bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of shear on local boundary layers in turbulent convection
Authors: Shevkar Prafulla P. , Mohanan Sanal K. , Puthenveettil Baburaj A.
Published: May 2023

In Rayleigh Bénard convection, for a range of Prandtl numbers

$4.69 \leqslant Pr \leqslant 5.88$

and Rayleigh numbers

$5.52\times 10^5 \leqslant Ra \leqslant 1.21\times 10^9$

, we study the effect of shear by the inherent large-scale flow (LSF) on the local boundary layers on the hot plate. The velocity distribution in a horizontal plane within the boundary layers at each

$Ra$

, at any instant, is (A) unimodal with a peak at approximately the natural convection boundary layer velocities

$V_{bl}$

; (B) bimodal with the first peak between

$V_{bl}$

and

$V_{L}$

, the shear velocities created by the LSF close to the plate; or (C) unimodal with the peak at approximately

$V_{L}$

. Type A distributions occur more at lower

$Ra$

, while type C occur more at higher

$Ra$

, with type B occurring more at intermediate

$Ra$

. We show that the second peak of the bimodal type B distributions, and the peak of the unimodal type C distributions, scale as

$V_{L}$

scales with

$Ra$

. We then show that the areas of such regions that have velocities of the order of

$V_{L}$

increase exponentially with increase in

$Ra$

and then saturate. The velocities in the remaining regions, which contribute to the first peak of the bimodal type B distributions and the single peak of type A distributions, are also affected by the shear. We show that the Reynolds number based on these velocities scale as

$Re_{bs}$

, the Reynolds number based on the boundary layer velocities forced externally by the shear due to the LSF, which we obtained as a perturbation solution of the scaling relations derived from integral boundary layer equations. For

$Pr=1$

and aspect ratio

$\varGamma =1$

,

$Re_{bs} \sim Ra^{0.375}$

for small shear, similar to the observed flux scaling in a possible ultimate regime. The velocity at the edge of the natural convection boundary layers was found to increase with

$Ra$

as

$Ra^{0.35}$

; since

$V_{bl}\sim Ra^{1/3}$

, this suggests a possible shear domination of the boundary layers at high

$Ra$

. The effect of shear, however, decreases with increase in

$Pr$

and with increase in

$\varGamma$

, and becomes negligible for

$Pr\geqslant 100$

at

$\varGamma =1$

or for

$\varGamma \geqslant 20$

at

$Pr=1$

, causing

$Re_{bs}\sim Ra_w^{1/3}$

.
Parasitic waves and micro-breaking on highly nonlinear gravity–capillary waves in a convergent channel
Authors: Xu Chang , Perlin Marc
Published: May 2023

Gravity–capillary waves are waves influenced by both the effects of surface tension and gravity; these waves are at small scales with wavelength range from approximately 10 cm to less than 1 cm. Gravity–capillary waves play a significant role in air–sea interactions, and they exhibit much different features compared with gravity waves. They can be observed widely on the sea surface. Parasitic waves (capillary waves generated by and that ride on gravity and/or gravity–capillary waves) and micro-breaking can be observed on the water surface with winds; however, the presence of wind makes it difficult to analyse the mechanisms of the wave itself. In this paper, parasitic waves and micro-breaking on gravity–capillary waves are examined experimentally, both in the absence of wind. Parasitic waves and axisymmetric micro-breaking waves are generated mechanically in a convergent channel, where energy density increases due to spatial convergence. Three experimental techniques are used to measure wave properties: planar laser-induced fluorescence, particle image velocimetry and shadowgraphs. The wave profile evolution and vortices beneath the parasitic waves are studied. The micro-breaking of gravity–capillary waves is observed on a surface with added surfactant. The surfactant increases the Bond number, and makes breaking possible in these small-scale waves. Energy dissipation of parasitic waves and micro-breaking is quantified, and the enhanced dissipation caused by parasitic waves is identified through the experiments. In this study, mechanically generated breaking waves with wavelengths less than 10 cm are studied for the first time, without the effect of wind. The results yield insight into wave characteristics and energy dissipation on the air–sea interface at small scales.
Repression and Dissent in Moments of Uncertainty: Panel Data Evidence from Zimbabwe
Authors: LEBAS ADRIENNE , YOUNG LAUREN E.
Published: May 2023

State repression and protest are common in modern authoritarian and hybrid regimes, yet individual responses to these events are not well understood. This article draws on unique panel data from the months spanning Zimbabwe’s 2018 election, which we view as a moment of uncertainty for most Zimbabwean citizens. Using a difference-in-difference estimator, we estimate change in individual protest intentions following exposure to repression and dissent and we assess three individual-level mechanisms hypothesized to drive responses. We find evidence that exposure to local repression and dissent are mobilizing among opposition supporters and nonpartisans. Analysis of potential mechanisms suggests that the effects of exposure to dissent may be driven by information updating, whereas relational and emotional mechanisms seem to drive backlash against repression, despite increased perceptions of risk. We find no evidence of counter-mobilization by ruling party supporters, and little effect of exposure to contentious events over social media.
Effect of postruminal supply of linseed oil in dairy cows: 2. Milk fatty acid profile and oxidative stability
Authors: Rico Daniel E. , Gervais Rachel , Peňa-Cotrino Sara M. , Lebeuf Yolaine , Chouinard P. Yvan
Published: May 2023

