bluuebunny/crossref_metadata_2025 huggingface dataset:
Primary restriction of S‐RNase cytotoxicity by a stepwise ubiquitination and degradation pathway in Petuniahybrida
Authors: Zhao Hong , Song Yanzhai , Li Junhui , Zhang Yue , Huang Huaqiu , Li Qun , Zhang Yu’e , Xue Yongbiao
Published: May 2021

In self‐incompatible Petunia species, the pistil S‐RNase acts as cytotoxin to inhibit self‐pollination but is polyubiquitinated by the pollen‐specific nonself S‐locus F‐box (SLF) proteins and subsequently degraded by the ubiquitin‐proteasome system (UPS), allowing cross‐pollination. However, it remains unclear how S‐RNase is restricted by the UPS.

Using biochemical analyses, we first show that Petunia hybrida S3‐RNase is largely ubiquitinated by K48‐linked polyubiquitin chains at three regions, R I, R II and R III. R I is ubiquitinated in unpollinated, self‐pollinated and cross‐pollinated pistils, indicating its occurrence before PhS3‐RNase uptake into pollen tubes, whereas R II and R III are exclusively ubiquitinated in cross‐pollinated pistils.

Transgenic analyses showed that removal of R II ubiquitination resulted in significantly reduced seed sets from cross‐pollination and that of R I and R III to a lesser extent, indicating their increased cytotoxicity. Consistent with this, the mutated R II of PhS3‐RNase resulted in a marked reduction of its degradation, whereas that of R I and R III resulted in less reduction.

Taken together, we demonstrate that PhS3‐RNase R II functions as a major ubiquitination region for its destruction and R I and R III as minor ones, revealing that its cytotoxicity is primarily restricted by a stepwise UPS mechanism for cross‐pollination in P. hybrida.
A promiscuous fatty acid ω‐hydroxylase CYP94A90 is likely to be involved in biosynthesis of a floral nitro compound in loquat (Eriobotrya japonica)
Authors: Yamaguchi Takuya , Matsui Yumi , Kitaoka Naoki , Kuwahara Yasumasa , Asano Yasuhisa , Matsuura Hideyuki , Sunohara Yukari , Matsumoto Hiroshi
Published: May 2021

Nitro groups are often associated with synthetically manufactured compounds such as medicines and explosives, and rarely with natural products. Loquat emits a nitro compound, (2‐nitroethyl)benzene, as a flower scent. The nitro compound exhibits fungistatic activity and is biosynthesised from l‐phenylalanine via (E/Z)‐phenylacetaldoxime. Although aldoxime‐producing CYP79s have been intensively studied, it is unclear what enzymes form nitro groups from aldoximes either in plants or in other organisms.

Here, we report the identification of two cytochrome P450s that are likely to be involved in (2‐nitroethyl)benzene biosynthesis in loquat through differential gene expression analysis using RNA‐seq and functional identification using yeast and tobacco.

CYP79D80 and CYP94A90 catalysed the formation of (E/Z)‐phenylacetaldoxime from l‐phenylalanine and (2‐nitroethyl)benzene from the aldoxime, respectively. Expression profiles of CYP79D80 and CYP94A90 were correlated with the emission of (2‐nitroethyl)benzene from loquat flowers. CYP94A90 also functioned as a fatty acid ω‐hydroxylase as do other CYP94A fatty acid ω‐hydroxylases. The CYP94As tested from other plants were all found to catalyse the formation of (2‐nitroethyl)benzene from (E/Z)‐phenylacetaldoxime.

CYP79D80 and CYP94A90 are likely to operate in concert to biosynthesise (2‐nitroethyl)benzene in loquat. CYP94A90 and other CYP94As are ‘promiscuous fatty acid ω‐hydroxylases’, catalysing the formation of nitro groups from aldoximes, and are widely distributed in dicot plants.
Grade of Membership models reveal geographical and environmental correlates of floristic structure in a temperate biodiversity hotspot
Authors: Li Qin , Sun Hang , Boufford David E. , Bartholomew Bruce , Fritsch Peter W. , Chen Jiahui , Deng Tao , Ree Richard H.
Published: May 2021

Identifying the contours and correlates of species turnover is central to understanding the nature of biogeographical regions. The Hengduan Mountains region of south‐central China (HMR) is well known for its high diversity of plants, but its boundaries and internal floristic structure are poorly understood, especially in relation to geographical and environmental factors.

With data on occurrences and elevational ranges of seed plants across the HMR and adjacent areas of the greater Qinghai‐Tibet Plateau, we identified motifs (distinct species assemblages) by Grade of Membership models, and characterized relative contributions of geography, elevation, and climate to their spatial patterns.

Motifs segregate primarily by latitude, elevation, and correlated environmental variables, most sharply across the tropical‐temperate divide. Secondarily, they segregate by longitude and geographical features, and reveal a novel divide across the Jinsha River. A core set of motifs corresponds to previous delineations of the HMR.

The HMR biodiversity hotspot is more a mosaic of floristic elements than a cohesive entity. Grade of Membership models effectively reveal the geographical contours of biotic structure, and are a valuable new tool for biogeographical analysis.
Phytohormone‐dependent plant defense signaling orchestrated by oral bacteria of the herbivore Spodoptera litura
Authors: Yamasaki Yukiyo , Sumioka Hiroka , Takiguchi Mayu , Uemura Takuya , Kihara Yuka , Shinya Tomonori , Galis Ivan , Arimura Gen‐ichiro
Published: May 2021

A vast array of herbivorous arthropods live with symbiotic microorganisms. However, little is known about the nature and functional mechanism of bacterial effects on plant defense responses towards herbivores.

