventually even spreads to the whole population, or becomes extinct. The outcome naturally depends on the fitness of the mutant and the rules by which mutants and residents may propagate on the network, but arguably the most determining factor is the network structure. Some structured networks are transient amplifiers. They increase for a certain fitness range the fixation probability of beneficial mutations as compared to a well-mixed population. We study a perturbation method for identifying transient amplifiers for death–birth updating. The method involves calculating the coalescence times of random walks on graphs and finding the vertex with the largest remeeting time. If the graph is perturbed by removing an edge from this vertex, there is a certain likelihood that the resulting perturbed graph is a transient amplifier. We test all pairwise nonisomorphic regular graphs up to a certain order and thus cover the whole structural range expressible by these graphs. For cubic and quartic regular graphs we find a sufficiently large number of transient amplifiers. For these networks we carry out a spectral analysis and show that the graphs from which transient amplifiers can be constructed share certain structural properties. Identifying spectral and structural properties may promote finding and designing such networks.
Commuting Involution Graphs for Certain Exceptional Groups of Lie Type
Authors: Aubad Ali , Rowley Peter
Published: May 2021

Suppose that G is a finite group and X is a G-conjugacy classes of involutions. The commuting involution graph $${\mathcal {C}}(G,X)$$

C
(
G
,
X
)

is the graph whose vertex set is X with $$x, y \in X$$

x
,
y
∈
X

being joined if $$x \ne y$$

x
≠
y

and $$xy = yx$$

x
y
=
y
x

. Here for various exceptional Lie type groups of characteristic two we investigate their commuting involution graphs.
Evaluation of diagnostic efficacy for localization of parathyroid adenoma in patients with primary hyperparathyroidism undergoing repeat surgery
Authors: Hendricks Anne , Lenschow Christina , Kroiss Matthias , Buck Andreas , Kickuth Ralph , Germer Christoph-Thomas , Schlegel Nicolas
Published: May 2021

Purpose

Repeat surgery in patients with primary hyperparathyroidism (pHPT) is associated with an increased risk of complications and failure. This stresses the need for optimized strategies to accurately localize a parathyroid adenoma before repeat surgery is performed. However, evidence on the extent of required diagnostics for a structured approach is sparse.

Methods

A retrospective single-center evaluation of 28 patients with an indication for surgery due to pHPT and previous thyroid or parathyroid surgery was performed. Diagnostic workup, surgical approach, and outcome in terms of complications and successful removement of parathyroid adenoma with biochemical cure were evaluated.

Results

Neck ultrasound, sestamibi scintigraphy, C11-methionine PET-CT, and selective parathyroid hormone venous sampling, but not MRI imaging, effectively detected the presence of a parathyroid adenoma with high positive predictive values. Biochemical cure was revealed by normalization of calcium and parathormone levels 24–48h after surgery and was achieved in 26/28 patients (92.9%) with an overall low rate of complications. Concordant localization by at least two diagnostic modalities enabled focused surgery with success rates of 100%, whereas inconclusive localization significantly increased the rate of bilateral explorations and significantly reduced the rate of biochemical cure to 80%.

Conclusion

These findings suggest that two concordant diagnostic modalities are sufficient to accurately localize parathyroid adenoma before repeat surgery for pHPT. In cases of poor localization, extended diagnostic procedures are warranted to enhance surgical success rates. We suggest an algorithm for better orientation when repeat surgery is intended in patients with pHPT.
Exploring possible links between Quaternary aggradation in the Upper Rhine Graben and the glaciation history of northern Switzerland
Authors: Preusser Frank , Büschelberger Matthias , Kemna Hans Axel , Miocic Johannes , Mueller Daniela , May Jan-Hendrik
Published: May 2021