Our objective was to study the effect of increasing postruminal supply of linseed oil (L-oil), as a source of cis-9, cis-12, cis-15 18:3, on milk fatty acid profile and to assess the resulting impact on the development of volatile degradation products during the storage of homogenized milk. Five Holstein dairy cows fitted with a rumen cannula were randomly distributed in a 5 × 5 Latin square design. Abomasal infusion of L-oil was performed at the rate of 0, 75, 150, 300, and 600 ml/d during periods of 14 d. The concentration of cis-9, cis-12, cis-15 18:3 in milk fat increased linearly with L-oil dose. Concentrations of primary (conjugated diene and triene hydroperoxides) and secondary oxidation products (1-octen-3-one, propanal, hexanal, trans-2 + cis-3-hexenals, cis-4-heptenal, trans-2, cis-6-nonadienal trans-2, trans-4-nonadienal) increased during 11 d of storage at 4°C of homogenized milk under fluorescent light. The magnitude of the increase (difference between final and initial measurements) was linearly greater for all nine lipid oxidation products evaluated in response to increasing level of infusion. Results of the current experiment have shown that milk enriched in cis-9, cis-12, cis-15 18:3 via postruminal supply of L-oil is highly prone to oxidative degradation. This low oxidative stability, exposed under controlled experimental conditions, would represent a major obstacle to those who aim to market milk enriched in polyunsaturated fatty acids.
Government Stock Purchase Undermines Price Informativeness: Evidence from China’s “National Team”
Authors: Dang Tri Vi , Li Wei , Wang Yongqin
Published: May 2023

We use the 2015 Chinese stock market crash to study the effects of government stock purchases. The Chinese government purchased stocks to stabilize the markets through state-owned financial institutions known as the “National Team.” We find that the intervention led to reduced volatility and price informativeness. These impacts are driven by the disclosure of government portfolios. Consistent with investors having a stronger incentive to acquire government intervention information instead of fundamental news, we find reduced information production and information asymmetry following intervention disclosure. The article suggests that government stock purchases involve a trade-off between stability and informational efficiency.
Fear signals vulnerability and appeasement, not threat
Authors: Marsh Abigail A.
Published: May 2023

Humans are not only fearful apes, but we also communicate our fear using social cues. Social fear displays typically elicit care and assistance in the real world and the lab. But in the psychology and neuroscience literature fearful expressions are commonly interpreted as “threat cues.” The fearful ape hypothesis suggests that fearful expressions should be instead considered appeasement and vulnerability cues.
The predictive processing of number information in subregular verb morphology in a first and second language
Authors: Koch Eva Marie , Bulté Bram , Housen Alex , Godfroid Aline
Published: May 2023

We investigated the predictive processing of grammatical number information through stem-vowel alternations in German strong verbs by adult first language (L1) speakers and Dutch-speaking advanced second language (L2) learners of German, and the influence of working memory and awareness (i.e., whether participants consciously registered the predictive cue) thereon. While changed stem vowels indicate a singular referent (e.g., /ε/ infällt3SG, “falls”), unchanged vowels indicate plural (e.g., /a/ infallt2PL, “fall”). This target structure presents a challenge for L2 learners of German due to its subregularity and low salience. With their eye movements being tracked, participants matched German auditory sentences (VSO order) with one of two pictures, displaying identical action scenes but varying in agent number. The number cue provided by the strong verbs allowed participants to predict whether the upcoming subject would be singular or plural. The analyses revealed significant prediction, measured as predictive eye movements toward the target picture and faster button-press responses. Prediction in the L2 group was weaker than in the L1 group and present in the eye movement data only. Higher working memory scores were linked to faster predictive presses. Approximately half of the participants had become aware of the predictive cue, and being aware facilitated prediction to a limited extent.
Coniveau filtrations and Milnor operation
Authors: YAGITA NOBUAKI
Published: May 2023

Let BG be the classifying space of an algebraic group G over the field
${\mathbb C}$
of complex numbers. There are smooth projective approximations X of
$BG\times {\mathbb P}^{\infty}$
, by Ekedahl. We compute a new stable birational invariant of X defined by the difference of two coniveau filtrations of X, by Benoist and Ottem. Hence we give many examples such that two coniveau filtrations are different.
Genuine Concern for Animals in England's Nineteenth-Century Animal Protection Movement: The Case Against Reductionist Interpretations
Authors: Fernandez Angela
Published: May 2023

Animal–human history is an increasingly popular area of historical research.1 Diana Donald's 2020 book, Women Against Cruelty: Protection of Animals in Nineteenth-Century Britain is a must-read for anyone interested in the history of animal protection and the role women have played in moral reform movements. Starting from the premise that the prevention of cruelty to animals is “a pure product of the nineteenth century” (p. 7), this dazzling book takes its reader through a wide range of important topics such as the early history of the Royal Society for the Prevention of Cruelty to Animals (RSPCA), differences between men and women's attitudes toward animals, and the role women played in humane education.2 This review will particularly highlight the way that Donald consistently attacks reductionist theses that discount the genuine concern women had for animals in the nineteenth-century British animal protection movement, and how her interpretations consistently refocus our attention on historical evidence of that genuine concern.
Horseradish (Armoracia rusticana G. Gaertn., B. Mey. & Scherb.) cultivated in Trentino-Alto Adige (northern Italy) characterized by biometric traits and glucosinolate content
Authors: Fusani Pietro , Aiello Nicola , Giannì Sergio , Camin Federica , Pagnotta Eleonora , Bagatta Manuela
Published: May 2023