We explored the role of microbes present in extracts of oral secretion (OS) isolated from larvae of Spodoptera litura, a generalist herbivore, in phytohormone signaling‐dependent defense responses in Arabidopsis thaliana (Arabidopsis).

In response to mechanical damage (MD) with application of bacteria‐free OS (OS–) prepared by sterilization or filtration of OS, Arabidopsis leaves exhibited enhanced de novo synthesis of oxylipins, and induction of transcript abundance of the responsible genes, in comparison to those in leaves with MD + nonsterilized OS (OS+), indicating that OS bacteria serve as suppressors of these genes. By contrast, de novo synthesis/signaling of salicylic acid and signaling of abscisic acid were enhanced by OS bacteria. These signaling networks were cross‐regulated by each other.

Meta‐analysis of OS bacteria identified 70 bacterial strains. Among them was Staphylococcus epidermidis, an anaerobic staphylococcus that was shown to contribute to the suppression/manipulation of phytohormone‐dependent plant defense signaling. The presence of OS bacteria was consequently beneficial for S. litura larvae hosted by Brassicaceae.
Local abnormal ventricular activity detection in scar‐related VT: Microelectrode versus conventional bipolar electrode
Authors: Nakashima Takashi , Cheniti Ghassen , Takagi Takamitsu , Vlachos Konstantinos , Goujeau Cyril , André Clémentine , Krisai Philipp , Ramirez F. Daniel , Pintican Gabriela , Kamakura Tsukasa , Nakatani Yosuke , Surget Elodie , Roux Jean‐Rodolphe , Meillet Valentin , Carapezzi Aline , Tixier Romain , Chauvel Remi , Pambrun Thomas , Duchateau Josselin , Derval Nicolas , Pillois Xavier , Cochet Hubert , Hocini Mélèze , Haïssaguerre Michel , Jaïs Pierre , Sacher Frédéric
Published: May 2021

Background

Conventional bipolar electrodes (CBE) may be suboptimal to detect local abnormal ventricular activities (LAVAs). Microelectrodes (ME) may improve the detection of LAVAs. This study sought to elucidate the detectability of LAVAs using ME compared with CBE in patients with scar‐related ventricular tachycardia (VT).

Methods

We included consecutive patients with structural heart disease who underwent radiofrequency catheter ablation for scar‐related VT using either of the following catheters equipped with ME: QDOTTM or IntellaTip MIFITM. Detection field of LAVA potentials were classified as three types: Type 1 (both CBE and ME detected LAVA), Type 2 (CBE did not detect LAVA while ME did), and Type 3 (CBE detected LAVA while ME did not).

Results

In 16 patients (68 ± 16 years; 14 males), 260 LAVAs electrograms (QDOT = 72; MIFI = 188) were analyzed. Type 1, type 2, and type 3 detections were 70.8% (QDOT, 69.4%; MIFI, 71.3%), 20.0% (QDOT, 23.6%; MIFI, 18.6%) and 9.2% (QDOT, 6.9%; MIFI, 10.1%), respectively. The LAVAs amplitudes detected by ME were higher than those detected by CBE in both catheters (QDOT: ME 0.79 ± 0.50 mV vs. CBE 0.41 ± 0.42 mV, p = .001; MIFI: ME 0.73 ± 0.64 mV vs. CBE 0.38 ± 0.36 mV, p < .001).

Conclusions

ME allow to identify 20% of LAVAs missed by CBE. ME showed higher amplitude LAVAs than CBE. However, 9.2% of LAVAs can still be missed by ME.
The rice RNase P protein subunit Rpp30 confers broad‐spectrum resistance to fungal and bacterial pathogens
Authors: Li Wei , Xiong Yehui , Lai Lien B. , Zhang Kai , Li Zhiqiang , Kang Houxiang , Dai Liangying , Gopalan Venkat , Wang Guo‐Liang , Liu Wende
Published: May 2021

RNase P functions either as a catalytic ribonucleoprotein (RNP) or as an RNA‐free polypeptide to catalyse RNA processing, primarily tRNA 5′ maturation. To the growing evidence of non‐canonical roles for RNase P RNP subunits including regulation of chromatin structure and function, we add here a role for the rice RNase P Rpp30 in innate immunity. This protein (encoded by LOC_Os11g01074) was uncovered as the top hit in yeast two‐hybrid assays performed with the rice histone deacetylase HDT701 as bait. We showed that HDT701 and OsRpp30 are localized to the rice nucleus, OsRpp30 expression increased post‐infection by Pyricularia oryzae (syn. Magnaporthe oryzae), and OsRpp30 deacetylation coincided with HDT701 overexpression in vivo. Overexpression of OsRpp30 in transgenic rice increased expression of defence genes and generation of reactive oxygen species after pathogen‐associated molecular pattern elicitor treatment, outcomes that culminated in resistance to a fungal (P. oryzae) and a bacterial (Xanthomonas oryzae pv. oryzae) pathogen. Knockout of OsRpp30 yielded the opposite phenotypes. Moreover, HA‐tagged OsRpp30 co‐purified with RNase P pre‐tRNA cleavage activity. Interestingly, OsRpp30 is conserved in grass crops, including a near‐identical C‐terminal tail that is essential for HDT701 binding and defence regulation. Overall, our results suggest that OsRpp30 plays an important role in rice immune response to pathogens and provides a new approach to generate broad‐spectrum disease‐resistant rice cultivars.
CO2 supply modulates lipid remodelling, photosynthetic and respiratory activities in Chlorella species
Authors: Cecchin Michela , Paloschi Matteo , Busnardo Giovanni , Cazzaniga Stefano , Cuine Stephan , Li‐Beisson Yonghua , Wobbe Lutz , Ballottari Matteo
Published: May 2021

