bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of Snow Cover Anomalies Over the Tibetan Plateau in Cold Seasons
Authors: Wang Zhibiao , Wu Renguang , Zhao Ping , Yao Shuai‐Lei , Jia Xiaojing
Published: April 2019

The present study investigates relationship between interannual variations of snow cover and local surface and atmospheric variables, and the formation of interannual snow cover anomalies over the Tibetan Plateau in the cold seasons (autumn, winter, and spring). It is shown that the snow‐related surface heat flux and atmospheric heat source anomalies increase from autumn to spring, whereas precipitation anomalies are most prominent in autumn. This suggests that snow cover anomalies over the central eastern Tibetan Plateau are mainly formed in autumn and their impacts are most prominent in spring. The central eastern Tibetan Plateau snow cover anomalies have high month‐to‐month persistence during October through April, indicative of a large contribution of persistence to snow cover anomalies in winter and spring. The Tibetan Plateau snow cover anomalies in cold seasons are influenced by large‐scale atmospheric circulation anomaly pattern of different paths. In autumn, a wave pattern from the North Pacific to the Tibetan Plateau via the North Atlantic, induced by eastern North Pacific and western North Atlantic sea surface temperature anomalies, plays an important role in the formation of snow cover anomalies. In winter, a North Atlantic Oscillation related wave pattern from the North Atlantic to East Asia may contribute to snow cover anomalies. In spring, a midlatitude wave pattern originating over the western North Atlantic and propagating through the Mediterranean Sea to southern Tibetan Plateau may have a supplementary contribution to snow cover anomalies.
Direct Comparison and Triple Collocation: Which Is More Reliable in the Validation of Coarse‐Scale Satellite Surface Albedo Products
Authors: Wu Xiaodan , Xiao Qing , Wen Jianguang , You Dongqin
Published: April 2019

A rigorous and reliable validation is the prerequisite and basis to properly understand the accuracy of satellite surface albedo products. However, the representativeness error of point scale in situ measurements, which mainly results from the spatial mismatch between in situ and satellite measurements as well as the surface heterogeneities, generally hinders an effective validation of satellite surface albedo products based on the conventional direct comparison method. Triple collocation technique has been recognized as a powerful tool to estimate the errors of satellite products without requiring the truth. Here, we evaluated the effectiveness of both the direct comparison and extended triple collocation (ETC) methods in tackling with the representativeness error of in situ measurements and characterizing the performances of satellite surface albedo products (MCD43A3 [V006], GLASS, and NPP VIIRS albedos) given whether the in situ‐based pixel‐scale albedo was available or not. The ETC method is shown to be advantageous over the direct comparison based on single “point” in situ measurements, because it is less affected by representativeness errors. However, it shall not substitute for the direct comparison method based on in situ‐based pixel‐scale albedo measurements, because its effectiveness in solving representativeness errors and estimating product errors is very limited and dependent on the choice of the data in the triplets. Furthermore, the ETC technique cannot be used to estimate the true physical errors of satellite surface albedo products.
SuperDARN Observations of Semidiurnal Tidal Variability in the MLT and the Response to Sudden Stratospheric Warming Events
Authors: Hibbins R. E. , Espy P. J. , Orsolini Y. J. , Limpasuvan V. , Barnes R. J.
Published: April 2019

Using meteor wind data from the Super Dual Auroral Radar Network (SuperDARN) in the Northern Hemisphere, we (1) demonstrate that the migrating (Sun‐synchronous) tides can be separated from the nonmigrating components in the mesosphere and lower thermosphere (MLT) region and (2) use this to determine the response of the different components of the semidiurnal tide (SDT) to sudden stratospheric warming (SSW) conditions. The radars span a limited range of latitudes around 60°N and are located over nearly 180° of longitude. The migrating tide is extracted from the nonmigrating components observed in the meridional wind recorded from meteor ablation drift velocities around 95‐km altitude, and a 20‐year climatology of the different components is presented. The well‐documented late summer and wintertime maxima in the semidiurnal winds are shown to be due primarily to the migrating SDT, whereas during late autumn and spring the nonmigrating components are at least as strong as the migrating SDT. The robust behavior of the SDT components during SSWs is then examined by compositing 13 SSW events associated with an elevated stratopause recorded between 1995 and 2013. The migrating SDT is seen to reduce in amplitude immediately after SSW onset and then return anomalously strongly around 10–17 days after the SSW onset. We conclude that changes in the underlying wind direction play a role in modulating the tidal amplitude during the evolution of SSWs and that the enhancement in the midlatitude migrating SDT (previously reported in modeling studies) is observed in the MLT at least up to 60°N.
Sedimentological and Geochemical Composition of Aeolian Sediments in the Taklamakan Desert: Implications for Provenance and Sediment Supply Mechanisms
Authors: Jiang Qida , Yang Xiaoping
Published: April 2019

Sediment provenance is a key issue in understanding the aeolian system of the Taklamakan Desert, an important source of global dust and the largest sand sea in the midlatitudes worldwide. In provenance research, it may be a mistake to assume that the sand and dust fractions of desert sediments have the same source, which has been the case in previous studies of the Taklamakan Desert. The aims of the present study were to identify the provenance of the sand and dust fractions of the sediments of the Taklamakan Desert, to determine the contemporary sediment supply mechanisms of the desert, and to assess the relative importance of silt‐producing mechanisms for the desert dust. We analyzed the grain size of desert sediment samples and measured the content of major, trace, and rare earth elements within the bulk samples, sand fractions (>63 μm), and dust fractions (<63 μm). Our grain size and geochemical data sets suggest that the Kunlun Mountains are the main source of the sand fraction, whereas both the Kunlun and Tian Shan Mountains are the main sources of the dust fraction. Our interpretation is supported by the elevation gradient within the Taklamakan Desert and by wind data.
A Novel Approach Using Time‐Depth Distortions to Assess Multicentennial Variability in Deep‐Sea Oxygen Deficiency in the Eastern Mediterranean Sea During Sapropel S5
Authors: Dirksen Jan Pieter , Hennekam Rick , Geerken Esmee , Reichart Gert‐Jan
Published: April 2019

