bluuebunny/crossref_metadata_2025 huggingface dataset:
Mean flow structure and velocity–bed shear stress maxima phase difference in smooth wall, transitionally turbulent oscillatory boundary layers: direct numerical simulations
Authors: Fytanidis Dimitrios K. , García Marcelo H. , Fischer Paul F.
Published: October 2021

Direct numerical simulations of oscillatory boundary-layer flows in the transitional regime were performed to explain discrepancies in the literature regarding the phase difference${\rm \Delta} \phi$between the bed-shear stress and free-stream velocity maxima. Recent experimental observations in smooth bed oscillatory boundary-layer (OBL) flows, showed a significant change in the widely used${\rm \Delta} \phi$diagram (Mieret al.,J. Fluid Mech., vol. 922, 2021, A29). However, the limitations of the point-wise measurement technique did not allow us to associate this finding with the turbulent kinetic energy budget and to detect the approach to a ‘near-equilibrium’ condition, defined in a narrow sense herein. Direct numerical simulation results suggest that a phase lag occurs as the result of a delayed and incomplete transition of OBL flows to a stage that mimics the fully turbulent regime. Data from the literature were also used to support the presence of the phase lag and propose a new${\rm \Delta} \phi$diagram. Simulations performed for${\textit {Re}}_{\delta }=671$confirmed the sensitivity in the development of self-sustained turbulence on the background disturbances ($\textit{Re}_{\delta}=U_{o}\delta/\nu$, where$\delta=[2\nu/\omega]^{1/2}$is the Stokes' length,$U_{o}$is the maximum free stream velocity of the oscillation,$\nu$is the kinematic viscosity and$\omega=2{\rm \pi}/T$is the angular velocity based on the period of the oscillationT). Variations of the mean velocity slope and intersect values for oscillatory flows are also explained in terms of the proximity to near-equilibrium conditions. Relaminarization and transition effects can significantly delay the development of OBL flows, resulting in an incomplete transition. The shape and defect factors are examined as diagnostic parameters for conditions that allow the formation of a logarithmic profile with the universal von Kármán constant and intersect. These findings are of relevance for environmental fluid mechanics and coastal morphodynamics/engineering applications.
El Niño Cave (Aýna, Albacete, Spain): Late Middle Palaeolithic, Rock Art, and Neolithic Occupations from Inland Iberia
Authors: García-Moreno Alejandro , Cubas Miriam , Davidson Iain , Garate Diego , López-Dóriga Inés , Marín-Arroyo Ana B. , Mateo Saura Miguel Ángel , Ortiz José E. , Polo-Díaz Ana , Rios-Garaizar Joseba , San Emeterio Aixa , de Torres Trinidad , Wood Rachel
Published: October 2021

El Niño cave, located on the south-eastern border of the Spanish Meseta, hosts a discontinuous sequence including Middle Palaeolithic and Neolithic levels, along with Upper Palaeolithic and Levantine style paintings. It is a key site for understanding human occupations of inland Iberia during the Palaeolithic and early prehistory. This paper summarises the main results of a multidisciplinary project aimed at defining the prehistoric human occupations at the site.
The signal of climate changes over the last two millennia in the Gulf of St. Lawrence, eastern Canada
Authors: Wu Xiner , de Vernal Anne , Fréchette Bianca , Moros Matthias , Perner Kerstin
Published: October 2021

Climate changes over the past two millennia in the central part of the Gulf of St. Lawrence are documented in this paper with the aim of determining and understanding the natural climate variability and the impact of anthropogenic forcing at a regional scale. The palynological content (dinocysts, pollen, and spores) of the composite marine sediment core MSM46-03 collected in the Laurentian Channel was used to reconstruct oceanographic and climatic changes with a multidecadal temporal resolution. Sea-surface conditions, including summer salinity and temperature, sea-ice cover, and primary productivity, were reconstructed from dinocyst assemblages. Results revealed a remarkable cooling trend of about 4°C after 1230 cal yr BP (720 CE) and a culmination with a cold pulse dated to 170–40 cal yr BP (1780–1910 CE), which likely corresponds to the regional signal of the Little Ice Age. This cold interval was followed by a rapid warming of about 3°C. In the pollen assemblages, the decrease ofPinusabundance over the past 1700 yr suggests changes in wind regimes, likely resulting from increased southerly incursions of cold and dry Arctic air masses into southeastern Canada.
Mangrove rice biodiversity valorization in Guinea Bissau. A bottom-up approach
Authors: Tesio Franco , Camerini Filippo , Maucieri Giovanni , Bertini Carlo , Cerise Streng
Published: October 2021

Rice is the staple crop of Guinea Bissau, and its production system is based on human labor with very limited possibility of mechanization, particularly in the Mangrove ecosystem. Due to this and to the low possibilities of controlling environment parameters, such as water level and availability, the genetic resistance to extreme abiotic factors was identified as a key point for increasing yields quantity and stability. Among the ample genetic material available in the country, no purification activities were carried out in the past decades. This led to the cultivation of mixtures or ecotypes and not to uniform varieties, with consequent issue related to cultivation and milling. On 103 samples collected, only on about 50% of ecotypes, the purification was carried out as the remaining half was too much variable. The purification ended with less than 20% of material considered stable and uniform varieties. Moreover, the program adopted a bottom-up approach for collection and variety conservation to drive the program and improve the genetic material.
Credit and investment between town and countryside: the market in grain annuities in Normandy (thirteenth-fourteenth centuries)
Authors: Arnoux Mathieu
Published: October 2021