Microalgae represent a potential solution to reduce CO2 emission exploiting their photosynthetic activity. Here, the physiologic and metabolic responses at the base of CO2 assimilation were investigated in conditions of high or low CO2 availability in two of the most promising algae species for industrial cultivation, Chlorella sorokiniana and Chlorella vulgaris. In both species, high CO2 availability increased biomass accumulation with specific increase of triacylglycerols in C. vulgaris and polar lipids and proteins in C. sorokiniana. Moreover, high CO2 availability caused only in C. vulgaris a reduced NAD(P)H/NADP+ ratio and reduced mitochondrial respiration, suggesting a CO2 dependent increase of reducing power consumption in the chloroplast, which in turn influences the redox state of the mitochondria. Several rearrangements of the photosynthetic machinery were observed in both species, differing from those described for the model organism Chlamydomonas reinhardtii, where adaptation to carbon availability is mainly controlled by the translational repressor NAB1. NAB1 homologous protein could be identified only in C. vulgaris but lacked the regulation mechanisms previously described in C. reinhardtii. Acclimation strategies to cope with a fluctuating inorganic carbon supply are thus diverse among green microalgae, and these results suggest new biotechnological strategies to boost CO2 fixation.
Association between atopic dermatitis and headaches throughout childhood and adolescence—A longitudinal birth cohort study
Authors: Manjunath Jaya , Silverberg Jonathan I.
Published: May 2021

Background/objectives

Atopic dermatitis (AD) is associated with sleep disturbance, psychosocial distress, anxiety, depression, and atopic comorbidities, which may be associated with increased headaches. Our objective was to understand the association of AD and comorbid asthma, sleep and mental health disturbances with headaches throughout childhood and adolescence.

Methods

Data were analyzed from The Fragile Families and Child Wellbeing Study, a longitudinal birth cohort study of 4898 urban children born in 1998‐2000.

Results

AD was associated with headaches at age 5 (adjusted odds ratio [95% confidence interval]: 2.14 [1.27‐3.59]), 9 (1.69 [1.27‐2.27]) and 15 years (1.71 [1.37‐2.14]). AD at age 9 was associated with higher odds of subsequent headaches at age 15 (1.36 [1.05‐1.76]). Children with AD at two (1.60 [1.12‐2.29]) or all three (1.79 [1.16‐2.75]) study‐waves had higher odds of headaches at age 15 years. In multivariable repeated measures logistic regression models, significant two‐way interactions were found for AD with sleep disturbance (4.59 [3.15‐6.69]), attention deficit (hyperactivity) disorder (2.85 [1.87‐4.35]), asthma (2.87 [2.18‐3.76]), anxiety (2.47 [1.76‐3.48]) or depression (2.86 [1.89‐4.34]) as predictors of headaches.

Conclusion

Children and adolescents with AD, particularly those with sleep disturbances, atopic and mental health comorbidities, had increased headaches. Persistent childhood AD was associated with headaches in adolescence.
Use of a home‐visit nursing service to manage severe atopic dermatitis in a child with difficult family environment
Authors: Horino Satoshi , Uneoka Kei , Ozaki Ayafumi , Aki Haruka , Miura Katsushi
Published: May 2021

Maintenance therapy of atopic dermatitis (AD) with frequent exacerbations needs proactive use of topical corticosteroids or topical calcineurin inhibitors. However, it can be difficult for children in an unfavorable family environment. Home‐visit nursing service (HVNS) plays an important role in delivering care to people who need medical help at home. We report a boy in a difficult family situation who received HVNS to successfully manage AD.
Flexural comedones and scar formation caused by inflammatory Tinea corporis
Authors: Llamas Carmona José Antonio , Vera Casaño Ángel , Martin González María Trinidad , Martinez Pilar Leandro , Gómez Moyano Elisabeth
Published: May 2021

Childhood flexural comedones are a recently described entity defined as comedones characterized by double orifices connected by a thin layer of epidermis showing the contents beneath. We present a case of flexural comedones and scar formation caused by inflammatory tinea corporis.
Expression of Concern: Humanitarian reversing higher education in the Russian Federation in light of the transhumanist challenges
Authors: Kochetkov Maksim V. , Avdeeva Elena A.
Published: May 2021

The aim of this paper is to study the methodological foundations of the humanities education for international students as an alternative to transhumanist ideology. The paradigmatic approach is used as a factor analysis of students' educational processes. Particular attention is paid to the substantiation of the methodological foundations of the education humanisation on the basis of modern ontologically anthropological and religious‐anthropological achievements of the philosophical field of knowledge. The novelty of the study is due to a discussion of the contradictions caused by all‐round technocratisation and informatisation, the fall of moral standards and the degradation of human behaviour. The practical significance of the study is determined by the need to develop a different pedagogy and model of education for modern students. It was concluded that the value‐oriented pedagogical cocreation is able to direct the learner's self‐development and strengthen it with effective means of self‐change.
“Revolution” tendencies in higher education system through actor–network theory
Authors: Danielyan Naira , Romanenko Yulia
Published: May 2021