The Quaternary filling of the Upper Rhine Graben is an excellent archive to reconstruct sediment dynamics in response to climate change, in particular related to past glaciations of the Swiss Alpine Foreland. Here, a sediment sequence recovered by drilling for exploration purposes near Kronau is investigated, using a combination of sedimentological logging, provenance studies (heavy minerals and clast petrography), and luminescence dating. Several phases of coarse sediment aggradation are identified that possibly correlate to Marine Isotope Stages (MIS) 12 (478–424 ka), 10 (374–337 ka), 8 (300–243 ka), 6 (191–130 ka) and/or 4 (71–57 ka), and 2 (29–14 ka). Several of these phases have previously also been reported from cores recovered in the major Quaternary depo-centre near Heidelberg. This suggests that the observed coarse aggradation in the Upper Rhine Graben can be assigned to various glaciations in northern Switzerland: Möhlin (MIS 12), Habsburg (MIS 10 or 8), Beringen (MIS 6), an unnamed glacial advance during MIS 4, and Birrfeld (MIS 2). However, due to the limited data available, this hypothesis and the suggested correlations require further confirmation by applying the approach presented here to further cores from the Upper Rhine Graben.
Discovery and development of trastuzumab deruxtecan and safety management for patients with HER2-positive gastric cancer
Authors: Shitara Kohei , Baba Eishi , Fujitani Kazumasa , Oki Eiji , Fujii Satoshi , Yamaguchi Kensei
Published: May 2021

Approximately 12–15% of gastric cancers (GCs) are human epidermal growth factor receptor-2 (HER2)-positive (HER2 immunohistochemistry 3 + or 2 + /in situ hybridization + [ERBB2/CEP17 ≥ 2.0]). While the anti-HER2 monoclonal antibody trastuzumab, in combination with chemotherapy, is the standard treatment for HER2-positive GC, other HER2-targeted therapies have not demonstrated survival benefits in patients with GC, despite showing efficacy in patients with HER2-positive breast cancer. This indicates that there are unique challenges to the use of currently available HER2-targeted therapies for the treatment of HER2-positive GC. Trastuzumab deruxtecan (T-DXd) is an antibody–drug conjugate consisting of an anti-HER2 human monoclonal IgG1 antibody with the same amino acid sequence as trastuzumab, an enzymatically cleavable peptide-based linker, and DXd, a novel topoisomerase I inhibitor, as its released payload. T-DXd has a high drug–antibody ratio (approximately 8) and a demonstrated bystander antitumor effect. It has demonstrated significant efficacy when compared with standard therapies and is approved as third- or later-line treatment for HER2-positive GC in Japan and second- or later-line treatment in the US. T-DXd treatment is associated with gastrointestinal and hematological adverse events, and a risk of interstitial lung disease (ILD), with the ILD risk being higher in Japan than in countries other than Japan. However, most adverse events, including ILD, can be managed with proactive monitoring and T-DXd dose modification, and initiation of adequate treatment. In this review, we summarize the discovery and development of T-DXd and provide guidance for T-DXd safety management, including ILD monitoring, for patients with HER2-positive GC.
Validation of GNSS-derived global ionosphere maps for different solar activity levels: case studies for years 2014 and 2018
Authors: Wielgosz P. , Milanowska B. , Krypiak-Gregorczyk A. , Jarmołowski W.
Published: May 2021

Ionosphere Associate Analysis Centers (IAACs) of the International GNSS Service (IGS) independently produce global ionosphere maps (GIMs) of the total electron content (TEC). The GIMs are based on different modeling techniques, resulting in different TEC levels and accuracies. In this study, we evaluated the accuracy and consistency of the IAAC GIMs during high (2014) and low (2018) solar activity periods of the 24th solar cycle. In our study, we applied two different evaluation methods. First, we carried out a comparison of the GIM-derived slant TEC (STEC) with carrier phase geometry-free combination of GNSS signals obtained from 25 globally distributed stations. Second, vertical TEC (VTEC) from GIMs was compared to altimetry-derived VTEC obtained from the Jason-2 and Jason-3 satellites and complemented for plasmaspheric TEC. The analyzed GIMs obtained STEC RMS values reaching from 1.98 to 3.00 TECU and from 0.96 to 1.29 TECU during 2014 and 2018, respectively. The comparison to altimetry data resulted in VTEC STD values that varied from 3.61 to 5.97 TECU and from 1.92 to 2.78 TECU during 2014 and 2018, respectively. The results show that among the IAACs, the Center for Orbit Determination in Europe global maps performed best in low and high solar activity periods. However, the highest accuracy was obtained by a non-IGS product—UQRG GIMs provided by Universitat Politècnica de Catalunya. It was also shown that the best results were obtained using a modified single layer model mapping function and that the map time interval has a relatively small influence on the resulting map accuracy.
“I Found Out I was Pregnant, and I Started Feeling Stressed”: A Longitudinal Qualitative Perspective of Mental Health Experiences Among Perinatal Women Living with HIV
Authors: Tuthill Emily L. , Maltby Ann E. , Odhiambo Belinda C. , Akama Eliud , Pellowski Jennifer A. , Cohen Craig R. , Weiser Sheri D. , Conroy Amy A.
Published: May 2021

