bluuebunny/crossref_metadata_2025 huggingface dataset:
Delta Deposits on Mars: A Global Perspective
Authors: De Toffoli B. , Plesa A.‐C. , Hauber E. , Breuer D.
Published: August 2021

Deltas have long been considered a constraining element to reconstruct the water level of an ancient ocean that may have once occupied the northern lowlands of Mars, and recently this hypothesis started to be challenged. We investigate this hypothesis and present a global inventory of fan‐shaped features showing typical deltaic traits across the entire Martian surface. For each element, we provide descriptive details and classifications based on morphology, location, and relation with characterizing environmental features. In this catalog of 161 deltas, we identified only six having high potential to constrain an oceanic paleoshoreline. Nonetheless, age and location of these candidates display discrepancies with what was previously suggested from independent data sets about shoreline age and locations. Our analyses hence indicate that deltas alone are insufficient to delineate a globally consistent ancient oceanic shoreline, but they have the potential to locally constrain the water level both in space and time.
Turbulence Analysis in Long‐Range‐Transported Saharan Dust Layers With Airborne Lidar
Authors: Gutleben M. , Groß S.
Published: August 2021

In this study, turbulent properties of long‐range‐transported Saharan dust layers are investigated for the first time using airborne backscatter and water vapor lidar measurements. This is achieved via the utilization of spectral signal decomposition to the collected lidar data. Additionally, measurements by dropsondes are analyzed in detail. The presented measurements were conducted during the Next‐Generation Aircraft Remote Sensing for Validation Studies II in boreal summer 2016 upstream Barbados. An analysis of two case studies shows that the derived mesoscale turbulence cascades inside the transported dust layers follow the predicted slopes for turbulence of −5/3. The turbulent nature of the Saharan air layers (SALs) is additionally indicated by small Richardson numbers, which are derived from data collected by launched dropsondes. These presented results also fortify the hypothesis that turbulence inside dust layers helps to keep large mineral dust particles aloft for a longer time, so that they can still be found after long‐range transport.
Earth's Albedo 1998–2017 as Measured From Earthshine
Authors: Goode P. R. , Pallé E. , Shoumko A. , Shoumko S. , Montañes‐Rodriguez P. , Koonin S. E.
Published: August 2021

The reflectance of the Earth is a fundamental climate parameter that we measured from Big Bear Solar Observatory between 1998 and 2017 by observing the earthshine using modern photometric techniques to precisely determine daily, monthly, seasonal, yearly and decadal changes in terrestrial albedo from earthshine. We find the inter‐annual fluctuations in albedo to be global, while the large variations in albedo within individual nights and seasonal wanderings tend to average out over each year. We measure a gradual, but climatologically significant 0.5 decline in the global albedo over the two decades of data. We found no correlation between the changes in the terrestrial albedo and measures of solar activity. The inter‐annual pattern of earthshine fluctuations are in good agreement with those measured by CERES (data began in 2001) even though the satellite observations are sensitive to retroflected light while earthshine is sensitive to wide‐angle reflectivity. The CERES decline is about twice that of earthshine.
Unsupervised Deep Clustering of Seismic Data: Monitoring the Ross Ice Shelf, Antarctica
Authors: Jenkins William F. , Gerstoft Peter , Bianco Michael J. , Bromirski Peter D.
Published: August 2021

Advances in machine learning (ML) techniques and computational capacity have yielded state‐of‐the‐art methodologies for processing, sorting, and analyzing large seismic data sets. In this study, we consider an application of ML for automatically identifying dominant types of impulsive seismicity contained in observations from a 34‐station broadband seismic array deployed on the Ross Ice Shelf (RIS), Antarctica from 2014 to 2017. The RIS seismic data contain signals and noise generated by many glaciological processes that are useful for monitoring the integrity and dynamics of ice shelves. Deep clustering was employed to efficiently investigate these signals. Deep clustering automatically groups signals into hypothetical classes without the need for manual labeling, allowing for the comparison of their signal characteristics and spatial and temporal distribution with potential source mechanisms. The method uses spectrograms as input and encodes their salient features into a lower‐dimensional latent representation using an autoencoder, a type of deep neural network. For comparison, two clustering methods are applied to the latent data: a Gaussian mixture model (GMM) and deep embedded clustering (DEC). Eight classes of dominant seismic signals were identified and compared with environmental data such as temperature, wind speed, tides, and sea ice concentration. The greatest seismicity levels occurred at the RIS front during the 2016 El Niño summer, and near grounding zones near the front throughout the deployment. We demonstrate the spatial and temporal association of certain classes of seismicity with seasonal changes at the RIS front, and with tidally driven seismicity at Roosevelt Island.
Rock Physics Model of Shale: Predictive Aspect
Authors: Asaka M. , Holt R. M. , Bakk A.
Published: August 2021

Shales often show strong elastic anisotropy that originate from the alignment and platy nature of its constituent minerals. Despite its impact on amplitude variation with offset response and seismic time‐shifts, elastic anisotropy of shales is, however, often ignored since it is difficult to measure enough parameters in the field. Being able to correctly estimate anisotropy parameters of shales can therefore significantly improve seismic reservoir characterization. A predictive model is developed by combining existing theories. Properties of locally aligned clay platelets, called domains, are calculated using a rock physics model based on the anisotropic Hashin‐Shtrikman estimates. The effect of domain orientation is then accounted for by the orientation distribution function of domains. The applicability of the model was investigated using existing core measurements. Interesting findings include: (a) most of modeled anisotropy parameters are consistent with the measured values even though only limited information was used for the model parameters optimization, and (b) most of optimized interplatelet medium properties are consistent with the saturated fluid and small interplatelet medium shear modulus suggested by existing studies. These findings imply that the model can be used to predict anisotropy parameters from limited information.
Regionalization for Ungauged Catchments — Lessons Learned From a Comparative Large‐Sample Study
Authors: Pool Sandra , Vis Marc , Seibert Jan
Published: August 2021