The replacement of rents in kind by payments in money is considered by many historians as a marker of the commercialization of the economy and thus of its modernization. The case of medieval Normandy does not confirm this development, however: the sources testify to a common use of money since the end of the eleventh century, but also to the persistence until the fifteenth century of payment in kind, including in the field of credit. The article examines the case of the Caen region, for which there is abundant evidence from the thirteenth and fourteenth centuries of annuities purchased with money from peasants in exchange for annual repayments in grain. This system allowed a significant transfer of monetary value to the countryside, while guaranteeing the supply of urban markets and welfare institutions. Although these contracts were usually secured by pledges on plots of land, they did not lead to the expropriation of peasants, but rather promoted the growth of credit markets in the countryside.
The Global Politics of Health Security before, during, and after COVID-19
Authors: Papamichail Andreas
Published: October 2021

The COVID-19 pandemic has been shaped by preexisting political, social, and economic relations and governance structures, and will remold these structures going forward. This review essay considers three books on global health politics written by Simon Rushton, Clare Wenham, and Jeremy Youde. Here, I explore what these books collectively and individually can tell us about these preexisting dynamics, the events of the first eighteen months of the COVID-19 pandemic, and possible future directions in the politics of global health. I argue that they provide a firm basis for understanding the inequitable burdens of the pandemic, while juxtaposing these inequities against the narratives of shared vulnerability that sit at the heart of the global health security regime. They also help us make sense of the surveillance, detection, containment, and response mechanisms we have seen during the pandemic; the failures to address the systemic dynamics that drive disease outbreaks; and the national and international politics that have shaped the pandemic response. However, COVID-19 has also vividly and brutally demonstrated how global health hierarchies, racism, border politics, and neoliberal forms of knowledge production have led to a stratified burden of the pandemic. These areas are less apparent in the three books, but ought to be situated front and center in future critical scholarship on global health security.
Yeasts from the Maritime Antarctic: tools for industry and bioremediation
Authors: Bezus Brenda , Garmendia Gabriela , Vero Silvana , Cavalitto Sebastián , Cavello Ivana Alejandra
Published: October 2021

We isolated 32 yeasts from King George Island, which we then identified and characterized. Twenty-six belonged to Basidiomycota among the genera Naganishia, Holtermaniella, Vishniacozyma, Phenoliferia, Mrakia and Cystobasidium, and only six were Ascomycota of the genera Metschnikowia and Debaryomyces. Thirteen were psychrophiles, while 19 were psychrotolerant. Certain isolates exhibited a high tolerance to NaCl (3.5 M), while most tolerated Ni2+, Zn2+ and Li+. Cu2+ and Cd2+, however, inhibited the growth of most of the isolates. We assessed a bioprospecting of extracellular enzymes and their ability to biodegrade or bioaccumulate textile dyes. β-Glucosidases (59%) and esterases (53%) were the main extracellular enzymes detected. A minor proportion of the yeasts produced pectinases and xylanases; only psychrophiles produced proteases. Vishniacozyma, Naganishia, Phenoliferia and Mrakia were the richest genera in terms of enzyme production. Greater than 70% of the isolates decolourized solid medium supplemented with various dyes at 4°C and 20°C. Isolates belonging to the genera Vishniacozyma, Cystobasidium, Mrakia and Phenoliferia seem to have potential for textile dye bio-decolourization. The results demonstrated that yeasts collected from the Maritime Antarctic are a potential source of new enzymes of biotechnological interest, and that certain isolates could potentially be considered in the design of textile wastewater decolourizations.
Environmental harshness and unpredictability: Do they affect the same parents and children?
Authors: Zhang Xiaoya , Schlomer Gabriel L. , Ellis Bruce J. , Belsky Jay
Published: October 2021

Differential susceptibility theory stipulates that individuals vary in their susceptibility to environmental effects, often implying that the same individuals differ in the same way in their susceptibility to different environmental exposures. The latter point is addressed herein by evaluating the extent to which early-life harshness and unpredictability affect mother's psychological well-being and parenting, as well as their adolescent's life-history strategy, as reflected in number of sexual partners by age 15 years, drawing on data from the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development. Results indicated that mothers whose well-being and parenting proved more susceptible to harshness also proved somewhat more susceptible to environmental unpredictability, with the same being true of adolescent sexual behavior. Nevertheless, findings caution against overgeneralizing sample-level findings to all individuals.
Transcending the Past: Singing and the Lingering Cold War in the Korean Christian Diaspora
Authors: CHANG HYUN KYONG HANNAH
Published: October 2021