Horseradish is a crop grown for its edible underground parts. The development of new cultivars is hindered by the species' predominant vegetative reproduction, making it essential to evaluate locally cultivated accessions to identify new types suitable for cultivation. To this end, 11 horseradish accessions from family vegetable gardens in Trentino-Alto Adige, Italy were examined using 26 qualitative and six quantitative morphological descriptors and characterized by the five major glucosinolates (GSLs) present in the rhizome compared to a reference cultivar. A wide range of variability was observed for the considered qualitative morphological traits. The rhizome's top and basal diameters were 9.9 and 6.2 cm, respectively, with an average fresh weight of 521 g. Total GSL content ranged between 79.5 and 133.5 μmol/g dry weight (DW), with sinigrin (SIN) being the primary component at an average content of 110.0 μmol/g DW. Differences among the investigated accessions were noted for quantitative traits describing their productive features and for GSL content. A positive correlation was discovered between the biometric traits of the plant's underground parts and the SIN and total GSL content, suggesting a link between the quality and yield of the edible product. According to the multivariate analysis, accessions were grouped into three main clusters: the largest of the reference cultivar and the majority of accessions with similar productive and qualitative traits; another featuring two with good qualitative and productive characteristics. The investigated accessions proved to be a valuable germplasm source for cultivating the species.
Race, Property, and Erasure in the Rust Belt
Authors: Herbert Claire W. , Brown Michael
Published: May 2023

This article builds on settler and domestic colonial histories and theories to advance our understanding of urban changes in segregated, disinvested, U.S. Rust Belt cities. While many major cities have rebounded in population and experienced gentrification since the mid-twentieth century, many Rust Belt cities have continued to decline. The resulting conditions call for new theories to describe their changes, trajectories, and the impacts for majority poor Black populations. We construct a Binocular Colonial Lens: an analytic framework that superimposes shared conceptual descriptions and theoretical explanations of settler and domestic colonialisms. With this lens, we can elucidate the practices of erasure that are deployed throughout colonized communities and focus them on phenomena associated with urban decline and revitalization. While some urban scholarship has used metaphors and language of settler colonialism to describe gentrification, most of these works at best reflect the salience of settler ideology, and at worst reinforce Indigenous erasure. Foregrounding shared conditions of colonization and conquest in the United States, we train this Binocular Colonial Lens on Detroit, which reveals myriad urban processes like ghettoization, urban renewal, suburbanization, and gentrification as ongoing colonization, wherein domestically colonized populations are subject to numerous forms of erasure at the behest of the settler state and toward the advancement of settler society. This lens advances urban theory by expanding the depth of our analyses of urban changes, and scaffolds connections with other axes of racialized inequality by revealing shared tools of erasure operative in, for example, mass incarceration and environmental injustices.
Weed control and highbush blueberry tolerance with indaziflam on sandy soils
Authors: Besançon Thierry E. , Bouchelle Wesley
Published: May 2023

Northern highbush blueberry is an important fresh market product in New Jersey where the plant was first domesticated in the early 20th century. Because of the short period for safely and timely applying postemergence (POST) herbicides, reliance on residual herbicides that provide season-long control of weeds is essential for blueberry growers to minimize the detrimental effect of weed competition on berry yield and quality and bush growth. Field studies were conducted from 2018 to 2020 in Chatsworth, New Jersey, on ‘Bluecrop’, ‘Duke’, and ‘Elliott’ blueberry cultivars growing on sandy acidic soil to evaluate weed control and crop tolerance in response to repeated annual applications of indaziflam at 73 or 146 g ai ha−1 applied in fall or spring. The efficacy of indaziflam treatments were compared to those of fall-applied dichlobenil at 3,300 g ai ha−1 or a spring-applied mix of diuron at 1,800 g ai ha−1, oryzalin at 3,360 g ai ha−1, and mesotrione at 210 g ai ha−1. Indaziflam at the currently labeled rate of 73 g ai ha−1 provided ≥85% and season-long control of horseweed, Canadian toadflax, and large crabgrass with fall applications on dormant blueberry, whereas spring applications were less effective. Whereas minor (≤8%) and transient leaf crinkling was noted in response to spring-applied indaziflam at 146 g ai ha−1, a fall application never caused leaf crinkling greater than that observed in the nontreated weedy and weed-free controls, regardless of rate. No negative effects on plant growth or fruit production were observed from indaziflam applied at 73 or 146 g ai ha−1 in fall or spring. Findings of this study suggest that indaziflam applied at 73 (1× commercial use rate) and 146 g ai ha−1 is safe to use on blueberry grown on New Jersey sandy acidic soils despite restrictions for using this herbicide on such soils.
More Than Meets the ERN
Authors: Petzel Zachary W. , Casad Bettina J.
Published: May 2023

