bluuebunny/crossref_metadata_2025 huggingface dataset:
Designing an optimal control strategy for a mobile manipulator and its application by considering the effect of uncertainties and wheel slipping
Authors: Habibnejad Korayem Moharam , Ghobadi Narges , Fathollahi Dehkordi Siavash
Published: May 2021

This article seeks to develop the dynamic model of a mobile robot for controlling purposes while the effects of uncertainties and longitudinal and lateral slip are assumed. The rise in the number of state variables and considering the effects of nonlinear parameters due to slip modeling can complicate the control procedure of wheeled mobile manipulators. In addition, the existence of uncertainties as well as holonomic and nonholonomic constraints would increase this complexity even more. On the one side, as wheels are considered to slip, unwanted movements due to slippage affect the movement of the manipulator and the manipulator may not be able to track the desired path. On the other side, the movement of weighted links of the manipulator constantly changes the normal forces of the wheels. As traction forces are dependent on these normal forces, the path tracked by the platform would be affected. Given these conditions, employing a robust control methodology and developing an optimal algorithm to reduce the effects of uncertainties and wheels slip seems mandatory. To this aim, a sliding mode control (SMC) strategy is formulated in this study. Furthermore, the suggested algorithm is optimized using a state‐dependent Riccati equation to reduce the consumed torque and increase the accuracy of the system. Simulations are conducted, and the presented algorithm is also checked with the experimental setup of a Scout robot. Simulation results show that the optimal sliding mode control (OSMC) successfully decreases sudden jumps due to slippage in the system. In addition, the consumed power of wheels and arm for SMC decreases from 9.15 and 1.02 N·m to, respectively, 1.46 and 0.54 N·m for OSMC.
The value and limitations of local ecological knowledge: Longitudinal and retrospective assessment of flagship species in Golfo Dulce, Costa Rica
Authors: Bessesen Brooke L. , González‐Suárez Manuela
Published: May 2021

Anthropogenic activities and climate change are affecting marine ecosystems world‐wide, but systematic biodiversity assessments through periodic biomonitoring can be challenging and costly. Local ecological knowledge (LEK), obtained from experienced residents, can complement other approaches and provide improved understanding of the conservation status of marine areas. Here we explore the value and limitations of LEK to assess the status of several flagship species of tourism interest: cetaceans, sea turtles, whale sharks and sea snakes in a unique tropical fiord and biodiversity hotspot, Golfo Dulce, Costa Rica.

We analysed the interviews conducted with fishermen and tour boat guides in 2010 and 2020 and compared their responses to biomonitoring data obtained through boat‐based sighting surveys during the same two time periods. Our questionnaire asked for the estimates of sighting frequencies in both years, and in 2020 it also inquired about perceived changes over the time gap.

A key limitation was that many interviewees from 2010 could not be relocated in 2020, though 13 repeat participants served as a panel. Their responses suggest shifts in abundance that vary across taxa. For example, changes in reported sighting frequencies from 2010 to 2020 indicate a possible decline in whales but an increase in sea snakes. Those changes were also reflected in our biomonitoring data, suggesting respondents were fairly accurate in their reports of current abundance. However, when asked about perceived changes over the decade we found their answers were not consistent with changes detected through their reported frequencies nor though biomonitoring.

Our results suggest LEK can be a good source of information for current assessment but highlight the potential biases of perceptions of change. Evaluating changes through LEK may best be done by obtaining interview data at multiple points in time and systematically assessing trends, though, notably, there can be challenges with acquiring consistent sample sizes. Interviews should not replace but can complement biomonitoring while also providing further value via community engagement and as an avenue to gain insights into local opinions regarding conservation measures.

A free Plain Language Summary can be found within the Supporting Information of this article.
Effect of polyhedral oligomeric silsesquioxanes with different structures on dielectric and mechanical properties of epoxy resin
Authors: Qin Jianyu , Zhao Hanpeng , Qin Zhaolu , Zhang Wenchao , Yang Rongjie
Published: May 2021

Polyhedral oligomeric silsesquioxane (POSS) is a hybrid material composed of an organic substituent shell and inorganic skeleton core. To study the influence of different shells and cage‐shaped cores on dielectric and mechanical properties, four kinds of epoxy resin composites (EPs) fabricated with 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO), DOPO‐containing polyhedral oligomeric silsesquioxane (DOPOPOSS), octaphenyl polyhedral oligomeric silsesquioxane (OPS), and epoxy phenyl polyhedral oligomeric silsesquioxane (EPOSS) with the addition of 5 and 10 wt% were prepared, respectively. The dispersion, transparency, glass transition, dielectric, mechanical tensile, flexural, and impact properties of these epoxy resins were studied. Dielectric constant and loss of EPs were significantly reduced through introduction of three POSSs owing to their inherent hollow cores, and dielectric constant of the resins was further decreased with additional increase. Compared with three POSSs, DOPOPOSS had the best compatible shell, and its composites exhibited favorable transparency similar to pure EP and the obvious reduction in dielectric constant and loss, due to its nano‐dispersion in matrix. EPOSS was dispersed in a perfect spherical shape and uniformly embedded in matrix, and the composites showed good mechanical tensile, flexural, and impact strength. OPS was disorderly dispersed in resins, but its eight phenyl rings symmetrical shell had the advantage of nonpolar molecule structure, which endowed epoxy resin lower dielectric loss over the high‐frequency range (105–106 Hz). Compared with DOPOPOSS, DOPO was effective in reducing dielectric constant and loss of epoxy resin due to its reactive addition, however, it decreased the glass transition temperature, mechanical tensile, flexural, and impact strength of epoxy resin either.
The Puzzle of Global Double Field Theory: Open Problems and the Case for a Higher Kaluza‐Klein Perspective
Authors: Alfonsi Luigi
Published: May 2021

The history of the geometry of Double Field Theory is the history of string theorists' effort to tame higher geometric structures. In this spirit, the first part of this paper will contain a brief overview on the literature of geometry of DFT, focusing on the attempts of a global description.