Protestant music in South Korea has received little attention in ethnomusicology despite the fact that Protestant Christianity was one of the most popular religions in twentieth-century Korea. This has meant a missed opportunity to consider the musical impact of a religious institution that mediated translocal experiences between South Korea and the United States during the Cold War period (1950s–1980s). This article explores the politics of music style in South Korean diasporic churches through an ethnography of a church choir in California. I document these singers’ preference for European-style choral music over neotraditional pieces that incorporate the aesthetics of suffering from certain Korean traditional genres. I argue that their musical judgement must be understood in the context of their lived and remembered experience of power inequalities between the United States and South Korea. Based on my interviews with the singers, I show that they understand hymns and related Euro-American genres as healing practices that helped them overcome a difficult past and hear traditional vocal music as sonic icons of Korea's sad past. The article outlines a pervasive South Korean/Korean diasporic historical consciousness that challenges easy conceptions of identity and agency in music studies.
Terrorist offences and international humanitarian law: The armed conflict exclusion clause
Authors: Van Poecke Thomas , Verbruggen Frank , Yperman Ward
Published: October 2021

While armed conflicts are principally governed by international humanitarian law (IHL), activities of members of non-State armed groups and their affiliates may also qualify as terrorist offences. After explaining why the concurrent application of IHL and criminal law instruments on terrorism causes friction, this article analyzes the chief mechanism for dissipating this friction: a clause excluding activities governed by IHL from the scope of criminal law instruments on terrorism. Such armed conflict exclusion clauses exist at the international, regional and national level. This article explains how an exclusion clause can best avoid friction between IHL and criminal law instruments on terrorism.
Classification of GLM Flashes Using Random Forests
Authors: Ringhausen Jacquelyn , Bitzer Phillip , Koshak William , Mecikalski John
Published: October 2021

[The Geostationary Lightning Mapper (GLM) detects total lightning continuously from space, and does not distinguish intra‐cloud (IC) from cloud‐to‐ground (CG) lightning. This research focuses on differentiating CG and IC lightning detected by GLM using a random forests (RF) model. GLM flash and group characteristics are implemented into the RF model and used to predict flash type. The most important flash characteristic for distinguishing flash type is the maximum group area. Other features with high feature importance include time‐of‐day, elongation, propagation, footprint, slope, maximum distance between groups and events, and mean energy. Skill scores showcase the model's ability to distinguish flash type with moderate skill, with 81% probability of detection, 71% percent correct, 36% false alarm rate, 36% false alarm ratio, and 56% critical success index. These scores improve further when study area is limited to CONUS and the Southeastern United States. These results can be used to aid in future climatological analysis of flash type.]
Transient and Quasi‐Equilibrium Climate States at 1.5°C and 2°C Global Warming
Authors: King Andrew D. , Borowiak Alexander R. , Brown Josephine R. , Frame David J. , Harrington Luke J. , Min Seung‐Ki , Pendergrass Angeline , Rugenstein Maria , Sniderman J. M. Kale , Stone Dáithí A.
Published: October 2021

Recent climate change is characterized by rapid global warming, but the goal of the Paris Agreement is to achieve a stable climate where global temperatures remain well below 2°C above pre‐industrial levels. Inferences about conditions at or below 2°C are usually made based on transient climate projections. To better understand climate change impacts on natural and human systems under the Paris Agreement, we must understand how a stable climate may differ from transient conditions at the same warming level. Here we examine differences between transient and quasi‐equilibrium climates using a statistical framework applied to greenhouse gas‐only model simulations. This allows us to infer climate change patterns at 1.5°C and 2°C global warming in both transient and quasi‐equilibrium climate states. We find substantial local differences between seasonal‐average temperatures dependent on the rate of global warming, with mid‐latitude land regions in boreal summer considerably warmer in a transient climate than a quasi‐equilibrium state at both 1.5°C and 2°C global warming. In a rapidly warming world, such locations may experience a temporary emergence of a local climate change signal that weakens if the global climate stabilizes and the Paris Agreement goals are met. Our research demonstrates that the rate of global warming must be considered in regional projections.
Explosive Behavior of Intermediate Magmas: The Example of Cotopaxi Volcano (Ecuador)
Authors: Pistolesi M. , Aravena A. , Costantini L. , Vigiani C. , Cioni R. , Bonadonna C.
Published: October 2021

The variability in intensity and style shown by explosive volcanism has been traditionally explained by a complex interplay among melt composition and pre‐eruptive volatile content, which modulate magma ascent and conduit dynamics. However, magmas having similar compositions may be characterized by subtle textural changes affecting magma rheology and eventually explosive dynamics. Here we study five eruptions occurred at Cotopaxi volcano (Ecuador) in the last 2000 years characterized by a small variation in magma composition but spanning a wide range of intensity to investigate how these parameters control variations in eruption dynamics. We combined eruption source parameters (ESPs), obtained from the application of recent models to all the available field data, with new textural data and state‐of‐the‐art conduit dynamics modeling. We found that, despite having variable microlite content and texture, the effect of microlite on magma rheology is partly counterbalanced by variable phenocryst abundance, resulting in a comparable total crystal content. The combination of modeling results with textural data and ESPs suggests that subtle variability in crystal content and magma composition may be accompanied by strong feedback effects among crystallization, changes in melt/magma viscosity and volatile exsolution, with microlite crystallization resulting in a rapid change of magma rheology and modifications in the explosive dynamics. By combining ESPs with quantitative textural data (i.e. melt normalized vesicle number density) and conduit modeling, we also show how general observed correlations between composition and texture of juvenile products with eruption intensity are not evident when applied to eruptions characterized by a small compositional range.
ULF Wave Transmission Across Collisionless Shocks: 2.5D Local Hybrid Simulations
Authors: Kajdič P. , Pfau‐Kempf Y. , Turc L. , Dimmock A. P. , Palmroth M. , Takahashi K. , Kilpua E. , Soucek J. , Takahashi N. , Preisser L. , Blanco‐Cano X. , Trotta D. , Burgess D.
Published: October 2021