Globally, depressive symptoms among pregnant and postpartum (i.e., perinatal) women living with HIV (WLWH) are alarmingly high and associated with poor outcomes such as suboptimal adherence to antiretroviral therapy (ART), and early cessation of exclusive breastfeeding (EBF). Few qualitative studies have described the experience of perinatal depression among WLWH to identify the underlying social-structural determinants of poor mental health and potential strategies to intervene. We conducted a longitudinal qualitative study applying semi-structured interviews with 30 WLWH at three timepoints (28–38 weeks pregnant, 6-weeks postpartum and 5–7 months postpartum) to understand mental health experiences of perinatal WLWH in western Kenya. Financial insecurity emerged as the central theme impacting the mental health of women across time. Financial insecurity was often attributed to the loss of employment, related to pregnancy and the demands of breastfeeding and caring for an infant, as well as a lack of support from male partners. The loss of income and subsequent financial strain contributed to worsening levels of food insecurity and relationship stress and challenged engagement in HIV care. In this way, increased financial strain during the perinatal period negatively impacted the mental health of perinatal WLWH. Our findings suggest support to meet basic needs and remain engaged in HIV care during pregnancy and postpartum could improve perinatal mental health for WLWH in this setting.
Assessment of single and double coronary bifurcation stenting techniques using multimodal imaging and 3D modeling in reanimated swine hearts using Visible Heart® methodologies
Authors: Valenzuela Thomas F. , Burzotta Francesco , Iles Tinen L. , Lassen Jens F. , Iaizzo Paul A.
Published: May 2021

Stent implantation in bifurcated coronary lesions is technically challenging so that procedural refinements are continuously investigated. Novel procedure modeling and intracoronary imaging techniques may offer critical insights on stent deformations and stent-wall interactions during bifurcation stenting procedures. Thus, we assessed coronary bifurcation stenting techniques using multimodal imaging and 3D modeling in reanimated swine hearts. Harvested swine hearts were reanimated using Visible Heart® methodologies and (under standard fluoroscopic guidance) used to test 1-stent (provisional and inverted provisional) and 2-stent (culotte, TAP and DK-crush) techniques on bifurcations within various coronary vessels using commercially available devices. Intracoronary angioscopy and frequency-domain optical-coherence-tomography (OCT) were obtained during the procedures. 3D OCT reconstruction and micro-computed tomography 3D modeling (post heart fixations) were used to assess stent deformations and stent-wall interactions. We conducted multiple stenting procedures and collected unique endoscopic and OCT images (and subsequent computational models from micro-CT) to assess stent deformations and device/wall interactions during different steps of bifurcation stenting procedures. Endoscopy, micro-CT and virtual reality processing documented that different 1- and 2-stent techniques, practiced according to experts’ recommended steps, achieve optimal post-intervention stent conformation. As compared with intra-procedural endoscopy, software-generated 3D OCT images accurately depicted stent deformations during 1-stent techniques. On the opposite, during more complex 2-stent techniques, some defects were appreciated at 3D OCT reconstruction despite optimal 2D OCT images. This study provided unique insights regarding both stent deformations occurring in the course of bifurcation stenting and the efficacy of OCT to visualize them.
What do humans feel with mistreated humans, animals, robots, and objects? Exploring the role of cognitive empathy
Authors: Mattiassi Alan D. A. , Sarrica Mauro , Cavallo Filippo , Fortunati Leopoldina
Published: May 2021

The aim of this paper is to present a study in which we compare the degree of empathy that a convenience sample of university students expressed with humans, animals, robots and objects. The present study broadens the spectrum of elements eliciting empathy that has been previously explored while at the same time comparing different facets of empathy. Here we used video clips of mistreated humans, animals, robots, and objects to elicit empathic reactions and to measure attributed emotions. The use of such a broad spectrum of elements allowed us to infer the role of different features of the selected elements, specifically experience (how much the element is able to understand the events of the environment) and degree of anthropo-/zoomorphization. The results show that participants expressed empathy differently with the various social actors being mistreated. A comparison between the present results and previous results on vicarious feelings shows that congruence between self and other experience was not always held, and it was modulated by familiarity with robotic artefacts of daily usage.
The Potential of Anti-Bullying Efforts to Prevent Academic Failure and Youth Crime. A Case Using the Olweus Bullying Prevention Program (OBPP)
Authors: Borgen Nicolai Topstad , Olweus Dan , Kirkebøen Lars Johannessen , Breivik Kyrre , Solberg Mona Elin , Frønes Ivar , Cross Donna , Raaum Oddbjørn
Published: May 2021

