bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct numerical simulation of the effects of Reynolds number in Mach 2.9 flows over an expansion–compression corner
Authors: Xie Zhuxuan , Xiao Zhixiang , Wang Gang , Yang Yanguang
Published: November 2022

In order to investigate the characteristics of shock wave/boundary layer interaction and its variation with Reynolds number in expansion–compression corner flows, direct numerical simulations of Mach 2.9 expansion–compression corner flows at Reδref=12 000,22 000, and 43 000 were carried out. The λ type shock wave structure appears near the compression corner. Compared with the flat-compression corner wave system, the separation shock wave is weaker, and the reattachment shock wave is stronger. With the increase in the Reynolds number, the separation angle of the separation bubble decreases, the separation pressure rise decreases, and the reattachment pressure rise increases. The separation flow has the unsteady characteristics of low frequency, and the main frequency after nondimensionalized with separation length is St = 0.032. The pressure gradient is the main factor affecting the turbulence change at the expansion corner. With the increase in the Reynolds number, the absolute peak value of pressure gradient at the expansion corner increases, but the spatial range of pressure variation decreases. These two trends together lead to the insignificant change of turbulent energy at the expansion corner. At the compression corner, the main reason for the change of turbulent energy is the strong shear above the separation bubble, which shows a monotone change with the Reynolds number. The results show that the Reynolds number obviously affects the near-wall pressure distribution in the shock disturbance region in the expansion–compression corner flow. The turbulent energy distribution at the expansion corner and compression corner is also affected, but the influence laws are different due to different influence mechanisms.
Distributed propulsion enables fast and efficient swimming modes in physonect siphonophores
Authors: Du Clos Kevin T. , Gemmell Brad J. , Colin Sean P. , Costello John H. , Dabiri John O. , Sutherland Kelly R.
Published: November 2022

Many fishes employ distinct swimming modes for routine swimming and predator escape. These steady and escape swimming modes are characterized by dramatically differing body kinematics that lead to context-adaptive differences in swimming performance. Physonect siphonophores, such as
Nanomia bijuga
, are colonial cnidarians that produce multiple jets for propulsion using swimming subunits called nectophores. Physonect siphonophores employ distinct routine and steady escape behaviors but–in contrast to fishes–do so using a decentralized propulsion system that allows them to alter the timing of thrust production, producing thrust either synchronously (simultaneously) for escape swimming or asynchronously (in sequence) for routine swimming. The swimming performance of these two swimming modes has not been investigated in siphonophores. In this study, we compare the performances of asynchronous and synchronous swimming in
N. bijuga
over a range of colony lengths (i.e., numbers of nectophores) by combining experimentally derived swimming parameters with a mechanistic swimming model. We show that synchronous swimming produces higher mean swimming speeds and greater accelerations at the expense of higher costs of transport. High speeds and accelerations during synchronous swimming aid in escaping predators, whereas low energy consumption during asynchronous swimming may benefit
N. bijuga
during vertical migrations over hundreds of meters depth. Our results also suggest that when designing underwater vehicles with multiple propulsors, varying the timing of thrust production could provide distinct modes directed toward speed, efficiency, or acceleration.
The RNA polymerase of cytoplasmically replicating Zika virus binds with chromatin DNA in nuclei and regulates host gene transcription
Authors: Li Ping , Wu Junyu , Liu Shujie , Lu Ruiqing , Jiang Hualian , Wang Niu , Luo Manhui , Guo Liping , Xiao Jingshu , Bu Lang , Liu Lihong , Xing Fan , Peng Hong , Li Chunmei , Ma Lan , Zhao Bo , Zhou Zhongwei , Guo Deyin
Published: November 2022

Zika virus (ZIKV) targets the neural progenitor cells (NPCs) in brain during intrauterine infections and consequently causes severe neurological disorders, such as microcephaly in neonates. Although replicating in the cytoplasm, ZIKV dysregulates the expression of thousands of host genes, yet the detailed mechanism remains elusive. Herein, we report that ZIKV encodes a unique DNA-binding protein to regulate host gene transcription in the nucleus. We found that ZIKV NS5, the viral RNA polymerase, associates tightly with host chromatin DNA through its methyltransferase domain and this interaction could be specifically blocked by GTP. Further study showed that expression of ZIKV NS5 in human NPCs markedly suppressed the transcription of its target genes, especially the genes involved in neurogenesis. Mechanistically, ZIKV NS5 binds onto the gene body of its target genes and then blocks their transcriptional elongation. The utero electroporation in pregnant mice showed that NS5 expression significantly disrupts the neurogenesis by reducing the number of Sox2- and Tbr2-positive cells in the fetal cortex. Together, our findings demonstrate a molecular clue linking to the abnormal neurodevelopment caused by ZIKV infection and also provide intriguing insights into the interaction between the host cell and the pathogenic RNA virus, where the cytoplasmic RNA virus encodes a DNA-binding protein to control the transcription of host cell in the nuclei.
Mechanism of actin filament branch formation by Arp2/3 complex revealed by a high-resolution cryo-EM structureof the branch junction
Authors: Chou Steven Z. , Chatterjee Moon , Pollard Thomas D.
Published: November 2022