We study the interaction of upstream ultralow frequency (ULF) waves with collisionless shocks by analyzing the outputs of 11 2D local hybrid simulation runs. Our simulated shocks have Alfvénic Mach numbers between 4.29 and 7.42 and their angles are , , , and . The ULF wave foreshocks develop upstream of all of them. The wavelength and the amplitude of the upstream waves exhibit a complex dependence on the shock's and . The wavelength positively correlates with both parameters, with the dependence on being much stronger. The amplitude of the ULF waves is proportional to the product of the reflected beam velocity and density, which also depend on and . The interaction of the ULF waves with the shock causes large‐scale (several tens of upstream ion inertial lengths) shock rippling. The properties of the shock ripples are related to the ULF wave properties, namely their wavelength and amplitude. In turn, the ripples have a large impact on the ULF wave transmission across the shock because they change local shock properties (, strength), so that different sections of the same ULF wavefront encounter shock with different characteristics. Downstream fluctuations do not resemble the upstream waves in terms the wavefront extension, orientation or their wavelength. However, some features are conserved in the Fourier spectra of downstream compressive waves that present a bump or flattening at wavelengths approximately corresponding to those of the upstream ULF waves. In the transverse downstream spectra, these features are weaker.
First ICON‐FUV Nighttime NmF2 and hmF2 Comparison to Ground and Space‐Based Measurements
Authors: Wautelet G. , Hubert B. , Gérard J.‐C. , Immel T. J. , Frey H. U. , Mende S. B. , Kamalabadi F. , Kamaci U. , England S. L.
Published: October 2021

The Far Ultra Violet (FUV) ultraviolet imager onboard the NASA‐ICON mission is dedicated to the observation and study of the ionosphere dynamics at mid and low latitudes. We compare density profiles provided by the ICON FUV instrument during nighttime with electron density profiles measured by the COSMIC‐2 constellation (C2) and ground‐based ionosondes. Co‐located simultaneous observations are compared, covering the period from November 2019 to July 2020, which produces several thousands of coincidences. Manual scaling of ionogram sequences ensures the reliability of the ionosonde profiles, while C2 data are carefully selected using an automatic quality control algorithm. Photoelectron contribution coming from the magnetically conjugated hemisphere is clearly visible in FUV data around solstices and has been filtered out from our analysis. We find that the FUV observations are consistent with the C2 and ionosonde measurements, with an average positive bias lower than 1 × /. When restricting the analysis to cases having an value larger than 5 × /, FUV provides the peak electron density with a mean difference with C2 of 10%. The peak altitude, also determined from FUV observations, is found to be 15 km above that obtained from C2, and 38 km above the ionosonde value on average.
3‐D Magnetic Unstructured Inversion
Authors: Zuo Boxin , Hu Xiangyun , Wang Lizhe , Cai Yi , Kass Mason Andrew , Leão‐Santos Marcelo
Published: October 2021

Magnetic inversion methods based on structured grids have been used extensively in geomagnetic research. Nevertheless, structured grids limit the modeling capability and accuracy of models with arbitrary geometries. To address these challenges, 3‐D magnetic numerical forward modeling and inversion methods using an unstructured tetrahedral grid based on a partial differential equation (PDE) framework are proposed. The methods are derived from Maxwell's partial equations and constructed using the finite element method. Arbitrary undulating topographies, complex geometries, and demagnetization effects can be represented exactly, leading to high‐accuracy forward modeling and inversion solutions. The proposed methods are suitable for both local‐ and global‐scale magnetic data interpretation, for example, in mineral exploration and tectonic research. A synthetic example and real airborne magnetic survey data collected from Mount Iliamna, Alaska, USA, are tested. The results demonstrate that the novel methods significantly improve the capability and accuracy of magnetic data interpretation.
Spatial and Temporal Variations of Aragonite Saturation States in the Surface Waters of the Western Arctic Ocean
Authors: Kim D. , Yang E.‐J. , Cho S. , Kim H.‐J. , Cho K.‐H. , Jung J. , Kang S.‐H.
Published: October 2021

The aragonite saturation state (Ωarag) was determined for the surface waters of the western Arctic Ocean over 3 years, from 2016 to 2018, in an investigation of the present state of acidification of its waters and the main factors controlling the spatial and temporal variations in the surface Ωarag. The study area was divided into the Chukchi marginal area (CMA) and the East Siberian marginal area (ESMA) along a longitude of 180°E. In the CMA, the surface Ωarag during the study period ranged from 0.86 to 1.77, with an average of 1.16, indicating near saturation with respect to aragonite. In the ESMA, the surface Ωarag during the study period ranged from 1.01 to 2.21, with a higher average (1.59) than the CMA. Aragonite undersaturation in the ESMA was not observed during any of the measurement periods, so ocean acidification was less serious there than in the CMA. The surface Ωarag of the CMA was mainly determined by the mixing of seawater and freshwater introduced from rivers and/or sea ice, whereas in the ESMA it was influenced by the mixing of seawater and freshwater but also biological production and lateral mixing.
Single-cell transcriptomics reveal the heterogeneity and dynamic of cancer stem-like cells during breast tumor progression
Authors: Jiang Guojuan , Tu Juchuanli , Zhou Lei , Dong Mengxue , Fan Jue , Chang Zhaoxia , Zhang Lixing , Bian Xiuwu , Liu Suling
Published: October 2021

