bluuebunny/crossref_metadata_2025 huggingface dataset:
Pennisetum ciliare: a review of treatment efficacy, competitive traits, and restoration opportunities
Authors: Farrell Hannah L. , Gornish Elise S.
Published: October 2019

Buffelgrass [Pennisetum ciliare (L.) Link] is a drought-tolerant invasive grass that is a threat to native biodiversity in the drylands of the Americas and Australia. Despite efforts from land managers to control P. ciliare, management approaches tend to have mixed success, treatment results can be poorly communicated among entities, and there are few long-term controlled studies. In this literature review, we synthesize data from both peer-reviewed and “gray” literature on the efficacy of management techniques to control P. ciliare and the secondary impacts to native plant communities. Our search resulted in 42 unique sources containing a total of 229 studies that we categorized into 10 treatment types, which included herbicide, seeding, manual removal, fire, grazing, biocontrol, fire + additional treatments, manual removal + additional treatments, herbicide + additional treatments, and herbicide + manual removal. We found that treatments that used multiple techniques in tandem along with follow-up treatments were the most effective at controlling P. ciliare. Fewer than one-third of the studies reported impacts of management on native species, and the most commonly studied treatment (herbicide, N = 130) showed detrimental impacts on native plant communities. However, the average time between treatment and outcome measurement was only 15 mo; we suggest the need for more long-term studies of treatment efficacy and secondary impacts of treatment on the ecosystem. Finally, we conducted a second literature review on P. ciliare biology and traits for mechanisms that allows P. ciliare to alter the invaded environment to facilitate a competitive advantage over native species. We found evidence of self-reinforcing feedbacks of invasion being generated by P. ciliare through its interactions with water availability, nutrient cycling, and disturbance regimes. We developed a conceptual model of P. ciliare based on these feedback loops and offer management considerations based on its invasion dynamics and biology.
The correspondence between drag enhancement and vortical structures in turbulent Taylor–Couette flows with polymer additives: a study of curvature dependence
Authors: Song Jiaxing , Teng Hao , Liu Nansheng , Ding Hang , Lu Xi-Yun , Khomami Bamin
Published: October 2019

We report direct numerical simulation results that clearly elucidate the mechanism that leads to curvature dependence of drag enhancement (DE) in viscoelastic turbulent Taylor–Couette flow. Change in the angular momentum transport and its inherent link to transitions in vortical flow structures have been explored to depict the influence of the curvature of the flow geometry on DE. Specifically, it has been demonstrated that a transition in vortical structures with increasing radius ratio leads to weakening and elimination of the small-scale Görtler vortices and development and better organization (occupying the entire gap) of large-scale Taylor vortices as also evinced by the patterns of angular momentum current. The commensurate change in DE and its underlying mechanism are examined by contributions of convective flux and polymeric stress to the angular momentum current. The present finding paves the way for capturing highly localized elastic turbulence structures in direct numerical simulation by increasing geometry curvature in traditional turbulent curvilinear flows.
Various approaches to determine active regions in an unstable global mode: application to transonic buffet
Authors: Paladini Edoardo , Marquet Olivier , Sipp Denis , Robinet Jean-Christophe , Dandois Julien
Published: October 2019

The transonic flow field around a supercritical airfoil is investigated. The objective of the present paper is to enhance the understanding of the physical mechanics behind two-dimensional transonic buffet. The paper is composed of two parts. In the first part, a global stability analysis based on the linearized Reynolds-averaged Navier–Stokes equations is performed. A recently developed technique, based on the direct and adjoint unstable global modes, is used to compute the local contribution of the flow to the growth rate and angular frequency of the unstable global mode. The results allow us to identify which zones are directly responsible for the existence of the instability. The technique is firstly used for the vortex-shedding cylinder mode, as a validating case. In the second part, in order to confirm the results of the first part, a selective frequency damping method is locally used in some regions of the flow field. This method consists of applying a low-pass filter on selected zones of the computational domain in order to damp the fluctuations. It allows us to identify which zones are necessary for the persistence of the instability. The two different approaches give the same results: the shock foot is identified as the core of the instability; the shock and the boundary layer downstream of the shock are also necessary zones while damping the fluctuations on the lower surface of the airfoil; and outside the boundary layer between the shock and the trailing edge or above the supersonic zone does not suppress the shock oscillation. A discussion on the several physical models, proposed until now for the buffet phenomenon, and a new model are finally offered in the last section.
Indices of association between anxiety and mindfulness: a guide for future mindfulness studies
Authors: Jaiswal Satish , Muggleton Neil G. , Juan Chi-Hung , Liang Wei-Kuang
Published: October 2019

Mindfulness and anxiety are often linked as inversely related traits and there have been several theoretical and mediational models proposed suggesting such a relationship between these two traits. The current review report offers an account of self-report measures, behavioral, electrophysiological, hemodynamic, and biological studies, which provide converging evidence for an inverse relationship between mindfulness and anxiety. To our knowledge, there are no comprehensive accounts of empirical evidence that investigate this relationship. After reviewing several empirical studies, we propose a schematic model, where a stressor can trigger the activation of amygdala which activates the hypothalamic–pituitary–adrenal (HPA) pathway. This hyperactive HPA axis leads to a cascade of psychological, behavioral, electrophysiological, immunological, endocrine, and genetic reactions in the body, primarily mediated by a sympathetic pathway. Conversely, mindfulness protects from deleterious effects of these triggered reactions by downregulating the HPA axis activity via a parasympathetic pathway. Finally, we propose a model suggesting a comprehensive scheme through which mindfulness and anxiety may interact through emotion regulation. It is recommended that future mindfulness intervention studies should examine a broad spectrum of measurement indices where possible, keeping logistic feasibility in mind and look at mindfulness in conjunction with anxiety rather than independently.
Strategic Legislative Subsidies: Informational Lobbying and the Cost of Policy
Authors: ELLIS CHRISTOPHER J. , GROLL THOMAS
Published: October 2019