We reconstructed the structure of actin filament branch junctions formed by fission yeast Arp2/3 complex at 3.5 Å resolution from images collected by electron cryo-microscopy. During specimen preparation, all of the actin subunits and Arp3 hydrolyzed their bound adenosine triphosphate (ATP) and dissociated the γ-phosphate, but Arp2 retained the γ-phosphate. Binding tightly to the side of the mother filament and nucleating the daughter filament growing as a branch requires Arp2/3 complex to undergo a dramatic conformational change where two blocks of structure rotate relative to each other about 25° to align Arp2 and Arp3 as the first two subunits in the branch. During branch formation, Arp2/3 complex acquires more than 8,000 Å
2
of new buried surface, accounting for the stability of the branch. Inactive Arp2/3 complex binds only transiently to the side of an actin filament, because its conformation allows only a subset of the interactions found in the branch junction.
Realizing the multifunctional metamaterial for fluid flow in a porous medium
Authors: Chen Mengyao , Shen Xiangying , Chen Zhen , Lo Jack Hau Yung , Liu Yuan , Xu Xinliang , Wu Yilin , Xu Lei
Published: November 2022

Metamaterials are artificial materials that can achieve unusual properties through unique structures. In particular, their “invisibility” property has attracted enormous attention due to its little or negligible disturbance to the background field that avoids detection. This invisibility feature is not only useful for the optical field, but it is also important for any field manipulation that requires minimum disturbance to the background, such as the flow field manipulation inside the human body. There are several conventional invisible metamaterial designs: a cloak can isolate the influence between the internal and external fields, a concentrator can concentrate the external field to form an intensified internal field, and a rotator can rotate the internal field by a specific angle with respect to the external field. However, a multifunctional invisible device that can continuously tune across all these functions has never been realized due to its challenging requirements on material properties. Inside a porous medium flow, however, we overcome these challenges and realize such a multifunctional metamaterial. Our hydrodynamic device can manipulate both the magnitude and the direction of the internal flow and, at the same time, make negligible disturbance to the external flow. Thus, we integrate the functions of the cloak, concentrator, and rotator within one single hydrodynamic metamaterial, and such metamaterials may find potential applications in biomedical areas such as tissue engineering and drug release.
Moderate activity of RNA chaperone maximizes the yield of self-spliced pre-RNA in vivo
Authors: Song Yonghyun , Thirumalai D. , Hyeon Changbong
Published: November 2022

CYT-19 is a DEAD-box protein whose adenosine-triphosphate (ATP)-dependent helicase activity facilitates the folding of group I introns in precursor RNA (pre-RNA) of
Neurospora crassa
(
N. crassa
). In the process, they consume a substantial amount of ATP. While much of the mechanistic insight into CYT-19 activity has been gained through the studies on the folding of
Tetrahymena
group I intron ribozyme, the more biologically relevant issue, namely the effect of CYT-19 on the self-splicing of pre-RNA, remains largely unexplored. Here, we employ a kinetic network model, based on the generalized iterative annealing mechanism (IAM), to investigate the relation between CYT-19 activity, rate of ribozyme folding, and the kinetics of the self-splicing reaction. The network rate parameters are extracted by analyzing the recent biochemical data for CYT-19-facilitated folding of
Tetrahymena
ribozyme. We then build extended models to explore the metabolism of pre-RNA. We show that the timescales of chaperone-mediated folding of group I ribozyme and self-splicing reaction compete with each other. As a consequence, in order to maximize the self-splicing yield of group I introns in pre-RNA, the chaperone activity must be sufficiently large to unfold the misfolded structures, but not too large to unfold the native structures prior to the self-splicing event. We discover that despite the promiscuous action on structured RNAs, the helicase activity of CYT-19 on group I ribozyme gives rise to self-splicing yields that are close to the maximum.
Ice friction at the nanoscale
Authors: Baran Łukasz , Llombart Pablo , Rżysko Wojciech , MacDowell Luis G.
Published: November 2022

The origin of ice slipperiness has been a matter of great controversy for more than a century, but an atomistic understanding of ice friction is still lacking. Here, we perform computer simulations of an atomically smooth substrate sliding on ice. In a large temperature range between 230 and 266 K, hydrophobic sliders exhibit a premelting layer similar to that found at the ice/air interface. On the contrary, hydrophilic sliders show larger premelting and a strong increase of the first adsorption layer. The nonequilibrium simulations show that premelting films of barely one-nanometer thickness are sufficient to provide a lubricating quasi-liquid layer with rheological properties similar to bulk undercooled water. Upon shearing, the films display a pattern consistent with lubricating Couette flow, but the boundary conditions at the wall vary strongly with the substrate’s interactions. Hydrophobic walls exhibit large slip, while hydrophilic walls obey stick boundary conditions with small negative slip. By compressing ice above atmospheric pressure, the lubricating layer grows continuously, and the rheological properties approach bulk-like behavior. Below 260 K, the equilibrium premelting films decrease significantly. However, a very large slip persists on the hydrophobic walls, while the increased friction on hydrophilic walls is sufficient to melt ice and create a lubrication layer in a few nanoseconds. Our results show that the atomic-scale frictional behavior of ice is a combination of spontaneous premelting, pressure melting, and frictional heating.
Local production of corticotropin-releasing hormone in prefrontal cortex modulates male-specific novelty exploration
Authors: Riad Michael H. , Park Kwanghoon , Ibañez-Tallon Ines , Heintz Nathaniel
Published: November 2022