Abstract. Women may suppress behavior and emotions during sexism, impairing subsequent self-control. However, suppression likely depends on social reprisal versus benefit of confronting (i.e., social cost). Experiment 1 ( N = 56) found behavioral self-control (i.e., Stroop task performance) was unaffected by sexism. Yet, sexism led to exaggerated amplitudes of the error-related negativity (ERN). Experiment 2 ( N = 114) examined the role of confrontation in response to sexism, with women instructed to suppress confrontation during a sexist interaction exhibiting longer reaction times and lower ERN amplitudes. Conversely, women encouraged to confront sexism exhibited heightened ERN amplitudes, as found in Experiment 1, which were mediated by negative affect. The findings suggest sexism reduces women’s self-control, but only within environments that may suppress confrontation.
Lithospheric Structure of the Red Sea Based on 3D Density Modeling: A Contrasting Rift Architecture
Authors: Issachar Ran , Gómez‐García Ángela María , Ebbing Jörg
Published: May 2023

The Red Sea is an ideal location for studying rifting processes, offering a young and active intra‐continental rift at the final stages of breakup. We explore the 3D lithospheric structure of the Red Sea by analyzing the gravity response of four end‐member models of rift architecture, including two end‐member types margin architecture Type I—narrow margins and exhumed lithospheric mantle, and Type II—(ultra)wide margins and removal of lithospheric mantle. Additionally, we test two options for the distribution of the oceanic crust (a) limited, that is, confined only to regions of magnetic stripes, and (b) extended, that is, available in vast areas within the basin. South of latitude 23°N, our results suggest the presence of ultrawide margins and limited oceanic crust. North of this latitude, the model of exhumed mantle and limited oceanic crust has minimized residuals compared to the observed gravity field, and agrees with a previously published regional tomographic model. Additionally, we find evidence for the presence of a high‐density body along the southern Arabian coast, probably associated with magmatic underplating. We discuss the lithospheric structure of the Red Sea with respect to the nearby Afar plume, agreeing that the close proximity of the central‐southern regions to the plume promoted a reduction in the strength of the lithosphere, and led to the development of ultrawide margins in these areas.
Southern Ocean Acidification Revealed by Biogeochemical‐Argo Floats
Authors: Mazloff Matthew R. , Verdy Ariane , Gille Sarah T. , Johnson Kenneth S. , Cornuelle Bruce D. , Sarmiento Jorge
Published: May 2023

Ocean acidification has potentially large impacts on calcifying organisms and ecosystems. Argo floats equipped with biogeochemical (BGC) sensors have been continuously measuring Southern Ocean pH since 2014. These BGC‐Argo floats were deployed as part of the Southern Ocean Carbon and Climate Observations and Modeling project. Here we present a SOCCOM‐era Objectively Mapped pH (SOM‐pH) 2014–2019 climatology and explain the method for constructing this product. We show example SOM‐pH fields demonstrating the spatial and temporal structure of Southern Ocean pH. Comparison with previous ship‐based measurements reveals decreases in pH of up to 0.02 per decade, with a structure decaying with depth. An assessment of the trend structure reveals a pattern indicative of the meridional overturning circulation. Upwelling waters that have not been in recent contact with the atmosphere show negligible or small trends, while surface and downwelling waters that have had more exposure to the atmosphere show the strongest trends. Thus comparison of this new BGC‐Argo mapped pH estimate to historic observations allows quantifying the structure of Southern Ocean acidification.
Evaporation From Six Water Bodies of Various Sizes in East Asia: An Analysis on Size Dependency
Authors: Han Songjun , Guo Fangju
Published: May 2023

One pond and five lakes in East Asia with area from 0.05 to 3,000 km2 were comparatively investigated to reveal the size‐dependency of the evaporation and its radiation and aerodynamic contributions. The available energy controls on the annual evaporation are independent on the sizes of the six water bodies, but the ratio of evaporation to Penman's open water evaporation decreases with areas from almost unity at the small pond to around 0.8 at the two large lakes. The aerodynamic related parameters of three combination equations can be well represented by the water body areas with a power law, which is attributed to the decreasing mass transfer coefficient with the fetch of the water body. The increasing size‐dependent wind speed offsets the effect of mass transfer coefficient, making the energy partitioning and evaporation rate size independent. Results imply that the energy‐based equations can be used for evaporation without considering the water body size in the study area. The size‐dependent parameters of the combination equations are required to be further investigated with more lakes.
National‐Scale Detection of Reservoir Impacts Through Hydrological Signatures
Authors: Salwey S. , Coxon G. , Pianosi F. , Singer M. B. , Hutton C.
Published: May 2023

Reservoirs play a vital role in the supply and management of water resources and their operation can significantly alter downstream flow. Despite this, reservoirs are frequently excluded or poorly represented in large‐scale hydrological models, which can be partly attributed to a lack of open‐access data describing reservoir operations, inflow and storage. To help inform the development of reservoir operation schemes, we collate a suite of hydrological signatures designed to detect the impacts of reservoirs on the flow regime at large‐scales from downstream flow records only. By removing the need for pre‐and‐post‐reservoir flow timeseries (a requirement of many pre‐existing techniques), these signatures facilitate the assessment of flow alteration across a much wider range of catchments. To demonstrate their application, we calculate the signatures across Great Britain in 111 benchmark (i.e., near‐natural) catchments and 186 reservoir catchments (where at least one upstream reservoir is present). We find that abstractions from water resource reservoirs induce deficits in the water balance, and that pre‐defined flow releases (e.g., the compensation flow) reduce variability in the downstream flow duration curve and in intra‐annual low flows. By comparing signatures in benchmark and reservoir catchments, we define thresholds above which the influence of reservoirs can be distinguished from natural variability and identify 40 catchments significantly impacted by the presence of reservoirs. The signatures also provide insights into local reservoir operations, which can inform the development of tailored reservoir operation schemes, and identify locations where current modeling practices (which lack reservoir representation) will be insufficient.
Trade‐Offs Between Spatial and Temporal Accuracy of Complementary Relationship Models for Evaporation in an Ungauged Basin
Authors: Zhang Xiaolong , Han Songjun , Wang Yan , Kong Xiaole , Guo Ying , Shen Yanjun , Zhang Yinsheng , Shen Yan‐Jun
Published: May 2023