The article considers modern tendencies prevailing in the higher education system while training technical specialists nowadays. According to the authors, excluding the humanitarian courses from curriculum results in the complete dissolution of subjectivity in the impersonal world, which is deprived of “living” knowledge, that is, definite knowledge of a definite person. The application of such an approach is illustrated by the actor–network theory (ANT). While studying several works by ANT founders, it turned out to be clear that such an approach eliminates any differences between natural and humanitarian, engineering, and philosophical knowledge. As a result, the net emerges consisting of numerous actants and which requires from every participant his “building‐in” a model with the functions being delegated to him in advance. The article concludes that an “alive” component is disappearing from the higher education nowadays when the main stress is being made on the knowledge acquired a priori, not a posteriori.
Effect of copper on the photosynthesis and growth of Eichhornia crassipes
Authors: Jin M.‐F. , You M.‐X. , Lan Q.‐Q. , Cai L.‐Y. , Lin M.‐Z.
Published: May 2021

Although copper is essential for plant growth and development and plays an important role in many physiological processes, excess copper, resulting from industrial development and population expansion in the recent decades, leads to environmental pollution and has been a cause of wide concern for the adverse effects on photosynthesis, metabolism and growth of plants.

The growth properties (e.g. fresh weight, root length, height), photosynthetic properties (e.g. gas exchange, chlorophyll a fluorescence, chlorophyll content) and the physiological index (e.g. activity of antioxidant enzymes and osmotic regulators) of Eichhornia crassipes were assessed under various Cu2+ concentrations in hydroponic experiments.

The growth of E. crassipes was negatively affected by Cu2+ treatments, especially at higher Cu2+ concentrations; the Cu2+ treatments resulted in decreased photosynthesis because of a decrease in leaf chlorophyll content and damage to PSII functions, except the oxygen‐evolving complex. The physiological tolerance of E. crassipes to Cu2+ relies on osmotic regulation, anti‐lipid peroxidation and improved antioxidant properties.

The results indicate that E. crassipes could be considered as a phytoremediation agent for Cu2+ pollution in aquatic environments. However, the benefit of E. crassipes for Cu2+ removal in a highly polluted aquatic environment will be limited, but it will be effective in remediating sites with low pollution (≤5 mg·l−1). The present results could provide not only a basis for understanding the effects of pollutants on photosynthesis in plants under heavy metal stress but also provide a basis for choosing plants for phytoremediation.
Misinterpreting the adaptive value of phenotypic plasticity in studies on plant adaptation to new and variable environments
Authors: Bonser S. P.
Published: May 2021

Phenotypic plasticity is an important mechanism for plant adaptation to variable environments, and plant responses to changing climates. However, plasticity in fitness or performance traits (i.e. fecundity, biomass, growth rate) is generally not adaptive since plasticity in these traits would require low fitness or poor performance in some environments. I assessed the use of plasticity in fitness and performance traits in recent plasticity studies, and in studies where I have recently acted as a reviewer or editor. I found that approximately one third of studies include plasticity in fitness and/or performance traits in their assessment of potentially adaptive responses to environmental variability. Misinterpreting plasticity may be due the simplicity and power of plasticity to investigate adaptation to heterogeneous environments, but no guidelines of how to interpret plasticity in fitness and performance traits. This review highlights the extent of the problem of misinterpreting plasticity, and as a guide to interpreting adaptive and maladaptive plastic responses in plants.
Gender‐Related Operational Issues Arising from On‐Demand Ride‐Hailing Platforms: Safety Concerns and System Configuration
Authors: Tang Yanli , Guo Pengfei , Tang Christopher S. , Wang Yulan
Published: May 2021

Female user (driver and rider) safety is a serious concern for ride‐hailing platforms. One way to address this concern is to migrate from the traditional “pooling” system that matches riders with drivers without considering gender to a “hybrid” system with a “female‐only” option. Will such a hybrid system result in a win‐win‐win outcome for all involved parties (riders, drivers, and the platform)? To answer this question, we investigate the performance of the two operational systems: a pooling system and a hybrid system. For each system, we analyze a two‐stage queueing game to determine the equilibrium “joining” and “participating” behavior of riders and drivers, and then derive the platform's optimal pricing and wage decisions. We posit a mismatch cost incurred by a safety‐concerned female user when she is matched with a male counterpart in a ride. By comparing the equilibrium outcomes associated with the pooling and the hybrid systems, we draw the following conclusions: when safety‐concerned female users’ mismatch cost is above a certain level, switching from a pooling system to a hybrid system can result in a win‐win outcome for safety‐concerned female users and the platform. However, male and safety‐unconcerned female users might be worse off due to this change in the system configuration. Our results also help us to rectify some of our intuitions about these two systems. One, in the pooling system, reducing the mismatch cost associated with safety‐concerned female drivers may not lead to more female riders joining the pooling system, even though it boosts the platform's profit in general. Two, in the hybrid system, it is not necessary for female riders to pay a higher price when they opt for female drivers instead of male drivers. We also relate our results to certain system configurations adopted by various ride‐hailing platforms to address female safety concerns in different countries.
Testicular shape, scrotal skin thickness and testicular artery blood flow changes in bulls of different ages
Authors: Claus Luís Afonso Marques , Barca Junior Flávio Antônio , Junior Celso Koetz , Pereira Gabriel Ribas , Fávaro Patrícia da Cruz , Ferreira Fabio Procópio , Galdioli Victor Hugo Gonçalves , Seneda Marcelo Marcondes , Ribeiro Edson Luís de Azambuja
Published: May 2021