Neuromodulatory substances can be released from distal afferents for communication between brain structures or produced locally to modulate neighboring circuit elements. Corticotropin-releasing hormone (CRH) from long-range neurons in the hypothalamus projecting to the medial prefrontal cortex (mPFC) has been shown to induce anxiety-like behaviors. However, the role of CRH produced in the mPFC has not been investigated. Here we demonstrate that a specific class of mPFC interneurons that express CRH (CrhINs) releases CRH upon high-frequency stimulation to enhance excitability of layer 2/3 pyramidal cells (L2/3 PCs) expressing the CRH receptors. When stimulated at low frequency, CrhINs release GABA resulting in the inhibition of oxytocin receptor-expressing interneurons (OxtrINs) and L2/3 PCs. Conditional deletion of CRH in mPFC CrhINs and chemogenetic activation of CrhINs have opposite effects on novelty exploration in male but not in female mice, and do not affect anxiety-related behaviors in either males or females. Our data reveal that CRH produced by local interneurons in the mPFC is required for sex-specific novelty exploration and suggest that our understanding of complex behaviors may require knowledge of local and remote neuromodulatory action.
Turnover of mammal sex chromosomes in the
Sry
-deficient Amami spiny rat is due to male-specific upregulation of
Sox9
Authors: Terao Miho , Ogawa Yuya , Takada Shuji , Kajitani Rei , Okuno Miki , Mochimaru Yuta , Matsuoka Kentaro , Itoh Takehiko , Toyoda Atsushi , Kono Tomohiro , Jogahara Takamichi , Mizushima Shusei , Kuroiwa Asato
Published: November 2022

Mammalian sex chromosomes are highly conserved, and sex is determined by
SRY
on the Y chromosome. Two exceptional rodent groups in which some species lack a Y chromosome and
Sry
offer insights into how novel sex genes can arise and replace
Sry
, leading to sex chromosome turnover. However, intensive study over three decades has failed to reveal the identity of novel sex genes in either of these lineages. We here report our discovery of a male-specific duplication of an enhancer of
Sox9
in the Amami spiny rat
Tokudaia osimensis
, in which males and females have only a single X chromosome (XO/XO) and the Y chromosome and
Sry
are completely lost. We performed a comprehensive survey to detect sex-specific genomic regions in the spiny rat. Sex-related genomic differences were limited to a male-specific duplication of a 17-kb unit located 430 kb upstream of
Sox9
on an autosome. Hi-C analysis using male spiny rat cells showed the duplicated region has potential chromatin interaction with
Sox9
. The duplicated unit harbored a 1,262-bp element homologous to mouse enhancer 14 (Enh14), a candidate
Sox9
enhancer that is functionally redundant in mice. Transgenic reporter mice showed that the spiny rat Enh14 can function as an embryonic testis enhancer in mice. Embryonic gonads of XX mice in which Enh14 was replaced by the duplicated spiny rat Enh14 showed increased
Sox9
expression and decreased
Foxl2
expression. We propose that male-specific duplication of this
Sox9
enhancer substituted for
Sry
function, defining a novel Y chromosome in the spiny rat.
Protein mishandling and impaired lysosomal proteolysis generated through calcium dysregulation in Alzheimer’s disease
Authors: Mustaly-Kalimi Sarah , Gallegos Wacey , Marr Robert A. , Gilman-Sachs Alice , Peterson Daniel A. , Sekler Israel , Stutzmann Grace E.
Published: November 2022

Impairments in neural lysosomal- and autophagic-mediated degradation of cellular debris contribute to neuritic dystrophy and synaptic loss. While these are well-characterized features of neurodegenerative disorders such as Alzheimer’s disease (AD), the upstream cellular processes driving deficits in pathogenic protein mishandling are less understood. Using a series of fluorescent biosensors and optical imaging in model cells, AD mouse models and human neurons derived from AD patients, we reveal a previously undescribed cellular signaling cascade underlying protein mishandling mediated by intracellular calcium dysregulation, an early component of AD pathogenesis. Increased Ca
2+
release via the endoplasmic reticulum (ER)-resident ryanodine receptor (RyR) is associated with reduced expression of the lysosome proton pump vacuolar-ATPase (vATPase) subunits (V1B2 and V0a1), resulting in lysosome deacidification and disrupted proteolytic activity in AD mouse models and human-induced neurons (HiN). As a result of impaired lysosome digestive capacity, mature autophagosomes with hyperphosphorylated tau accumulated in AD murine neurons and AD HiN, exacerbating proteinopathy. Normalizing AD-associated aberrant RyR-Ca
2+
signaling with the negative allosteric modulator, dantrolene (Ryanodex), restored vATPase levels, lysosomal acidification and proteolytic activity, and autophagic clearance of intracellular protein aggregates in AD neurons. These results highlight that prior to overt AD histopathology or cognitive deficits, aberrant upstream Ca
2+
signaling disrupts lysosomal acidification and contributes to pathological accumulation of intracellular protein aggregates. Importantly, this is demonstrated in animal models of AD, and in human iPSC-derived neurons from AD patients. Furthermore, pharmacological suppression of RyR-Ca
2+
release rescued proteolytic function, revealing a target for therapeutic intervention that has demonstrated effects in clinically-relevant assays.
JAZ is essential for ligand specificity of the COI1/JAZ co-receptor
Authors: Monte Isabel , Caballero Julio , Zamarreño Angel M. , Fernández-Barbero Gemma , García-Mina José M. , Solano Roberto
Published: November 2022