The complementary relationship (CR) between actual and potential evaporation has undergone rapid development over the past decades. Commonly, the evaluation of CR models does not comprehensively cover spatial and temporal aspects of model performance; thus, the spatial and temporal accuracy and parameter sensitivity of different CR models remain relatively unknown, especially in ungauged basins. We examine the spatial and temporal performance and parameter sensitivity of four CR models with fixed parameters at the monthly scale over the source region of the Yellow River in China. Additionally, two CR models with distributed parameters were selected as comparisons. Because of the lack of evaporation spatiotemporal “true” values, the corrected water‐balance‐derived evaporation was used as the temporal reference, and the ensemble mean of multiple evaporation products was used as the spatial reference. We find that trade‐offs between the spatial and temporal accuracy of CR models with fixed parameters for basin evaporation should be considered in the application. Although four CR models with fixed parameters exhibited different spatial and temporal performances, their overall performance was generally similar. The parameters of CR models had consistent spatial and temporal sensitivities, and the sensitivity of parameter αe was stronger than that of other parameters. This study demonstrates that CR models with distributed parameters have a promising future in estimating basin or regional evaporation. An integrated spatial and temporal evaluation framework can better distinguish the performance of CR models. The methodologies can be used as a guideline for evaluating and calibrating CR models that match an application's needs.
Modeling the Day‐To‐Day Variability of Midnight Equatorial Plasma Bubbles With SAMI3/SD‐WACCM‐X
Authors: Chou Min‐Yang , Yue Jia , Sassi Fabrizio , McDonald Sarah , Tate Jennifer , Pedatella Nicholas , Randall Cora E. , Harvey V. Lynn
Published: May 2023

It is well‐known that equatorial plasma bubbles (EPBs) are highly correlated to the post‐sunset rise of the ionosphere on a climatological basis. However, when proceeding to the daily EPB development, what controls the day‐to‐day/longitudinal variability of EPBs remains a puzzle. In this study, we investigate the underlying physics responsible for the day‐to‐day/longitudinal variability of EPBs using the Sami3 is A Model of the Ionosphere (SAMI3) and the Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere‐ionosphere eXtension (SD‐WACCM‐X). Simulation results on October 20, 22, and 24, 2020 were presented. SAMI3/SD‐WACCM‐X self‐consistently generated midnight EPBs on October 20 and 24, displaying irregular and regular spatial distributions, respectively. However, EPBs are absent on October 22. We investigate the role of gravity waves on upwelling growth and EPB development and discuss how gravity waves contribute to the distributions of EPBs. We found the westward wind associated with solar terminator waves and gravity waves induces polarization electric fields that map to the equatorial ionosphere from higher latitudes, resulting in midnight vertical drift enhancement and retrograde plasma flow. The upward vertical drift and retrograde flow further lead to shear flow instability and midnight plasma vortex, creating background conditions identical to the post‐sunset ionosphere. This provides conditions favorable for the upwelling growth and EPB development. The converging and diverging winds associated with solar terminator waves and midnight temperature maximum also affect the longitudinal distribution of EPBs. The absence of EPBs on October 22 is related to the weak westward wind associated with solar terminator waves.
Efficient ultrafast laser writing with appropriate polarization
Authors: Li Xiujian , Xie Wenke
Published: May 2023

Appropriate polarization utilization makes the electric field vector direction and the statistically oriented localized states suitable for enhancing light-matter interactions so as to improve the efficiency of ultrafast laser writing, which will remarkably reduce the pulse energy and increase the processing speed for high density optical data storage, as well as manufacturing three-dimensional integrated optics and geometric phase optical elements.
Mania-related effects on structural brain changes in bipolar disorder – a narrative review of the evidence
Authors: Abé Christoph , Liberg Benny , Klahn Anna Luisa , Petrovic Predrag , Landén Mikael
Published: May 2023

Cross-sectional neuroimaging studies show that bipolar disorder is associated with structural brain abnormalities, predominantly observed in prefrontal and temporal cortex, cingulate gyrus, and subcortical regions. However, longitudinal studies are needed to elucidate whether these abnormalities presage disease onset or are consequences of disease processes, and to identify potential contributing factors. Here, we narratively review and summarize longitudinal structural magnetic resonance imaging studies that relate imaging outcomes to manic episodes. First, we conclude that longitudinal brain imaging studies suggest an association of bipolar disorder with aberrant brain changes, including both deviant decreases and increases in morphometric measures. Second, we conclude that manic episodes have been related to accelerated cortical volume and thickness decreases, with the most consistent findings occurring in prefrontal brain areas. Importantly, evidence also suggests that in contrast to healthy controls, who in general show age-related cortical decline, brain metrics remain stable or increase during euthymic periods in bipolar disorder patients, potentially reflecting structural recovering mechanisms. The findings stress the importance of preventing manic episodes. We further propose a model of prefrontal cortical trajectories in relation to the occurrence of manic episodes. Finally, we discuss potential mechanisms at play, remaining limitations, and future directions.
Glycosylation and behavioral symptoms in neurological disorders
Authors: Pradeep Prajitha , Kang Hyeyeon , Lee Boyoung
Published: May 2023