We analyze the strategic considerations inherent in legislative subsidies and develop an informational lobbying model with costly policy reforms. In contrast to other models of informational lobbying, we focus on the implications of a policymaker’s and a lobby’s resource constraints for lobbying activities. We allow both a policymaker and a lobby to gather information, and each can either fund or subsidize policymaking. Our analysis highlights that legislative subsidies are both chosen strategically by lobbyists and strategically induced by policymakers, dependent on the circumstances. These involve which resource constraints bind the policymaker’s prior beliefs, the salience of policy, and the policymaker’s and lobby’s expertise in information gathering. Our results highlight five distinct motives for informational lobbying and demonstrate that for both a lobby and policymaker, there can be strategic advantages arising from being resource-constrained.
Pliocene–Pleistocene sedimentary and geomorphologic development of the Vasilikos river catchment, S Cyprus, in relation to uplift of the Troodos ophiolite and climate-related changes
Authors: Murray Hannah , Robertson Alastair HF
Published: October 2019

The Pleistocene development of the Vasilikos River exemplifies the interaction of focused, tectonically induced surface uplift and climate-influenced changes. The resulting sediments are well exposed in Vasilikos Quarry and in the main river catchment further east. An important erosional surface incises the highest-level (oldest) fluvial conglomerates, down into Late Pliocene – Early Pleistocene open-marine mudrocks (Nicosia Formation), allowing integration with the circum-Cyprus sedimentary–geomorphic development (F1–F4 stages). To determine where the quarry deposits lie in relation to the Vasilikos river catchment, the fluvial deposits were mapped and valley profiles were constructed, revealing four main episodes, each associated with incision and distinctive fluvial deposition. Source lithology strongly influenced channel morphology, infill and adjacent slope-sediment (colluvium) composition. Palaeosols, particularly red-brown terra rossa, developed on abandoned fluvial terraces and adjacent hillslopes, especially overlying F3 surfaces. The combined evidence allows close correlation of the Vasilikos river and quarry deposits. Relatively coarse (chalky conglomerate/breccia) and fine-grained colluvium (calcareous silt – Cyprus harvara) developed especially on lower hillslopes following incision (mainly above F2 and F3 surfaces). Based on regional comparisons, overall sediment aggregation ended during the Early Pleistocene. The F1–F2 surfaces and deposits are inferred to be Middle Pleistocene, the F3 ones later Middle Pleistocene and the F4 ones near the Middle–Late Pleistocene boundary. Geomorphology and deposition were tectonically forced during strong, focused Early–Middle Pleistocene surface uplift. Coarse clastic ruff-off and palaeosol development (terra rossa) and related sediment aggradation are inferred to have increased during warm, humid periods. Late Pleistocene geomorphology and deposition were more influenced by climatic change, with semi-perennial streamflow, rapid sediment aggradation and palaeosol (terra rossa) development during warm, humid periods (interglacials). Cooler (glacial) periods enhanced fluvial-incision, sediment-bypassing and hillslope colluvial processes (e.g. frost shattering, downslope creep and mass flow) when sediment transport (bypassing) exceeded sediment supply. Neotectonic faulting affected the catchment but did not greatly affect geomorphology or sediment supply. Although climate / climate change (and eustatic sea-level change) had an important influence, tectonics is interpreted as the fundamental driver of geomorphological development and fluvial sedimentation, with implications for other areas, regionally to globally.
Marriage patterns in Sri Lanka and the prevalence of parental consanguinity in patients with β-thalassaemia: a cross-sectional descriptive analysis
Authors: Premawardhena Anuja P. , De Silva Shamila T. , Goonatilleke M. D. Dilith C. , Ediriweera Dileepa S. , Mettananda Sachith , Rodrigo B. K. Rexan P. , Allen Angela , Weatherall David J.
Published: October 2019

Consanguineous marriages potentially play an important role in the transmission of β-thalassaemia in many communities. This study aimed to determine the rate and socio-demographic associations of consanguineous marriages and to assess the influence on the prevalence of β-thalassaemia in Sri Lanka. Three marriage registrars from each district of Sri Lanka were randomly selected to prospectively collect data on all couples who registered their marriage during a 6-month period starting 1st July 2009. Separately, the parents of patients with β-thalassaemia were interviewed to identify consanguinity. A total of 5255 marriages were recorded from 22 districts. The average age at marriage was 27.3 (±6.1) years for males and 24.1 (±5.7) years for females. A majority (71%) of marriages were ‘love’ marriages, except in the Moor community where 84% were ‘arranged’ marriages. Overall, the national consanguinity rate was 7.4%. It was significantly higher among ethnic Tamils (22.4%) compared with Sinhalese (3.8%) and Moors (3.2%) (p < 0.001). Consanguinity rates were also higher in ‘arranged’ as opposed to ‘love’ marriages (11.7% vs 5.6%, p < 0.001). In patients with β-thalassaemia, the overall consanguinity rate was 14.5%; it was highest among Tamils (44%) and lowest among Sinhalese (12%). Parental consanguinity among patients with β-thalassaemia was double the national average. Although consanguinity is not the major factor in the transmission of the disease in the country, emphasis should be given to this significant practice when conducting β-thalassaemia prevention and awareness campaigns, especially in high-prevalence communities.
Does Board Independence Increase Firm Value? Evidence from Closed-End Funds
Authors: Souther Matthew E.
Published: October 2019