In [1] we proposed that the global doubled space is not a manifold, but the total space of a bundle gerbe. This would mean that DFT is a field theory on a bundle gerbe, in analogy with ordinary Kaluza‐Klein Theory being a field theory on a principal bundle.

In this paper we make the original construction by [1] significantly more immediate. This is achieved by introducing an atlas for the bundle gerbe. This atlas is naturally equipped with 2d‐dimensional local charts, where d is the dimension of physical spacetime. We argue that the local charts of this atlas should be identified with the usual coordinate description of DFT.

In the last part we will discuss aspects of the global geometry of tensor hierarchies in this bundle gerbe picture. This allows to identify their global non‐geometric properties and explain how the picture of non‐abelian String‐bundles emerges. We interpret the abelian T‐fold and the Poisson‐Lie T‐fold as global tensor hierarchies.
Integrability Ex Machina
Authors: Krippendorf Sven , Lüst Dieter , Syvaeri Marc
Published: May 2021

Determining whether a dynamical system is integrable is generally a difficult task which is currently done on a case by case basis requiring large human input. Here we propose and test an automated method to search for the existence of relevant structures, the Lax pair and Lax connection respectively. By formulating this search as an optimization problem, we are able to identify appropriate structures via machine learning techniques. We test our method on standard systems of classical integrability and find that we can single out some integrable deformations of a system. Due to the ambiguity in defining a Lax pair our algorithm identifies novel Lax pairs which can be easily verified analytically.
Electrocaloric Effect in Sn‐ and Y‐Codoped BaTiO3 Ceramics
Authors: Qiang Hua , Fu Shiwen , Xu Zunping
Published: May 2021

BaSnxTi1–xO3 + 0.5 mol% Y ceramics (x = 0.06, 0.08, 0.11, and 0.13) are synthesized using citrate combustion technique and the electrocaloric effect (ECE) is investigated. Dense microstructures with fine grain are observed as increasing Sn contents. The dielectric results reveal that TO–T (tetragonal‐to‐orthorhombic phase) shifts toward higher temperature, whereas TC (cubic‐to‐tetragonal phase) shifts toward lower temperature as increasing Sn, and TO–T merges with TC at x = 0.11. An improving EC temperature change accompanying with large electrocaloric efficiency (ΔT/ΔE) of 0.28 × 10−6 K mV−1 over a wide temperature span is obtained at x = 0.11 under electric field of 50 kV cm−1. The enhanced ECE is mainly attributed to the multiphase coexistence. The dielectric properties and the grain boundary resistance are enhanced by optimizing Sn doping contents.
A hybrid homogeneously weighted moving average control chart for process monitoring: Discussion
Authors: Malela‐Majika Jean‐Claude , Shongwe Sandile Charles , Adeoti Olatunde Adebayo
Published: May 2021

The sensitivity of a monitoring scheme depends on many factors including the variance of the charting statistic which is very important in the computation of the control limits. This paper discusses the computation of the variance of the recently proposed hybrid homogeneously weighted moving average (HHWMA) scheme which was based on an incorrect assumption. The correct variance is used to evaluate the run‐length characteristics of the HHWMA scheme. It is observed that the incorrect variance has a significant impact on the sensitivity (or performance) of the HHWMA scheme.
Robust proportional hazard‐based monitoring schemes for reliability data
Authors: Nabeel Moezza , Ali Sajid , Shah Ismail
Published: May 2021

Reliability of products is a key factor for successful businesses. In general, the existing monitoring schemes have poor performance as reliability data are often censored. Also, the products are manufactured in multistage processes where the outgoing quality gets affected by the previous stage quality. Besides this cascade property, historical data with outliers make the analysis even more complicated. This paper discusses exponentially weighted moving average (EWMA) and cumulative sum (CUSUM) control charts for monitoring a two‐stage dependent process. In particular, the proportional hazard (PH) model is assumed for modeling the relationship of quality characteristics. Furthermore, to remove the detrimental effects of outliers on the results, robust regression method known as the M‐estimation is used. Besides a real case study, the performance of the proposed monitoring approach is assessed through a comprehensive simulation study. The results suggested that the EWMA chart outperforms the CUSUM chart.
Event‐triggered prescribed performance adaptive fuzzy asymptotic tracking of nonstrict‐feedback nonlinear systems
Authors: Hu Xiaoyan , Li Yuan‐Xin , Hou Zhongsheng , Niu Ben
Published: May 2021