Glycosylation, the addition of glycans or carbohydrates to proteins, lipids, or other glycans, is a complex post-translational modification that plays a crucial role in cellular function. It is estimated that at least half of all mammalian proteins undergo glycosylation, underscoring its importance in the functioning of cells. This is reflected in the fact that a significant portion of the human genome, around 2%, is devoted to encoding enzymes involved in glycosylation. Changes in glycosylation have been linked to various neurological disorders, including Alzheimer’s disease, Parkinson’s disease, autism spectrum disorder, and schizophrenia. Despite its widespread occurrence, the role of glycosylation in the central nervous system remains largely unknown, particularly with regard to its impact on behavioral abnormalities in brain diseases. This review focuses on examining the role of three types of glycosylation: N-glycosylation, O-glycosylation, and O-GlcNAcylation, in the manifestation of behavioral and neurological symptoms in neurodevelopmental, neurodegenerative, and neuropsychiatric disorders.
The mitochondrial protein TIMM44 is required for angiogenesis in vitro and in vivo
Authors: Ma Zhou-rui , Li Hong-Peng , Cai Shi-zhong , Du Sheng-Yang , Chen Xia , Yao Jin , Cao Xu , Zhen Yun-Fang , Wang Qian
Published: May 2023

The mitochondrial integrity and function in endothelial cells are essential for angiogenesis. TIMM44 (translocase of inner mitochondrial membrane 44) is essential for integrity and function of mitochondria. Here we explored the potential function and the possible mechanisms of TIMM44 in angiogenesis. In HUVECs, human retinal microvascular endothelial cells and hCMEC/D3 brain endothelial cells, silence of TIMM44 by targeted shRNA largely inhibited cell proliferation, migration and in vitro capillary tube formation. TIMM44 silencing disrupted mitochondrial functions in endothelial cells, causing mitochondrial protein input arrest, ATP reduction, ROS production, and mitochondrial depolarization, and leading to apoptosis activation. TIMM44 knockout, by Cas9-sgRNA strategy, also disrupted mitochondrial functions and inhibited endothelial cell proliferation, migration and in vitro capillary tube formation. Moreover, treatment with MB-10 (“MitoBloCK-10”), a TIMM44 blocker, similarly induced mitochondrial dysfunction and suppressed angiogenic activity in endothelial cells. Contrarily, ectopic overexpression of TIMM44 increased ATP contents and augmented endothelial cell proliferation, migration and in vitro capillary tube formation. In adult mouse retinas, endothelial knockdown of TIMM44, by intravitreous injection of endothelial specific TIMM44 shRNA adenovirus, inhibited retinal angiogenesis, causing vascular leakage, acellular capillary growth, and retinal ganglion cells degeneration. Significant oxidative stress was detected in TIMM44-silenced retinal tissues. Moreover, intravitreous injection of MB-10 similarly induced oxidative injury and inhibited retinal angiogenesis in vivo. Together, the mitochondrial protein TIMM44 is important for angiogenesis in vitro and in vivo, representing as a novel and promising therapeutic target of diseases with abnormal angiogenesis.
Double DAP-seq uncovered synergistic DNA binding of interacting bZIP transcription factors
Authors: Li Miaomiao , Yao Tao , Lin Wanru , Hinckley Will E. , Galli Mary , Muchero Wellington , Gallavotti Andrea , Chen Jin-Gui , Huang Shao-shan Carol
Published: May 2023

Many eukaryotic transcription factors (TF) form homodimer or heterodimer complexes to regulate gene expression. Dimerization of BASIC LEUCINE ZIPPER (bZIP) TFs are critical for their functions, but the molecular mechanism underlying the DNA binding and functional specificity of homo- versus heterodimers remains elusive. To address this gap, we present the double DNA Affinity Purification-sequencing (dDAP-seq) technique that maps heterodimer binding sites on endogenous genomic DNA. Using dDAP-seq we profile twenty pairs of C/S1 bZIP heterodimers and S1 homodimers in Arabidopsis and show that heterodimerization significantly expands the DNA binding preferences of these TFs. Analysis of dDAP-seq binding sites reveals the function of bZIP9 in abscisic acid response and the role of bZIP53 heterodimer-specific binding in seed maturation. The C/S1 heterodimers show distinct preferences for the ACGT elements recognized by plant bZIPs and motifs resembling the yeast GCN4 cis-elements. This study demonstrates the potential of dDAP-seq in deciphering the DNA binding specificities of interacting TFs that are key for combinatorial gene regulation.
Molecular determinants of inhibition of UCP1-mediated respiratory uncoupling
Authors: Gagelin Antoine , Largeau Corentin , Masscheleyn Sandrine , Piel Mathilde S. , Calderón-Mora Daniel , Bouillaud Frédéric , Hénin Jérôme , Miroux Bruno
Published: May 2023