Researchers disagree about the impact of board independence on firm value. The disagreement generally stems from the endogenous nature of board appointments. I add new evidence to this discussion by using a sample of closed-end funds to document the value-enhancing effects of independent boards. Using cross-sectional, difference-in-differences, and instrumental variables techniques, I address these endogeneity concerns and find consistent evidence that board independence is associated with higher firm value.
Phosphorus Transport in Intensively Managed Watersheds
Authors: Dolph Christine L. , Boardman Evelyn , Danesh‐Yazdi Mohammad , Finlay Jacques C. , Hansen Amy T. , Baker Anna C. , Dalzell Brent
Published: October 2019

Understanding controls of P movement through watersheds are essential for improved landscape management in intensively managed regions. Here, we analyze observational data from 104 gaged river sites and 176 nongaged river sites within agriculturally dominated watersheds of Minnesota, USA, to understand the role of landscape features, land use practices, climate variability, and biogeochemical processes in total, dissolved and particulate P dynamics at daily to annual scales. Our analyses demonstrate that factors mediating P concentration‐discharge relationships varied greatly across watersheds and included near‐channel sediment sources, lake and wetland interception, assimilation by algal P, and artificial land drainage. The majority of gaged sites exhibited mobilizing behavior for all forms of P at event (i.e., daily) timescales and chemostatic behavior at annual timescales. The large majority of watershed P export (>70%, on average) occurred during high flow conditions, suggesting that more frequent large storm events arising from climate change will drive increased P losses from agricultural watersheds without substantial management changes. We found that P export could be dominated by dissolved P, particulate P, or an even mix of the two forms, depending on watershed attributes. Implementation of management practices to control P losses must be guided by understanding of how local landscapes interact with current and future climate conditions. Managing for both dissolved and particulate P is required to reduce overall P load in many agricultural watersheds.
Can We Detect Changes in Amazon Forest Structure Using Measurements of the Isotopic Composition of Precipitation?
Authors: Pattnayak K.C. , Tindall J .C. , Brienen R. J. W. , Barichivich J. , Gloor E.
Published: October 2019

Large‐scale (>500 km) spatial gradients of precipitation oxygen isotope ratios (δ18Op) hold information about the hydrological cycle. They result from the interplay between rainout and evapotranspiration along air‐parcel paths, but these counteracting effects are difficult to disentangle, complicating quantification of the effect of land cover change on δ18Op. We show that disentangling can qualitatively be achieved using climate model simulations with a land‐derived precipitation tracer for tropical South America. We then either vary land cover as observed since 1870 or replace Amazon forests with bare land to determine the resulting signals. Our results indicate that effects of historically changing land cover on annual mean δ18O isotope‐ratio gradients are small and unlikely detectable, although there is a noticeable signal during the dry season. Furthermore, the effect of changes in water recycling on Amazon δ18Op in paleo‐records may have been overestimated and need reinterpretation.
Effective Rheology Across the Fragmentation Transition for Sea Ice and Ice Shelves
Authors: Åström J.A. , Benn D.I.
Published: October 2019

Sea ice and ice shelves can be described by a viscoelastic rheology that is approximately linear elastic and brittle at high strain rates and viscously shear thinning at low strain rates. Brittle ice easily fractures under compressive shear and forms shear bands as the material undergoes a transition to a fragmented, granular state. This transition plays a central role in the mechanical behavior at large scales of sea ice in the Arctic Ocean or Antarctic ice shelves. Here we demonstrate that the fragmentation transition is characterized by an essentially discontinuous drop of three to five orders of magnitude in effective viscosity and stress relaxation time. Beyond the fragmentation transition, grinding in shear zones further reduces both effective viscosity and shear stiffness, but with an essentially constant relaxation time of ∼10 s. These results are relevant for ice rheology implementation in large‐scale climate‐related models of sea ice and thin ice shelves.
Sulfur Cycling and Mass Balance at Meridiani, Mars
Authors: Hynek Brian M. , McCollom Thomas M. , Szynkiewicz Anna
Published: October 2019

The Opportunity rover was sent to Meridiani Planum, Mars, to investigate aqueous processes as inferred from orbiter observations of hematite. While the rover found the source of the hematite signal, it also identified abundant bedrock enriched in SO3 on average by >20 wt% throughout its >40‐km traverse. Geological mapping and orbiter data show that the layered sulfate deposits occur over ~4 × 105 km2, an area larger than Germany. Multiple scenarios for formation of the sediment and sulfur sources in the Meridiani sulfate‐rich bedrock have been proposed, including groundwater upwelling in a playa environment, volcanic ash, ice deposits, and fluvial input. Mass balance calculations show that none of the existing scenarios as currently portrayed can account for the total sediment volume and sulfur mass in the Meridiani region. Thus, after 14 Earth years of rover observations, there are still fundamental questions that remain regarding formation mechanisms of the sulfate‐rich bedrock.
Isopycnal Mixing Controls Deep Ocean Ventilation
Authors: Jones C. S. , Abernathey Ryan P.
Published: October 2019