This paper considers the performance‐guaranteed event‐triggered adaptive asymptotic tracking control problem for nonstrict feedback nonlinear systems with uncertain external disturbances. More precisely, the upper bounds of control gain function in stability analysis are eliminated by establishing Lyapunov function with lower bounds of control coefficients. Compared with the previous guaranteed performance results where the tracking errors converge to the neighborhood of the origin, the control scheme proposed in this paper ensures that the tracking error asymptotically converges to zero by constructing the smooth functions and boundary estimation method. So that the prescribed performance of the system is always achieved. In addition, the event‐triggered strategy is developed to reduce the waste of communication resources. The proposed control law can ensures that all the signals of system are bounded. Meanwhile, the Zeno behavior can be effectively avoid. Finally, two examples are provided to prove the effectiveness of the proposed scheme.
Impacts of regional climate change on hydrological drought characteristics in headwaters of the Ore Mountains
Authors: Vlach Vojtech , Matouskova Milada , Ledvinka Ondrej
Published: May 2021

Changes in the frequency, magnitude, and seasonality of hydrological extremes are one of the expected consequences of climate change. Recent years suggested an increasing risk of drought occurrence and restricted water supply even in usually humid mountain regions. Our research is focused on the evaluation of regional climate change and its effect on hydrological drought characteristics in headwater areas in the Ore Mountains along the Czech/German border. The main aim was to evaluate and compare streamflow regime changes and trends in long‐term hydrological and climatic time series within selected sub‐catchments of the Svatava (Zwota) River, the Rolava River, and the Načetínský Brook (Natzschung). A comparative statistical analysis for the 1967–2018 period was performed using various homogeneity and trend tests. Longer runoff time series with earlier beginnings were examined for two catchments as well. The results pointed to significant, continuous warming in the region which is accompanied by decreasing trends in snow cover depths in the colder half of the year. Drought indices based on runoff data were derived in the Indicators of Hydrologic Alterations (IHA 7.1) software environment. The seasonality of hydrological drought occurrence changed markedly after 1992, when most severe drought events started to concentrate between August and October in the study area. Increasing trends in deficit volumes were found in two catchments characterized by lower elevation. Furthermore, there was a significant decrease in average and minimum flows in spring and summer months in all catchments observed between 1967 and 2018 despite relatively stable amounts of precipitation and land cover.
Solar‐Enhanced CO2 Conversion with CH4 over Synergetic NiCo Alloy Catalysts with Light‐to‐Fuel Efficiency of 33.8%
Authors: Liu Xianglei , Shi Hang , Meng Xianguang , Sun Chen , Zhang Kai , Gao Lei , Ma Yuan , Mu Zekai , Ling Yueyue , Cheng Bo , Li Yongliang , Xuan Yimin , Ding Yulong
Published: May 2021

Conversion of CO2 into useful chemical feedstocks or fuels using solar energy is a promising technology to tackle both climate change and energy shortage challenges. Here, NiCo alloys derived from AlMg hydrotalcite are introduced for photothermal synergetic CO2 conversion with CH4 with an ultrahigh light‐to‐fuel efficiency of 33.8% and a low carbon deposition rate of 0.011 gc g−1
cat h−1. The ultrahigh efficiency is attributed to the high solar absorptance of NiCo alloys, unique synergistic catalysis of NiCo active sites, and the photo‐enhanced reactant activation. Inhibition of carbon formation lies in concurrent reduced energy barriers of CH* oxidation to CHO* and increased energy barriers of CH* dissociation to C*, enabled by the unique synergistic catalysis of NiCo alloys. Direct light illumination results in an obvious decrease of the apparent activation energy of CO2 conversion with CH4, making light‐driven CO2 conversion superior to conventional thermal‐driven techniques. Herein, a new platform for achieving efficient solar‐driven CO2 conversion with ultrahigh light‐to‐fuel efficiency based on NiCo alloy catalyst is provided and the way for sclable deployment of photothermal CO2‐to‐fuel techniques is paved.
Is signalment associated with clinicopathological findings in dogs with leishmaniosis?
Authors: Cabré Maria , Planellas Marta , Ordeix Laura , Solano‐Gallego Laia
Published: May 2021

Background

Canine leishmaniosis (CanL) is a common infectious disease. Age, sex and breed might influence the type of clinical and pathological manifestations that dogs develop. The main objective of this retrospective cross‐sectional study was to determine if an association between age, sex, breed and size and the clinical findings of CanL exists.

Material and methods

Dogs with a diagnosis of leishmaniosis were enrolled (n = 123). Clinical information, including signalment, clinical signs and laboratory abnormalities, was retrieved from medical records from different veterinary facilities from Catalonia.

Results

Young dogs developed less frequently systemic signs (p = 0.0046), renal (p = 0.0019) and haematologic (p = 0.0275) abnormalities, while dermatologic signs were more common in young and adult dogs compared with old ones (p = 0.0451). Young dogs showed proteinuria less often than adult and old dogs (p = 0.0029). Young dogs did not present renal azotemia, while old dogs showed occasionally renal azotemia (p = 0.0478). Young dogs were mainly classified as mild‐moderate LeishVet clinical stages of the disease, and very rarely as severe‐very severe LeishVet clinical stages, compared with adult and old dogs (p = 0.0457). Purebred dogs significantly developed ulcerative dermatitis more frequently than crossbred dogs (p = 0.0460).