Reconstructing millennial‐ to centennial‐scale climate variability for the Eemian—an interval with estimated sea surface temperatures ~0.5 °C warmer than “preindustrial”—requires records with high temporal resolution. Sapropel S5 sediments, deposited under anoxic conditions in the Eastern Mediterranean Sea, offer the rare opportunity to assess multicentennial climate variability during this time. Here we present high‐resolution S5 piston core data from the Nile delta region. Specifically, we focus on Ba/Ti, Br/Ti, and Mo/Ti, as they are proxies for paleo‐productivity, marine organic carbon, and sediment anoxia, respectively. A high correlation between our Ba/Ti values in core 64PE‐406‐E1 and well‐dated Ba records of nearby cores (LC21 and ODP967) was found. We, therefore, tuned our data to these cores obtaining an initial age model. A time‐frequency analyses indicated significant frequency content in the multicentennial band, although the frequency components drifted over time. Assuming spectral simplicity, we corrected for sedimentation rate changes on a multicentennial time scale. This novel approach grants a higher‐resolution age model. The resulting variability in sedimentation rate is similar to records of monsoon variability, indicating a possible link between sedimentation at the core location and low‐latitude monsoon variability, linked via the River Nile. Moreover, the periodicities found in the sapropel time series are similar to the frequency content of total solar irradiance and sunspot records known for the Holocene, at least at high frequencies (~50–150 years). Hence, our data suggest cyclic intrasapropel variability, at least during the deposition of sapropel S5, may be linked to solar cycles.
Using Multiple Models to Improve Seasonal Forecasting
Authors: Cook Terri
Published: April 2019

The first study to examine the ability of a suite of general circulation models to predict sudden warmings in Earth’s stratosphere highlights the potential for improving Northern Hemisphere forecasts.
NSEE Yielding Electron Temperature Measurements at the Arecibo Observatory
Authors: Mahmoudian A. , Nossa E. , Isham B. , Bernhardt P. A. , Briczinski S. J. , Sulzer M.
Published: April 2019

Narrowband stimulated electromagnetic emissions (NSEE), a component of radio emissions created during high‐frequency (HF) radiowave ionospheric modification experiments, occur within 1 kHz of the HF pump frequency. NSEE was observed and studied for the first time at the HAARP (High Frequency Active Auroral Research Program) facility in Alaska (Norin et al., 2009, https://doi.org/10.1103/PhysRevLett.102.065003; Bernhardt et al., 2010, https://doi.org/10.1103/PhysRevLett.104.165004). Magnetized stimulated Brillouin scatter (MSBS) is a component of NSEE, which was also first observed at HAARP (Norin et al., 2009, https://doi.org/10.1103/PhysRevLett.102.065003; Bernhardt et al., 2010, https://doi.org/10.1103/PhysRevLett.104.165004) and later at European Incoherent Scatter Scientific Association (Fu et al., 2015, https://doi.org/10.5194/angeo-33-983-2015). Ion‐acoustic and electrostatic ion cyclotron modes are the daughter products of MSBS and can be used for the determination of the electron temperature and of the presence of minor ion species, respectively, in the HF‐modified ionosphere. Here we present the first observations of the MSBS process at magnetic midlatitudes, excited during radio wave ionospheric modification experiments at the Arecibo Observatory. The NSEE observations, in combination with a theoretical model and the wave matching conditions, are used to estimate background ionospheric parameters. A qualitative comparison of the MSBS component of the NSEE spectrum with the thermal ion line measured by incoherent scatter radar is presented.
Particulate Matter Fluxes in a Mediterranean Mountain Forest: Interspecific Differences Between Throughfall and Stemflow in Oak and Pine Stands
Authors: Cayuela Carles , Levia Delphis F. , Latron Jérôme , Llorens Pilar
Published: April 2019

In forested areas, canopies play an important role in the partitioning of rainfall. During this process there is also a redistribution of particulate matter (PM) that is deposited from the atmosphere on vegetative surfaces and transported to soil layers by throughfall and stemflow. We collected samples of rainfall, throughfall, and stemflow from two different forest plots (pine and oak) in a Mediterranean mountainous area and analyzed the amount and size distributions of PM (0.45 μm < PM < 500 μm). The exploration of backward trajectories revealed that PM content varied significantly. This depended on the origin of the air mass, with Atlantic fronts transporting less PM in the atmosphere than North African dust intrusions, which added disproportionate inputs of PM. Overall, throughfall provided the largest proportion of incoming PM under trees, but, at the base of each tree, stemflow led to a localized input of water that was more PM enriched than water through open precipitation or throughfall. Interspecific differences in PM fluxes were noted with pines retaining more PM in their crowns than oaks. Furthermore, the presence of leaves on oak increased the size and the amount of particulates released by throughfall. The PM in stemflow was smaller and rounder than in throughfall. This study adds to our understanding knowledge of the processes that control the deposition and distribution of PM delivered to forest soils, a fraction that is often ignored in studies of nutrient and energy fluxes in ecosystems.
Colour routing with single silver nanorods
Authors: Zhuo Xiaolu , Yip Hang Kuen , Cui Ximin , Wang Jianfang , Lin Hai-Qing
Published: April 2019