Climate models often parameterize isopycnal mixing by mesoscale eddies using a diffusion operator that acts in the isopycnal direction, multiplied by an isopycnal‐mixing coefficient. The magnitude of this coefficient is uncertain, with observational estimates ranging from 10 to 10,000 m2/s. In an idealized‐geometry ocean model, the isopycnal‐mixing coefficient is varied across a similar range without allowing the circulation to change: This leads to large changes in the ventilation of the deep ocean. Passive tracers are used to assess the impact of varying the isopycnal‐mixing coefficient on water mass distributions. Increasing the isopycnal‐mixing coefficient from 50 to 5,000 m2/s leads to a 63% reduction in the amount of North Atlantic Deep Water and a doubling in the amount of Antarctic Bottom Water in the deep Pacific ocean. This change is associated with a 700‐yr reduction in the ideal age of water in the deep Pacific ocean.
Observation of Very Short Period Atmospheric Gravity Waves in the Lower Ionosphere Using Very Low Frequency Waves
Authors: Maurya Ajeet K. , Cohen Morris B. , Niranjan Kumar Kondapalli , Phanikumar D.V. , Singh Rajesh , Vineeth P.K. , Kishore Kumar K.
Published: October 2019

We present observations of very short period (<5 min) wavy fluctuations (WFs) in the lower ionosphere (75–85 km) on the night of 21 January 2016, using subionospherically propagating very low frequency signals. Four out of six transmitter signals recorded by the very low frequency/low frequency receiver at the Pisgah Astronomical Research Institute showed WFs simultaneously. However, their time of occurrence and intensities were different. Power spectral analysis indicates a period of ~3–4 mins, largely associated with the two regions of strong convective and lightning activity in the lower troposphere. Background wind (at ~15 and 80 km) direction shows westward propagation, suggesting important role of the convective storm located east of Pisgah Astronomical Research Institute. The GPS total electron content analysis also divulges similar WFs at upper ionospheric altitude (~300 km) on the GPS total electron content stations around the two storms. The observational analysis suggests atmospheric gravity waves from the convective regions propagate upward up into the ionospheric altitudes. Hence, the present study reinforces the strong coupling of troposphere and ionosphere through the convectively generated very short period waves.
The natural compound gracillin exerts potent antitumor activity by targeting mitochondrial complex II
Authors: Min Hye-Young , Jang Hyun-Ji , Park Kwan Hee , Hyun Seung Yeob , Park So Jung , Kim Ji Hye , Son Jaekyoung , Kang Sam Sik , Lee Ho-Young
Published: October 2019

Mitochondria play a pivotal role in cancer bioenergetics and are considered a potential target for anticancer therapy. Considering the limited efficacy and toxicity of currently available mitochondria-targeting agents, it is necessary to develop effective mitochondria-targeting anticancer drugs. By screening a large chemical library consisting of natural products with diverse chemical entities, we identified gracillin, a steroidal saponin, as a mitochondria-targeting antitumor drug. Gracillin displayed broad-spectrum inhibitory effects on the viability of a large panel of human cancer cell lines, including those carrying acquired resistance to chemotherapy or EGFR-targeting drugs, by inducing apoptosis. We show that gracillin attenuates mitochondria-mediated cellular bioenergetics by suppressing ATP synthesis and by producing reactive oxygen species (ROS). Mechanistically, gracillin disrupts complex II (CII) function by abrogating succinate dehydrogenase (SDH) activity without affecting the succinate:ubiquinone reductase. The gracillin-induced cell death was potentiated by 3-nitropropionic acid (3-NPA) or thenoyltrifluoroacetone (TTFA), which inhibit CII by binding to the active site of SDHA or to the ubiquinone-binding site, respectively. Finally, we show that gracillin effectively suppressed the mutant-Kras-driven lung tumorigenesis and the growth of xenograft tumors derived from cell lines or patient tissues. Gracillin displayed no obvious pathophysiological features in mice. Collectively, gracillin has potential as a CII-targeting antitumor drug.
TET2-interacting long noncoding RNA promotes active DNA demethylation of the MMP-9 promoter in diabetic wound healing
Authors: Zhou Liyan , Ren Meng , Zeng Tingting , Wang Wei , Wang Xiaoyi , Hu Mengdie , Su Shicheng , Sun Kan , Wang Chuan , Liu Jing , Yang Chuan , Yan Li
Published: October 2019

Wound healing in diabetic skin is impaired by excessive activation of matrix metalloproteinase-9 (MMP-9). MMP-9 transcription is activated by Ten-eleven translocation 2 (TET2), a well-known DNA demethylation protein that induces MMP-9 promoter demethylation in diabetic skin tissues. However, how TET2 is targeted to specific loci in the MMP-9 promoter is unknown. Here, we identified a TET2-interacting long noncoding RNA (TETILA) that is upregulated in human diabetic skin tissues. TETILA regulates TET2 subcellular localization and enzymatic activity, indirectly activating MMP-9 promoter demethylation. TETILA also recruits thymine-DNA glycosylase (TDG), which simultaneously interacts with TET2, for base excision repair-mediated MMP-9 promoter demethylation. Together, our results suggest that the TETILA serves as a genomic homing signal for TET2-mediated demethylation specific loci in MMP-9 promoter, thereby disrupting the process of diabetic skin wound healing.
TGF-β1 facilitates cell–cell communication in osteocytes via connexin43- and pannexin1-dependent gap junctions
Authors: Liu Wenjing , Zhang Demao , Li Xin , Zheng Liwei , Cui Chen , Cui Yujia , Sun Jianxun , Xie Jing , Zhou Xuedong
Published: October 2019