The aim of this study was to compare the biometric testicular characteristics, skin thickness and haemodynamics of the testicular artery of 12‐ and 24‐month‐old bulls using Doppler ultrasonography, the study was conducted using 48indicus‐taurusanimals. The scrotal circumference (SC) and biometry characteristics of the bulls were measured to calculate the testicular volume. Doppler ultrasonography was used to obtain the haemodynamic values of the testicular artery. The skin thickness and volume were lower (p<.01) in the younger bulls (12 months:4.68 ± 0.68 mm; 168.76 ± 47.96 cm3) versus 24 months (5.05 ± 0.89; 499.73 ± 129.24 cm3) animals (p<.01). During diastole, mean velocity was lower in the 12 months (7.98 ± 3.83) than in the 24 months (11.37 ± 4.15) animals (p<.05). The 12‐month‐old animals had higher pulsatility and resistivity indices (0.49 ± 0.02; 0.51 ± 0.20) compared to the 24‐month‐old animals (0.32 ± 0.16; 0.40 ± 0.15) (p< .05). The final testicular end velocity was lower in animals with long/moderate‐shaped (L/M) (7.31 ± 2.91) than in those moderate/oval‐shaped (M/O) (11.48 ± 3.88) testicles (p< .05). Animals with L/M testes presented higher pulsatility values and resistivity indices (0.51 ± 0.05; 0.55 ± 0.04) compared to animals with M/O shape (0.29 ± 0.20; 0.36 ± 0.15). We showed that the blood flow of the supra testicular artery between the two evaluated ages differed, and that 24‐month‐old bulls presented better thermoregulation capacity. Animals with a long/moderate testicular format presented a greater vascular resistance, which was imposed on the blood flow due to the anatomical differences in the testicular artery, resulting in lower velocity, and indicating better heat dissipation in this format.
Bilateral responsive regulation and international tax competition: Anagent‐basedsimulation
Authors: Gerbrands Peter , Unger Brigitte , Ferwerda Joras
Published: May 2021

Country‐by‐Country Reporting and Automatic Exchange of Information have recently been implemented in European Union (EU) countries. These international tax reforms increase tax compliance in the short term. In the long run, however, taxpayers will continue looking abroad to avoid taxation and, countries, looking for additional revenues, will provide opportunities. As a result, tax competition intensifies and the initial increase in compliance could reverse. To avoid international tax reforms being counteracted by tax competition, this paper suggests bilateral responsive regulation to maximize compliance. This implies that countries would use different tax policy instruments toward other countries, including tax and secrecy havens. Our agent‐based simulation finds that a differentiated policy response could increase tax compliance by 6.54 percent, which translates into an annual increase of €105 billion in EU tax revenues on income, profits, and capital gains. Corporate income tax revenues in France, Spain, and the UK alone would already account for €35 billion.
The interrelation between formal and informal institutions through international trade
Authors: Park Se Mi
Published: May 2021

This paper theoretically examines how country‐specific formal and informal institutions are interrelated through international trade within a two‐country general‐equilibrium framework. When formal and informal institutions collectively generate institutional quality, formal institutions endogenously arise based on exogenously given informal institutions. Institutional quality governs the productivity of an institutionally intensive sector that features increasing returns. I find that in open economies, formal institutions tend to improve with the quality of informal institutions. In contrast, under autarky, formal institutions deteriorate with informal institutional quality. These results reveal that trade opens up the opportunity for enhancing formal institutions of countries with rich informal institutions.
Relating seafloor geomorphology to subsurface architecture: How mass‐transport deposits and knickpoint‐zones build the stratigraphy of the deep‐water Hikurangi Channel
Authors: Tek Daniel E. , McArthur Adam D. , Poyatos‐Moré Miquel , Colombera Luca , Patacci Marco , Craven Benjamin , McCaffrey William D.
Published: May 2021

Monitoring of modern deep‐water channels has revealed how migrating channel‐floor features generate and remove stratigraphy, improving understanding of how channel morphologies relate to their deposits. Here, seafloor and subsurface data are reconciled through an integrated study of high‐resolution bathymetry and three‐dimensional seismic data imaging aca150 km stretch of the trench‐axial Hikurangi Channel, offshore New Zealand. On the seafloor, terraced channel‐walls bound a flat, wide, channel‐floor, ornamented with three scales of features that increase then decrease in longitudinal gradient downstream, and widen downstream: cyclic‐steps, knickpoints and knickpoint‐zones (in increasing size). Mass‐transport deposits derived from channel‐wall collapse, are bordered by wide and flat reaches of channel‐floor upstream and by knickpoint‐zones (reaches containing multiple knickpoints) downstream. In the subsurface, recognition of ten seismofacies and five types of surface enables identification of four depositional elements: channel‐fill, sheet or terrace, levée, and mass‐transport deposits. Integration of subsurface and seafloor interpretations reveals that knickpoint‐zones initiate on the downstream margins of channel‐damming mass‐transport deposits; they migrate and incise through the mass‐transport deposits and weakly‐confined deposits formed upstream, as the channel tends towards equilibrium. Downstream of a knickpoint‐zone, a flat channel‐floor is bounded by newly‐formed terraces. Knickpoints migrate by eroding upstream and depositing downstream, generating filled concave‐up (cross‐sectional) surfaces in their wake. Within knickpoint‐zones, knickpoint‐generated surfaces are re‐incised by subsequently‐passing knickpoints to produce a composite bounding surface; this surface does not delineate the morphology of any palaeo‐conduit. The Hikurangi Channel’s subsurface architecture records the localized erosional response to mass‐transport deposit emplacement via knickpoint‐zone migration, showcasing how transient seafloor features can build channelized stratigraphy. This model provides an additional mechanism to conventional models of channel deposit formation through ‘cut‐and‐fill’ over long stretches of channel. These findings may aid subsurface interpretation in systems lacking a contemporary self‐analogue or with poor data coverage.
Revisiting Husserl’s Concept of Leib Using Merleau‐Ponty’s Ontology
Authors: Halák Jan
Published: May 2021