Elongated plasmonic nanoparticles have been extensively explored over the past two decades. However, in comparison with the dipolar plasmon mode that has attracted the most interest, much less attention has been paid to multipolar plasmon modes because they are usually thought to be “dark modes”, which are unable to interact with far-field light efficiently. Herein, we report on an intriguing far-field scattering phenomenon, colour routing, based on longitudinal multipolar plasmon modes supported by high-aspect-ratio single Ag nanorods. Taking advantage of the distinct far-field behaviours of the odd and even multipolar plasmon modes, we demonstrate two types of colour routing, where the incident white light can be scattered into several beams with different colours as well as different propagation directions. Because of the narrow linewidths of the longitudinal multipolar plasmon modes, there is little spectral overlap between the adjacent peaks, giving rise to outstanding colour selectivity. Our experimental results and theoretical model provide a simple yet effective picture for understanding the far-field behaviour of the longitudinal multipolar plasmon modes and the resultant colour routing phenomenon. Moreover, the outstanding colour routing capability of the high-aspect-ratio Ag nanorods enables nanoscale optical components with simple geometries for controlling the propagation of light below the diffraction limit of light.
Multi-platform discovery of haplotype-resolved structural variation in human genomes
Authors: Chaisson Mark J. P. , Sanders Ashley D. , Zhao Xuefang , Malhotra Ankit , Porubsky David , Rausch Tobias , Gardner Eugene J. , Rodriguez Oscar L. , Guo Li , Collins Ryan L. , Fan Xian , Wen Jia , Handsaker Robert E. , Fairley Susan , Kronenberg Zev N. , Kong Xiangmeng , Hormozdiari Fereydoun , Lee Dillon , Wenger Aaron M. , Hastie Alex R. , Antaki Danny , Anantharaman Thomas , Audano Peter A. , Brand Harrison , Cantsilieris Stuart , Cao Han , Cerveira Eliza , Chen Chong , Chen Xintong , Chin Chen-Shan , Chong Zechen , Chuang Nelson T. , Lambert Christine C. , Church Deanna M. , Clarke Laura , Farrell Andrew , Flores Joey , Galeev Timur , Gorkin David U. , Gujral Madhusudan , Guryev Victor , Heaton William Haynes , Korlach Jonas , Kumar Sushant , Kwon Jee Young , Lam Ernest T. , Lee Jong Eun , Lee Joyce , Lee Wan-Ping , Lee Sau Peng , Li Shantao , Marks Patrick , Viaud-Martinez Karine , Meiers Sascha , Munson Katherine M. , Navarro Fabio C. P. , Nelson Bradley J. , Nodzak Conor , Noor Amina , Kyriazopoulou-Panagiotopoulou Sofia , Pang Andy W. C. , Qiu Yunjiang , Rosanio Gabriel , Ryan Mallory , Stütz Adrian , Spierings Diana C. J. , Ward Alistair , Welch AnneMarie E. , Xiao Ming , Xu Wei , Zhang Chengsheng , Zhu Qihui , Zheng-Bradley Xiangqun , Lowy Ernesto , Yakneen Sergei , McCarroll Steven , Jun Goo , Ding Li , Koh Chong Lek , Ren Bing , Flicek Paul , Chen Ken , Gerstein Mark B. , Kwok Pui-Yan , Lansdorp Peter M. , Marth Gabor T. , Sebat Jonathan , Shi Xinghua , Bashir Ali , Ye Kai , Devine Scott E. , Talkowski Michael E. , Mills Ryan E. , Marschall Tobias , Korbel Jan O. , Eichler Evan E. , Lee Charles
Published: April 2019

The incomplete identification of structural variants (SVs) from whole-genome sequencing data limits studies of human genetic diversity and disease association. Here, we apply a suite of long-read, short-read, strand-specific sequencing technologies, optical mapping, and variant discovery algorithms to comprehensively analyze three trios to define the full spectrum of human genetic variation in a haplotype-resolved manner. We identify 818,054 indel variants (<50 bp) and 27,622 SVs (≥50 bp) per genome. We also discover 156 inversions per genome and 58 of the inversions intersect with the critical regions of recurrent microdeletion and microduplication syndromes. Taken together, our SV callsets represent a three to sevenfold increase in SV detection compared to most standard high-throughput sequencing studies, including those from the 1000 Genomes Project. The methods and the dataset presented serve as a gold standard for the scientific community allowing us to make recommendations for maximizing structural variation sensitivity for future genome sequencing studies.
Late Pleistocene human genome suggests a local origin for the first farmers of central Anatolia
Authors: Feldman Michal , Fernández-Domínguez Eva , Reynolds Luke , Baird Douglas , Pearson Jessica , Hershkovitz Israel , May Hila , Goring-Morris Nigel , Benz Marion , Gresky Julia , Bianco Raffaela A. , Fairbairn Andrew , Mustafaoğlu Gökhan , Stockhammer Philipp W. , Posth Cosimo , Haak Wolfgang , Jeong Choongwon , Krause Johannes
Published: April 2019

Anatolia was home to some of the earliest farming communities. It has been long debated whether a migration of farming groups introduced agriculture to central Anatolia. Here, we report the first genome-wide data from a 15,000-year-old Anatolian hunter-gatherer and from seven Anatolian and Levantine early farmers. We find high genetic continuity (~80–90%) between the hunter-gatherers and early farmers of Anatolia and detect two distinct incoming ancestries: an early Iranian/Caucasus related one and a later one linked to the ancient Levant. Finally, we observe a genetic link between southern Europe and the Near East predating 15,000 years ago. Our results suggest a limited role of human migration in the emergence of agriculture in central Anatolia.
The rise in ocean plastics evidenced from a 60-year time series
Authors: Ostle Clare , Thompson Richard C. , Broughton Derek , Gregory Lance , Wootton Marianne , Johns David G.
Published: April 2019