Breast cancer stem-like cells (BCSCs) play vital roles in tumorigenesis and progression. However, the origin and dynamic changes of BCSCs are still to be elucidated. Using the breast cancer mouse model MMTV-PyMT, we constructed a single-cell atlas of 31,778 cells from four distinct stages of tumor progression (hyperplasia, adenoma/MIN, early carcinoma and late carcinoma), during which malignant transition occurs. We identified that the precise cell type of ERlow epithelial cell lineage gave rise to the tumors, and the differentiation of ERhigh epithelial cell lineage was blocked. Furthermore, we discovered a specific signature with a continuum of gene expression profiles along the tumor progression and significantly correlated with clinical outcomes, and we also found a stem-like cell cluster existed among ERlow epithelial cells. Further clustering on this stem-like cluster showed several sub-clusters indicating heterogeneity of stem-like epithelial cells. Moreover, we distinguished normal and cancer stem-like cells in this stem-like epithelial cell cluster and profiled the molecular portraits from normal stem-like cell to cancer stem-like cells during the malignant transition. Finally, we found the diverse immune cell infiltration displayed immunosuppressive characteristics along tumor progression. We also found the specific expression pattern of cytokines and their corresponding cytokine receptors in BCSCs and immune cells, suggesting the possible cross-talk between BCSCs and the immune cells. These data provide a useful resource for illuminating BCSC heterogeneity and the immune cell remodeling during breast tumor progression, and shed new light on transcriptomic dynamics during the progression at the single-cell level.
Exciton-polaron Rydberg states in monolayer MoSe2 and WSe2
Authors: Liu Erfu , van Baren Jeremiah , Lu Zhengguang , Taniguchi Takashi , Watanabe Kenji , Smirnov Dmitry , Chang Yia-Chung , Lui Chun Hung
Published: October 2021

Exciton polaron is a hypothetical many-body quasiparticle that involves an exciton dressed with a polarized electron-hole cloud in the Fermi sea. It has been evoked to explain the excitonic spectra of charged monolayer transition metal dichalcogenides, but the studies were limited to the ground state. Here we measure the reflection and photoluminescence of monolayer MoSe2 and WSe2 gating devices encapsulated by boron nitride. We observe gate-tunable exciton polarons associated with the 1 s–3 s exciton Rydberg states. The ground and excited exciton polarons exhibit comparable energy redshift (15~30 meV) from their respective bare excitons. The robust excited states contradict the trion picture because the trions are expected to dissociate in the excited states. When the Fermi sea expands, we observe increasingly severe suppression and steep energy shift from low to high exciton-polaron Rydberg states. Their gate-dependent energy shifts go beyond the trion description but match our exciton-polaron theory. Our experiment and theory demonstrate the exciton-polaron nature of both the ground and excited excitonic states in charged monolayer MoSe2 and WSe2.
Spin-orbit interactions of transverse sound
Authors: Wang Shubo , Zhang Guanqing , Wang Xulong , Tong Qing , Li Jensen , Ma Guancong
Published: October 2021

Spin-orbit interactions (SOIs) endow light with intriguing properties and applications such as photonic spin-Hall effects and spin-dependent vortex generations. However, it is counterintuitive that SOIs can exist for sound, which is a longitudinal wave that carries no intrinsic spin. Here, we theoretically and experimentally demonstrate that airborne sound can possess artificial transversality in an acoustic micropolar metamaterial and thus carry both spin and orbital angular momentum. This enables the realization of acoustic SOIs with rich phenomena beyond those in conventional acoustic systems. We demonstrate that acoustic activity of the metamaterial can induce coupling between the spin and linear crystal momentum k, which leads to negative refraction of the transverse sound. In addition, we show that the scattering of the transverse sound by a dipole particle can generate spin-dependent acoustic vortices via the geometric phase effect. The acoustic SOIs can provide new perspectives and functionalities for sound manipulations beyond the conventional scalar degree of freedom and may open an avenue to the development of spin-orbit acoustics.
Enabling three-dimensional porous architectures via carbonyl functionalization and molecular-specific organic-SERS platforms
Authors: Deneme Ibrahim , Liman Gorkem , Can Ayse , Demirel Gokhan , Usta Hakan
Published: October 2021

Molecular engineering via functionalization has been a great tool to tune noncovalent intermolecular interactions. Herein, we demonstrate three-dimensional highly crystalline nanostructured D(C7CO)-BTBT films via carbonyl-functionalization of a fused thienoacene π-system, and strong Raman signal enhancements in Surface-Enhanced Raman Spectroscopy (SERS) are realized. The small molecule could be prepared on the gram scale with a facile synthesis-purification. In the engineered films, polar functionalization induces favorable out-of-plane crystal growth via zigzag motif of dipolar C = O···C = O interactions and hydrogen bonds, and strengthens π-interactions. A unique two-stage film growth behavior is identified with an edge-on-to-face-on molecular orientation transition driven by hydrophobicity. The analysis of the electronic structures and the ratio of the anti-Stokes/Stokes SERS signals suggests that the π-extended/stabilized LUMOs with varied crystalline face-on orientations provide the key properties in the chemical enhancement mechanism. A molecule-specific Raman signal enhancement is also demonstrated on a high-LUMO organic platform. Our results demonstrate a promising guidance towards realizing low-cost SERS-active semiconducting materials, increasing structural versatility of organic-SERS platforms, and advancing molecule-specific sensing via molecular engineering.
Structural insights into RNA polymerase III-mediated transcription termination through trapping poly-deoxythymidine
Authors: Hou Haifeng , Li Yan , Wang Mo , Liu Aijun , Yu Zishuo , Chen Ke , Zhao Dan , Xu Yanhui
Published: October 2021