The effectiveness of bullying prevention programs has led to expectations that these programs could have effects beyond their primary goals. By reducing the number of victims and perpetrators and the harm experienced by those affected, programs may have longer-term effects on individual school performance and prevent crime. In this paper, we use Norwegian register data to study the long-term impact of the Olweus Bullying Prevention Program (OBPP) on academic performance, high school dropout, and youth crime for the average student, which we call population-level effects. The OBPP program is widely acknowledged as one of the most successful programs reducing school-level bullying; yet, using a difference-in-difference design, no statistically significant population-level effects of the OBPP were found on any of the long-term outcomes in this study. When studied at the population level, as in the current project, the base rate prevalence of bullying is a major explanatory factor for these results. Earlier studies have shown that OBPP reduces bullying prevalence by 30–50%. This decrease translates into absolute reductions in bullying victimization and perpetration at the population level of “only” four and two percentage points, respectively. Our results suggest the average causal effects of school bullying involvement are too small to translate this reduction in bullying into a sizeable population-level impact on students’ long-term outcomes. However, a limited potential of anti-bullying programs to prevent population-level adversity can very well be compatible with substantial program effects for individual bullies and victims. Further, our results do not speak to the main objective of anti-bullying programs of limiting childhood abuse and safeguarding children’s human rights.
Searching on campus? The marriage market effects of changing student sex ratios
Authors: Pestel Nico
Published: May 2021

This paper studies how secular changes in the student sex ratio affect marriage market outcomes for university graduates. Using data from Germany, I find that a higher own-gender share within the field of study reduces marriage market opportunities for women, while the opposite is true for men. Moreover, an imbalanced student sex ratio changes the composition of couples. For women, a higher female share decreases the probability of having a spouse from the same field, while men are more likely to marry down with respect to educational status when the male share is high. These findings suggest that the secular changes in the sex ratio of university students have important implications beyond the labor market by affecting the household composition among the high-skilled population.
Vacillating time: a metaphysics for time travel and Geachianism
Authors: Effingham Nikk
Published: May 2021

‘Past vacillators’ believe that what was once the case may change over time. This has obvious applications to the possibility of changing the past via time travel. ‘Future vacillators’ believe that some things will happen and yet, later, will not. Further to issues in time travel, future vacillation has applications when it comes to ‘Geachian’ views about the open future. This paper argues that if you deny that the ‘earlier than’ and ‘later than’ relations are converses of one another then you can develop metaphysical systems underpinning the possibility of such vacillation.
A kind route from grounding to fundamentality
Authors: Correia Fabrice
Published: May 2021

I offer an account of fundamentality for facts in terms of metaphysical grounding. The account does justice to the idea that whether a fact is absolutely fundamental, and whether a fact is more fundamental than, or as fundamental as, another fact, are a matter of where in a grounding-induced hierarchy ofkindsof facts these facts appear.
Tattoo tomography: Freehand 3D photoacoustic image reconstruction with an optical pattern
Authors: Holzwarth Niklas , Schellenberg Melanie , Gröhl Janek , Dreher Kris , Nölke Jan-Hinrich , Seitel Alexander , Tizabi Minu D , Müller-Stich Beat P , Maier-Hein Lena
Published: May 2021

Purpose

Photoacoustic tomography (PAT) is a novel imaging technique that can spatially resolve both morphological and functional tissue properties, such as vessel topology and tissue oxygenation. While this capacity makes PAT a promising modality for the diagnosis, treatment, and follow-up of various diseases, a current drawback is the limited field of view provided by the conventionally applied 2D probes.