Plastic production has increased exponentially since its use became widespread in the 1950s. This has led to increased concern as plastics have become prevalent in the oceanic environment, and evidence of their impacts on marine organisms and human health has been highlighted. Despite their prevalence, very few long-term (>40 years) records of the distribution and temporal trends of plastics in the world’s oceans exist. Here we present a new time series, from 1957 to 2016 and covering over 6.5 million nautical miles, based on records of when plastics have become entangled on a towed marine sampler. This consistent time series provides some of the earliest records of plastic entanglement, and is the first to confirm a significant increase in open ocean plastics in recent decades.
Ultra-high performance wearable thermoelectric coolers with less materials
Authors: Kishore Ravi Anant , Nozariasbmarz Amin , Poudel Bed , Sanghadasa Mohan , Priya Shashank
Published: April 2019

Thermoelectric coolers are attracting significant attention for replacing age-old cooling and refrigeration devices. Localized cooling by wearable thermoelectric coolers will decrease the usage of traditional systems, thereby reducing global warming and providing savings on energy costs. Since human skin as well as ambient air is a poor conductor of heat, wearable thermoelectric coolers operate under huge thermally resistive environment. The external thermal resistances greatly influence thermoelectric material behavior, device design, and device performance, which presents a fundamental challenge in achieving high efficiency for on-body applications. Here, we examine the combined effect of heat source/sink thermal resistances and thermoelectric material properties on thermoelectric cooler performance. Efficient thermoelectric coolers demonstrated here can cool the human skin up to 8.2 °C below the ambient temperature (170% higher cooling than commercial modules). Cost-benefit analysis shows that cooling over material volume for our optimized thermoelectric cooler is 500% higher than that of the commercial modules.
Polygenic prediction via Bayesian regression and continuous shrinkage priors
Authors: Ge Tian , Chen Chia-Yen , Ni Yang , Feng Yen-Chen Anne , Smoller Jordan W.
Published: April 2019

Polygenic risk scores (PRS) have shown promise in predicting human complex traits and diseases. Here, we present PRS-CS, a polygenic prediction method that infers posterior effect sizes of single nucleotide polymorphisms (SNPs) using genome-wide association summary statistics and an external linkage disequilibrium (LD) reference panel. PRS-CS utilizes a high-dimensional Bayesian regression framework, and is distinct from previous work by placing a continuous shrinkage (CS) prior on SNP effect sizes, which is robust to varying genetic architectures, provides substantial computational advantages, and enables multivariate modeling of local LD patterns. Simulation studies using data from the UK Biobank show that PRS-CS outperforms existing methods across a wide range of genetic architectures, especially when the training sample size is large. We apply PRS-CS to predict six common complex diseases and six quantitative traits in the Partners HealthCare Biobank, and further demonstrate the improvement of PRS-CS in prediction accuracy over alternative methods.
Microbial and metabolic succession on common building materials under high humidity conditions
Authors: Lax Simon , Cardona Cesar , Zhao Dan , Winton Valerie J. , Goodney Gabriel , Gao Peng , Gottel Neil , Hartmann Erica M. , Henry Chris , Thomas Paul M. , Kelley Scott T. , Stephens Brent , Gilbert Jack A.
Published: April 2019

Despite considerable efforts to characterize the microbial ecology of the built environment, the metabolic mechanisms underpinning microbial colonization and successional dynamics remain unclear, particularly at high moisture conditions. Here, we applied bacterial/viral particle counting, qPCR, amplicon sequencing of the genes encoding 16S and ITS rRNA, and metabolomics to longitudinally characterize the ecological dynamics of four common building materials maintained at high humidity. We varied the natural inoculum provided to each material and wet half of the samples to simulate a potable water leak. Wetted materials had higher growth rates and lower alpha diversity compared to non-wetted materials, and wetting described the majority of the variance in bacterial, fungal, and metabolite structure. Inoculation location was weakly associated with bacterial and fungal beta diversity. Material type influenced bacterial and viral particle abundance and bacterial and metabolic (but not fungal) diversity. Metabolites indicative of microbial activity were identified, and they too differed by material.
Selective photoelectrochemical oxidation of glycerol to high value-added dihydroxyacetone
Authors: Liu Dong , Liu Jin-Cheng , Cai Weizheng , Ma Jun , Yang Hong Bin , Xiao Hai , Li Jun , Xiong Yujie , Huang Yanqiang , Liu Bin
Published: April 2019

It is highly profitable to transform glycerol – the main by-product from biodiesel production to high value-added chemicals. In this work, we develop a photoelectrochemical system based on nanoporous BiVO4 for selective oxidation of glycerol to 1,3-dihydroxyacetone – one of the most valuable derivatives of glycerol. Under AM 1.5G front illumination (100 mW cm−2) in an acidic medium (pH = 2) without adscititious oxidant, the nanoporous BiVO4 photoanode achieves a glycerol oxidation photocurrent density of 3.7 mA cm−2 at a potential of 1.2 V versus RHE with 51% 1,3-dihydroxyacetone selectivity, equivalent to a production rate of 200 mmol of 1,3-dihydroxyacetone per m2 of illumination area in one hour.
Nodal rings and drumhead surface states in phononic crystals
Authors: Deng Weiyin , Lu Jiuyang , Li Feng , Huang Xueqin , Yan Mou , Ma Jiahong , Liu Zhengyou
Published: April 2019