Termination of the RNA polymerase III (Pol III)-mediated transcription requires the conversion of an elongation complex (EC) to a pre-termination complex (PTC) on poly-deoxythymidine (dT)-containing non-template strand, a mechanism distinct from Pol I and Pol II. Here, our in vitro transcription elongation assay showed that 5-7 dT-containing DNA template led to transcription termination of Pol III, but not Pol I or Pol II. We assembled human Pol III PTC on a 7 dT-containing DNA template and determined the structure at 3.6 Å resolution. The structure reveals that poly-dT are trapped in a narrow exit tunnel formed by RPC2. A hydrophobic gate of the exit tunnel separates the bases of two connected deoxythymidines and may prevent translocation of the non-template strand. The fork loop 2 stabilizes both template and non-template strands around the transcription fork, and may further prevent strand translocation. Our study shows that the Pol III-specific exit tunnel and FL2 allow for efficient translocation of non-poly-dT sequence during transcription elongation but trap poly-dT to promote DNA retention of Pol III, revealing molecular mechanism of poly-dT-dependent transcription termination of Pol III.
In-situ spectroscopic observation of dynamic-coupling oxygen on atomically dispersed iridium electrocatalyst for acidic water oxidation
Authors: Su Hui , Zhou Wanlin , Zhou Wu , Li Yuanli , Zheng Lirong , Zhang Hui , Liu Meihuan , Zhang Xiuxiu , Sun Xuan , Xu Yanzhi , Hu Fengchun , Zhang Jing , Hu Tiandou , Liu Qinghua , Wei Shiqiang
Published: October 2021

Uncovering the dynamics of active sites in the working conditions is crucial to realizing increased activity, enhanced stability and reduced cost of oxygen evolution reaction (OER) electrocatalysts in proton exchange membrane electrolytes. Herein, we identify at the atomic level potential-driven dynamic-coupling oxygen on atomically dispersed hetero-nitrogen-configured Ir sites (AD-HN-Ir) in the OER working conditions to successfully provide the atomically dispersed Ir electrocatalyst with ultrahigh electrochemical acidic OER activity. Using in-situ synchrotron radiation infrared and X-ray absorption spectroscopies, we directly observe that one oxygen atom is formed at the Ir active site with an O-hetero-Ir-N4 structure as a more electrophilic active centre in the experiment, which effectively promotes the generation of key *OOH intermediates under working potentials; this process is favourable for the dissociation of H2O over Ir active sites and resistance to over-oxidation and dissolution of the active sites. The optimal AD-HN-Ir electrocatalyst delivers a large mass activity of 2860 A gmetal−1 and a large turnover frequency of 5110 h−1 at a low overpotential of 216 mV (10 mA cm−2), 480–510 times larger than those of the commercial IrO2. More importantly, the AD-HN-Ir electrocatalyst shows no evident deactivation after continuous 100 h OER operation in an acidic medium.
Application of Er,Cr:YSGG laser versus photopolymerization after silver diamine fluoride in primary teeth
Authors: Hassan Mohamed , Bakhurji Eman , AlSheikh Rasha
Published: October 2021

Examine the effect of dental curing light and laser treatments applied after Silver Diamine Fluoride (SDF) on dentin hardness in carious primary molars. This in-vitro study consisted of 30 extracted primary molars with caries extending into dentin without pulpal involvement. The collected teeth were randomly divided into three groups: group 1: received SDF then Sub-ablative low-energy of Er,Cr:YSGG laser, group 2: received SDF followed by application of curing light for 40 s, group 3: had SDF treatment only. In all groups, 38% Ag (NH3)2F SDF was used. Vickers hardness test was performed on sound dentin below carious lesion. Kruskal–Wallis Test was used to determine the mean difference in dentin hardness of the groups at 5% Significance level using SPSS software. Surface hardness of sound dentin below the carious lesion was statistically significantly higher in the laser + SDF group (891.24 ± 37.33 kgf/mm2) versus the two other groups (Light cure + SDF = 266.65 ± 90.81 kgf/mm2 and SDF only = 117.91 ± 19.19 kgf/mm2) with p-value ≤ 0.001. Although Photopolymerization of SDF increases the surface hardness of sound dentin below the carious lesion, applying laser after SDF has the highest surface hardness due to the laser’s sub-ablation of dentin.
Magneto-optical binding in the near field
Authors: Edelstein Shulamit , García-Martín Antonio , Serena Pedro A. , Marqués Manuel I.
Published: October 2021