Model parameter values for ungauged catchments can be regionalized from hydrologically similar gauged catchments. Achieving reliable and robust predictions in ungauged catchments by regionalization, however, is still a major challenge. Here, we conduct a comparative assessment of 19 regionalization approaches based on previously published literature to contribute new insights into their performance in different geographic regions. The approaches use geographical information, physical catchment attributes, hydrological signatures, or a combination thereof to select donor catchments and to subsequently transfer their entire parameter sets to the ungauged receiver catchment. Each regionalization approach was tested in a leave‐one‐out cross‐validation with a bucket‐type catchment model (the HBV model) using 671 gauged catchments in the United States with a diverse hydroclimatology. We then evaluated regionalization performance for several hydrograph aspects, compared it against calibration and regionalization benchmarks, and linked it to catchment descriptors. The results of this large‐sample regionalization study can be summarized in three major lessons: (a) Catchments can benefit from a well‐chosen regionalization approach independent of their geographic region and independent of how well they can be modeled or regionalized at best. (b) Almost perfect donors exist for most catchments and an excellent relative model performance can be reached for most catchments with current regionalization approaches. This implies that there is considerable potential for improvement in the prediction in ungauged catchments. (c) The ranking of regionalization approaches depends on how the predicted hydrographs are evaluated. These findings indicate that a multi‐criteria evaluation is essential for a robust assessment of regionalization performance.
Predicting Characteristics of the Water Cycle From Scaling Relationships
Authors: Hunt A. G. , Faybishenko B. , Ghanbarian B.
Published: August 2021

Over multi‐decadal time scales, assuming that changes in subsurface water storage are negligible, the continental precipitative water flux, P, can be divided into two principal components, Q (run‐off, including soil infiltration and groundwater recharge) and ET (evapotranspiration). Taking into account a broadly applied Budyko's phenomenology to describe the relationship of ET/P as a function of PET/P, where PET is the potential evapotranspiration, we propose a theoretical framework for predicting characteristics of the water cycle from scaling relationships. In this framework, the ecosystem net primary productivity is expressed in terms of soil formation and vegetation growth, which is mathematically optimized with respect to the water partitioning, generating directly the value ET/P. The mathematical optimization is based on the general ecological principle that dominant ecosystems tend to be those that, for any given conditions, maximize conversion of atmospheric carbon to biomass. It is shown that application of the results of mathematical optimization to water‐limited ecosystems is possible by applying the optimization only to a vegetation covered portion of the surface. For energy‐limited ecosystems, the optimization can be applied only to a portion of the precipitation equal to PET, assuming that the remaining P simply runs off. We use theoretical and actual values of plant root fractal dimensionalities, df, to predict ranges of ET/P as a function of PET/P for 0 ≤ PET/P ≤ 1 and compare with annual and multi‐decadal means of ET/P. By comparing the developed approach with a large amount of data collected from the literature, we demonstrate its successful applications to both water‐ and energy‐limited systems.
0.75 Gbit/s high-speed classical key distribution with mode-shift keying chaos synchronization of Fabry–Perot lasers
Authors: Gao Hua , Wang Anbang , Wang Longsheng , Jia Zhiwei , Guo Yuanyuan , Gao Zhensen , Yan Lianshan , Qin Yuwen , Wang Yuncai
Published: August 2021

High-speed physical key distribution is diligently pursued for secure communication. In this paper, we propose and experimentally demonstrate a scheme of high-speed key distribution using mode-shift keying chaos synchronization between two multi-longitudinal-mode Fabry–Perot lasers commonly driven by a super-luminescent diode. Legitimate users dynamically select one of the longitudinal modes according to private control codes to achieve mode-shift keying chaos synchronization. The two remote chaotic light waveforms are quantized to generate two raw random bit streams, and then those bits corresponding to chaos synchronization are sifted as shared keys by comparing the control codes. In this method, the transition time, i.e., the chaos synchronization recovery time is determined by the rising time of the control codes rather than the laser transition response time, so the key distribution rate is improved greatly. Our experiment achieved a 0.75-Gbit/s key distribution rate with a bit error rate of 3.8 × 10−3 over 160-km fiber transmission with dispersion compensation. The entropy rate of the laser chaos is evaluated as 16 Gbit/s, which determines the ultimate final key rate together with the key generation ratio. It is therefore believed that the method pays a way for Gbit/s physical key distribution.
Silencing of O-linked N-acetylglucosamine transferase ameliorates hypercalcemia-induced neurotoxicity in renal failure by regulating EZH2/KLF2/CXCL1 axis
Authors: Cao Yaochen , Chen Xin , Sun Hongming
Published: August 2021