Three-dimensional topological nodal lines, the touching curves of two bands in momentum space, which give rise to drumhead surface states, provide an opportunity to explore a variety of exotic phenomena. However, solid evidence for a flat drumhead surface state remains elusive. In this paper, we report a realization of three-dimensional nodal line dispersions and drumhead surface states in phononic crystal. Profiting from its macroscopic nature, the phononic crystal permits a flexible and accurate fabrication for materials with ring-like nodal lines and drumhead surface states. Phononic nodal rings of the lowest two bands and, more importantly, topological drumhead surface states are unambiguously demonstrated. Our system provides an ideal platform to explore the intriguing properties of acoustic waves endowed with extraordinary dispersions.
Stem cell-associated heterogeneity in Glioblastoma results from intrinsic tumor plasticity shaped by the microenvironment
Authors: Dirkse Anne , Golebiewska Anna , Buder Thomas , Nazarov Petr V. , Muller Arnaud , Poovathingal Suresh , Brons Nicolaas H. C. , Leite Sonia , Sauvageot Nicolas , Sarkisjan Dzjemma , Seyfrid Mathieu , Fritah Sabrina , Stieber Daniel , Michelucci Alessandro , Hertel Frank , Herold-Mende Christel , Azuaje Francisco , Skupin Alexander , Bjerkvig Rolf , Deutsch Andreas , Voss-Böhme Anja , Niclou Simone P.
Published: April 2019

The identity and unique capacity of cancer stem cells (CSC) to drive tumor growth and resistance have been challenged in brain tumors. Here we report that cells expressing CSC-associated cell membrane markers in Glioblastoma (GBM) do not represent a clonal entity defined by distinct functional properties and transcriptomic profiles, but rather a plastic state that most cancer cells can adopt. We show that phenotypic heterogeneity arises from non-hierarchical, reversible state transitions, instructed by the microenvironment and is predictable by mathematical modeling. Although functional stem cell properties were similar in vitro, accelerated reconstitution of heterogeneity provides a growth advantage in vivo, suggesting that tumorigenic potential is linked to intrinsic plasticity rather than CSC multipotency. The capacity of any given cancer cell to reconstitute tumor heterogeneity cautions against therapies targeting CSC-associated membrane epitopes. Instead inherent cancer cell plasticity emerges as a novel relevant target for treatment.
Sexual selection predicts the rate and direction of colour divergence in a large avian radiation
Authors: Cooney Christopher R. , Varley Zoë K. , Nouri Lara O. , Moody Christopher J. A. , Jardine Michael D. , Thomas Gavin H.
Published: April 2019

Sexual selection is proposed to be a powerful driver of phenotypic evolution in animal systems. At macroevolutionary scales, sexual selection can theoretically drive both the rate and direction of phenotypic evolution, but this hypothesis remains contentious. Here, we find that differences in the rate and direction of plumage colour evolution are predicted by a proxy for sexual selection intensity (plumage dichromatism) in a large radiation of suboscine passerine birds (Tyrannida). We show that rates of plumage evolution are correlated between the sexes, but that sexual selection has a strong positive effect on male, but not female, interspecific divergence rates. Furthermore, we demonstrate that rapid male plumage divergence is biased towards carotenoid-based (red/yellow) colours widely assumed to represent honest sexual signals. Our results highlight the central role of sexual selection in driving avian colour divergence, and reveal the existence of convergent evolutionary responses of animal signalling traits under sexual selection.
Application of pan-sharpening algorithm for correlative multimodal imaging using AFM-IR
Authors: Borodinov Nikolay , Bilkey Natasha , Foston Marcus , Ievlev Anton V. , Belianinov Alex , Jesse Stephen , Vasudevan Rama K. , Kalinin Sergei V. , Ovchinnikova Olga S.
Published: April 2019

The coupling of atomic force microscopy with infrared spectroscopy (AFM-IR) offers the unique capability to characterize the local chemical and physical makeup of a broad variety of materials with nanoscale resolution. However, in order to fully utilize the measurement capability of AFM-IR, a three-dimensional dataset (2D map with a spectroscopic dimension) needs to be acquired, which is prohibitively time-consuming at the same spatial resolution of a regular AFM scan. In this paper, we provide a new approach to process spectral AFM-IR data based on a multicomponent pan-sharpening algorithm. This approach requires only a low spatial resolution spectral and a limited number of high spatial resolution single wavenumber chemical maps to generate a high spatial resolution hyperspectral image, greatly reducing data acquisition time. As a result, we are able to generate high-resolution maps of component distribution, produce chemical maps at any wavenumber available in the spectral range, and perform correlative analysis of the physical and chemical properties of the samples. We highlight our approach via imaging of plant cell walls as a model system and showcase the interplay between mechanical stiffness of the sample and its chemical composition. We believe our pan-sharpening approach can be more generally applied to different material classes to enable deeper understanding of that structure-property relationship at the nanoscale.
Aspirin impairs acetyl-coenzyme A metabolism in redox-compromised yeast cells
Authors: Farrugia Gianluca , Azzopardi Maria , Saliba Christian , Grech Godfrey , Gross Angelina S. , Pistolic Jelena , Benes Vladimir , Vassallo Neville , Borg Joseph , Madeo Frank , Eisenberg Tobias , Balzan Rena
Published: April 2019