This article reconsiders Husserl’s concept of Leib in light of Merleau‐Ponty’s interpretation of the human body as an ontologically significant phenomenon. I first analyze Husserl’s account of the body as a “two‐fold unity” and demonstrate the problematic nature of its four implications, namely, the ambiguous ontological status of the body as subject‐object, the view of “my body” as “my object,” the preconstitutive character of the unity of the body, and the restriction of the constitution of the body to touch alone. Building on this analysis, I explain how Merleau‐Ponty resolves the difficulties raised by Husserl’s account by reversing it. According to Merleau‐Ponty, “flesh” is not a two‐fold reality comprising subjective and objective aspects, but an ontological dimension from which these aspects can be abstracted through specific cognitive operations. Consequently, all subjective and objective aspects, even beyond the boundaries of one’s body, must be understood as founded in the indivisible unity of flesh. I argue that a thorough phenomenological description of the human body requires abandoning Husserl’s concept of Leib because it contributes to perpetuating subject‐object dualism. In contrast, Merleau‐Ponty’s notion of flesh reveals the circularity between subject and object and its general ontological significance.
Dealing with the loss of the village supermarket: The perceived effects two years after closure
Authors: Haartsen Tialda , Gieling Joost
Published: May 2021

In 2015, the local supermarket of the depopulating village of Ulrum closed its doors. After a first survey around the closure, a second survey was conducted two years later, to investigate changes in the different meanings of the local supermarket and the perceived effects of its closure over time. The results show that respondents state that the liveability and status of the village have decreased because of the loss of the supermarket. This strongly relates to the symbolic and village level meanings of the supermarket: A village ‘needs’ a supermarket for the villages’ status and as a place to do groceries, and people feel that a village without a supermarket is a village without a heart. The article concludes by alleging that the symbolic meaning of facilities plays an important role in explaining the perceived effects of the loss of the local supermarket.
Ride to cell wall: Arabidopsis XTH11, XTH29 and XTH33 exhibit different secretion pathways and responses to heat and drought stress
Authors: De Caroli Monica , Manno Elisa , Piro Gabriella , Lenucci Marcello S.
Published: May 2021

The xyloglucan endotransglucosylase/hydrolases (XTHs) are enzymes involved in cell wall assembly and growth regulation, cleaving and re‐joining hemicellulose chains in the xyloglucan–cellulose network. Here, in a homologous system, we compare the secretion patterns of XTH11, XTH33 and XTH29, three members of the Arabidopsis thaliana XTH family, selected for the presence (XTH11 and XTH33) or absence (XTH29) of a signal peptide, and the presence of a transmembrane domain (XTH33). We show that XTH11 and XTH33 reached, respectively, the cell wall and plasma membrane through a conventional protein secretion (CPS) pathway, whereas XTH29 moves towards the apoplast following an unconventional protein secretion (UPS) mediated by exocyst‐positive organelles (EXPOs). All XTHs share a common C‐terminal functional domain (XET‐C) that, for XTH29 and a restricted number of other XTHs (27, 28 and 30), continues with an extraterminal region (ETR) of 45 amino acids. We suggest that this region is necessary for the correct cell wall targeting of XTH29, as the ETR‐truncated protein never reaches its final destination and is not recruited by EXPOs. Furthermore, quantitative real‐time polymerase chain reaction analyses performed on 4‐week‐old Arabidopsis seedlings exposed to drought and heat stress suggest a different involvement of the three XTHs in cell wall remodeling under abiotic stress, evidencing stress‐, organ‐ and time‐dependent variations in the expression levels. Significantly, XTH29, codifying the only XTH that follows a UPS pathway, is highly upregulated with respect to XTH11 and XTH33, which code for CPS‐secreted proteins.
Outcome of bilateral equid laparoscopic ovariectomies
Authors: Collar Elizabeth M. , Duesterdieck‐Zellmer Katja F. , Huber Michael J. , Semevolos Stacy A. , Parker Jill E. , Husby Kirsty A.
Published: May 2021

Objective

To assess outcomes and behavior changes associated with bilateral laparoscopic ovariectomies.

Study design

Retrospective study.

Sample population

Fifty‐one equids.

Methods

Medical records were evaluated from equid bilateral laparoscopic ovariectomies from January 2012 to October 2018 with a potential of 6 months follow‐up. Follow‐up information obtained by telephone interviews included behavior before and after surgery. Likelihood ratio chi‐square tests and odds ratios (OR) with 95% CI were calculated where applicable, with statistical significance atp < .05.

Results

Bilateral ovariectomy was performed in 51 cases, with elective (no pathologic ovaries) ovariectomies performed in 41/51 cases. Occasional estrus‐like behavior was observed postoperatively in 14/51 (27%) mares, but the behavior was mild and manageable in all cases. There was no age effect on outcome in all bilateral (p = .56) or elective only (p = .36) cases. In 37/41 (90%) elective cases, improvement was observed in the reason for presentation. Some response to altrenogest administration for behavior modification was observed preoperatively in 12/18 (67%) elective cases. Response to altrenogest was not associated with (p = .31) or able to predict a beneficial response to surgery (OR = 5.5; 95% CI = 0.38–78.57;p = .21).

Conclusion

Response to altrenogest in elective cases may not predict behavioral outcome with ovariectomy. Occasional estrus‐like behavior in mares postoperatively was not problematic for any owners. Bilateral ovariectomy is a viable treatment option for owners seeking to alleviate undesirable behavior in mares.