Hypocalcemia, associated with Calcium neurotoxicity, has been reported to induce nerve dysfunction, which is a significant problem of renal failure. This study identifies a molecular mechanism of the O-linked N-acetylglucosamine transferase (OGT)-mediated enhancer of zeste homolog 2 (EZH2)/krüppel-like factor 2 (KLF2)/chemokine (C-X-C motif) ligand 1 (CXCL1) axis underlying the hypercalcemia-induced nerve injury in renal failure. Bioinformatics analyses were used to screen out the key factors in hypercalcemia-induced nerve injury in renal failure. Chronic kidney disease (CKD) was induced by an adenine diet in mice, followed by injection of adenovirus vector carrying short hairpin RNA targeting OGT, followed by behavioral tests and collection of the cerebral cortex for primary neurons. Calcium level in neurons was measured by Fluo-4-am and Perkin Elmer+ Operetta. Neuronal apoptosis and viability were detected by flow cytometry and the MTS method. The binding of EZH2 to KLF2 promoter was verified by chromatin immunoprecipitation assay. The concentration of Ca2+ in brain tissues of CKD model mice was increased, and nerve functions were obviously damaged. High expression of OGT occurred in kidney tissue of CKD model mice. Silencing OGT reduced the hypercalcemia-induced toxicity of neurons by inhibiting the expression of EZH2, which elevated the expression of CXCL1 in primary neurons by diminishing KLF2. Silencing OGT attenuated hypercalcemia-induced neurotoxicity by regulating the EZH2/KLF2/CXCL1 axis. In vivo experiments further confirmed that silencing OGT could reduce hypercalcemia-induced nerve injury in CKD mice. Taken together, silencing OGT downregulates EZH2, which increases the expression of KLF2 and then decreases the expression of CXCL1, thus alleviating hypercalcemia-induced nerve injury in renal failure.
Increased expression of fragmented tRNA promoted neuronal necrosis
Authors: Cao Yanyan , Liu Kai , Xiong Ying , Zhao Chunyue , Liu Lei
Published: August 2021

Neuronal necrosis induced by excessive glutamate release is well known to contribute morbidity and mortality in ischemic stroke. Over the past decades, strategies on targeting glutamate receptor did not achieve desirable clinical outcomes. Finding the downstream mechanism of the glutamate receptor activation may provide new targets to suppress the cell death. Previously, our study demonstrated that the increase of H3K4 trimethylation (H3K4me3) played a key detrimental role on neuronal necrosis; however, the mechanism of this histone modification is unclear. Through a genome-wide small RNA sequencing, we identified several tRNA-derived fragments (tRFs) and piwi-interacting RNA (piRNAs) species were enriched in glutamate-induced neuronal necrosis in rat primary neuron cultures, and this enrichment was dependent on the H3K4me3 increase. Strikingly, when we transfected several synthesized tRFs and piRNA species into neurons, the tRFs but not the piRNAs induced neuron swelling and death. The cell death morphology recapitulated neuronal necrosis induced by glutamate. For the cytotoxic effect of tRFs, our data suggested that protein synthesis was inhibited likely through induction of ribosomal stalling. By proteomic analysis of tRFs effect, the most affected pathway was enriched in the mitochondrial metabolism. Consistently, mitochondrial fragmentation was increased in neuronal necrosis, and suppression of mitochondrial fission by genetic manipulation or drug rescued neuronal necrosis. Using our previously established Drosophila model of neuronal necrosis, we found that inhibition of small RNA transcription, blocking RNA transport from nucleus to cytosol, or knocking down Ago1/2 to suppress the RNA interference effect, all rescued the fly death, suggesting transcription and processing of small RNAs contribute to neuronal necrosis. Together, these results indicate that the abnormal transcription of tRFs may play a key role downstream of the H3K4me3 increase. This provides a potential new strategy to suppress neuronal necrosis.
LncRNA coordinates Hippo and mTORC1 pathway activation in cancer
Authors: Zhang Shugeng , Liang Shuhang , Wu Dehai , Guo Hongrui , Ma Kun , Liu Lianxin
Published: August 2021

The Hippo and mammalian target of rapamycin complex 1 (mTORC1) pathways are the two predominant pathways that regulate tumour growth and metastasis. Therefore, we explored the potential crosstalk between these two functionally relevant pathways to coordinate their tumour growth-control functions. We found that a Hippo pathway-related long noncoding RNA, HPR, directly interacts with Raptor, an essential component of mTORC1, to upregulate mTORC1 activation by impairing the phosphorylation of Raptor by AMPK. Knockdown or knockout of HPR in breast cancer and cholangiocarcinoma cells led to a reduction in tumour growth. Compared with HPR WT cells, HPR-overexpressing cells exhibited nuclear accumulation of YAP1, and significantly blocked the downregulation of mTORC1 signalling induced by energy stress. Thus, our study reveals a direct link between the Hippo and mTORC1 pathways in the control of tumour growth.
CHFR regulates chemoresistance in triple-negative breast cancer through destabilizing ZEB1
Authors: Luo Hong , Zhou Zhicheng , Huang Shan , Ma Mengru , Zhao Manyu , Tang Lixu , Quan Yuan , Zeng Yiming , Su Li , Kim Jongchan , Zhang Peijing
Published: August 2021

Failures to treat triple-negative breast cancer (TNBC) are mainly due to chemoresistance or radioresistance. We and others previously discovered that zinc finger E-box-binding homeobox 1 (ZEB1) is a massive driver causing these resistance. However, how to dynamically modulate the intrinsic expression of ZEB1 during cell cycle progression is elusive. Here integrated affinity purification combined with mass spectrometry and TCGA analysis identify a cell cycle-related E3 ubiquitin ligase, checkpoint with forkhead and ring finger domains (CHFR), as a key negative regulator of ZEB1 in TNBC. Functional studies reveal that CHFR associates with and decreases ZEB1 expression in a ubiquitinating-dependent manner and that CHFR represses fatty acid synthase (FASN) expression through ZEB1, leading to significant cell death of TNBC under chemotherapy. Intriguingly, a small-molecule inhibitor of HDAC under clinical trial, Trichostatin A (TSA), increases the expression of CHFR independent of histone acetylation, thereby destabilizes ZEB1 and sensitizes the resistant TNBC cells to conventional chemotherapy. In patients with basal-like breast cancers, CHFR levels significantly correlates with survival. These findings suggest the therapeutic potential for targeting CHFR-ZEB1 signaling in resistant malignant breast cancers.
Programming ultrasensitive threshold response through chemomechanical instability
Authors: Kim Young-Joo , Park Junho , Lee Jae Young , Kim Do-Nyun
Published: August 2021