In this paper we show analytically and numerically the formation of a near-field stable optical binding between two identical plasmonic particles, induced by an incident plane wave. The equilibrium binding distance is controlled by the angle between the polarization plane of the incoming field and the dimer axis, for which we have calculated an explicit formula. We have found that the condition to achieve stable binding depends on the particle’s dielectric function and happens near the frequency of the dipole plasmonic resonance. The binding stiffness of this stable attaching interaction is four orders of magnitude larger than the usual far-field optical binding and is formed orthogonal to the propagation direction of the incident beam (transverse binding). The binding distance can be further manipulated considering the magneto-optical effect and an equation relating the desired equilibrium distance with the required external magnetic field is obtained. Finally, the effect induced by the proposed binding method is tested using molecular dynamics simulations. Our study paves the way to achieve complete control of near-field binding forces between plasmonic nanoparticles.
Rapid and accurate electrochemical sensor for food allergen detection in complex foods
Authors: Sundhoro Madanodaya , Agnihotra Srikanth R. , Khan Nazir D. , Barnes Abigail , BelBruno Joseph , Mendecki Lukasz
Published: October 2021

Food allergies are estimated to affect about 2–5% of adults and 6–8% of children, globally. Currently, the most effective strategy for food allergy management is stringent avoidance of the offending allergen. Unlike other major food allergens, soy is uniquely challenging to avoid due to its prevalence and insidiousness in a wide variety of foods, such as infant formulas. Recently, we demonstrated a simple, accurate, and consumer-friendly sensor using molecularly imprinted polymers (MIPs) for rapid detection of soy allergenic tracers in complex food matrices at clinically relevant levels. In this work, we build on these findings by subjecting MIP-based soy allergen sensors to test trials in 42 different food products, representing over 300 ingredients. Foods were selected based on their compositional complexity to capture a wide range of preparatory methods and processing conditions. In each case, the Allergy Amulet correctly reported on the presence or absence of soy allergen tracer in investigated samples and were subjected to immunoassay confirmatory analysis. The outcome of this research will help resolve persistent difficulties with commercial technologies in detecting allergenic tracers with minimal cross-interference in foods, and will give those with soy allergies the ability to easily, rapidly, and accurately identify and avoid foods with soy allergens.
Extraction of Rhododendron arboreum Smith flowers from the forest for the livelihood and rural income in Garhwal Himalaya, India
Authors: Chauhan D. S. , Lal Pankaj , Shrama A. K.
Published: October 2021

Rhododendron arboreum locally known as ‘Burans', that bears magnificent flowers is one of the valuable non timber forest produces (NTFPs) in Garhwal Himalaya. These flowers are good source of income for local populace and help them to their subsistence up to some extent. R. arboreum flower can help local population to improve their livelihoods if potential harvesting is carried out sustainably. An attempt has been made to estimate the flower yield, examine extraction techniques, marketing trends and various uses of flowers. Stratified random sampling method was carried out in eight sites varying in altitudes and geographic locations. Flower yield kg/ha for each site was calculated as standard process. Questionnaire based survey was carried out in selected villages for flower extraction and marketing trends. Projections of potential (probable/-could generate) income were made and cost–benefit analysis was also estimated. Tree density of R. arboreum ranked first and Q. leucotrichophora had second rank while 16–25 cm cbh class tree density for R. arboreum was found highest across the sites. Flower yield was significantly (p < 0.001) higher at Khirsu site with 26–35 and 46–55 cm cbh class. There was positively significant correlation (n = 446, p < 0.001, r = 0.53) between flower yield and actual cbh. Flower yield has a direct relation with size of tree whereas yield has been less impacted by the sites. Average yield of flowers across the sites was about 25.3 ton/ha. On average 30% households are engaged in the extraction and trade activities with the extraction rate of 25–350 kg/household/year. A net household income of Rs. 6000–37,000 (89–545 USD) per year was computed from Rhododendron flower extraction and marketing business. The total monetary benefit was significantly higher than the inputs for all value added items on a per day basis. R. arboreum plays important role in ecological and economic sustainability of poor rural people and unemployed youths in Himalayan region. This can reduce unemployment through development of small cottage industry and entrepreneurship at village level by making different food products i.e. juice, squash, sauce and pickle etc.
Analyzing a phenological anomaly in Yucca of the southwestern United States
Authors: Brenskelle Laura , Barve Vijay , Majure Lucas C. , Guralnick Rob P. , Li Daijiang
Published: October 2021

Yuccain the American desert Southwest typically flowers in early spring, but a well-documented anomalous bloom event occurred during an unusually cold and wet late fall and early winter 2018–2019. We used community science photographs to generate flowering presence and absence data. We fit phenoclimatic models to determine which climate variables are explanatory for normal flowering, and then we tested if the same conditions that drive normal blooming also drove the anomalous blooming event. Flowering forYucca brevifolia(Joshua tree) andYucca schidigera(Mojave yucca) is driven by complex, nonlinear interactions between daylength, temperature, and precipitation. To our surprise, early-season flowering odds are highest in colder and drier conditions, especially for Joshua trees, but increase with precipitation late-season. However, the models used to fit normal blooming overpredicted the number of anomalous blooms compared to what was actually observed. Thus, predicting anomalous flowering events remains a challenge for quantitative phenological models. Because our model overpredicted the number of anomalous blooms, there are likely other factors, such as biotic interactions or other seasonal factors, which may be especially important in controlling what is presumed to be rare, out-of-season flowering in desert-adaptedYucca.
Screening and predicted value of potential biomarkers for breast cancer using bioinformatics analysis
Authors: Zeng Xiaoyu , Shi Gaoli , He Qiankun , Zhu Pingping
Published: October 2021