Methods

In this paper, we present a novel approach to 3D reconstruction of PAT data (Tattoo tomography) that does not require an external tracking system and can smoothly be integrated into clinical workflows. It is based on an optical pattern placed on the region of interest prior to image acquisition. This pattern is designed in a way that a single tomographic image of it enables the recovery of the probe pose relative to the coordinate system of the pattern, which serves as a global coordinate system for image compounding.

Results

To investigate the feasibility of Tattoo tomography, we assessed the quality of 3D image reconstruction with experimental phantom data and in vivo forearm data. The results obtained with our prototype indicate that the Tattoo method enables the accurate and precise 3D reconstruction of PAT data and may be better suited for this task than the baseline method using optical tracking.

Conclusions

In contrast to previous approaches to 3D ultrasound (US) or PAT reconstruction, the Tattoo approach neither requires complex external hardware nor training data acquired for a specific application. It could thus become a valuable tool for clinical freehand PAT.
Study on the Relationship between the miRNA-centered ceRNA Regulatory Network and Fatigue
Authors: Yang Xingzhe , Li Feng , Ma Jie , Liu Yan , Wang Xuejiao , Wang Ruochong , Zhang Yifei , Zhang Wei , He Qingyun , Song Dandan , Yu Jiaojiao
Published: May 2021

In recent years, the incidence of fatigue has been increasing, and the effective prevention and treatment of fatigue has become an urgent problem. As a result, the genetic research of fatigue has become a hot spot. Transcriptome-level regulation is the key link in the gene regulatory network. The transcriptome includes messenger RNAs (mRNAs) and noncoding RNAs (ncRNAs). MRNAs are common research targets in gene expression profiling. Noncoding RNAs, including miRNAs, lncRNAs, circRNAs and so on, have been developed rapidly. Studies have shown that miRNAs are closely related to the occurrence and development of fatigue. MiRNAs can regulate the immune inflammatory reaction in the central nervous system (CNS), regulate the transmission of nerve impulses and gene expression, regulate brain development and brain function, and participate in the occurrence and development of fatigue by regulating mitochondrial function and energy metabolism. LncRNAs can regulate dopaminergic neurons to participate in the occurrence and development of fatigue. This has certain value in the diagnosis of chronic fatigue syndrome (CFS). CircRNAs can participate in the occurrence and development of fatigue by regulating the NF-κB pathway, TNF-α and IL-1β. The ceRNA hypothesis posits that in addition to the function of miRNAs in unidirectional regulation, mRNAs, lncRNAs and circRNAs can regulate gene expression by competitive binding with miRNAs, forming a ceRNA regulatory network with miRNAs. Therefore, we suggest that the miRNA-centered ceRNA regulatory network is closely related to fatigue. At present, there are few studies on fatigue-related ncRNA genes, and most of these limited studies are on miRNAs in ncRNAs. However, there are a few studies on the relationship between lncRNAs, cirRNAs and fatigue. Less research is available on the pathogenesis of fatigue based on the ceRNA regulatory network. Therefore, exploring the complex mechanism of fatigue based on the ceRNA regulatory network is of great significance. In this review, we summarize the relationship between miRNAs, lncRNAs and circRNAs in ncRNAs and fatigue, and focus on exploring the regulatory role of the miRNA-centered ceRNA regulatory network in the occurrence and development of fatigue, in order to gain a comprehensive, in-depth and new understanding of the essence of the fatigue gene regulatory network.
Homogenization of the interfacial bonding of compound-cast AA7075/6060 bilayer billets by co-extrusion
Authors: Chen Hui , Giannopoulou Danai , Greß Thomas , Isakovic Jonas , Mittler Tim , Volk Wolfram , Khalifa Noomane Ben
Published: May 2021

A process chain of compound casting and co-extrusion of AA7075/6060 bilayer billets is introduced to manufacture hybrid components with strength in the core and good corrosion-resistance in the shell. Using optimized compound casting parameter, metallurgical bonding between the shell AA6060 and the core AA7075 can be achieved through remelting and recrystallization of the substrate AA7075. The locally unequal thermal conditions at the interface induces partially weak bonding. The bonding strength in greater distance from the casting gate is generally lower. Hot extrusion is applied to improve the interfacial bonding. Comparisons of the microstructure and the shear strength between as-cast billet and extrudate present the homogenization of the interfacial bonding through the process chain.
Acid-Induced Phosphorus Release from Hydrothermally Carbonized Sewage Sludge
Authors: Pérez Carla , Boily Jean-François , Jansson Stina , Gustafsson Tomas , Fick Jerker
Published: May 2021