The ultrasensitive threshold response is ubiquitous in biochemical systems. In contrast, achieving ultrasensitivity in synthetic molecular structures in a controllable way is challenging. Here, we propose a chemomechanical approach inspired by Michell’s instability to realize it. A sudden reconfiguration of topologically constrained rings results when the torsional stress inside reaches a critical value. We use DNA origami to construct molecular rings and then DNA intercalators to induce torsional stress. Michell’s instability is achieved successfully when the critical concentration of intercalators is applied. Both the critical point and sensitivity of this ultrasensitive threshold reconfiguration can be controlled by rationally designing the cross-sectional shape and mechanical properties of DNA rings.
NTS Prlh overcomes orexigenic stimuli and ameliorates dietary and genetic forms of obesity
Authors: Cheng Wenwen , Ndoka Ermelinda , Maung Jessica N. , Pan Warren , Rupp Alan C. , Rhodes Christopher J. , Olson David P. , Myers Martin G.
Published: August 2021

Calcitonin receptor (Calcr)-expressing neurons of the nucleus tractus solitarius (NTS; CalcrNTS cells) contribute to the long-term control of food intake and body weight. Here, we show that Prlh-expressing NTS (PrlhNTS) neurons represent a subset of CalcrNTS cells and that Prlh expression in these cells restrains body weight gain in the face of high fat diet challenge in mice. To understand the relationship of PrlhNTS cells to hypothalamic feeding circuits, we determined the ability of PrlhNTS-mediated signals to overcome enforced activation of AgRP neurons. We found that PrlhNTS neuron activation and Prlh overexpression in PrlhNTS cells abrogates AgRP neuron-driven hyperphagia and ameliorates the obesity of mice deficient in melanocortin signaling or leptin. Thus, enhancing Prlh-mediated neurotransmission from the NTS dampens hypothalamically-driven hyperphagia and obesity, demonstrating that NTS-mediated signals can override the effects of orexigenic hypothalamic signals on long-term energy balance.
Hybrid halide perovskite neutron detectors
Authors: Andričević Pavao , Náfrádi Gábor , Kollár Márton , Náfrádi Bálint , Lilley Steven , Kinane Christy , Frajtag Pavel , Sienkiewicz Andrzej , Pautz Andreas , Horváth Endre , Forró László
Published: August 2021

Interest in fast and easy detection of high-energy radiation (x-, γ-rays and neutrons) is closely related to numerous practical applications ranging from biomedicine and industry to homeland security issues. In this regard, crystals of hybrid halide perovskite have proven to be excellent detectors of x- and γ-rays, offering exceptionally high sensitivities in parallel to the ease of design and handling. Here, we demonstrate that by assembling a methylammonium lead tri-bromide perovskite single crystal (CH3NH3PbBr3 SC) with a Gadolinium (Gd) foil, one can very efficiently detect a flux of thermal neutrons. The neutrons absorbed by the Gd foil turn into γ-rays, which photo-generate charge carriers in the CH3NH3PbBr3 SC. The induced photo-carriers contribute to the electric current, which can easily be measured, providing information on the radiation intensity of thermal neutrons. The dependence on the beam size, bias voltage and the converting distance is investigated. To ensure stable and efficient charge extraction, the perovskite SCs were equipped with carbon electrodes. Furthermore, other types of conversion layers were also tested, including borated polyethylene sheets as well as Gd grains and Gd2O3 pellets directly engulfed into the SCs. Monte Carlo N-Particle (MCNP) radiation transport code calculations quantitatively confirmed the detection mechanism herein proposed.
Simultaneous EEG-fMRI reveals theta network alterations during reward feedback processing in borderline personality disorder
Authors: Schauer Paul A. , Rauh Jonas , Biedermann Sarah V. , Haaf Moritz , Steinmann Saskia , Leicht Gregor , Mulert Christoph
Published: August 2021

Previous studies using imaging techniques such as electroencephalography (EEG) or functional magnetic resonance imaging (fMRI) have identified neurophysiological markers of impaired feedback processing in patients with Borderline Personality Disorder (BPD). These mainly include reduced oscillatory activity in the theta frequency range in the EEG and altered activations in frontal and striatal regions in fMRI studies. The aim of the present study is to integrate these results using a coupling of simultaneously recorded EEG and fMRI. Simultaneous EEG (64-channel) and fMRI (3-Tesla Siemens Prisma) was recorded whilst participants (19 BPD patients and 18 controls) performed a gambling task. Data was analysed for the two imaging techniques separately as well as in a single-trial coupling of both modalities. Evoked theta oscillatory power as a response to loss feedback was reduced in BPD patients. EEG-fMRI coupling revealed an interaction between feedback valence and group in prefrontal regions centering in the dorsolateral prefrontal cortex (dlPFC), with healthy controls showing stronger modulation by theta responses during loss when compared to gain feedback and the opposite effect in BPD patients. Our results show multiple alterations in the processing of feedback in BPD, which were partly linked to impulsivity. The dlPFC was identified as the seed of theta-associated activation differences.
The importance of the UGT1A1 variants in the development of osteopenia and osteoporosis in postmenopausal women
Authors: Bogacz Anna , Kamiński Adam , Łochyńska Małgorzata , Uzar Izabela , Gorący Jarosław , Kotrych Daniel , Seremak-Mrozikiewicz Agnieszka , Czerny Bogusław
Published: August 2021