Breast cancer is the most common cancer and the leading cause of cancer-related deaths in women. Increasing molecular targets have been discovered for breast cancer prognosis and therapy. However, there is still an urgent need to identify new biomarkers. Therefore, we evaluated biomarkers that may aid the diagnosis and treatment of breast cancer. We searched three mRNA microarray datasets (GSE134359, GSE31448 and GSE42568) and identified differentially expressed genes (DEGs) by comparing tumor and non-tumor tissues using GEO2R. Functional and pathway enrichment analyses of the DEGs were performed using the DAVID database. The protein–protein interaction (PPI) network was plotted with STRING and visualized using Cytoscape. Module analysis of the PPI network was done using MCODE. The associations between the identified genes and overall survival (OS) were analyzed using an online Kaplan–Meier tool. The redundancy analysis was conducted by DepMap. Finally, we verified the screened HUB gene at the protein level. A total of 268 DEGs were identified, which were mostly enriched in cell division, cell proliferation, and signal transduction. The PPI network comprised 236 nodes and 2132 edges. Two significant modules were identified in the PPI network. Elevated expression of the genes Discs large-associated protein 5 (DLGAP5), aurora kinase A (AURKA), ubiquitin-conjugating enzyme E2 C (UBE2C), ribonucleotide reductase regulatory subunit M2(RRM2), kinesin family member 23(KIF23), kinesin family member 11(KIF11), non-structural maintenance of chromosome condensin 1 complex subunit G (NCAPG), ZW10 interactor (ZWINT), and denticleless E3 ubiquitin protein ligase homolog(DTL) are associated with poor OS of breast cancer patients. The enriched functions and pathways included cell cycle, oocyte meiosis and the p53 signaling pathway. The DEGs in breast cancer have the potential to become useful targets for the diagnosis and treatment of breast cancer.
Modulation of the N13 component of the somatosensory evoked potentials in an experimental model of central sensitization in humans
Authors: Di Lionardo A. , Di Stefano G. , Leone C. , Di Pietro G. , Sgro E. , Malara E. , Cosentino C. , Mollica C. , Blockeel A. J. , Caspani O. , Garcia-Larrea L. , Mouraux A. , Treede R. D. , Phillips K. G. , Valeriani M. , Truini Andrea
Published: October 2021

The N13 component of somatosensory evoked potential (N13 SEP) represents the segmental response of dorsal horn neurons. In this neurophysiological study, we aimed to verify whether N13 SEP might reflect excitability changes of dorsal horn neurons during central sensitization. In 22 healthy participants, we investigated how central sensitization induced by application of topical capsaicin to the ulnar nerve territory of the hand dorsum modulated N13 SEP elicited by ulnar nerve stimulation. Using a double-blind placebo-controlled crossover design, we also tested whether pregabalin, an analgesic drug with proven efficacy on the dorsal horn, influenced capsaicin-induced N13 SEP modulation. Topical application of capsaicin produced an area of secondary mechanical hyperalgesia, a sign of central sensitization, and increased the N13 SEP amplitude but not the peripheral N9 nor the cortical N20-P25 amplitude. This increase in N13 SEP amplitude paralleled the mechanical hyperalgesia and persisted for 120 min. Pregabalin prevented the N13 SEP modulation associated with capsaicin-induced central sensitization, whereas capsaicin application still increased N13 SEP amplitude in the placebo treatment session. Our neurophysiological study showed that capsaicin application specifically modulates N13 SEP and that this modulation is prevented by pregabalin, thus suggesting that N13 SEP may reflect changes in dorsal horn excitability and represent a useful biomarker of central sensitization in human studies.
Influence of native ureolytic microbial community on biocementation potential of Sporosarcina pasteurii
Authors: Murugan Raja , Suraishkumar G. K. , Mukherjee Abhijit , Dhami Navdeep K.
Published: October 2021

Microbially induced calcium carbonate precipitation (MICP)/Biocementation has emerged as a promising technique for soil engineering applications. There are chiefly two methods by which MICP is applied for field applications including biostimulation and bioaugmentation. Although bioaugmentation strategy using efficient ureolytic biocementing culture of Sporosarcina pasteurii is widely practiced, the impact of native ureolytic microbial communities (NUMC) on CaCO3 mineralisation via S. pasteurii has not been explored. In this paper, we investigated the effect of different concentrations of NUMC on MICP kinetics and biomineral properties in the presence and absence of S. pasteurii. Kinetic analysis showed that the biocementation potential of S. pasteurii is sixfold higher than NUMC and is not significantly impacted even when the concentration of the NUMC is eight times higher. Micrographic results revealed a quick rate of CaCO3 precipitation by S. pasteurii leading to generation of smaller CaCO3 crystals (5–40 µm), while slow rate of CaCO3 precipitation by NUMC led to creation of larger CaCO3 crystals (35–100 µm). Mineralogical results showed the predominance of calcite phase in both sets. The outcome of current study is crucial for tailor-made applications of MICP.