Conclusion

This study describes that age is associated with differences in clinicopathological findings of CanL.
Programmable materials for efficient CTCs isolation: From micro/nanotechnology to biomimicry
Authors: Hou Jianwen , Liu Xia , Zhou Shaobing
Published: May 2021

Escaping from primary tumors and entering into blood flow, circulating tumor cells (CTCs) contain significant information for both the original tumors and metastasis mechanisms. CTCs detection has become an effective liquid biopsy of tumors and shows great promise in early cancer detection, disease monitoring, prognosis and personalized medicine. Despite the urgent need from clinics, CTCs isolation from blood is still a huge challenge due to their extreme rareness in blood. Well‐defined micro/nanostructures and nature‐inspired hierarchical architectures offer unique avenues to address this challenge by matching well with the special physical properties of CTCs to sort cells or forming local topographic interactions to strengthen cell adhesion, thereby improving the CTC‐isolation performance. In this review, we first summarize researches on CTCs isolation with diverse micro/nanostructured substrates, which mainly include nanomaterials, microfluidics, DNA nanostructures, micromotors and in vivo detection devices. In sequence, various CTC‐isolation biomimetic architectures, which are inspired by different natural creatures (e.g., viruses, cells, extracellular matrix [ECM], plants, and animals), have been highlighted. At last, remaining challenges and future perspectives in designing CTC‐isolation platforms for clinical applications are also discussed.
Sub‐epiglottic pharyngeal pouch remnant cyst in a 6‐month‐old female Labrador Retriever
Authors: Bonanno Giuseppe , Laird Catriona , Cox Alistair , White Robert
Published: May 2021

A 6‐month‐old entire female Labrador Retriever was presented for intermittent respiratory rasping and rattling made worse with excitement and exercise, which appeared to be distressing for the patient. Clinical findings revealed a fluid‐filled cystic structure at the base of the tongue in a sub‐epiglottic position. Serum concentrations of total thyroxine, free thyroxine and thyroid‐stimulating hormone were within normal limits. A CT scan revealed a 2‐cm diameter spherical, encapsulated structure, filled with fluid attenuating material, positioned in the midline at the base of the tongue adjacent to the basihyoid. The cyst was surgically excised via an oral approach, and histopathological findings were suggestive of a pharyngeal pouch remnant cyst. There were no post‐surgical complications, and the dog made an unremarkable recovery. At 12‐month long‐term follow‐up, the owner reported that the dog remained fit and well showing no further signs of respiratory noise, exercise restriction or evidence of recurrence.
Simplified characteristic time method for accurate estimation of the soil hydraulic parameters from one‐dimensional infiltration experiments
Authors: Rahmati Mehdi , Rezaei Meisam , Lassabatere Laurent , Morbidelli Renato , Vereecken Harry
Published: May 2021

Recently, a novel approach with excellent performance based on the concept of the characteristic infiltration time, the characteristic time method (CTM), is proposed to infer soil sorptivity (S) and saturated hydraulic conductivity (Ks) from one‐dimensional (1D) cumulative infiltration. The current work provides a simplified version of the CTM, called the SCTM, by eliminating the necessity of the iteration method used in CTM and providing a similar accuracy as the original method when estimating S and Ks. We used both synthetic and experimental data to evaluate SCTM in comparison with the original CTM, as well as Sharma (SH) and curve‐fitting methods. In the case of synthetically simulated infiltration experiments, the predicted S and Ks values showed an excellent agreement with their theoretical values, with Nash–Sutcliffe (E) values higher than 0.9 and RMSE values of 0.11 cm h1/2 and 0.35 cm h–1, respectively. In the case of experimental data, the SCTM showed E values larger than 0.73 and RMSE values of 0.64 cm h1/2 and 0.35 cm h–1, respectively. The accuracy and the robustness of SCTM was comparable with the original CTM when applied on synthetic infiltration curves as well as on experimental data. Similar to the original CTM, the simplified approach also does not require the knowledge of the time validity, which is needed when using approaches based on Philip's infiltration theory. The method is applicable to infiltrations with durations from 15 min to 24 h. The supplemental material presents the calculation of S and Ks using SCTM in an Excel spreadsheet.
Effect of overlying water pH, temperature, and hydraulic disturbance on heavy metal and nutrient release from drinking water reservoir sediments
Authors: Peng Cheng , Huang Yunying , Yan Xuchen , Jiang Lei , Wu Xuefei , Zhang Wei , Wang Xianyun
Published: May 2021

How environmental factors impact the release of pollutants from sediment is critical to ensure the safety of drinking water, especially when the seasons change. Here, we investigated the effect of water pH, temperature, and hydraulic disturbance on the release of heavy metals and nutrients from the sediment of drinking water reservoir. The results show that lower initial water pH promoted the Zn release, while low temperature enhanced the Mn flux after 15 days. Meanwhile, continuous disturbance caused more metals releasing from sediment than intermittent disturbance due to greater shear stress and turbulence effect. However, intermittent high‐speed disturbance greatly altered the dynamic release of Zn from L‐shaped curve to U‐shape in water column. Moreover, lower water pH caused higher ammonium in water but lower nitrate since H+ restrained the nitrification. Yet, higher temperature inhibited the release of ammonium from sediment, which might relate to the accelerated mineralization of organic nitrogen and elevated dissolved oxygen caused by the algae growth. Notably, hydraulic disturbance with various intensity and duration greatly influenced the fluxes of various species of nitrogen and soluble phosphate in water column, because the disturbance facilitated the nitrogen and phosphorus exchanges between sediment–water and water–air interfaces.