The UDP-glucuronosyltransferase 1A1 (UGT1A1) is involved in the process of estrogen conjugation and elimination. The aim of the study was to analyze whether the UGT1A1 genetic variants are associated with the development of osteopenia and osteoporosis in postmenopausal women. The analysis of the rs4148323 (UGT1A1*6) and rs3064744 (UGT1A1*28) variants in the UGT1A1 gene was conducted using real-time PCR. A significant correlation was observed between the genotypes of the rs3064744 (UGT1A1*28) sequence variant and body mass in women with osteoporosis. The analysis of the Z-score values revealed that women with osteoporosis and carrying the 6/6 variant had the lowest Z-score values as compared to women with the 6/7 and the 7/7 variants (− 1.966 ± 0.242 vs. − 1.577 ± 0.125 and − 1.839 ± 0.233). In addition, the odds ratio for the investigated genotypes (6/6, 6/7, 7/7) indicated an increased risk for osteopenia and osteoporosis in women with the 7/7 homozygous genotype. The analysis of the frequencies of the GG, GA and AA genotypes of the rs4148323 UGT1A1 gene showed no statistically significant differences between the groups. Our analysis revealed that the UGT1A1 rs3064744 variant may affect the risk of developing osteoporosis in postmenopausal Polish women. The UGT1A1 rs4148323 variant is not directly associated with the development of osteopenia and osteoporosis.
The impact of face masks on interpersonal trust in times of COVID-19
Authors: Malik Samreen , Mihm Benedikt , Reichelt Malte
Published: August 2021

Despite the widespread use of face masks to combat COVID-19, little is known about their social and behavioral consequences. To understand the impact of face masks on interpersonal trust, we designed a novel experiment to assess the causal impact of face mask use on whether individuals follow economically relevant advice from a stranger. From a survey of more than 2000 US citizens, conducted during July and August 2020, we find that almost 5% fewer individuals trust advice when it is given by someone wearing a mask than when it is given by someone not wearing a mask. While, surprisingly, health-related risks do not seem to alter the way masks affect trust, the effects of masks are particularly large among individuals whose households face economic risks due to COVID-19 and those with below-average normative beliefs about mask wearing. Our results highlight the non-health-related meaning that face masks have developed during COVID-19 and suggest that mask use undermines trust in others among a substantial share of the US population.
Weakly supervised underwater fish segmentation using affinity LCFCN
Authors: Laradji Issam H. , Saleh Alzayat , Rodriguez Pau , Nowrouzezahrai Derek , Azghadi Mostafa Rahimi , Vazquez David
Published: August 2021

Estimating fish body measurements like length, width, and mass has received considerable research due to its potential in boosting productivity in marine and aquaculture applications. Some methods are based on manual collection of these measurements using tools like a ruler which is time consuming and labour intensive. Others rely on fully-supervised segmentation models to automatically acquire these measurements but require collecting per-pixel labels which are also time consuming. It can take up to 2 minutes per fish to acquire accurate segmentation labels. To address this problem, we propose a segmentation model that can efficiently train on images labeled with point-level supervision, where each fish is annotated with a single click. This labeling scheme takes an average of only 1 second per fish. Our model uses a fully convolutional neural network with one branch that outputs per-pixel scores and another that outputs an affinity matrix. These two outputs are aggregated using a random walk to get the final, refined per-pixel output. The whole model is trained end-to-end using the localization-based counting fully convolutional neural network (LCFCN) loss and thus we call our method Affinity-LCFCN (A-LCFCN). We conduct experiments on the DeepFish dataset, which contains several fish habitats from north-eastern Australia. The results show that A-LCFCN outperforms a fully-supervised segmentation model when the annotation budget is fixed. They also show that A-LCFCN achieves better segmentation results than LCFCN and a standard baseline.
A comparative recombination analysis of human coronaviruses and implications for the SARS-CoV-2 pandemic
Authors: Pollett Simon , Conte Matthew A. , Sanborn Mark , Jarman Richard G. , Lidl Grace M. , Modjarrad Kayvon , Maljkovic Berry Irina
Published: August 2021

The SARS-CoV-2 pandemic prompts evaluation of recombination in human coronavirus (hCoV) evolution. We undertook recombination analyses of 158,118 public seasonal hCoV, SARS-CoV-1, SARS-CoV-2 and MERS-CoV genome sequences using the RDP4 software. We found moderate evidence for 8 SARS-CoV-2 recombination events, two of which involved the spike gene, and low evidence for one SARS-CoV-1 recombination event. Within MERS-CoV, 229E, OC43, NL63 and HKU1 datasets, we noted 7, 1, 9, 14, and 1 high-confidence recombination events, respectively. There was propensity for recombination breakpoints in the non-ORF1 region of the genome containing structural genes, and recombination severely skewed the temporal structure of these data, especially for NL63 and OC43. Bayesian time-scaled analyses on recombinant-free data indicated the sampled diversity of seasonal CoVs emerged in the last 70 years, with 229E displaying continuous lineage replacements. These findings emphasize the importance of genomic based surveillance to detect recombination in SARS-CoV-2, particularly if recombination may lead to immune evasion.
N-Acetylcysteine prevents amyloid-β secretion in neurons derived from human pluripotent stem cells with trisomy 21
Authors: Toshikawa Hiromitsu , Ikenaka Akihiro , Li Li , Nishinaka-Arai Yoko , Niwa Akira , Ashida Akira , Kazuki Yasuhiro , Nakahata Tatsutoshi , Tamai Hiroshi , Russell David W. , Saito Megumu K.
Published: August 2021