Jasmonates are phytohormones that regulate defense and developmental processes in land plants. Despite the chemical diversity of jasmonate ligands in different plant lineages, they are all perceived by COI1/JAZ co-receptor complexes, in which the hormone acts as a molecular glue between the COI1 F-box and a JAZ repressor. It has been shown that COI1 determines ligand specificity based on the receptor crystal structure and the identification of a single COI1 residue, which is responsible for the evolutionary switch in ligand binding. In this work, we show that JAZ proteins contribute to ligand specificity together with COI1. We propose that specific features of JAZ proteins, which are conserved in bryophytes and lycophytes, enable perception of dn-OPDA ligands regardless the size of the COI1 binding pocket. In vascular plant lineages beyond lycophytes, JAZ evolved to limit binding to JA-Ile, thus impeding dn-OPDA recognition by COI1.
Early microbial exposure shapes adult immunity by altering CD8+ T cell development
Authors: Tabilas Cybelle , Iu David S. , Daly Ciarán W. P. , Yee Mon Kristel J. , Reynaldi Arnold , Wesnak Samantha P. , Grenier Jennifer K. , Davenport Miles P. , Smith Norah L. , Grimson Andrew , Rudd Brian D.
Published: November 2022

Microbial exposure during development can elicit long-lasting effects on the health of an individual. However, how microbial exposure in early life leads to permanent changes in the immune system is unknown. Here, we show that the microbial environment alters the set point for immune susceptibility by altering the developmental architecture of the CD8+ T cell compartment. In particular, early microbial exposure results in the preferential expansion of highly responsive fetal-derived CD8+ T cells that persist into adulthood and provide the host with enhanced immune protection against intracellular pathogens. Interestingly, microbial education of fetal-derived CD8+ T cells occurs during thymic development rather than in the periphery and involves the acquisition of a more effector-like epigenetic program. Collectively, our results provide a conceptual framework for understanding how microbial colonization in early life leads to lifelong changes in the immune system.
The mud-dwelling clam
Meretrix petechialis
secretes endogenously synthesized erythromycin
Authors: Yue Xin , Zhang Shujing , Wang Hongxia , Yu Jiajia , Peng Quancai , McFall-Ngai Margaret , Liu Baozhong
Published: November 2022

Although lacking an adaptive immune system and often living in habitats with dense and diverse bacterial populations, marine invertebrates thrive in the presence of potentially challenging microbial pathogens. However, the mechanisms underlying this resistance remain largely unexplored and promise to reveal novel strategies of microbial resistance. Here, we provide evidence that a mud-dwelling clam,
Meretrix petechiali
s, synthesizes, stores, and secretes the antibiotic erythromycin. Liquid chromatography coupled with mass spectrometry, immunocytochemistry, fluorescence in situ hybridization, RNA interference, and enzyme-linked immunosorbent assay revealed that this potent macrolide antimicrobial, thought to be synthesized only by microorganisms, is produced by specific mucus-rich cells beneath the clam’s mantle epithelium, which interfaces directly with the bacteria-rich environment. The antibacterial activity was confirmed by bacteriostatic assay. Genetic, ontogenetic, phylogenetic and genomic evidence, including genotypic segregation ratios in a family of full siblings, gene expression in clam larvae, phylogenetic tree, and synteny conservation in the related genome region further revealed that the genes responsible for erythromycin production are of animal origin. The detection of this antibiotic in another clam species showed that the production of this macrolide is not exclusive to
M. petechialis
and may be a common strategy among marine invertebrates. The finding of erythromycin production by a marine invertebrate offers a striking example of convergent evolution in secondary metabolite synthesis between the animal and bacterial domains. These findings open the possibility of engineering-animal tissues for the localized production of an antibacterial secondary metabolite.
Tumor-targeted delivery of a STING agonist improves cancer immunotherapy
Authors: Wu You-tong , Fang Yan , Wei Qi , Shi Heping , Tan Huiling , Deng Yafang , Zeng Zhiqun , Qiu Jian , Chen Chuo , Sun Lijun , Chen Zhijian J.
Published: November 2022