Aspirin is a widely used anti-inflammatory and antithrombotic drug also known in recent years for its promising chemopreventive antineoplastic properties, thought to be mediated in part by its ability to induce apoptotic cell death. However, the full range of mechanisms underlying aspirin’s cancer-preventive properties is still elusive. In this study, we observed that aspirin impaired both the synthesis and transport of acetyl-coenzyme A (acetyl-CoA) into the mitochondria of manganese superoxide dismutase (MnSOD)-deficient Saccharomyces cerevisiae EG110 yeast cells, but not of the wild-type cells, grown aerobically in ethanol medium. This occurred at both the gene level, as indicated by microarray and qRT-PCR analyses, and at the protein level as indicated by enzyme assays. These results show that in redox-compromised MnSOD-deficient yeast cells, but not in wild-type cells, aspirin starves the mitochondria of acetyl-CoA and likely causes energy failure linked to mitochondrial damage, resulting in cell death. Since acetyl-CoA is one of the least-studied targets of aspirin in terms of the latter’s propensity to prevent cancer, this work may provide further mechanistic insight into aspirin’s chemopreventive behavior with respect to early stage cancer cells, which tend to have downregulated MnSOD and are also redox-compromised.
eBrain: a Three Dimensional Simulation Tool to Study Drug Delivery in the Brain
Authors: Setty Yaki
Published: April 2019

Neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease are severe disorders with acute symptoms that gradually progress. In the course of developing disease-modifying treatments for neurodegenerative disorders there is a need to develop novel strategies to increase efficacy of drugs and accelerate the development process. We developed a tool for simulating drug delivery in the brain by translating MRI data into an interactive 3D model. This tool, the eBrain, superimposes simulated drug diffusion and tissue uptake by inferring from the MRI data with a seamless display from any angle, magnification, or position. We discuss a representative implementation of eBrain that is inspired by clinical data in which insulin is intranasally administered to Alzheimer patients. Using extensive analysis of multiple eBrain simulations with varying parameters, we show the potential for eBrain to determine the optimal dosage to ensure drug delivery without overdosing the tissue. Specifically, we examined the efficacy of combined drug doses and potential compounds for tissue stimulation. Interestingly, our analysis uncovered that the drug efficacy is inferred from tissue intensity levels. Finally, we discuss the potential of eBrain and possible applications of eBrain to aid both inexperienced and experienced medical professionals as well as patients.
A semi-synthetic neolignan derivative from dihydrodieugenol B selectively affects the bioenergetic system of Leishmania infantum and inhibits cell division
Authors: Amaral Maiara , de Sousa Fernanda S. , Silva Thais A. Costa , Junior Andrés Jimenez G. , Taniwaki Noemi N. , Johns Deidre M. , Lago João Henrique G. , Anderson Edward A. , Tempone Andre G.
Published: April 2019

Leishmaniasis is a neglected disease that affects more than 12 million people, with a limited therapy. Plant-derived natural products represent a useful source of anti-protozoan prototypes. In this work, four derivatives were prepared from neolignans isolated from the Brazilian plantNectandra leucantha, and their effects against intracellular amastigotes ofLeishmania(L.)infantumevaluatedin vitro. IC50values between 6 and 35 µM were observed andin silicopredictions suggested good oral bioavailability, no PAINS similarities, and ADMET risks typical of lipophilic compounds. The most selective (SI > 32) compound was chosen for lethal action and immunomodulatory studies. This compound caused a transient depolarization of the plasma membrane potential and induced an imbalance of intracellular Ca2+, possibly resulting in a mitochondrial impairment and leading to a strong depolarization of the membrane potential and decrease of ATP levels. The derivative also interfered with the cell cycle ofLeishmania, inducing a programmed cell death-like mechanism and affecting DNA replication. Further immunomodulatory studies demonstrated that the compound eliminates amastigotes via an independent activation of the host cell, with decrease levels of IL-10, TNF and MCP-1. Additionally, this derivative caused no hemolytic effects in murine erythrocytes and could be considered promising for future lead studies.
RNA recognition motifs of disease-linked RNA-binding proteins contribute to amyloid formation
Authors: Agrawal Sashank , Kuo Pan-Hsien , Chu Lee-Ya , Golzarroshan Bagher , Jain Monika , Yuan Hanna S.
Published: April 2019

Aberrant expression, dysfunction and particularly aggregation of a group of RNA-binding proteins, including TDP-43, FUS and RBM45, are associated with neurological disorders. These three disease-linked RNA-binding proteins all contain at least one RNA recognition motif (RRM). However, it is not clear if these RRMs contribute to their aggregation-prone character. Here, we compare the biophysical and fibril formation properties of five RRMs from disease-linked RNA-binding proteins and five RRMs from non-disease-associated proteins to determine if disease-linked RRMs share specific features making them prone to self-assembly. We found that most of the disease-linked RRMs exhibit reversible thermal unfolding and refolding, and have a slightly lower average thermal melting point compared to that of normal RRMs. The full domain of TDP-43 RRM1 and FUS RRM, as well as the β-peptides from these two RRMs, could self-assemble into fibril-like aggregates which are amyloids of parallel β-sheets as verified by X-ray diffraction and FT-IR spectroscopy. Our results suggest that some disease-linked RRMs indeed play important roles in amyloid formation and shed light on why RNA-binding proteins with RRMs are frequently identified in the cellular inclusions of neurodegenerative diseases.
Development and validation of a prediction model for active tuberculosis case finding among HIV-negative/unknown populations
Authors: Shih Yun-Ju , Ayles Helen , Lönnroth Knut , Claassens Mareli , Lin Hsien-Ho
Published: April 2019