Connexins and pannexins are two families of channel forming proteins that are able to pass small molecules to achieve communication between cells. While connexins have been recognized to mediate gap junctional intercellular communication (GJIC), pannexins are far less known. Our previous study reported the potential role of TGF-β1 in mediating of connexins in osteocytes in vitro. Herein, we aimed to elucidate the influence of TGF-β1 on cell–cell communication based on gap junctions assembled by connexins and pannexins in vitro and ex vivo. We first showed that TGF-β1 positively affected the elongation of dendritic processes of osteocytes. Our data indicated that TGF-β1 increased expressions of connexin43 (Cx43) and pannexin1 (panx1), which are indispensable for hemichannel formation in gap junctions, in osteocytes in vitro and ex vivo. TGF-β1 enhanced gap junction formation and impacted cell–cell communication in living osteocytes, as indicated by the scrape loading and Lucifer yellow transfer assays. TGF-β1 enhanced the expressions of Cx43 and panx1 via activation of ERK1/2 and Smad3/4 signalling. The TGF-β1-restored expressions of Cx43 and panx1 in osteocytes in the presence of an ERK inhibitor, U0126, further demonstrated the direct participation of Smad3/4 signalling. TGF-β1 increased the accumulation of Smad3 in the nuclear region (immunofluorescence assay) and promoted the enrichment of Smad3 at the binding sites of the promoters of Gja1 (Cx43) and Panx1 (ChIP assay), thereby initiating the enhanced gene expression. These results provide a deep understanding of the molecular mechanisms involved in the modulation of cell–cell communication in osteocytes induced by TGF-β1.
Complementary hybrid electrodes for high contrast electrochromic devices with fast response
Authors: Kortz Carsten , Hein Alexander , Ciobanu Marius , Walder Lorenz , Oesterschulze Egbert
Published: October 2019

Fast switching ‘transparent-to-black’ electrochromic devices are currently under investigation as potential candidates in modern applications like e-papers or with additional functionality as ultracompact iris or switchable neutral filter in camera systems. However, recent electrochromic devices show either a lack of contrast or slow response times. To overcome these deficiencies we focus on a careful material composition of the colouring hybrid electrodes in our device. We have established a nanoporous Sb-doped SnO$${}_{2}$$2electrode as supporting electrode for chemisorbed electrochromic tetraphenylbenzidine molecules due to its good conductivity in the redox potential range of the molecule. This hybrid electrode was combined with a modified nanoporous TiO$${}_{2}$$2/ viologen electrode to realize a high performance, complementary electrochromic device. Fast switching time constants of 0.5 s and concurrently high change in optical density$$\Delta$$ΔOD = 2.04 at 605 nm confirm our successful concept. The achieved colouration efficiency of 440 cm$${}^{2}$$2C$${}^{-1}$$−1exceeds every high contrast device presented so far.
Identification of stable adsorption sites and diffusion paths on nanocluster surfaces: an automated scanning algorithm
Authors: Szilvási Tibor , Chen Benjamin W. J. , Mavrikakis Manos
Published: October 2019

The diverse coordination environments on the surfaces of discrete, three-dimensional (3D) nanoclusters contribute significantly to their unique catalytic properties. Identifying the numerous adsorption sites and diffusion paths on these clusters is however tedious and time-consuming, especially for large, asymmetric nanoclusters. Here, we present a simple, automated method for constructing approximate 2D potential energy surfaces for the adsorption of atomic species on the surfaces of 3D nanoclusters with minimal human intervention. These potential energy surfaces fully characterize the important adsorption sites and diffusion paths on the nanocluster surfaces with accuracies similar to current approaches and at comparable computational cost. Our method can treat complex nanoclusters, such as alloy nanoclusters, and accounts for cluster relaxation and adsorbate-induced reconstruction, important for obtaining accurate energetics. Moreover, its highly parallelizable nature is ideal for modern supercomputer architectures. We showcase our method using two clusters: Au18 and Pt55. For Au18, diffusion of atomic hydrogen between the most stable sites occurs via non-intuitive paths, underlining the necessity of exploring the complete potential energy surface. By enabling the rapid and unbiased assessment of adsorption and diffusion on large, complex nanoclusters, which are particularly difficult to handle manually, our method will help advance materials discovery and the rational design of catalysts.
A nonlocal game for witnessing quantum networks
Authors: Luo Ming-Xing
Published: October 2019

Nonlocal game as a witness of the nonlocality of entanglement is of fundamental importance in various fields. The well-known nonlocal games or equivalent linear Bell inequalities are only useful for Bell networks consisting of single entanglement. Our goal in this paper is to propose a unified method for constructing cooperating games in network scenarios. We propose an efficient method to construct multipartite nonlocal games from any graphs. The main idea is the graph representation of entanglement-based quantum networks. We further specify these graphic games with quantum advantages by providing a simple sufficient and necessary condition. The graphic games imply a linear Bell testing of the nonlocality of general quantum networks consisting of EPR states. It also allows generating new instances going beyond CHSH game. These results have interesting applications in quantum networks, Bell theory, computational complexity, and theoretical computer science.
Generation of a frequency-degenerate four-photon entangled state using a silicon nanowire
Authors: Feng Lan-Tian , Zhang Ming , Zhou Zhi-Yuan , Chen Yang , Li Ming , Dai Dao-Xin , Ren Hong-Liang , Guo Guo-Ping , Guo Guang-Can , Tame Mark , Ren Xi-Feng
Published: October 2019