Phosphorus (P) recovery from P-rich residues is crucial to sustain food and industrial demands globally, as phosphate rock reserves are being depleted. The aim of this study is to investigate the speciation and recovery of P from hydrochars (HC) of a metal-bearing sewage sludge (SS) produced by hydrothermal carbonization (HTC). We here focus on extractions by acid leaching as P cannot be directly recovered by HTC due to insoluble metal-P compounds. Acid leaching of SS and HCs was investigated using H2SO4 and HCl over a range of leaching times, and explained in terms of how composition affects P and metal release efficiency. HTC at 180, 215 and 250 °C showed that P remained immobilized (> 75% of total P) in the HCs. More than 95% was present as inorganic P, and was the direct consequence of the double addition of iron salts in the wastewater treatment plant. Leaching experiments in 2.5 M acid solutions showed that a near complete release of P could be achieved in HCs, while it was only incomplete in SS (up to 85%). Lower acid concentrations were ineffective for total P recovery. Treatment temperature exceeding 180 °C however decreased P release rates, such that total removal took at least 2 h of reaction time instead of a few minutes. On the other hand, acid leaching transferred more than 70% of iron, manganese, copper and zinc into the leachate, necessitating a post-treatment purification process. This work therefore reveals that HC produced at low HTC temperatures could offer promising avenues for time- and energy-efficient P recovery from SS.

Graphic Abstract
Emission trading systems and the optimal technology mix
Authors: Zoettl Gregor
Published: May 2021

Cap and trade mechanisms enjoy increasing importance in environmental legislations worldwide. One of the important aspects of designing cap and trade mechanisms is the possibility of authorities to grant emission permits for free. Unlike analyzed in the seminal contributions on cap and trade systems, in reality free allocations are not made lump sum, but are updated contingent on firms’ actions, i.e., contingent on production decisions and contingent on facilities entering the market or retiring (see IEA, https://www.oecd-ilibrary.org/content/publication/b7d0842b-en, 2020). As it has already been shown in the literature, such updating yields distorted production decisions of firms (see e.g., Böhringer and Lange in Eur Econ Rev 49(8):2041–2055, 2005, Mackenzie et al. in Environ Resour Econ 39(3):265–282, 2008, or Damon et al. in Rev Environ Econ Policy 13(1):23–42, 2019). The impact of updating on firms’ investment and retiring decisions and the resulting technology mix has received much less attention up to now, however. It is the purpose of the present article to shed light on this aspect and to study the impact of a cap and trade mechanism not only on firms’ output decisions, but also on their investment incentives in different technologies and to analyze the optimal design of emission trading systems in such an environment.
Correction to: Application of hourglass control to Eulerian smoothed particle hydrodynamics
Authors: Mohseni-Mofidi Shoya , Bierwisch Claas
Published: May 2021

A Correction to this paper has been published: https://doi.org/10.1007/s40571-021-00412-2.
Status of an MWth integrated gasification fuel cell power-generation system in China
Authors: Wei Chang , Liu Zhien , Li Chufu , Singh Surinder , Lu Haoren , Gong Yudong , Li Pingping , Wang Hanlin , Yang Xia , Xu Ming , Mu Shujun
Published: May 2021

Here, we provide a status update of an integrated gasification fuel cell (IGFC) power-generation system being developed at the National Institute of Clean-and-Low-Carbon in China at the megawatt thermal (MWth) scale. This system is designed to use coal as fuel to produce syngas as a first step, similar to that employed for the integrated gasification combined cycle. Subsequently, the solid-oxide fuel-cell (SOFC) system is used to convert chemical energy to electricity directly through an electrochemical reaction without combustion. This system leads to higher efficiency as compared with that from a traditional coal-fired power plant. The unreacted fuel in the SOFC system is transported to an oxygen-combustor to be converted to steam and carbon dioxide (CO2). Through a heat-recovery system, the steam is condensed and removed, and CO2is enriched and captured for sequestration or utilization. Comprehensive economic analyses for a typical IGFC system was performed and the results were compared with those for a supercritical pulverized coal-fired power plant. The SOFC stacks selected for IGFC development were tested and qualified under hydrogen and simulated coal syngas fuel. Experimental results using SOFC stacks and thermodynamic analyses indicated that the control of hydrogen/CO ratio of syngas and steam/CO ratio is important to avoid carbon deposition with the fuel pipe. A 20-kW SOFC unit is under development with design power output of 20 kW and DC efficiency of 50.41%. A 100 kW-level subsystem will consist of 6 × 20-kW power-generation units, and the MWthIGFC system will consist of 5 × 100 kW-level subsystems.
The emerging technology of biohybrid micro-robots: a review
Authors: Lin Zening , Jiang Tao , Shang Jianzhong
Published: May 2021