Practitioner points

Lower water pH induced Zn release, while low temperature gradually enhanced Mn level.

More metals were released from sediment under continuous disturbance than intermittent disturbance.

Lower water pH caused higher ammonium nitrogen in water but lower nitrate nitrogen.

Higher temperature inhibited the release of ammonium nitrogen from sediment.

Hydraulic disturbance greatly changed the release of different species of nitrogen and soluble phosphate from sediment.
Metabolic Intersection of Cancer and Cardiovascular Diseases: Opportunities for Cancer Therapy
Authors: Hoang Giang , Nguyen Kiet , Le Anne
Published: May 2021

According to data from the World Health Organization, cardiovascular diseases and cancer are the two leading causes of mortality in the world [1]. Despite the immense effort to study these diseases and the constant innovation in treatment modalities, the number of deaths associated with cardiovascular diseases and cancer is predicted to increase in the coming decades [1]. From 2008 to 2030, due to population growth and population aging in many parts of the world, the number of deaths caused by cancer globally is projected to increase by 45%, corresponding to an annual increase of around four million people [1]. For cardiovascular diseases, this number is six million people [1]. In the United States, treatments for these two diseases are among the most costly and result in a disproportionate impact on low- and middleincome people. As the fight against these fatal diseases continues, it is crucial that we continue our investigation and broaden our understanding of cancer and cardiovascular diseases to innovate our prognostic and treatment approaches. Even though cardiovascular diseases and cancer are usually studied independently [2–12], there are some striking overlaps between their metabolic behaviors and therapeutic targets, suggesting the potential application of cardiovascular disease treatments for cancer therapy. More specifically, both cancer and many cardiovascular diseases have an upregulated glutaminolysis pathway, resulting in low glutamine and high glutamate circulating levels. Similar treatment modalities, such as glutaminase (GLS) inhibition and glutamine supplementation, have been identified to target glutamine metabolism in both cancer and some cardiovascular diseases. Studies have also found similarities in lipid metabolism, specifically fatty acid oxidation (FAO) and synthesis. Pharmacological inhibition of FAO and fatty acid synthesis have proven effective against many cancer types as well as specific cardiovascular conditions. Many of these treatments have been tested in clinical trials, and some have been medically prescribed to patients to treat certain diseases, such as angina pectoris [13, 14]. Other metabolic pathways, such as tryptophan catabolism and pyruvate metabolism, were also dysregulated in both diseases, making them promising treatment targets. Understanding the overlapping traits exhibited by both cancer metabolism and cardiovascular disease metabolism can give us a more holistic view of how important metabolic dysregulation is in the progression of diseases. Using established links between these illnesses, researchers can take advantage of the discoveries from one field and potentially apply them to the other. In this chapter, we highlight some promising therapeutic discoveries that can support our fight against cancer, based on common metabolic traits displayed in both cancer and cardiovascular diseases.
Appropriation and Configuration
Authors: Greiner Rasmus
Published: May 2021

This chapter will seek to demonstrate that the process of appropriation also irrevocably inscribes the aesthetic parameters of a cinematic-historical way of thinking into our historical consciousness. Building on theories of the phenomenological relationship between the spectator’s body and the world, the first section develops a model of incorporative appropriation of history, which it connects to constructivist and cognitive approaches. The second section raises the specific experience of historical films described in the previous section to the status of paradigmatic core of a historical film genre, which it fleshes out based on a phenomenological conception of genre. Its systematic account of this genre integrates the theoretical discussion of the distinctive characteristics of historical films from the preceding chapters.
Conformal blocks from celestial gluon amplitudes
Authors: Fan Wei , Fotopoulos Angelos , Stieberger Stephan , Taylor Tomasz R. , Zhu Bin
Published: May 2021

Abstract

In celestial conformal field theory, gluons are represented by primary fields with dimensions ∆ = 1 + iλ, λ ∈ ℝ and spin J = ±1, in the adjoint representation of the gauge group. All two- and three-point correlation functions of these fields are zero as a consequence of four-dimensional kinematic constraints. Four-point correlation functions contain delta-function singularities enforcing planarity of four-particle scattering events. We relax these constraints by taking a shadow transform of one field and perform conformal block decomposition of the corresponding correlators. We compute the conformal block coefficients. When decomposed in channels that are “compatible” in two and four dimensions, such four-point correlators contain conformal blocks of primary fields with dimensions ∆ = 2 + M + iλ, where M ≥ 0 is an integer, with integer spin J = −M, −M + 2, …, M − 2, M. They appear in all gauge group representations obtained from a tensor product of two adjoint representations. When decomposed in incompatible channels, they also contain primary fields with continuous complex spin, but with positive integer dimensions.
Conformal Floquet dynamics with a continuous drive protocol
Authors: Das Diptarka , Ghosh Roopayan , Sengupta Krishnendu
Published: May 2021