Brown adipose tissue expresses uncoupling protein 1 (UCP1), which dissipates energy as heat, making it a target for treating metabolic disorders. Here, we investigate how purine nucleotides inhibit respiration uncoupling by UCP1. Our molecular simulations predict that GDP and GTP bind UCP1 in the common substrate binding site in an upright orientation, where the base moiety interacts with conserved residues R92 and E191. We identify a triplet of uncharged residues, F88/I187/W281, forming hydrophobic contacts with nucleotides. In yeast spheroplast respiration assays, both I187A and W281A mutants increase the fatty acid-induced uncoupling activity of UCP1 and partially suppress the inhibition of UCP1 activity by nucleotides. The F88A/I187A/W281A triple mutant is overactivated by fatty acids even at high concentrations of purine nucleotides. In simulations, E191 and W281 interact with purine but not pyrimidine bases. These results provide a molecular understanding of the selective inhibition of UCP1 by purine nucleotides.
Catch bond models may explain how force amplifies TCR signaling and antigen discrimination
Authors: Choi Hyun-Kyu , Cong Peiwen , Ge Chenghao , Natarajan Aswin , Liu Baoyu , Zhang Yong , Li Kaitao , Rushdi Muaz Nik , Chen Wei , Lou Jizhong , Krogsgaard Michelle , Zhu Cheng
Published: May 2023

The TCR integrates forces in its triggering process upon interaction with pMHC. Force elicits TCR catch-slip bonds with strong pMHCs but slip-only bonds with weak pMHCs. We develop two models and apply them to analyze 55 datasets, demonstrating the models’ ability to quantitatively integrate and classify a broad range of bond behaviors and biological activities. Comparing to a generic two-state model, our models can distinguish class I from class II MHCs and correlate their structural parameters with the TCR/pMHC’s potency to trigger T cell activation. The models are tested by mutagenesis using an MHC and a TCR mutated to alter conformation changes. The extensive comparisons between theory and experiment provide model validation and testable hypothesis regarding specific conformational changes that control bond profiles, thereby suggesting structural mechanisms for the inner workings of the TCR mechanosensing machinery and plausible explanations of why and how force may amplify TCR signaling and antigen discrimination.
Methionine consumption by cancer cells drives a progressive upregulation of PD-1 expression in CD4 T cells
Authors: Pandit Mahesh , Kil Yun-Seo , Ahn Jae-Hee , Pokhrel Ram Hari , Gu Ye , Mishra Sunil , Han Youngjoo , Ouh Yung-Taek , Kang Ben , Jeong Myeong Seon , Kim Jong-Oh , Nam Joo-Won , Ko Hyun-Jeong , Chang Jae-Hoon
Published: May 2023

Programmed cell death protein 1 (PD-1), expressed on tumor-infiltrating T cells, is a T cell exhaustion marker. The mechanisms underlying PD-1 upregulation in CD4 T cells remain unknown. Here we develop nutrient-deprived media and a conditional knockout female mouse model to study the mechanism underlying PD-1 upregulation. Reduced methionine increases PD-1 expression on CD4 T cells. The genetic ablation of SLC43A2 in cancer cells restores methionine metabolism in CD4 T cells, increasing the intracellular levels of S-adenosylmethionine and yielding H3K79me2. Reduced H3K79me2 due to methionine deprivation downregulates AMPK, upregulates PD-1 expression and impairs antitumor immunity in CD4 T cells. Methionine supplementation restores H3K79 methylation and AMPK expression, lowering PD-1 levels. AMPK-deficient CD4 T cells exhibit increased endoplasmic reticulum stress and Xbp1s transcript levels. Our results demonstrate that AMPK is a methionine-dependent regulator of the epigenetic control of PD-1 expression in CD4 T cells, a metabolic checkpoint for CD4 T cell exhaustion.
Probing spin dynamics of ultra-thin van der Waals magnets via photon-magnon coupling
Authors: Zollitsch Christoph W. , Khan Safe , Nam Vu Thanh Trung , Verzhbitskiy Ivan A. , Sagkovits Dimitrios , O’Sullivan James , Kennedy Oscar W. , Strungaru Mara , Santos Elton J. G. , Morton John J. L. , Eda Goki , Kurebayashi Hidekazu
Published: May 2023

Layered van der Waals (vdW) magnets can maintain a magnetic order even down to the single-layer regime and hold promise for integrated spintronic devices. While the magnetic ground state of vdW magnets was extensively studied, key parameters of spin dynamics, like the Gilbert damping, crucial for designing ultra-fast spintronic devices, remains largely unexplored. Despite recent studies by optical excitation and detection, achieving spin wave control with microwaves is highly desirable, as modern integrated information technologies predominantly are operated with these. The intrinsically small numbers of spins, however, poses a major challenge to this. Here, we present a hybrid approach to detect spin dynamics mediated by photon-magnon coupling between high-Q superconducting resonators and ultra-thin flakes of Cr2Ge2Te6 (CGT) as thin as 11 nm. We test and benchmark our technique with 23 individual CGT flakes and extract an upper limit for the Gilbert damping parameter. These results are crucial in designing on-chip integrated circuits using vdW magnets and offer prospects for probing spin dynamics of monolayer vdW magnets.
Single-pulse terahertz spectroscopy monitoring sub-millisecond time dynamics at a rate of 50 kHz
Authors: Couture Nicolas , Cui Wei , Lippl Markus , Ostic Rachel , Fandio Défi Junior Jubgang , Yalavarthi Eeswar Kumar , Vishnuradhan Aswin , Gamouras Angela , Joly Nicolas Y. , Ménard Jean-Michel
Published: May 2023