A prediction model of prevalent pulmonary tuberculosis (TB) in HIV negative/unknown individuals was developed to assist systematic screening. Data from a large TB screening trial were used. A multivariable logistic regression model was developed in the South African (SA) training dataset, using TB symptoms and risk factors as predictors. The model was converted into a scoring system for risk stratification and was evaluated in separate SA and Zambian validation datasets. The number of TB cases were 355, 176, and 107 in the SA training, SA validation, and Zambian validation datasets respectively. The area under curve (AUC) of the scoring system was 0·68 (95% CI 0·64-0·72) in the SA validation set, compared to prolonged cough (0·58, 95% CI 0·54-0·62) and any TB symptoms (0·6, 95% CI 0·56–0·64). In the Zambian dataset the AUC of the scoring system was 0·66 (95% CI 0·60–0·72). In the cost-effectiveness analysis, the scoring system dominated the conventional strategies. The cost per TB case detected ranged from 429 to 1,848 USD in the SA validation set and from 171 to 10,518 USD in the Zambian dataset. The scoring system may help targeted TB case finding under budget constraints.
Maslinic acid alleviates ischemia/reperfusion-induced inflammation by downregulation of NFκB-mediated adhesion molecule expression
Authors: Ampofo Emmanuel , Berg Julian J. , Menger Michael D. , Laschke Matthias W.
Published: April 2019

Ischemia/reperfusion (I/R)-induced inflammation is associated with enhanced leukocyte rolling, adhesion and transmigration within the microcirculation. These steps are mediated by hypoxia-triggered signaling pathways, which upregulate adhesion molecule expression on endothelial cells and pericytes. We analyzed whether these cellular events are affected by maslinic acid (MA). Mitochondrial activity and viability of MA-exposed endothelial cells and pericytes were assessed by water-soluble tetrazolium (WST)-1 and lactate dehydrogenase (LDH) assays as well as Annexin V/propidium iodide (PI) stainings. Effects of MA on hypoxia and reoxygenation-induced expression of E-selectin, intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 were determined by flow cytometry. The subcellular localization of the NFκB subunit p65 was analyzed by immunofluorescence and Western blot. I/R-induced leukocytic inflammation was studied in MA- and vehicle-treated mouse dorsal skinfold chambers by intravital fluorescence microscopy and immunohistochemistry. MA did not affect viability, but suppressed the mitochondrial activity of endothelial cells. Furthermore, MA reduced adhesion molecule expression on endothelial cells and pericytes due to an inhibitory action on NFκB signaling. Numbers of adherent and transmigrated leukocytes were lower in post-ischemic tissue of MA-treated mice when compared to vehicle-treated controls. In addition, MA affected reactive oxygen species (ROS) formation, resulting in a diminished oxidative DNA damage. Hence, MA represents an attractive compound for the establishment of novel therapeutic approaches against I/R-induced inflammation.
Combined use of satellite and surface observations to study aerosol optical depth in different regions of China
Authors: Filonchyk Mikalai , Yan Haowen , Zhang Zhongrong , Yang Shuwen , Li Wei , Li Yanming
Published: April 2019

Aerosol optical depth (AOD) is one of essential atmosphere parameters for climate change assessment as well as for total ecological situation study. This study presents long-term data (2000–2017) on time-space distribution and trends in AOD over various ecological regions of China, received from Moderate Resolution Imaging Spectroradiometer (MODIS) (combined Dark Target and Deep Blue) and Multi-angle Imaging Spectroradiometer (MISR), based on satellite Terra. Ground-based stations Aerosol Robotic Network (AERONET) were used to validate the data obtained. AOD data, obtained from two spectroradiometers, demonstrate the significant positive correlation relationships (r = 0.747), indicating that 55% of all data illustrate relationship among the parameters under study. Comparison of results, obtained with MODIS/MISR Terra and AERONET, demonstrate high relation (r = 0.869 - 0.905), while over 60% of the entire sampling fall within the range of the expected tolerance, established by MODIS and MISR over earth (±0.05 ± 0.15 × AODAERONETand 0.05 ± 0.2 × AODAERONET) with root-mean-square error (RMSE) of 0.097–0.302 and 0.067–0.149, as well as low mean absolute error (MAE) of 0.068–0.18 and 0.067–0.149, respectively. The MODIS search results were overestimated for AERONET stations with an average overestimation ranging from 14 to 17%, while there was an underestimate of the search results using MISR from 8 to 22%.
Diversity of nasal microbiota and its interaction with surface microbiota among residents in healthcare institutes
Authors: Chen Chang-Hua , Liou Ming-Li , Lee Cheng-Yang , Chang Ming-Chuan , Kuo Han-Yueh , Chang Tzu-Hao
Published: April 2019

Nasal microbial communities may have crucial implications for human health, including for residents of healthcare institutes (HCIs). Factors that determine the diversity of nasal microbiota in HCIs remain unclear. Herein, we used 16S rRNA amplicon sequencing to investigate the relationship between nasal and surface microbiota in three HCIs. Participants were classified into a hospitalised or nonhospitalised group based on their most recent date of hospitalisation. A total of 88 nasal samples and 83 surface samples were analysed. Dysgonomonas and Corynebacterium were the most abundant taxa in the surface and nasal samples, respectively. Significant differences were discovered in microbiota diversity among HCIs when comparing the surface and nasal samples. Fifteen taxa were identified as present in all the surface and nasal samples. SourceTracker analysis revealed that the ventilation conditions of environment might be associated with the proportion of shared microbial communities between nasal and surface. Additionally, as compared with the nonhospitalised group, the hospitalised group had a higher proportion of surface microbiota in their nasal samples, which might lead to a higher risk of human-related microorganisms or pathogens colonising the nasal cavity. The data suggest that nasal bacterial diversity could be influenced by both health status and living environment. Our results therefore highlight the importance of the indoor environment for HCI residents.
Clinical efficacy of Professional Continuous Glucose Monitoring in improving glycemic control among children with Type 1 Diabetes Mellitus: An Open-label Randomized Control Trial
Authors: Raviteja K. V. , Kumar Rakesh , Dayal Devi , Sachdeva Naresh
Published: April 2019