Abstract

We study the properties of a conformal field theory (CFT) driven periodically with a continuous protocol characterized by a frequency ωD. Such a drive, in contrast to its discrete counterparts (such as square pulses or periodic kicks), does not admit exact analytical solution for the evolution operator U. In this work, we develop a Floquet perturbation theory which provides an analytic, albeit perturbative, result for U that matches exact numerics in the large drive amplitude limit. We find that the drive yields the well-known heating (hyperbolic) and non-heating (elliptic) phases separated by transition lines (parabolic phase boundary). Using this and starting from a primary state of the CFT, we compute the return probability (Pn), equal (Cn) and unequal (Gn) time two-point primary correlators, energy density(En), and the mth Renyi entropy ($$ {S}_n^m $$

S
n
m

) after n drive cycles. Our results show that below a crossover stroboscopic time scale nc, Pn, En and Gn exhibits universal power law behavior as the transition is approached either from the heating or the non-heating phase; this crossover scale diverges at the transition. We also study the emergent spatial structure of Cn, Gn and En for the continuous protocol and find emergence of spatial divergences of Cn and Gn in both the heating and non-heating phases. We express our results for $$ {S}_n^m $$

S
n
m

and Cn in terms of conformal blocks and provide analytic expressions for these quantities in several limiting cases. Finally we relate our results to those obtained from exact numerics of a driven lattice model.
Existence analysis of a degenerate diffusion system for heat-conducting gases
Authors: Favre Gianluca , Jüngel Ansgar , Schmeiser Christian , Zamponi Nicola
Published: May 2021

The existence of global weak solutions to a parabolic energy-transport system in a bounded domain with no-flux boundary conditions is proved. The model can be derived in the diffusion limit from a kinetic equation with a linear collision operator involving a non-isothermal Maxwellian. The evolution of the local temperature is governed by a heat equation with a source term that depends on the energy of the distribution function. The limiting model consists of cross-diffusion equations with an entropy structure. The main difficulty is the nonstandard degeneracy, i.e., ellipticity is lost when the gas density or temperature vanishes. The existence proof is based on a priori estimates coming from the entropy inequality and the $$H^{-1}$$

H

-
1

method and on techniques from mathematical fluid dynamics (renormalized formulation, div-curl lemma).
Genetic architecture of root and shoot ionomes in rice (Oryza sativa L.)
Authors: Cobb Joshua N. , Chen Chen , Shi Yuxin , Maron Lyza G. , Liu Danni , Rutzke Mike , Greenberg Anthony , Craft Eric , Shaff Jon , Paul Edyth , Akther Kazi , Wang Shaokui , Kochian Leon V. , Zhang Dabao , Zhang Min , McCouch Susan R.
Published: May 2021

Key message

Association analysis for ionomic concentrations of 20 elements identified independent genetic factors underlying the root and shoot ionomes of rice, providing a platform for selecting and dissecting causal genetic variants.

Understanding the genetic basis of mineral nutrient acquisition is key to fully describing how terrestrial organisms interact with the non-living environment. Rice (Oryza sativaL.) serves both as a model organism for genetic studies and as an important component of the global food system. Studies in rice ionomics have primarily focused on above ground tissues evaluated from field-grown plants. Here, we describe a comprehensive study of the genetic basis of the rice ionome in both roots and shoots of 6-week-old rice plants for 20 elements using a controlled hydroponics growth system. Building on the wealth of publicly available rice genomic resources, including a panel of 373 diverse rice lines, 4.8 M genome-wide single-nucleotide polymorphisms, single- and multi-marker analysis pipelines, an extensive tome of 321 candidate genes and legacy QTLs from across 15 years of rice genetics literature, we used genome-wide association analysis and biparental QTL analysis to identify 114 genomic regions associated with ionomic variation. The genetic basis for root and shoot ionomes was highly distinct; 78 loci were associated with roots and 36 loci with shoots, with no overlapping genomic regions for the same element across tissues. We further describe the distribution of phenotypic variation across haplotypes and identify candidate genes within highly significant regions associated with sulfur, manganese, cadmium, and molybdenum. Our analysis provides critical insight into the genetic basis of natural phenotypic variation for both root and shoot ionomes in rice and provides a comprehensive resource for dissecting and testing causal genetic variants.
Functionally graded optimisation of adsorption systems with phase change materials
Authors: Prado D. S. , Amigo R. C. R. , Hewson R. W. , Silva E. C. N.
Published: May 2021

Adsorption phenomena are encountered in several engineering applications. One of its uses is in the storage and transport of gas in the form of adsorption tanks. The exothermic nature of the adsorption process decreases adsorption capacity presenting an impetus to understand the thermal characteristics of the gas storage process. Studies using mixtures of phase change materials and adsorbents in adsorption tanks demonstrate potential improvements in the adsorption capacity of the tanks. They also show that the distribution of phase change materials and adsorbent are important. Thus, this work presents two approaches for optimising the adsorbent domain. The first is to use a semi-analytic model to determine the best homogeneous material concentration for the adsorbent and phase change material for the vessel composition. The other is to use a 2D axisymmetric model to perform FGM optimisation to distribute material in the tank. Results for both models are presented and discussed for different conditions. The study shows that, for the cylindrical geometry, FGM optimisation is always, at least, marginally better than the homogeneous distribution from the semi-analytic model. However, FGM optimisation demands more computing time increases the complexity of implementation and results assembling. The semi-analytic approach is a possible alternative for optimising adsorption systems with phase change material mixed with adsorbents.
Corporate boards, interorganizational ties and profitability: the case of Japan
Authors: Raddant Matthias , Takahashi Hiroshi
Published: May 2021