In the past few decades, robotics research has witnessed an increasingly high interest in miniaturized, intelligent, and integrated robots. The imperative component of a robot is the actuator that determines its performance. Although traditional rigid drives such as motors and gas engines have shown great prevalence in most macroscale circumstances, the reduction of these drives to the millimeter or even lower scale results in a significant increase in manufacturing difficulty accompanied by a remarkable performance decline. Biohybrid robots driven by living cells can be a potential solution to overcome these drawbacks by benefiting from the intrinsic microscale self-assembly of living tissues and high energy efficiency, which, among other unprecedented properties, also feature flexibility, self-repair, and even multiple degrees of freedom. This paper systematically reviews the development of biohybrid robots. First, the development of biological flexible drivers is introduced while emphasizing on their advantages over traditional drivers. Second, up-to-date works regarding biohybrid robots are reviewed in detail from three aspects: biological driving sources, actuator materials, and structures with associated control methodologies. Finally, the potential future applications and major challenges of biohybrid robots are explored.

Graphic abstract
A Holistic Assessment of 1979–2016 Global Cryospheric Extent
Authors: Peng Xiaoqing , Zhang Tingjun , Frauenfeld Oliver W. , Du Ran , Jin Haodong , Mu Cuicui
Published: May 2021

The cryosphere plays a major role in earth's climate system. Most cryospheric assessments focus on one or more of its components and their response to climate change. However, to date, there has not been a comprehensive evaluation of the entire global cryosphere. We therefore determine such a holistic estimate and quantify changes to the hemispheric and global cryosphere due to climate change, by synthesizing sea ice, snow cover, and frozen ground extents into one global cryospheric extent data set. The 1981–2010 climatology of daily global cryospheric extent ranges from 45.7 ± 0.7 × 106 to 87.2 ± 2.0 × 106 km2 (9.0%–17.1%), from 13.3 ± 0.8 × 106–66.3 ± 1.7 × 106 km2 (5.2%–26.0%) in the Northern Hemisphere (NH), and from 17.9 ± 0.3 × 106 to 33.6 ± 0.4 × 106 km2 (7.0%–13.2%) in the Southern Hemisphere (SH). The monthly maximum cryospheric extent of 85.84 ± 1.91 × 106 km2 occurs in December, whereas minimum occurs in July with 45.92 ± 0.70 × 106 km2. During 1979–2016, global cryospheric area extent lost approximately 87 ± 11 × 103 km2/yr, with a decrease of 102 ± 9.7 × 103 km2/yr in the NH that was partly offset by an increase of 14.6 ± 4.4 × 103 km2/yr in the SH. The first day of cryospheric cover was delayed by 3.6 days at a rate of 0.95 days/decade, and the last day advanced by 5.7 days, at a rate of 1.5 days/decade. The duration and number of cryospheric cover days decreased by 8.7 days and 7.6 days over the study period, respectively. These variations of global cryospheric extent are correlated with rising air temperatures. Our findings highlight the importance of assessing the cryosphere as a whole, and provide a way to quantitatively estimate its overall changes.
Influence of Shear Heating and Thermomechanical Coupling on Earthquake Sequences and the Brittle‐Ductile Transition
Authors: Allison Kali L. , Dunham Eric M.
Published: May 2021