Down syndrome (DS) is caused by the trisomy of chromosome 21. Among the many disabilities found in individuals with DS is an increased risk of early-onset Alzheimer's disease (AD). Although higher oxidative stress and an upregulation of amyloid β (Aβ) peptides from an extra copy of the APP gene are attributed to the AD susceptibility, the relationship between the two factors is unclear. To address this issue, we established an in vitro cellular model using neurons differentiated from DS patient-derived induced pluripotent stem cells (iPSCs) and isogenic euploid iPSCs. Neurons differentiated from DS patient-derived iPSCs secreted more Aβ compared to those differentiated from the euploid iPSCs. Treatment of the neurons with an antioxidant, N-acetylcysteine, significantly suppressed the Aβ secretion. These findings suggest that oxidative stress has an important role in controlling the Aβ level in neurons differentiated from DS patient-derived iPSCs and that N-acetylcysteine can be a potential therapeutic option to ameliorate the Aβ secretion.
Tropical cyclones shape mangrove productivity gradients in the Indian subcontinent
Authors: Rasquinha Dina Nethisa , Mishra Deepak R.
Published: August 2021

Recent literature on the impact of cyclones on mangrove forest productivity indicates that nutrient fertilizations aided by tropical cyclones enhance the productivity of mangrove forests. We probe the implications of these predictions in the context of Indian mangroves to propose potential future directions for mangrove research in the subcontinent. First, we look at the time series trend (2000–2020) in satellite-derived gross primary productivity (GPP) datasets for seven mangrove forests across the country’s coastline. Second, we compare seasonal changes in soil nutrient levels for a specific site to further the arguments proposed in the literature and investigate the role of potential drivers of mangrove productivity. We find overall increasing trends for GPP over the past two decades for all seven mangrove sites with seasonal fluctuations closely connected to the tropical storm activities for three sites (Bhitarkanika, Pichavaram, and Charao). Additionally, organic carbon and nitrogen levels showed no significant trend, but phosphorus levels were higher during the post-monsoon-winter period for Bhitarkanika. Our findings expand the predictions of previous studies that emphasized the role of storm-induced nutrient fluxes and freshwater supply as primary drivers of productivity gradients in mangroves. Our study provides insights on how mangrove productivity may change with fluctuating frequency and magnitude of cyclones under a changing climate, implying the need for more mechanistic studies in understanding the long-term impact on mangrove productivity in the region.
Holiday gatherings, mobility and SARS-CoV-2 transmission: results from 10 US states following Thanksgiving
Authors: Mehta Shruti H. , Clipman Steven J. , Wesolowski Amy , Solomon Sunil S.
Published: August 2021

Public health officials discouraged travel and non-household gatherings for Thanksgiving, but data suggests that travel increased over the holidays. The objective of this analysis was to assess associations between holiday gatherings and SARS-CoV-2 positivity in the weeks following Thanksgiving. Using an online survey, we sampled 7770 individuals across 10 US states from December 4–18, 2020, about 8–22 days post-Thanksgiving. Participants were asked about Thanksgiving, COVID-19 symptoms, and SARS-CoV-2 testing and positivity in the prior 2 weeks. Logistic regression was used to identify factors associated with SARS-CoV-2 positivity and COVID-19 symptoms in the weeks following Thanksgiving. An activity score measured the total number of non-essential activities an individual participated in the prior 2 weeks. The probability of community transmission was estimated using Markov Chain Monte Carlo (MCMC) methods. While 47.2% had Thanksgiving at home with household members, 26.9% had guests and 25.9% traveled. There was a statistically significant interaction between how people spent Thanksgiving, the frequency of activities, and SARS-CoV-2 test positivity in the prior 2 weeks (p < 0.05). Those who had guests for Thanksgiving or traveled were only more likely to test positive for SARS-CoV-2 if they also had high activity (e.g., participated in > one non-essential activity/day in the prior 2 weeks). Had individuals limited the number and frequency of activities post-Thanksgiving, cases in surveyed individuals would be reduced by > 50%. As travel continues to increase and the more contagious Delta variant starts to dominate transmission, it is critical to promote how to gather in a “low-risk” manner (e.g., minimize other non-essential activities) to mitigate the need for nationwide shelter-at-home orders.
Photobiomodulation as an antioxidant substitute in post-thawing trauma of human stem cells from the apical papilla
Authors: Choi Woori , Baik Ku Youn , Jeong Seung , Park Sangbae , Kim Jae Eun , Kim Hong Bae , Chung Jong Hoon
Published: August 2021

Cryopreservation, the most common method of preserving stem cells, requires post-processing because it produces trauma to the cells. Post-thawing trauma typically induces cell death, elevates reactive oxygen species (ROS) concentration, and lowers mitochondrial membrane potential (MMP). Although this trauma has been solved using antioxidants, we attempted to use photobiomodulation (PBM) instead of chemical treatment. We used a 950-nm near-infrared LED to create a PBM device and chose a pulsed-wave mode of 30 Hz and a 30% duty cycle. Near-infrared radiation (NIR) at 950 nm was effective in reducing cell death caused by hydrogen peroxide induced-oxidative stress. Cryodamage also leads to apoptosis of cells, which can be avoided by irradiation at 950 nm NIR. Irradiation as post-processing for cryopreservation had an antioxidant effect that reduced both cellular and mitochondrial ROS. It also increased mitochondrial mass and activated mitochondrial activity, resulting in increased MMP, ATP generation, and increased cytochrome c oxidase activity. In addition, NIR increased alkaline phosphatase (ALP) activity, a biomarker of differentiation. As a result, we identified that 950 nm NIR PBM solves cryodamage in human stem cells from the apical papilla, indicating its potential as an alternative to antioxidants for treatment of post-thawing trauma, and further estimated its mechanism.
The human type 2 diabetes-specific visceral adipose tissue proteome and transcriptome in obesity
Authors: Carruthers Nicholas J. , Strieder-Barboza Clarissa , Caruso Joseph A. , Flesher Carmen G. , Baker Nicki A. , Kerk Samuel A. , Ky Alexander , Ehlers Anne P. , Varban Oliver A. , Lyssiotis Costas A. , Lumeng Carey N. , Stemmer Paul M. , O’Rourke Robert W.
Published: August 2021