Integrated photonics is becoming an ideal platform for generating two-photon entangled states with high brightness, high stability, and scalability. This high brightness and high quality of photon pair sources encourages researchers further to study and manipulate multiphoton entangled states. Here, we experimentally demonstrate frequency-degenerate four-photon entangled state generation based on a single silicon nanowire 1 cm in length. The polarization encoded entangled states are generated with the help of a Sagnac loop using additional optical elements. The states are analyzed using quantum interference and state tomography techniques. As an example, we show that the generated quantum states can be used to achieve phase super-resolution. Our work provides a method for preparing indistinguishable multi-photon entangled states and realizing quantum algorithms in a compact on-chip setting.
A data driven approach reveals disease similarity on a molecular level
Authors: Lakiotaki Kleanthi , Georgakopoulos George , Castanas Elias , Røe Oluf Dimitri , Borboudakis Giorgos , Tsamardinos Ioannis
Published: October 2019

Could there be unexpected similarities between different studies, diseases, or treatments, on a molecular level due to common biological mechanisms involved? To answer this question, we develop a method for computing similarities between empirical, statistical distributions of high-dimensional, low-sample datasets, and apply it on hundreds of -omics studies. The similarities lead to dataset-to-dataset networks visualizing the landscape of a large portion of biological data. Potentially interesting similarities connecting studies of different diseases are assembled in a disease-to-disease network. Exploring it, we discover numerous non-trivial connections between Alzheimer’s disease and schizophrenia, asthma and psoriasis, or liver cancer and obesity, to name a few. We then present a method that identifies the molecular quantities and pathways that contribute the most to the identified similarities and could point to novel drug targets or provide biological insights. The proposed method acts as a “statistical telescope” providing a global view of the constellation of biological data; readers can peek through it at:http://datascope.csd.uoc.gr:25000/.
A multigene and morphological analysis expands the diversity of the seabod shrimp Xiphopenaeus Smith, 1869 (Decapoda: Penaeidae), with descriptions of two new species
Authors: Carvalho-Batista Abner , Terossi Mariana , Zara Fernando J. , Mantelatto Fernando L. , Costa Rogerio C.
Published: October 2019

After being stable for nearly a century, the taxonomic history of the genus Xiphopenaeus has been marked by many changes in the last three decades. The taxonomic status of the Atlantic species has a low resolution, and many species are still undefined and grouped as cryptic species. Here we employed an integrative approach to define the species of Xiphopenaeus and the morphological characters needed to differentiate them. We combined the analyses of two molecular markers (COI and 16 S rDNA), scanning electron microscopy and light microscopy. Based on specimens from 17 localities from the Atlantic and Pacific oceans, we detected five divergent genetic groups, three in the Atlantic (A1, A2, A3) and two in the Pacific (P1, P2). Male secondary sexual characters were able to differentiate four out of the five genetic groups. Group A1 corresponds to X. kroyeri, and A2 and A3 correspond to new species. We redescribed the genus and two new species are described and illustrated: Xiphopenaeus dincao nov. sp. (A2) and Xiphopenaeus baueri nov. sp. (A3). Since the holotype of X. riveti was missing and the specimen analysed from group P2 was a female, the status of the species of Xiphopenaeus from the Pacific remains unresolved.
Spring peaks and autumn troughs identified in peripheral inflammatory markers during the peripartum period
Authors: Henriksson Hanna E. , White Richard A. , Iliadis Stavros I. , Fransson Emma , Papadopoulos Fotios C. , Sundström-Poromaa Inger , Skalkidou Alkistis
Published: October 2019

Seasonal variations have recently been described in biomarkers, cell types, and gene expression associated with the immune system, but so far no studies have been conducted among women in the peripartum period. It is of note that pregnancy complications and outcomes, as well as autoimmune diseases, have also been reported to exhibit seasonal fluctuations. We report here a clear-cut seasonal pattern of 23 inflammatory markers, analysed using proximity-extension assay technology, in pregnant women. The inflammatory markers generally peaked in the spring and had a trough in the autumn. During the postpartum period we found seasonality in one inflammatory marker, namely monocyte chemotactic protein 4 (MCP-4). Our findings suggest that seasonal variations in peripheral inflammatory markers are only observed during pregnancy. The results of this study could be valuable to professionals working within the field of immunology-related areas, and provide insight for the understanding of obstetric complications.
Modeling lamellar disruption within the aortic wall using a particle-based approach
Authors: Ahmadzadeh H. , Rausch M. K. , Humphrey J. D.
Published: October 2019