Clinical significance

This study should aid veterinarians and horse owners in case selection for bilateral ovariectomy.
Cerebral blood flow, cerebrovascular reactivity and their influence on ventilatory sensitivity
Authors: Carr Jay M. J. R. , Caldwell Hannah G. , Ainslie Philip N.
Published: May 2021

New Findings

What is the topic of this review?

Cerebrovascular reactivity to CO2, which is a principal factor in determining ventilatory responses to CO2 through the role reactivity plays in determining cerebral extra‐ and intracellular pH.

What advances does it highlight?

Recent animal evidence suggests central chemoreceptor vasculature may demonstrate regionally heterogeneous cerebrovascular reactivity to CO2, potentially as a protective mechanism against excessive CO2 washout from the central chemoreceptors, thereby allowing ventilation to reflect the systemic acid–base balance needs (respiratory changes in ) rather than solely the cerebral needs. Ventilation per se does not influence cerebrovascular reactivity independent of changes in .

Alveolar ventilation and cerebral blood flow are both predominantly regulated by arterial blood gases, especially arterial , and so are intricately entwined. In this review, the fundamental mechanisms underlying cerebrovascular reactivity and central chemoreceptor control of breathing are covered. We discuss the interaction of cerebral blood flow and its reactivity with the control of ventilation and ventilatory responsiveness to changes in , as well as the lack of influence of ventilation itself on cerebrovascular reactivity. We briefly summarize the effects of arterial hypoxaemia on the relationship between ventilatory and cerebrovascular response to both and . We then highlight key methodological considerations regarding the interaction of reactivity and ventilatory sensitivity, including the following: regional heterogeneity of cerebrovascular reactivity; a pharmacological approach for the reduction of cerebral blood flow; reactivity assessment techniques; the influence of mean arterial blood pressure; and sex‐related differences. Finally, we discuss ventilatory and cerebrovascular control in the context of high altitude and congestive heart failure. Future research directions and pertinent questions of interest are highlighted throughout.
The role of mitochondria in metabolic disease: a special emphasis on heart dysfunction
Authors: Federico Marilen , De la Fuente Sergio , Palomeque Julieta , Sheu Shey‐Shing
Published: May 2021

Metabolic diseases (MetDs) embrace a series of pathologies characterized by abnormal body glucose usage. The known diseases included in this group are metabolic syndrome, prediabetes and diabetes mellitus types 1 and 2. All of them are chronic pathologies that present metabolic disturbances and are classified as multi‐organ diseases. Cardiomyopathy has been extensively described in diabetic patients without overt macrovascular complications. The heart is severely damaged during the progression of the disease; in fact, diabetic cardiomyopathies are the main cause of death in MetDs. Insulin resistance, hyperglycaemia and increased free fatty acid metabolism promote cardiac damage through mitochondria. These organelles supply most of the energy that the heart needs to beat and to control essential cellular functions, including Ca2+ signalling modulation, reactive oxygen species production and apoptotic cell death regulation. Several aspects of common mitochondrial functions have been described as being altered in diabetic cardiomyopathies, including impaired energy metabolism, compromised mitochondrial dynamics, deficiencies in Ca2+ handling, increases in reactive oxygen species production, and a higher probability of mitochondrial permeability transition pore opening. Therefore, the mitochondrial role in MetD‐mediated heart dysfunction has been studied extensively to identify potential therapeutic targets for improving cardiac performance. Herein we review the cardiac pathology in metabolic syndrome, prediabetes and diabetes mellitus, focusing on the role of mitochondrial dysfunctions.

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NAD+ and NAFLD – caution, causality and careful optimism
Authors: Dall Morten , Hassing Anna S. , Treebak Jonas T.
Published: May 2021

The prevalence of non‐alcoholic fatty liver disease (NAFLD) is increasing worldwide, and new treatments are sorely needed. Nicotinamide adenine dinucleotide (NAD+) has been proposed as a potential target to prevent and reverse NAFLD. NAD+ is an important redox factor for energy metabolism and is used as a substrate by a range of enzymes, including sirtuins (SIRT), which regulates histone acetylation, transcription factor activity and mitochondrial function. NAD+ is also a precursor for reduced nicotinamide adenine dinucleotide phosphate (NADPH), which is an important component of the antioxidant defense system. NAD+ precursors such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are available as over‐the‐counter dietary supplements, and oral supplementation with these precursors increases hepatic NAD+ levels and prevents hepatic lipid accumulation in pre‐clinical models of NAFLD. NAD+ precursors have also been found to improve hepatic mitochondrial function and decrease oxidative stress in pre‐clinical NAFLD models. NAD+ repletion also prevents NAFLD progression to non‐alcoholic steatohepatitis (NASH), as NAD+ precursor supplementation is associated with decreased hepatic stellate cell activation, and decreased fibrosis. However, initial clinical trials have only shown modest effects when NAD+ precursors were administrated to people with obesity. We review the available pre‐clinical investigations of NAD+ supplementation for targeting NAFLD, and discuss how data from the first clinical trials can be reconciled with observations from preclinical research.

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Oxidant‐resistant LRRC8A/C anion channels support superoxide production by NADPH oxidase 1
Authors: Choi Hyehun , Rohrbough Jeffrey C. , Nguyen Hong N. , Dikalova Anna , Lamb Fred S.
Published: May 2021

Key points

LRRC8A‐containing anion channels associate with NADPH oxidase 1 (Nox1) and regulate superoxide production and tumour necrosis factor‐α (TNFα) signalling. Here we show that LRRC8C and 8D also co‐immunoprecipitate with Nox1 in vascular smooth muscle cells.