Slow motion movies allow us to see intricate details of the mechanical dynamics of complex phenomena. If the images in each frame are replaced by terahertz (THz) waves, such movies can monitor low-energy resonances and reveal fast structural or chemical transitions. Here, we combine THz spectroscopy as a non-invasive optical probe with a real-time monitoring technique to demonstrate the ability to resolve non-reproducible phenomena at 50k frames per second, extracting each of the generated THz waveforms every 20 μs. The concept, based on a photonic time-stretch technique to achieve unprecedented data acquisition speeds, is demonstrated by monitoring sub-millisecond dynamics of hot carriers injected in silicon by successive resonant pulses as a saturation density is established. Our experimental configuration will play a crucial role in revealing fast irreversible physical and chemical processes at THz frequencies with microsecond resolution to enable new applications in fundamental research as well as in industry.
EmbryoNet: using deep learning to link embryonic phenotypes to signaling pathways
Authors: Čapek Daniel , Safroshkin Matvey , Morales-Navarrete Hernán , Toulany Nikan , Arutyunov Grigory , Kurzbach Anica , Bihler Johanna , Hagauer Julia , Kick Sebastian , Jones Felicity , Jordan Ben , Müller Patrick
Published: May 2023

Evolutionarily conserved signaling pathways are essential for early embryogenesis, and reducing or abolishing their activity leads to characteristic developmental defects. Classification of phenotypic defects can identify the underlying signaling mechanisms, but this requires expert knowledge and the classification schemes have not been standardized. Here we use a machine learning approach for automated phenotyping to train a deep convolutional neural network, EmbryoNet, to accurately identify zebrafish signaling mutants in an unbiased manner. Combined with a model of time-dependent developmental trajectories, this approach identifies and classifies with high precision phenotypic defects caused by loss of function of the seven major signaling pathways relevant for vertebrate development. Our classification algorithms have wide applications in developmental biology and robustly identify signaling defects in evolutionarily distant species. Furthermore, using automated phenotyping in high-throughput drug screens, we show that EmbryoNet can resolve the mechanism of action of pharmaceutical substances. As part of this work, we freely provide more than 2 million images that were used to train and test EmbryoNet.
Nd:YAG 1064-nm laser for residual infantile hemangioma after propranolol treatment
Authors: Khamaysi Z. , Pam N. , Zaaroura H. , Avitan-Hersh E.
Published: May 2023

Infantile hemangiomas (IH) are common benign tumors of infancy. Most IH involute, either spontaneously, or secondary to pharmacological treatment with systemic propranolol. Propranolol treatment mostly leads to regression of hemangiomas with satisfactory aesthetic results, but unfortunately not in all cases. To assess the safety and efficacy of long pulsed Nd:YAG 1064 nm laser in treating patients with residual infantile hemangioma after systemic propranolol treatment. This is an open-label prospective cohort study. 30 patients with focal residual IH that had sub-optimal responses to systemic propranolol treatment were enrolled in the study. The patients were treated with 1 to 3 sessions with long pulsed Nd:YAG 1064 nm laser. The maximal response of the IH was assessed using a 4-point scale evaluation scale system. Of the 30 patients enrolled, 18 patients exhibited a great response (> 76% improvement), 10 patients had a good response (> 51–75% improvement), while only 2 patients showed a moderate response (< 50% improvement) to the treatment. No patients had an unsatisfactory response. No serious side effects were observed, and only minor side effects were reported. The treatment with long pulsed Nd:YAG 1064 nm laser for residual IH, which were resistant to systemic propranolol treatment, is safe and effective. Thus, we suggest its use as a second-line treatment for patients with sub-optimal aesthetic results following systemic propranolol.
Experimental evaluation of cobalt adsorption capacity of walnut shell by organic acid activation
Authors: Irshad Adnan , Atif Muhammad , Ghani Ambreen , Ali Basharat , Ahmad Sheikh Asrar , Alex Musinguzi
Published: May 2023

Cobalt, from industrial waste and nuclear laundry, possess health risk to human beings, animals and plants. Number of methods, other than adsorption, have been reported in literature for Co removal from waste water. In this research walnut shell powder after modification has been utilized for Co adsorption. First step of modification involved chemical treatment by four different organic acids for 72 h. Samples were collected at 24, 48 and 72 h. Second step involved thermal treatment of 72 h samples. Unmodified and modified particles have been analyzed by chemical methods and instruments i.e. UV spectrometer, FTIR, cyclic voltammetry (CV) and microscopic imaging. Thermally treated samples have shown augmented Co adsorption. CV analysis showed thermally treated samples with better capacitance. Particles modified by oxalic acid presented better Co adsorption. Oxalic acid treated particles activated for 72 h with thermal treatment provided maximum adsorption capacity 1327 ± 20.6 mg/g against Co(II) at pH 7, stirring 200 rpm, initial concentration 20 ml, adsorbent dosage (5 mg) and contact time 240 min at room temperature.