We analyze the ties between 4000 Japanese corporations in the time period from 2004 until 2013. We combine data about the board composition with ownership relationships and indicators of corporate profitability. The board network exhibits some clustering, which can partly be explained by ownership relations, and a tendency to form ties to other corporations from the same sector. Connectivity in the board network (corporate board interlocks) and ownership network (shareholdings) does have an influence profitability. Firms that are linked to peers with above average profitability are more profitable than firms in other relationships. Hence, network effects partly explain why board interlocks and ownership ties are not always beneficial.
Molecularly imprinted polymers by epitope imprinting: a journey from molecular interactions to the available bioinformatics resources to scout for epitope templates
Authors: Pasquardini Laura , Bossi Alessandra Maria
Published: May 2021

The molecular imprinting of proteins is the process of forming biomimetics with entailed protein-recognition by means of a template-assisted synthesis. Protein-imprinted polymers (pMIPs) have been successfully employed in separations, assays, sensors, and imaging. From a technical point of view, imprinting a protein is both costly, for protein expression and purification, and challenging, for the preservation of the protein’s structural properties. In fact, the imprinting process needs to guarantee the preservation of the same protein three-dimensional conformation that later would be recognized. So far, the captivating idea to imprint just a portion of the protein, i.e., an epitope, instead of the whole, proved successful, offering reduced costs, compatibility with many synthetic conditions (solvents, pH, temperatures), and fine-tuning of the peptide sequence so to target specific physiological and functional conditions of the protein, such as post-translational modifications. Here, protein-protein interactions and the biochemical features of the epitopes are inspected, deriving lessons to prepare more effective pMIPs. Epitopes are categorized in linear or structured, immunogenic or not, located at the protein’s surface or buried in its core and the imprinting strategies are discussed. Moreover, attention is given to freely available online bioinformatics resources that might offer key tools to gain further rationale amid the selection process of suitable epitopes templates.
Preclinical trial of a MAP4K4 inhibitor to reduce infarct size in the pig: does cardioprotection in human stem cell-derived myocytes predict success in large mammals?
Authors: te Lintel Hekkert Maaike , Newton Gary , Chapman Kathryn , Aqil Rehan , Downham Robert , Yan Robert , Merkus Daphne , Whitlock Gavin , Lane Charlotte A. L. , Cawkill Darren , Perrior Trevor , Duncker Dirk J. , Schneider Michael D.
Published: May 2021

Reducing infarct size (IS) by interfering with mechanisms for cardiomyocyte death remains an elusive goal. DMX-5804, a selective inhibitor of the stress-activated kinase MAP4K4, suppresses cell death in mouse myocardial infarction (MI), human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs), and 3D human engineered heart tissue, whose fidelity to human biology is hoped to strengthen the route to clinical success. Here, DMX-10001, a soluble, rapidly cleaved pro-drug of DMX-5804, was developed for i.v. testing in large-mammal MI. Following pharmacodynamic studies, a randomized, blinded efficacy study was performed in swine subjected to LAD balloon occlusion (60 min) and reperfusion (24 h). Thirty-six animals were enrolled; 12 were excluded by pre-defined criteria, death before infusion, or technical issues. DMX-10001 was begun 20 min before reperfusion (30 min, 60 mg/kg/h; 23.5 h, 17 mg/kg/h). At all times tested, beginning 30 min after the start of infusion, DMX-5804 concentrations exceeded > fivefold the levels that rescued hPSC-CMs and reduced IS in mice after oral dosing with DMX-5804 itself. No significant reduction occurred in IS or no-reflow corrected for the area at ischemic risk, even though DMX-10001 reduced IS, expressed in grams or % of LV mass, by 27%. In summary, a rapidly cleaved pro-drug of DMX-5804 failed to reduce IS in large-mammal MI, despite exceeding the concentrations for proven success in both mice and hPSC-CMs.
Arthroscopic modified Broström operation versus open reconstruction with local periosteal flap in chronic ankle instability
Authors: Mederake Moritz , Hofmann Ulf Krister , Ipach Ingmar
Published: May 2021

Introduction

The modified Broström operation (MBO) has found widespread use in the therapy of lateral chronic ankle instability (CAI). However, alternative surgical techniques like the open reconstruction using a periosteal flap (RPF) are still an important part of the surgical treatment of lateral CAI. Both procedures differ in terms of the reconstruction material used and the surgical procedure. Comparative studies on the surgical therapy of CAI are limited and generally refer to similar surgical procedures. Aim of this study was to compare the arthroscopic MBO and the RPF.

Materials and methods

We retrospectively analysed 25 patients with lateral CAI after a tear of the anterior talofibular ligament (ATFL). 14 patients received arthroscopic MBO and 11 patients received RPF. We compared the postoperative outcome between both groups with respect to subjective instability, the number of ankle sprains, pain, complications and follow-up operations as well as the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score.

Results

Both surgical procedures resulted in a significant improvement in pain, in subjective instability, in the reduction in the frequency of ankle sprains and improvement in the AOFAS ankle-hindfoot score one year postoperatively. Three months postoperatively, the values for pain and instability of the MBO group were significantly better compared to the RPF. One year after the operation, these differences were evened out. Also in terms of complications and follow-up operations, no significant difference was found between the two procedures.