LRRC8C knockdown inhibited TNFα‐induced O2•− production, receptor endocytosis, nuclear factor‐κB (NF‐κB) activation and proliferation while LRRC8D knockdown enhanced NF‐κB activation. Significant changes in LRRC8 isoform expression in human atherosclerosis and psoriasis suggest compensation for increased inflammation.

The oxidant chloramine‐T (ChlorT, 1 mM) weakly (∼25%) inhibited LRRC8C currents but potently (∼80%) inhibited LRRC8D currents. Substitution of the extracellular loop (EL1, EL2) domains of 8D into 8C conferred significantly stronger (69%) ChlorT‐dependent inhibition.

ChlorT exposure impaired subsequent current block by DCPIB, which occurs through interaction with EL1, further implicating external oxidation sites.

LRRC8A/C channels most effectively sustain Nox1 activity at the plasma membrane. This may result from their ability to remain active in an oxidized microenvironment.

Tumour necrosis factor‐α (TNFα) activates NADPH oxidase 1 (Nox1) in vascular smooth muscle cells (VSMCs), producing superoxide (O2•–) required for subsequent signalling. LRRC8 family proteins A–E comprise volume‐regulated anion channels (VRACs). The required subunit LRRC8A physically associates with Nox1, and VRAC activity is required for Nox activity and the inflammatory response to TNFα. VRAC currents are modulated by oxidants, suggesting that channel oxidant sensitivity and proximity to Nox1 may play a physiologically relevant role. In VSMCs, LRRC8C knockdown (siRNA) recapitulated the effects of siLRRC8A, inhibiting TNFα‐induced extracellular and endosomal O2•− production, receptor endocytosis, nuclear factor‐κB (NF‐κB) activation and proliferation. In contrast, siLRRC8D potentiated NF‐κB activation. Nox1 co‐immunoprecipitated with 8C and 8D, and colocalized with 8D at the plasma membrane and in vesicles. We compared VRAC currents mediated by homomeric and heteromeric LRRC8C and LRRC8D channels expressed in HEK293 cells. The oxidant chloramine T (ChlorT, 1 mM) weakly inhibited 8C, but potently inhibited 8D currents. ChlorT exposure also impaired subsequent current block by the VRAC blocker DCPIB, implicating external sites of oxidation. Substitution of the 8D extracellular loop domains (EL1, EL2) into 8C conferred significantly stronger ChlorT‐mediated inhibition of 8C currents. Our results suggest that LRRC8A/C channel activity can be effectively maintained in the oxidized microenvironment expected to result from Nox1 activation at the plasma membrane. Increased ratios of 8D:8C expression may potentially depress inflammatory responses to TNFα. LRRC8A/C channel downregulation represents a novel strategy to reduce TNFα‐induced inflammation.
Inhomogeneous distribution of lithic clasts within the Daskop granophyre dike, Vredefort impact structure: Implications for emplacement of impact melt in large impact structures
Authors: Huber Matthew S. , Kovaleva Elizaveta , Clark Martin D. , Prevec Stephen A.
Published: May 2021

The Vredefort granophyre dikes have long been recognized as being derived from the now-eroded Vredefort melt sheet. One dike, in particular, the Daskop granophyre dike, is notable for a high abundance of lithic clasts derived from various stratigraphic levels. In this study, we mapped the distribution of the clasts throughout the continuously exposed section of the dike using field mapping and aerial drone photography and attempted to constrain the emplacement mechanisms of the dike. We found that the clasts are not homogeneously spread but instead are distributed between clast-rich zones, which have up to 50% by area clasts, and clast-poor zones, which have 0–10% by area clasts. We examined three models to explain this distribution: gravitational settling of clasts, thermally driven local assimilation of clasts, and mechanical sorting of clasts due to turbulent flow. Of the three models, the gravitational settling cannot be supported based on our field and geophysical data. The assimilation of clasts and turbulent flow of clasts, however, can both potentially result in inhomogeneous clast distribution. Zones of fully assimilated clasts and nonassimilated clasts can occur from spatial temperature differences of 100 °C. Mechanical sorting driven by a turbulent flow can also generate zones of inhomogeneous clast distribution. Both local assimilation and mechanical sorting due to turbulent flow likely contributed to the observed distribution of clasts.
Effect of initial water composition on thermodynamic modeling of hydrothermal alteration in basalt—A case study of the Vargeão Dome impact structure
Authors: Alsemgeest*† Jitse , Auqué* Luis F.
Published: May 2021

The impact-generated hydrothermal system at Vargeão Dome, Brazil, is a unique potential analogue for impact-generated hydrothermal systems on Mars. Its evolution can be understood through thermodynamic modeling, for which one of the necessary parameters is the composition of the involved water. The exact water composition for Vargeão at the time of the impact is unknown, and, moreover, the effect of this uncertainty is often underestimated in thermodynamic modeling. Here, the effect of initial water composition was tested by using a randomized set of initial solutions for thermodynamic modeling of the evolution of the Vargeão Dome impact-generated hydrothermal system. It was found that even small changes in composition could affect the precipitation of common minerals like calcite and quartz. Therefore, it is necessary to perform a sensitivity analysis for any thermodynamic model in which the initial solution is poorly constrained. Subsequently, the found effects were used to constrain water compositions for the Vargeão Dome system at the time of the impact, by eliminating randomized solutions of models precipitating different minerals from those observed in reality. Using a simple set of rules, it was possible to constrain the total amount of dissolved solids between 6 and 2000 mg/L, as well as provide approximate boundaries for all individual elements present in the solution.