Dysfunctional visceral adipose tissue (VAT) in obesity is associated with type 2 diabetes (DM) but underlying mechanisms remain unclear. Our objective in this discovery analysis was to identify genes and proteins regulated by DM to elucidate aberrant cellular metabolic and signaling mediators. We performed label-free proteomics and RNA-sequencing analysis of VAT from female bariatric surgery subjects with DM and without DM (NDM). We quantified 1965 protein groups, 23 proteins, and 372 genes that were differently abundant in DM vs. NDM VAT. Proteins downregulated in DM were related to fatty acid synthesis and mitochondrial function (fatty acid synthase, FASN; dihydrolipoyl dehydrogenase, mitochondrial, E3 component, DLD; succinate dehydrogenase-α, SDHA) while proteins upregulated in DM were associated with innate immunity and transcriptional regulation (vitronectin, VTN; endothelial protein C receptor, EPCR; signal transducer and activator of transcription 5B, STAT5B). Transcriptome indicated defects in innate inflammation, lipid metabolism, and extracellular matrix (ECM) function, and components of complement classical and alternative cascades. The VAT proteome and transcriptome shared 13 biological processes impacted by DM, related to complement activation, cell proliferation and migration, ECM organization, lipid metabolism, and gluconeogenesis. Our data revealed a marked effect of DM in downregulating FASN. We also demonstrate enrichment of complement factor B (CFB), coagulation factor XIII A chain (F13A1), thrombospondin 1 (THBS1), and integrins at mRNA and protein levels, albeit with lower q-values and lack of Western blot or PCR confirmation. Our findings suggest putative mechanisms of VAT dysfunction in DM.
Magnetic solid-phase extraction using polydopamine-coated magnetic multiwalled carbon nanotube composites coupled with high performance liquid chromatography for the determination of chlorophenols
Authors: Lu Wenhui , Fu Shanchao , Sun Xiaoze , Liu Jie , Zhu Deyi , Li Jinhua , Chen Lingxin
Published: August 2021

PDA-coated M-MWCNTs synthesized in two facile preparation steps were used as adsorbents for MSPE coupled with HPLC for simultaneous analysis of five chlorophenols in water samples.
Visible light-driven self-powered aptasensors for ultrasensitive Microcystin-LR detection based on the carrier density effect of N-doped graphene hydrogel/hematite Schottky junctions
Authors: Zhang Linhua , Jiang Ding , Shan Xueling , Du Xiaojiao , Wei Meng , Zhang Yude , Chen Zhidong
Published: August 2021

In this work, a novel visible light-driven self-powered photoelectrochemical (PEC) platform was designed based on 3D N-doped graphene hydrogel/hematite nanocomposites (NGH/Fe2O3) via a facile one-pot hydrothermal route.
A selective sensing platform for the simultaneous detection of ascorbic acid, dopamine, and uric acid based on AuNPs/carboxylated COFs/Poly(fuchsin basic) film
Authors: He Yasan , Lin Xiaogeng , Tang Yuan , Ye Ling
Published: August 2021

Selective electrochemical sensing via H-bonding and electrostatic interactions.
Comparison and recent progress of molecular imprinting technology and dummy template molecular imprinting technology
Authors: Chen Ru-Nan , Kang Shu-He , Li Jia , Lu Li-Na , Luo Xing-Ping , Wu Lan
Published: August 2021

Molecular imprinting technology for the preparation of polymers with specific molecular recognition function had become one of the current research hotspots.
Dual-readout performance of Eu3+-doped nanoceria as a phosphatase mimic for degradation and detection of organophosphate
Authors: Lv Wendi , Yuan Xiaoying , Yan Chenglu , Ma Qiuting , Wang Bing , Du Juan , Zheng Baozhan , Xiao Dan
Published: August 2021

A novel dual-readout analytical platform for degradation and detection of p-NPP was conveniently established using Eu:CeO2.
Designer protein pseudo-capsids targeting intracellular bacteria
Authors: Rey Stephanie , Faruqui Nilofar , Hoose Alex , Dondi Camilla , Ryadnov Maxim G.
Published: August 2021

Designer protein pseudo-capsids attack and destroy bacteria internalised in macrophages.
Same knot, longer rope: altering ligand geometry provides control over nuclearity in self-assembled trefoil knots
Authors: Wang Qi-Li-Sha , Lin Yue-Jian , Jin Guo-Xin
Published: August 2021

Selective constructions of Cp*Rh(iii)-based hexanuclear and octanuclear trefoil knots are realized using two ester bipyridyl ligands bearing minor differences in geometry.
A heavy-metal-free desulfonylative Giese-type reaction of benzothiazole sulfones under visible-light conditions
Authors: Sengoku Tetsuya , Ogawa Daichi , Iwama Haruka , Inuzuka Toshiyasu , Yoda Hidemi
Published: August 2021

A heavy-metal-free desulfonylative Giese-type reaction has been achieved by using Hantzsch ester as a photoreductant under blue light.
The effect of particle size on the optical and electronic properties of magnesium oxide nanoparticles
Authors: Zwijnenburg Martijn A.
Published: August 2021