Aortic dissections associate with medial degeneration, thus suggesting a need to understand better the biophysical interactions between the cells and matrix that constitute the middle layer of the aortic wall. Here, we use a recently extended “Smoothed Particle Hydrodynamics” formulation to examine potential mechanisms of aortic delamination arising from smooth muscle cell (SMC) dysfunction or apoptosis, degradation of or damage to elastic fibers, and pooling of glycosaminoglycans (GAGs), with associated losses of medial collagen in the region of the GAGs. First, we develop a baseline multi-layered model for the healthy aorta that delineates medial elastic lamellae and intra-lamellar constituents. Next, we examine stress fields resulting from the disruption of individual elastic lamellae, lost SMC contractility, and GAG production within an intra-lamellar space, focusing on the radial transferal of loading rather than on stresses at the tip of the delaminated tissue. Results suggest that local disruptions of elastic lamellae transfer excessive loads to nearby intra-lamellar constituents, which increases cellular vulnerability to dysfunction or death. Similarly, lost SMC function and accumulations of GAGs increase mechanical stress on nearby elastic lamellae, thereby increasing the chance of disruption. Overall these results suggest a positive feedback loop between lamellar disruption and cellular dropout with GAG production and lost medial collagen that is more pronounced at higher distending pressures. Independent of the initiating event, this feedback loop can catastrophically propagate intramural delamination.
Distinct downstream signaling and the roles of VEGF and PlGF in high glucose-mediated injuries of human retinal endothelial cells in culture
Authors: Jiao Wanzhen , Ji Jia-Fu , Xu Wenwen , Bu Wenjuan , Zheng Yuanjie , Ma Aihua , Zhao Bojun , Fan Qingfeng
Published: October 2019

Vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) plays a crucial role in breakdown of the blood-retinal barrier due to hyperpermeability in diabetic retinopathy (DR). However, the distinct signaling driven by VEGF and PlGF in the pathogenesis of DR remains unclear. In this study, we investigated VEGF- and PlGF- related signaling pathways and their roles in cultured human microvascular retinal endothelial cells (hRECs) under high glucose conditions (HG; 25 mM). Apoptotic cell death was evaluated, and FITC conjugated bovine serum albumin across monolayer hRECs served as an index of permeability. Western blots were used to assess the protein levels of VEGF and PlGF, as well as the phosphorylation of p38MAPK, STAT1 and Erk1/2. Knockdown of VEGF and PlGF was performed by using siRNA. Following HG treatment, increases of VEGF and PlGF as well as PKC activity were detected in hRECs. Increased phosphorylations of p38MAPKThr180/Thr182, STAT1Ser727, and Erk1/2Tyr202/Tyr185 as well as VEGFR1Tyr1213 and VEGFR2Tyr1175 were also detected in HG-treated hRECs. Inhibition of PKC activity by Go 6976 prevented HG-induced increases of phosphor-Erk1/2 and nitric oxide synthase (NOS1) expressions as well as hyperpermeability, whereas inhibition of p38MAPK pathway by SB203580 selectively suppressed activation of STAT1 and decreased apoptotic cell death under HG conditions. Moreover, VEGF knockdown predominantly inhibited activation of VEGFR2, and phosphorylation of p38MAPK and STAT1, as well as apoptotic cell death in HG-treated hRECs. Nevertheless, PlGF knockdown mainly suppressed phosphorylation of VEGFR1, PKC, and Erk1/2, as well as NOS1 expressions and hyperpermeability. Taken together, we provide evidence demonstrating that HG-induced elevation of PlGF is responsible for hyperpermeability mainly through increasing activation of PKC-Erk1/2-NOS axis via VEGFR1, while HG-induced elevation of VEGF is associated with induction of apoptotic cell death mainly through increasing activation of p38MAPK/STAT1 signaling via VEGFR2.
Tracing the sources of nutrients fueling dinoflagellate red tides occurring along the coast of Korea using radium isotopes
Authors: Kwon Hyeong Kyu , Kim Guebuem , Han Yongjin , Seo Junhyeong , Lim Weol Ae , Park Jong Woo , Park Tae Gyu , Han In-Seong
Published: October 2019

It is a well held concept that the magnitude of red-tide occurrence is dependent on the amount of nutrient supply if the conditions are same for temperature, salinity, light, interspecific competition, etc. However, nutrient sources fueling dinoflagellate red-tides are difficult to identify since red tides usually occur under very low inorganic-nutrient conditions. In this study, we used short-lived Ra isotopes (223Ra and 224Ra) to trace the nutrient sources fueling initiation and spread of Cochlodinium polykrikoides blooms along the coast of Korea during the summers of 2014, 2016, and 2017. Horizontal and vertical distributions of nutrient concentrations correlated well with 224Ra activities in nutrient-source waters. The offshore red-tide areas showed high 224Ra activities and low-inorganic and high-organic nutrient concentrations, which are favorable for blooming C. polykrikoides in competition with diatoms. Based on Ra isotopes, the nutrients fueling red-tide initiation (southern coast of Korea) are found to be transported horizontally from inner-shore waters. However, the nutrients in the spread region (eastern coast of Korea), approximately 200 km from the initiation region, are supplied continuously from the subsurface layer by vertical mixing or upwelling. Our study highlights that short-lived Ra isotopes are excellent tracers of nutrients fueling harmful algal blooms in coastal waters.
Scrapie susceptibility-associated indel polymorphism of shadow of prion protein gene (SPRN) in Korean native black goats
Authors: Kim Yong-Chan , Kim Seon-Kwan , Jeong Byung-Hoon
Published: October 2019