Frequent self-monitoring of blood glucose (SMBG) is the only accurate method available for insulin dose titration in patients with T1DM. Professional continuous glucose monitoring (p-CGM) is blinded recording of glucose trends over 5–7 days and helps physicians to guide insulin titration to patient. This study was planned to assess efficacy of insulin dose adjustments, based on p-CGM plus SMBG in improving glycemic control compared to SMBG alone. We did an open-label, parallel design, randomized control trial among children (2–10 years) having T1DM for at least 6 months. Subjects in theintervention groupwere placed on p-CGM (iPRO 2™ Professional CGM, Medtronic, USA) for 3–5 days along with regular SMBG. Data from p-CGM was analyzed by physician and used to guide insulin titration along with SMBG over following 3 months.Control grouphad only SMBG records for titrating insulin doses. Primary outcome was change in HbA1c 3 months after intervention. A total of 68 eligible children were randomized, 34 each to either arms. Thirty children in intervention group and 33 in control group completed the study and were analyzed. It was found that there was more decreased unit change in HbA1c, percentage of low sugar records and total insulin requirement per day, after 3 months follow-up, in intervention group. However, difference was not significant except for total insulin Units/kg/day (p = 0.014). In sub-group analysis of children with baseline HbA1c >7.5%, there was a significant mean fall of HbA1c by 1.27% (p = 0.045). There were no major adverse events associated with p-CGM. We conclude that addition of p-CGM along with SMBG may help in adjusting insulin dose more effectively especially in children with higher baseline HbA1c.
A whole-body FDG PET/MR atlas for multiparametric voxel-based analysis
Authors: Sjöholm Therese , Ekström Simon , Strand Robin , Ahlström Håkan , Lind Lars , Malmberg Filip , Kullberg Joel
Published: April 2019

Quantitative multiparametric imaging is a potential key application for Positron Emission Tomography/Magnetic Resonance (PET/MR) hybrid imaging. To enable objective and automatic voxel-based multiparametric analysis in whole-body applications, the purpose of this study was to develop a multimodality whole-body atlas of functional 18F-fluorodeoxyglucose (FDG) PET and anatomical fat-water MR data of adults. Image registration was used to transform PET/MR images of healthy control subjects into male and female reference spaces, producing a fat-water MR, local tissue volume and FDG PET whole-body normal atlas consisting of 12 male (66.6 ± 6.3 years) and 15 female (69.5 ± 3.6 years) subjects. Manual segmentations of tissues and organs in the male and female reference spaces confirmed that the atlas contained adequate physiological and anatomical values. The atlas was applied in two anomaly detection tasks as proof of concept. The first task automatically detected anomalies in two subjects with suspected malignant disease using FDG data. The second task successfully detected abnormal liver fat infiltration in one subject using fat fraction data.
Optical Coherence Tomography Angiography Compared with Indocyanine Green Angiography in Central Serous Chorioretinopathy
Authors: Hu Jie , Qu Jinfeng , Piao Zhenyu , Yao Yuou , Sun Guosheng , Li Mengyang , Zhao Mingwei
Published: April 2019

The purpose of this article is to compare optical coherence tomography angiography (OCTA) and indocyanine green angiography (ICGA) in patients with central serous chorioretinopathy (CSC). OCTA, ICGA and fluorescein angiography (FA) images of all enrolled patients were collected and compared. Abnormal areas were annotated on en face choriocapillaris OCTA and ICGA images and compared with each other. We found three main types of anomalies in choriocapillaris OCTA images: type A, coarse granulated high reflective area (61 eyes [92.4%]); type B, roundish dark halo around Type A (54 eyes [81.8%]); and type C, coarse granulated low reflective area (66 eyes [100%]). There were 54 eyes (81.8%) that exhibited all three types abnormalities, 7 (10.6%) had only type A and C abnormalities, and 5 (7.6%) had only type C abnormalities. The Mean JI of type A on OCTA and hyperfluorescence area on ICGA was 0.84 ± 0.15 and 0.82 ± 0.23 for grader 1 and 2, respectively. Type A area on OCTA had a statistically larger area than hyperfluorescence on ICGA (P = 0.01 [paired t-test]). In summary, abnormalities were found on OCTA images of CSC. Coarse granulated high reflective area in OCTA corresponded well with the hyper-permeability area in ICGA in most of the eyes.
An innate interaction between IL-18 and the propeptide that inactivates its precursor form
Authors: Tsutsumi Naotaka , Yokota Ayumi , Kimura Takeshi , Kato Zenichiro , Fukao Toshiyuki , Shirakawa Masahiro , Ohnishi Hidenori , Tochio Hidehito
Published: April 2019

Uncontrolled secretion of mature interleukin (IL)-1β and IL-18 is responsible for severe autoinflammatory or autoimmune disorders and various allergic diseases. Here we report an intramolecular interaction between IL-18 and its propeptide, which is proteolytically removed from its precursor proIL-18 during maturation. The intramolecular interaction was recapitulated intermolecularly using recombinant propeptide. These results suggest the possibility of developing a novel class of peptide-based IL-18 inhibitors that could serve as therapeutic agents for IL-18-related inflammatory diseases.