The cGAS-STING pathway is essential for immune defense against microbial pathogens and malignant cells; as such, STING is an attractive target for cancer immunotherapy. However, systemic administration of STING agonists poses safety issues while intratumoral injection is limited by tumor accessibility. Here, we generated antibody-drug conjugates (ADCs) by conjugating a STING agonist through a cleavable linker to antibodies targeting tumor cells. Systemic administration of these ADCs was well tolerated and exhibited potent antitumor efficacy in syngeneic mouse tumor models. The STING ADC further synergized with an anti-PD-L1 antibody to achieve superior antitumor efficacy. The STING ADC promoted multiple aspects of innate and adaptive antitumor immune responses, including activation of dendritic cells, T cells, natural killer cells and natural killer T cells, as well as promotion of M2 to M1 polarization of tumor-associated macrophages. These results provided the proof of concept for clinical development of the STING ADCs.
Elucidation of tropane alkaloid biosynthesis inErythroxylum cocausing a microbial pathway discovery platform
Authors: Chavez Benjamin G. , Srinivasan Prashanth , Glockzin Kayla , Kim Neill , Montero Estrada Olga , Jirschitzka Jan , Rowden Gage , Shao Jonathan , Meinhardt Lyndel , Smolke Christina D. , D’Auria John C.
Published: November 2022

Tropane alkaloids (TAs) are heterocyclic nitrogenous metabolites found across seven orders of angiosperms, including Malpighiales (Erythroxylaceae) and Solanales (Solanaceae). Despite the well-established euphorigenic properties of Erythroxylaceae TAs like cocaine, their biosynthetic pathway remains incomplete. Using yeast as a screening platform, we identified and characterized the missing steps of TA biosynthesis inErythroxylum coca. We first characterize putativeE. cocapolyamine synthase- and amine oxidase-like enzymes in vitro, in yeast, and in planta to show that the first tropane ring closure in Erythroxylaceae occurs via bifunctional spermidine synthase/N-methyltransferases and both flavin- and copper-dependent amine oxidases. We next identify a SABATH family methyltransferase responsible for the 2-carbomethoxy moiety characteristic of Erythroxylaceae TAs and demonstrate that its coexpression with methylecgonone reductase in yeast engineered to express the Solanaceae TA pathway enables the production of a hybrid TA with structural features of both lineages. Finally, we use clustering analysis ofErythroxylumtranscriptome datasets to discover a cytochrome P450 of the CYP81A family responsible for the second tropane ring closure in Erythroxylaceae, and demonstrate the function of the core coca TA pathway in vivo via reconstruction and de novo biosynthesis of methylecgonine in yeast. Collectively, our results provide strong evidence that TA biosynthesis in Erythroxylaceae and Solanaceae is polyphyletic and that independent recruitment of unique biosynthetic mechanisms and enzyme classes occurred at nearly every step in the evolution of this pathway.
Strong Coulomb coupling influences ion and neutral temperatures in atmospheric pressure plasmas
Authors: Acciarri M D , Moore C , Baalrud S D
Published: November 2022

Molecular dynamics simulations are used to model ion and neutral temperature evolution in partially-ionized atmospheric pressure plasma at different ionization fractions. Results show that ion–ion interactions are strongly coupled at ionization fractions as low as 10−5 and that the temperature evolution is influenced by effects associated with the strong coupling. Specifically, disorder-induced heating is found to rapidly heat ions on a timescale of the ion plasma period (∼10 s ps) after an ionization pulse. This is followed by the collisional relaxation of ions and neutrals, which cools ions and heats neutrals on a longer (∼ns) timescale. Slight heating then occurs over a much longer (∼100 s ns) timescale due to ion-neutral three-body recombination. An analytic model of the temperature evolution is developed that agrees with the simulation results. A conclusion is that strong coupling effects are important in atmospheric pressure plasmas.
Identification of the Kirkendall effect as a mechanism responsible for thermal decomposition of the InGaN/GaN MQWs system
Authors: Hrytsak Roman , Kempisty Pawel , Leszczynski Michal , Sznajder Malgorzata
Published: November 2022

A drop in the efficiency of light-emitting diodes based on InGaN/GaN QWs known as the ‘green gap’ has been studied intensively over the past dozen years. Several factors were revealed to contribute to its origin, such as random fluctuations in the indium concentration or the diffusion of point defects during the growth of QWs. The aim of this paper is to demonstrate that the Kirkendall effect can be the mechanism responsible for the thermal decomposition of InGaN/GaN MQWs structures, contributing to the green gap problem. By applying density functional theory, harmonic approximation, and harmonic transition state theory, we calculated the heights of the migration energy barriers of In and Ga atoms diffusing in

I

n

x

G

a

1
−

x

N

alloys (

x
=
0
,
0.11
,
0.22

), the vibrational frequencies of

I

n

x

G

a

1
−

x

N

alloys in the presence of migrating point defects, the temperature dependencies of the defect migration energy barriers and diffusion coefficients of Ga and In atoms migrating in

I

n

x

G

a

1
−

x

N

alloys. We demonstrated the presence of unbalanced diffusion rates of In and Ga atoms at the

I

n

x

G

a

1
−

x

N

/

G
a
N

interfaces and finally explained the experimentally observed mechanism of void formation at the

I

n

x

G

a

1
−

x

N

/

G
a
N

interfaces by means of the Kirkendall effect.
Dark matter indirect detection limits from complete annihilation patterns
Authors: Armand C. , Herrmann B.
Published: November 2022