Localized frictional sliding on faults in the continental crust transitions at depth to distributed deformation in viscous shear zones. This brittle‐ductile transition (BDT), and/or the transition from velocity‐weakening (VW) to velocity‐strengthening (VS) friction, are controlled by the lithospheric thermal structure and composition. Here, we investigate these transitions, and their effect on the depth extent of earthquakes, using 2D antiplane shear simulations of a strike‐slip fault with rate‐and‐state friction. The off‐fault material is viscoelastic, with temperature‐dependent dislocation creep. We solve the heat equation for temperature, accounting for frictional and viscous shear heating that creates a thermal anomaly relative to the ambient geotherm which reduces viscosity and facilitates viscous flow. We explore several geotherms and effective normal stress distributions (by changing pore pressure), quantifying the thermal anomaly, seismic and aseismic slip, and the transition from frictional sliding to viscous flow. The thermal anomaly can reach several hundred degrees below the seismogenic zone in models with hydrostatic pressure but is smaller for higher pressure (and these high‐pressure models are most consistent with San Andreas Fault heat flow constraints). Shear heating raises the BDT, sometimes to where it limits rupture depth rather than the frictional VW‐to‐VS transition. Our thermomechanical modeling framework can be used to evaluate lithospheric rheology and thermal models through predictions of earthquake ruptures, postseismic and interseismic crustal deformation, heat flow, and the geological structures that reflect the complex deformation beneath faults.
Optical Progressing and Electric Field Change Characteristics of Altitude—Triggered Lightning Flash With Different Development Paths
Authors: Cai Li , Li Jin , Wang Jianguo , Su Rui , Wang Fukun , Li Quanxin
Published: May 2021

The characteristics of optical and electric field waveforms from altitude triggered lightning flash at Guangzhou Field Experiment Site for Lightning Research and Testing (GFESLRT) during the summer of 2019 are presented. The altitude triggered lightning flash had eight return strokes with nine M‐components along four development paths. And the terminal heights of four paths are over 1,626 m above the ground. Our study presented an arithmetic mean of 0.62 kV/m and an arithmetic mean of 0.63 ms of half‐peak width for 16 initial continuous current (ICC) pulses values, as well as an arithmetic mean of 1.24 kV/m and an arithmetic mean of 0.47 ms of half peak width for nine M‐components values. The average 2‐D speed ranged from 3.80°× 105 to 2.94 × 106 m/s for the attempted leaders and from 1.26 × 106 to 6.96 × 106 m/s for the dart leaders. Basically, the greater the downward leader’s 2‐D propagation speed, the larger the electric field change. The electric field waveform in the rising edge of return stroke can be divided into three parts: “SF” indicates the slow front of the return stroke; “FT” indicates the fast transition of the return stroke; “SS” indicates shoulder structure of the return stroke. The arithmetic mean of SF electric field change is 1.45 kV/m and that of SF risetime is 110.6 μs. The arithmetic mean of the first FT electric field change is 4.71 kV/m and that of the first FT risetime is 1.1 μs. The arithmetic mean of the SS electric field change is 3.89 kV/m and that of the SS risetime is 28.1 μs.
Seasonal Trends of Aerosol Hygroscopicity and Mixing State in Clean Marine and Polluted Continental Air Masses Over the Northeast Atlantic
Authors: Xu Wei , Ovadnevaite Jurgita , Fossum Kirsten N. , Lin Chunshui , Huang Ru‐Jin , O'Dowd Colin , Ceburnis Darius
Published: May 2021

Five years of nearly continuous measurements of aerosol hygroscopicity by a Humidified Tandem Differential Mobility Analyzer (HTDMA) at Mace Head research station are presented, making it the longest aerosol hygroscopicity data set in marine environment and Northeast Atlantic region in particular. The main goal of this work was to examine seasonal patterns of aerosol hygroscopicity and mixing state in a variety of air masses. The entire data set was categorized into clean marine and polluted continental sectors to reveal contrasting physicochemical features. Distinct seasonal patterns were revealed where hygroscopicity of the clean sector aerosol was significantly higher than that of the polluted sector aerosol. The median growth factors (GF) of clean and polluted sectors were 1.67 and 1.31, respectively. Clean sector aerosol median GF reached the lowest values in summer and the highest in winter pointing at an impact of marine biological activity and wind speed driven sea spray production to aerosol hygroscopicity. Conversely, polluted sector aerosol reached the highest median GF of all sizes in summer due to the decrease of anthropogenic emission, enhanced photochemical aging, and secondary inorganic aerosol formation. Wintertime aerosols in both sectors were largely externally mixed, while summertime aerosols were relatively internally mixed. A distinct subset of near‐hydrophobic Aitken mode particles smaller than 50 nm in diameter was observed in the wintertime clean sector which most likely originated in the clean marine atmosphere based on the evolution of air mass back trajectory clustering.