Conclusions

Both surgical procedures give very good results one year postoperatively in terms of pain, instability, function and complication rate. With significantly better results regarding pain and instability three months postoperatively, the MBO allows a faster recovery in patients operated with this technique.
Selective involution of thymic medulla by cyclosporine A with a decrease of mature thymic epithelia, XCR1+ dendritic cells, and epithelium-free areas containing Foxp3+ thymic regulatory T cells
Authors: Sawanobori Yasushi , Kitazawa Yusuke , Ueta Hisashi , Matsuno Kenjiro , Tokuda Nobuko
Published: May 2021

Immunosuppressive drugs such as cyclosporine A (CSA) can disrupt thymic structure and functions, ultimately inducing syngeneic/autologous graft-versus-host disease together with involuted medullas. To elucidate the effects of CSA on the thymus more precisely, we analyzed the effects of CSA on the thymus and T cell system using rats. In addition to confirming the phenomena already reported, we newly found that the proportion of recent thymic emigrants also greatly decreased, suggesting impaired supply. Immunohistologically, the medullary thymic epithelial cells (mTECs) presented with a relative decrease in the subset with a competent phenotype and downregulation of class II major histocompatibility complex molecules. In control rats, thymic dendritic cells (DCs) comprised two subsets, XCR1+SIRP1α−CD4−and XCR1−SIRP1α+CD4+. The former had a tendency to selectively localize in the previously-reported epithelium-containing areas of the rat medullas, and the number was significantly reduced by CSA treatment. The epithelium-free areas, another unique domains in the rat medullas, contained significantly more Foxp3+thymic Tregs. With CSA treatment, the epithelium-free areas presented strong involution, and the number and distribution of Tregs in the medulla were greatly reduced. These results suggest that CSA inhibits the production of single-positive thymocytes, including Tregs, and disturbs the microenvironment of the thymic medulla, with a decrease of the competent mTECs and disorganization of epithelium-free areas and DC subsets, leading to a generation of autoreactive T cells with selective medullary involution.
Role of lung and gut microbiota on lung cancer pathogenesis
Authors: Zhao Yue , Liu Yuxia , Li Shuang , Peng Zhaoyun , Liu Xiantao , Chen Jun , Zheng Xin
Published: May 2021

Background

Lung cancer is the leading cause of cancer-related deaths worldwide (Ferlay et al., Int J Cancer 136:E359–386, 2015). In addition, lung cancer is associated with the highest mortality among all cancer types (Wu et al., Exp Ther Med 16:3004–3010, 2018). Previous studies report that microbiota play an important role in lung cancer. Notably, changes in lung and gut microbiota, are associated with progression of lung cancer. Several studies report that lung and gut microbiome promote lung cancer initiation and development by modulating metabolic pathways, inhibiting the function of immune cells, and producing pro-inflammatory factors. In addition, some factors such as microbiota dysbiosis, affect production of bacteriotoxins, genotoxicity and virulence effect, therefore, they play a key role in cancer progression. These findings imply that lung and gut microbiome are potential markers and targets for lung cancer. However, the role of microbiota in development and progression of lung cancer has not been fully explored.

Purpose

The aim of this study was to systemically review recent research findings on relationship of lung and gut microbiota with lung cancer. In addition, we explored gut–lung axis and potential mechanisms of lung and gut microbiota in modulating lung cancer progression.

Conclusion

Pulmonary and intestinal flora influence the occurrence, development, treatment and prognosis of lung cancer, and will provide novel strategies for prevention, diagnosis, and treatment of lung cancer.
Five-year follow-up of nivolumab treatment in Japanese patients with esophageal squamous-cell carcinoma (ATTRACTION-1/ONO-4538-07)
Authors: Satoh Taroh , Kato Ken , Ura Takashi , Hamamoto Yasuo , Kojima Takashi , Tsushima Takahiro , Hironaka Shuichi , Hara Hiroki , Iwasa Satoru , Muro Kei , Yasui Hirofumi , Minashi Keiko , Yamaguchi Kensei , Ohtsu Atsushi , Doki Yuichiro , Matsumura Yasuhiro , Kitagawa Yuko
Published: May 2021

Background

In the phase II ATTRACTION-1 study, nivolumab demonstrated a promising antitumor activity among Japanese patients with treatment-refractory advanced esophageal cancer. Here, we report the follow-up results of ATTRACTION-1 of > 5 years.

Methods

We enrolled patients with esophageal cancer that was refractory or intolerant to a standard chemotherapy. Then, nivolumab (3 mg/kg) was administered every 2 weeks. The primary endpoint was a centrally assessed objective response rate.

Results

Nivolumab was administered to 65 patients with esophageal squamous-cell carcinoma (ESCC). The centrally assessed objective response rate was 17.2%. The overall survival rates at 3 and 5 years were 10.9% and 6.3%, respectively. Three-year survivors tended to have more reduced target lesions. A total of 63.1% of the patients exhibited treatment-related adverse events, and no new safety signal was observed. Patients with select adverse events tended to have better overall survival than those without. No apparent chronological order was observed between the first response and the onset of select adverse events.

Conclusion

Our follow-up analysis of more than 5 years is currently the longest and is the first to demonstrate that nivolumab has long-term efficacy and safety for advanced ESCC.