While cosmological and astrophysical probes suggest that dark matter would make up for 85% of the total matter content of the Universe, the determination of its nature remains one of the greatest challenges of fundamental physics. Assuming the ΛCDM cosmological model, Weakly Interacting Massive Particles would annihilate into Standard Model particles, yielding γ-rays, which could be detected by ground-based telescopes. Dwarf spheroidal galaxies represent promising targets for such indirect searches as they are assumed to be highly dark matter dominated with the absence of astrophysical sources nearby. Previous studies have led to upper limits on the annihilation cross-section assuming single exclusive annihilation channels. In this work, we consider a more realistic situation and take into account the complete annihilation pattern within a given particle physics model. This allows us to study the impact on the derived upper limits on the dark matter annihilation cross-section from a full annihilation pattern compared to the case of a single annihilation channel. We use mock data for the Cherenkov Telescope Array simulating the observations of the promising dwarf spheroidal galaxy Sculptor. We show the impact of considering the full annihilation pattern within a simple framework where the Standard Model of particle physics is extended by a singlet scalar. Such a model shows new features in the shape of the predicted upper limit which reaches a value of 〈σv〉 = 3.8 × 10-24 cm-3s-1 for a dark matter mass of 1 TeV at 95% confidence level. We suggest considering the complete particle physics information in order to derive more realistic limits.
Segment Linking: A Highly Parallelizable Track Reconstruction Algorithm for HL-LHC
Authors: Chang P , Elmer P , Gu Y , Krutelyov V , Niendorf G , Reid M , Sathia Narayanan B V , Tadel M , Vourliotis E , Wang B , Wittich P , Yagil A
Published: November 2022

The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) will produce particle collisions with up to 200 simultaneous proton-proton interactions. These unprecedented conditions will create a combinatorial complexity for charged-particle track reconstruction that demands a computational cost that is expected to surpass the projected computing budget using conventional CPUs. Motivated by this and taking into account the prevalence of heterogeneous computing in cutting-edge High Performance Computing centers, we propose an efficient, fast and highly parallelizable bottom-up approach to track reconstruction for the HL-LHC, along with an associated implementation on GPUs, in the context of the Phase 2 CMS outer tracker. Our algorithm, called Segment Linking (or Line Segment Tracking), takes advantage of localized track stub creation, combining individual stubs to progressively form higher level objects that are subject to kinematical and geometrical requirements compatible with genuine physics tracks. The local nature of the algorithm makes it ideal for parallelization under the Single Instruction, Multiple Data paradigm, as hundreds of objects can be built simultaneously. The computing and physics performance of the algorithm has been tested on an NVIDIA Tesla V100 GPU, already yielding efficiency and timing measurements that are on par with the latest, multi-CPU versions of existing CMS tracking algorithms.
Air shower radio signal electric field orientation as measured with the Astroneu Cosmic Ray telescope.
Authors: Nonis S , Leisos A , Tsirigotis A , Bourlis G , Papageorgiou K , Gkialas I , Manthos I , Tzamarias S
Published: November 2022

The Astroneu cosmic ray telescope is a small scale hybrid array consisting of both scintillator counters and electromagnetic radiation detectors in the radio-wave frequency (RF) band (antennas). Astroneu was installed and operated in the area of the Hellenic Open University (HOU) campus near the city of Patras in Greece. In the present development phase, the Astroneu telescope includes two stations consisting of 3 scintillation detectors modules (SDM) and one RF antenna while a third station includes 3 particle detectors and 4 RF antennas (3SDM-4RF). In this context we present the resent results from both the 3SDM-4RF autonomous station and simulations related to the estimation of the direction of the electric field emitted during the air shower development. The electric field measured in the ground level is the superposition of the two dominant emission mechanism, the time depended transverse current induced by the geomagnetic field and the net negative charge variation at the shower front. Since the electric field emitted by the two contributions is polarized in different directions the measured electric field in the ground encloses information about the charge-excess to geomagnetic ratio (CGR). Furthermore the orientation of the electric field emitted by charge-excess mechanism is strongly depends from the distance to the shower core (the intersection of the shower axis with the ground level). In this study we use the core information as reconstructed using the radio data and simulations. The estimated charge-excess to geomagnetic ratio is in agreement with previous studies which reveals that the shower core reconstruction method is efficient. Finally we report on that CGR measurements can be used for an efficient noise rejection in a future self trigger mode
The Detector Control System of the New Small Wheel Electronics for the ATLAS experiment
Authors: Tzanis Polyneikis
Published: November 2022

The present ATLAS Small Wheel Muon detector is be replaced with a New Small Wheel(NSW) detector in order to cope up with the future LHC runs of high luminosit. One crucial part of the integration procedure concerns the validation of the electronics for a system with more than 2.1 M electronic channels. The readout chain is based on optical link technology connecting the back-end to the front-end electronics via the FELIX, which is a newly developed system that serves as the next generation readout driver for ATLAS. For the configuration, calibration and monitoring path the various electronics boards are supplied with the GBT-SCA ASIC and its purpose is to distribute control and monitoring signals to the electronics. Due to its complexity, NSW electronics requires the development of a sophisticated Control System. The use of such a system is necessary to allow the electronics to function consistently, safely and as a seamless interface to all sub-detectors and the technical infrastructure of the experiment. The central system handles the transition between the probe’s possible operating states while ensuring continuous monitoring and archiving of the system’s operating parameters.
Formulating E- & T-Model Inflation in Supergravity
Authors: Pallis C
Published: November 2022