Prion diseases in sheep and goats are called scrapie and belong to a group of transmissible spongiform encephalopathies (TSEs) caused by the abnormal misfolding of the prion protein encoded by the prion protein gene (PRNP). The shadow of the prion protein gene (SPRN) is the only prion gene family member that shows a protein expression profile similar to that of the PRNP gene in the central nervous system. In addition, genetic susceptibility of the SPRN gene has been reported in variant Creutzfeldt–Jakob disease (CJD), bovine spongiform encephalopathy (BSE) and scrapie. However, genetic studies of the SPRN gene have not been carried out in Korean native black goats. Here, we investigated the genotype and allele frequencies of SPRN polymorphisms in 213 Korean native black goats and compared these polymorphisms with those previously reported for scrapie-affected animals. We found a total of 6 polymorphisms including 1 nonsynonymous single nucleotide polymorphism (SNP) and 1 synonymous SNP in the open reading frame (ORF) region and 3 SNPs and 1 indel polymorphism (c.495_496insCTCCC) in the 3′ untranslated region (UTR) by direct DNA sequencing. A significant difference in the allele frequency of the c.495_496insCTCCC indel polymorphism was found between the Italian scrapie-affected goats and the Korean native black goats (P < 0.001). Furthermore, there was a significant difference in the allele frequencies of the c.495_496insCTCCC indel polymorphism between Italian healthy goats and Korean native black goats (P < 0.001). To evaluate the biological impact of the novel nonsynonymous SNP c.416G > A (Arg139Gln), we carried out PROVEAN analysis. PROVEAN predicted the SNP as ‘Neutral’ with a score of −0.297. To the best of our knowledge, this is the first genetic study of the SPRN gene in Korean native black goats.
Predicting the Dispersion Relations of One-Dimensional Phononic Crystals by Neural Networks
Authors: Liu Chen-Xu , Yu Gui-Lan
Published: October 2019

In this paper, deep back propagation neural networks (DBP-NNs) and radial basis function neural networks (RBF-NNs) are employed to predict the dispersion relations (DRs) of one-dimensional (1D) phononic crystals (PCs). The data sets generated by transfer matrix method (TMM) are used to train the NNs and detect their prediction accuracy. In our work, filling fractions, mass density ratios and shear modulus ratios of PCs are considered as the input values of NNs. The results show that both the DBP-NNs and the RBF-NNs exhibit good performances in predicting the DRs of PCs. For one-parameter prediction, the RBF-NNs have shorter training time and remarkable prediction accuracy, for two- and three-parameter prediction, the DBP-NNs have more stable performance. The present work confirms the feasibility of predicting the DRs of PCs by NNs, and provides a useful reference for the application of NNs in the design of PCs and metamaterials.
Slow freezing versus vitrification for the cryopreservation of zebrafish (Danio rerio) ovarian tissue
Authors: Marques Lis S. , Fossati Ana A. N. , Rodrigues Rômulo B. , Da Rosa Helen T. , Izaguirry Aryele P. , Ramalho Juliana B. , Moreira José C. F. , Santos Francielli Weber , Zhang Tiantian , Streit Danilo P.
Published: October 2019

The aim of the present study was to compare the efficiency of vitrification and slow freezing techniques for the cryopreservation of zebrafish ovarian tissue containing immature follicles. In Experiment 1, assessment of cell membrane integrity by trypan blue exclusion staining was used to select the best cryoprotectant solution for each cryopreservation method. Primary growth (PG) oocytes showed the best percentage of membrane integrity (63.5 ± 2.99%) when SF4 solution (2 M methanol + 0.1 M trehalose + 10% egg yolk solution) was employed. The vitrification solution, which presented the highest membrane integrity (V2; 1.5 M methanol + 5.5 M Me2SO + 0.5 M sucrose + 10% egg yolk solution) was selected for Experiment 2. Experiment 2 aimed to compare the vitrification and slow freezing techniques in the following parameters: morphology, oxidative stress, mitochondrial activity, and DNA damage. Frozen ovarian tissue showed higher ROS levels and lower mitochondrial activity than vitrified ovarian tissue. Ultrastructural observations of frozen PG oocytes showed rupture of the plasma membrane, loss of intracellular contents and a large number of damaged mitochondria, while vitrified PG oocytes had intact mitochondria and cell plasma membranes. We conclude that vitrification may be more effective than slow freezing for the cryopreservation of zebrafish ovarian tissue.
Mayaro Virus Induction of Oxidative Stress is Associated With Liver Pathology in a Non-Lethal Mouse Model
Authors: da Silva Caetano Camila Carla , Camini Fernanda Caetano , Almeida Letícia Trindade , Ferraz Ariane Coelho , da Silva Tales Fernando , Lima Rafaela Lameira Souza , de Freitas Carvalho Mayara Medeiros , de Freitas Castro Thalles , Carneiro Cláudia Martins , de Mello Silva Breno , de Queiroz Silva Silvana , de Magalhães José Carlos , de Brito Magalhães Cintia Lopes
Published: October 2019

Mayaro virus (MAYV) causes Mayaro fever in humans, a self-limiting acute disease, with persistent arthralgia and arthritis. Although MAYV has a remerging potential, its pathogenic mechanisms remain unclear. Here, we characterized a model of MAYV infection in 3–4-week BALB/c mice. We investigated whether the liver acts as a site of viral replication and if the infection could cause histopathological alterations and an imbalance in redox homeostasis, culminating with oxidative stress. MAYV-infected mice revealed lower weight gain; however, the disease was self-resolving. High virus titre, neutralizing antibodies, and increased levels of aspartate and alanine aminotransferases were detected in the serum. Infectious viral particles were recovered in the liver of infected animals and the histological examination of liver tissues revealed significant increase in the inflammatory infiltrate. MAYV induced significant oxidative stress in the liver of infected animals, as well as a deregulation of enzymatic antioxidant components. Collectively, this is the first study to report that oxidative stress occurs in MAYV infection in vivo, and that it may be crucial in virus pathogenesis. Future studies are warranted to address the alternative therapeutic strategies for Mayaro fever, such as those based on antioxidant compounds.