We use evGW/BSE calculations to demonstrate that the optical and electronic properties of MgO nanoparticles are governed by the low-coordinated atoms on their surfaces.
The in situ growth of Cu2O with a honeycomb structure on a roughed graphite paper for the efficient electroreduction of CO2 to C2H4
Authors: Yan Zuoyu , Wang Xiuxiu , Tan Yang , Liu Aihua , Luo Fenqiang , Zhang Miaorong , Zeng Lingxing , Zhang Yan
Published: August 2021

A Cu2O/NGP self-supporting electrocatalyst is used for the electrocatalytic reduction of CO2 to ethylene to solve environmental and energy problems.
Breaking the scaling relationship of ORR on carbon-based single-atom catalysts through building a local collaborative structure
Authors: Fu Cehuang , Luo Liuxuan , Yang Lijun , Shen Shuiyun , Wei Guanghua , Zhang Junliang
Published: August 2021

The local collaborative structure further stabilizes the OOH*/OH* and weakens the on metal site by hydrogen bond and repulsive interaction, for which the scaling relationship of ORR could be broken.
Fluorophores in surface freshwaters: importance, likely structures, and possible impacts of climate change
Authors: Vione Davide , Minero Claudio , Carena Luca
Published: August 2021

Fluorescence spectroscopy is very useful for the characterisation of organic matter in natural water samples. The importance of protein-like fluorescence might be enhanced by several events induced by warming in natural waters such as lake water.
Bio-based poly(ester-alt-thioether)s synthesized by organo-catalyzed ring-opening copolymerizations of eugenol-based epoxides and N-acetyl homocysteine thiolactone
Authors: Le Luyer Simon , Quienne Baptiste , Bouzaid Matthieu , Guégan Philippe , Caillol Sylvain , Illy Nicolas
Published: August 2021

A series of fully bio-based poly(ester-alt-thioether)s are efficiently synthesized by organo-catalyzed alternating ring-opening copolymerizations of eugenol-derived monomers, vanillin glycidyl ether and N-acetyl homocysteine thiolactone.
Room-temperature quasi-catalytic hydrogen generation from waste and water
Authors: Wu Hongguo , Zhang Li-Long , Wang Junqi , Jiang Yiyuan , Li Hu , Sudarsanam Putla , Yang Song
Published: August 2021

A cost-effective, green solvent-enabled waste hydrosilane hydrolysis/alcoholysis protocol is developed for the quantitative generation of H2in minutes without any catalyst at room temperature.
Covalent organic functionalization of graphene nanosheets and reduced graphene oxidevia1,3-dipolar cycloaddition of azomethine ylide
Authors: Basta Luca , Moscardini Aldo , Fabbri Filippo , Bellucci Luca , Tozzini Valentina , Rubini Silvia , Griesi Andrea , Gemmi Mauro , Heun Stefan , Veronesi Stefano
Published: August 2021

Organic functionalization of graphene nanosheets and rGOvia1,3-dipolar cycloaddition of azomethine ylide is shown to be a significant step towards a controlled synthesis of graphene-based advanced nanoscale devices with engineered functionalities.
Size-dependent trends in the hydrogen evolution activity and electronic structure of MoS2 nanotubes
Authors: Ruffman Charlie , Gilmour J. T. A. , Garden Anna L.
Published: August 2021

The thermodynamics of hydrogen evolution on MoS2 nanotubes is studied for the first time using periodic density functional theory calculations to obtain hydrogen adsorption free energies (ΔGHads) on pristine nanotubes and those with S-vacancy defects.
A three-dimensional electrode fabricated by electrophoretic deposition of graphene on nickel foam for structural supercapacitors
Authors: Wang Juan , Xu Chang , Zhang Dong
Published: August 2021

The synthesis of a 3D rGO@NF structural electrode was optimized by adjusting the electrophoretic deposition parameters and thermal reduction time.
Visible-light-driven photo-Fenton degradation of ceftriaxone sodium using SnS2/LaFeO3 composite photocatalysts
Authors: Guo Yuting , Chen Cong , Ling Liwei , Wang Jun , Qi Huixiu , Zhang Bingjie , Wu Min
Published: August 2021

The LaFeO3-based heterostructure photocatalyst and photo-Fenton process are combined to effectively treat ceftriaxone sodium (CRS) contaminant under visible light.
Power discontinuity and shift of the energy onset of a molecular de-bromination reaction induced by hot-electron tunneling
Authors: Barragán Ana , Robles Roberto , Lorente Nicolás , Vitali Lucia
Published: August 2021

We describe the electron-induced dissociation of Br atoms in the Au(Br-MBP)2 complex, showing that the reaction onset can be shifted from 2.4 to 4.4 V while the required power drops sharply to 20% when a second molecular resonance is involved.
Electrical and optical properties of transition metal dichalcogenides on talc dielectrics
Authors: Nutting Darren , Prando Gabriela A. , Severijnen Marion , Barcelos Ingrid D. , Guo Shi , Christianen Peter C. M. , Zeitler Uli , Galvão Gobato Yara , Withers Freddie
Published: August 2021

We find significant optical and electronic enhancements of transition metal dichalcogenides on talc dielectrics compared to SiO2 substrates, making talc dielectrics promising for future van der Waals optoelectronics.
Facile fabrication of CuCo2S4 nanoparticles/MXene composite as anode for high-performance asymmetric supercapacitor
Authors: Chen Xiaobo , Ding Zimin , Yu Huan , Ge Huiran , Liu Weiwei , Sun Shixin
Published: August 2021

An organ-like MXene/CuCo2S4 hybrid composite was prepared for high-performance asymmetric supercapacitors. The MXene/CuCo2S4//AC supercapacitor displayed high specific energy and cycle stability.