We present novel realizations of E- and T-model inflation within Supergravity which are largely associated with the existence of a pole of order one and two respectively in the kinetic term of the inflaton superfield. This pole arises due to the selected logarithmic Kahler potentials K, which parameterize hyperbolic manifolds with scalar curvature related to the coefficient (−N) < 0 of a logarithmic term. The associated superpotential W exhibits the same R charge with the inflaton-accompanying superfield and includes all the allowed terms. The role of the inflaton can be played by a gauge singlet or non-singlet superfield. Models with one logarithmic term in K for the inflaton, require N = 2, some tuning – of the order of 10−5 – between the terms of W and predict a tensor-to-scalar ratio r at the level of 0.001. The tuning can be totally eluded for more structured K’s, with N values increasing with r and spectral index close or even equal to its present central observational value.
Overview of tribological properties of UHMW polyethylene under rotation
Authors: Studeny Z. , Dobrocky D. , Viliš J. , Adam J.
Published: November 2022

The paper works with ultra-high molecular weight polyethylene (UHMW). This polyethylene is widely used in technology, in engineering or its applications are also in the field of medicine in prosthetics in the lining of joint replacements. This wide use is mainly due to its properties. It is mainly its abrasion resistance and very low coefficient of friction (COF), so it has excellent sliding properties. It is these properties that are the subject of research on UHMW polyethylene. The investigation of these properties is always linked in tribological tests to the material in the friction pair, which consists of the material under test (UHMW) and the indenter. For the purpose of tribological testing, 6.35 mm diameter balls of ZrO2 ceramic material and a cobalt-chromium alloy known as Stellit 6 were chosen as indentors. Practical applications are the above mentioned fields of technology, engineering, etc.
Cooling ability of smooth and dimpled surfaces
Authors: Dobsakova L , Nguyen T D
Published: November 2022

Reliable cooling of electronic components is an essential factor in electrical engineering. Every electronic device produces a certain amount of heat during its operation. This heat can cause overheating and a device can suffer damage. Therefore, the issue of cooling plays a significant role and is an important theme appropriate for continuously finding new improvements.

The paper describes a quantification of the heat transfer coefficients between a body and a surrounding environment. Experimental research of the heat transfer by cooling is focused on the plane smooth and structured surfaces. Surface structures improving the heat transfer rate are of dimples. The cooling process was measured by using a thermal imaging camera to obtain a cooling curve – the change in temperature time course during air cooling. The analysis of the cooling curve gradient allows us to identify convective and radiant components of the heat transfer. The presented results in the form of diagrams include different cases of air flow around smooth and dimpled surfaces.
Skull Walls
Authors: Heaney Christopher
Published: November 2022

From 1820 through 1920, American anthropologists acquired more human remains of Andean origin than those of any other individual population worldwide. Samuel George Morton, the Smithsonian, Harvard’s Peabody Museum of Archaeology and Ethnology, and the American Museum of Natural History all made “ancient Peruvians” core to their collections, racializing the Americas’ past and present by using “ancient Peruvians” as a historic set against which living Native Americans might be compared. This process fueled the collection of Indigenous remains in general and confirms Americanist historians’ need to attend to entanglement: US scholars were adapting a Peruvian tradition of knowledge and grave robbing in which the Andes possessed the Americas’ oldest, wealthiest, most “civilized,” and most plentiful human remains. It also reminds us that recent and useful conceptualizations of early American history as vast had disturbing early republican counterparts—in this case, a violent science that entangled precolonial, colonial, and republican North and South American temporalities and embodied them in the “historic” Indigenous dead. Reckoning with history’s role in colonization includes recognizing the literal, even spirited, remains of entanglement as historical forces in their own right, with temporalities beyond those of the United States.
Bolster Equalization Suture Technique (BEST) Neck: Optimization of Skin Redraping Following Necklift Surgery
Authors: Mentz Henry , Rodriguez Abigail , Garlick Jared , Mentz James , Ogley Scott , Kumbla Pallavi A
Published: November 2022

Background

Skin laxity of the neck is a primary concern of patients seeking facial rejuvenation. Traditional methods for redraping neck skin have well-described shortcomings.

Objectives

The aim of this study was to optimize skin redraping after necklift surgery while reducing risk, and the Bolster Equalization Suture Technique (BEST).

Methods

At the conclusion of the facelift and necklift, 3 external quilting sutures are placed with protective bolsters. The first suture is placed at the midline, advancing the skin posteriorly toward the hyoid and anchoring the skin to the platysma. The second and third are placed in the cervicomandibular groove over the sternocleidomastoid muscle, advancing the skin posteriorly. Complications such as skin necrosis, skin ischemia, dimpling, hypopigmentation, hyperpigmentation, and scarring were documented. A control group of 20 patients who underwent the same surgery without the BEST was compared to the next 20 patients in which the BEST was applied. Preoperative and postoperative photographs were blindly reviewed by 2 plastic surgeons. The photographs were analyzed for residual central neck skin laxity and cervicomental angle improvement and surveyed according to the pertinent sections of the FACE-Q.

Results

In necklift patients who received the BEST, cervicomental angle improvement and decreased central skin laxity were statistically significant. Patient perceived age on a visual analog scale was 2.5 years younger in the BEST group.

Conclusions

The BEST is a safe and efficient method which can be used to improve cervical skin redraping and contour. The BEST creates a more defined cervicomental angle while reducing central skin neck laxity with minimal complications.

Level of Evidence: 4
BIA-ALCL Epidemiological Findings From a Retrospective Study of 248 Cases Extracted From Relevant Case Reports and Series: A Systematic Review
Authors: Santanelli Di Pompeo Fabio , Panagiotakos Demosthenes , Firmani Guido , Sorotos Michail
Published: November 2022

Background

The epidemiologic picture of breast implant–associated anaplastic large cell lymphoma (BIA-ALCL) is unclear, with no high-level evidence, because only case reports and series are available.

Objectives

The aim of this study was to update knowledge on BIA-ALCL epidemiology by utilizing all available data through a systematic review of scientific literature.

Methods

A search on PubMed, Scopus, and Web of Science was conducted between October 2021 and April 2022. Out of the 2799 available records, 114 pertinent articles were selected, featuring 248 BIA-ALCL cases which were retrospectively analyzed by means of descriptive statistics, incidence rate (IR), Kaplan-Meier survival curves, and Pearson correlation coefficients.

Results

The United States, the Netherlands, Italy, and Australia were the countries reporting the most cases. The mean age at first implantation was 42 years, and the mean age at diagnosis was 53 years. Aesthetic indications were the reason for 52% of cases, and reconstruction for 48%; macrotextured surface was linked to 73.8% of cases, and seroma to 83%. Total follow-up was 492 months, and mean event-free time (EFT) to BIA-ALCL development was 129 months. The IR was 96 new cases/1,000 women per year after first implantation, and was directly correlated to the number of replacements. EFT was directly correlated to the number of replacements, implant rupture, and capsule contracture, and was inversely associated with patients' age at first implantation and to BRACA1/2 and TP53 mutations.

Conclusions

Macrotextured implant use in older patients and in patients with BRCA1/2 and TP53 mutations should be reconsidered, because this is associated with earlier disease onset. Implant replacement of asymptomatic, risk-stratified patients can be indicated due to its protective role against BIA-ALCL, reducing IR and risk, while increasing the EFT.
Synthesis and structure-activity relationship study of aldose reductase inhibiting marine alkaloid lukianol A and its derivatives
Authors: Ishibashi Fumito , Zha Shijiao , Kondo Taiyo , Sakamoto Mayu , Ueno Mikinori , Fukuda Tsutomu
Published: November 2022

Lukianol A (1a) and its six derivatives 1b-1g, in which each hydroxyl groups of 1a was individually modified, were synthesized via the common intermediate 7a, which was obtained by condensation of the styryl carbazate 10 with p-hydroxyphenylpyruvic acid and subsequent [3,3]-sigmatropic rearrangement. The synthesized lukianol derivatives were evaluated for their ability to inhibit human aldose reductase. 4′-O-methyl (1b) and 4′-dehydroxy (1g) derivatives showed the same level of inhibitory activity as 1a (IC50 2.2 µm), indicating that the 4′-OH is irrelevant for the activity. In contrast, methylation of the hydroxyl group at the 4″′-position (1d) resulted in the loss of activity at a concentration of 10 µm, and masking the hydroxyl group at the 4″-position (1e) caused a 9-fold decrease in activity compared with that of 1b, suggesting that the 4″-OH is an essential group, and the 4″′-OH is required for higher activity.
Multi-view spectral clustering with latent representation learning for applications on multi-omics cancer subtyping
Authors: Ge Shuguang , Liu Jian , Cheng Yuhu , Meng Xiaojing , Wang Xuesong
Published: November 2022

Driven by multi-omics data, some multi-view clustering algorithms have been successfully applied to cancer subtypes prediction, aiming to identify subtypes with biometric differences in the same cancer, thereby improving the clinical prognosis of patients and designing personalized treatment plan. Due to the fact that the number of patients in omics data is much smaller than the number of genes, multi-view spectral clustering based on similarity learning has been widely developed. However, these algorithms still suffer some problems, such as over-reliance on the quality of pre-defined similarity matrices for clustering results, inability to reasonably handle noise and redundant information in high-dimensional omics data, ignoring complementary information between omics data, etc. This paper proposes multi-view spectral clustering with latent representation learning (MSCLRL) method to alleviate the above problems. First, MSCLRL generates a corresponding low-dimensional latent representation for each omics data, which can effectively retain the unique information of each omics and improve the robustness and accuracy of the similarity matrix. Second, the obtained latent representations are assigned appropriate weights by MSCLRL, and global similarity learning is performed to generate an integrated similarity matrix. Third, the integrated similarity matrix is used to feed back and update the low-dimensional representation of each omics. Finally, the final integrated similarity matrix is used for clustering. In 10 benchmark multi-omics datasets and 2 separate cancer case studies, the experiments confirmed that the proposed method obtained statistically and biologically meaningful cancer subtypes.