bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrooxidation behavior of ethanol toward carbon microbead-encapsulated ZnO particles derived from coffee waste
Authors: Ghouri Zafar Khan , Elsaid Khaled , Abdel-Wahab Ahmed , Abdala Ahmed , Farhad Mohammad Zahid
Published: March 2020

Carbon microbead-encapsulated ZnO (CM-ZnO) particles have been synthesized from the spent coffee ground (SCG) by chemical activation with ZnCl2 followed by calcination at 700 ℃ in N2 environment. Interestingly, ZnCl2 can act as an activating agent as well as a precursor for ZnO particles. The structure of the core and shell of the CM-ZnO was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Moreover, X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) studies confirmed the presence of the encapsulated ZnO particles. The Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) plots showed a well-developed porous structure with a specific surface area of 210 m2/g, average pore volume of 1.12 cm3/g, and an average pore radius of 31.7 Å. The electrooxidation behavior of ethanol toward the synthesized CM-ZnO was then studied using cyclic voltammetry (CV) technique. For comparison, two types of modified electrodes were prepared: the first one with the non-activated SCG and the second one with the CM-ZnO. The electrochemical measurements of the prepared CM-ZnO demonstrated higher electrocatalytic activity with a current density of ~ 35 mA/cm2 at 0.4 V vs. Ag/AgCl for ethanol electrooxidation in an alkaline medium. The electrochemical measurements specified that the presence of ZnO particles and the high surface area of the activated sample have a significant influence on electrooxidation activity. Therefore, the introduced CM-ZnO particles could be an alternative and effective non-precious electrocatalyst for ethanol electrooxidation.
Application-Aware Firewall Mechanism for Software Defined Networks
Authors: Nife Fahad N. , Kotulski Zbigniew
Published: March 2020

Software-Defined-Networking (SDN) has been recently arising as a new technology in the IT industry. It is a network architecture that hopes to provide better solutions to most of the constraints in contemporary networks. SDN is a centralized control architecture for networking in which the control plane is separated from the data plane, the network services are abstracted from the underlying forwarding devices, and the network’s intelligence is centralized in a software-based directly-programmed device called a controller. These features of SDN provide more flexible, programmable and innovative network’s architecture. However, they may pose new vulnerabilities and may lead to new security problems. In this paper, we propose the application-aware firewall mechanism for SDN, which can be implemented as an extension to the network’s controller. In order to provide more control and visibility in applications running over the network, the system is able to detect network applications that may at some point affect network’s performance, and it is capable to dynamically enforce constraint rules on applications. The firewall architecture is designed as four cooperating modules: the Main Module, the Filtering Module, the Application Identification Module, and the Security-Enforcement Module. The proposed mechanism checks the network traffic at the network, transport, and application levels, and installs appropriate security instructions down into the network. The proposed solution features were implemented and tested using a Python-based POX controller, and the network topology was built using Mininet emulation tool.
A Large Deviation Perspective on Ratio Observables in Reset Processes: Robustness of Rate Functions
Authors: Coghi Francesco , Harris Rosemary J.
Published: March 2020

We study large deviations of a ratio observable in discrete-time reset processes. The ratio takes the form of a current divided by the number of reset steps and as such it is not extensive in time. A large deviation rate function can be derived for this observable via contraction from the joint probability density function of current and number of reset steps. The ratio rate function is differentiable and we argue that its qualitative shape is ‘robust’, i.e. it is generic for reset processes regardless of whether they have short- or long-range correlations. We discuss similarities and differences with the rate function of the efficiency in stochastic thermodynamics.
Tracking self-citations in academic publishing
Authors: Kacem Ameni , Flatt Justin W. , Mayr Philipp
Published: March 2020

Citation metrics have value because they aim to make scientific assessment a level playing field, but urgent transparency-based adjustments are necessary to ensure that measurements yield the most accurate picture of impact and excellence. One problematic area is the handling of self-citations, which are either excluded or inappropriately accounted for when using bibliometric indicators for research evaluation. Here, in favor of openly tracking self-citations we report on self-referencing behavior among various academic disciplines as captured by the curated Clarivate Analytics Web of Science database. Specifically, we examined the behavior of 385,616 authors grouped into 15 subject areas like Biology, Chemistry, Science and Technology, Engineering, and Physics. These authors have published 3,240,973 papers that have accumulated 90,806,462 citations, roughly five percent of which are self-citations. Up until now, very little is known about the buildup of self-citations at the author-level and in field-specific contexts. Our view is that hiding self-citation data is indefensible and needlessly confuses any attempts to understand the bibliometric impact of one’s work. Instead we urge academics to embrace visibility of citation data in a community of peers, which relies on nuance and openness rather than curated scorekeeping.
ESMO 2019: breast cancer
Authors: Bartsch Rupert
Published: March 2020

This articles reviews results of relevant breast cancer trials presented at the 2019 ESMO Meeting. In triple-negative disease, addition of pembrolizumab to standard neoadjuvant chemotherapy yielded a pathologic complete response (pCR) rate of 64.8%, the highest pCR rate reported to date in this setting; in addition, a trend towards improved event-free survival was observed in the immunotherapy group. In pretreated patients with metastatic triple-negative breast cancer, single-agent pembrolizumab was not superior to conventional chemotherapy. In metastatic hormone-receptor positive disease, an update of the MONARCH2 and MonaLEEsa‑3 studies indicated an overall-survival benefit in favour of the respective CDK4/6 inhibitor groups emphasizing the clinical importance of this class of drugs.
Valorization of Waste Feathers in the Production of New Thermal Insulation Materials
Authors: Dieckmann Elena , Onsiong Richard , Nagy Balázs , Sheldrick Leila , Cheeseman Christopher
Published: March 2020

Poultry has become the primary source of dietary protein consumed globally and as a result the by-product feathers are an increasingly problematic industrial waste. Developing a circular economy for feathers is, therefore, an important research area that provides an opportunity to make use of the unique combination of properties of this abundant natural material. This paper reports on the thermal properties of novel feather-based thermal insulation materials. Waste feathers were collected, cleaned and processed into fibres, which were then used to form air-laid nonwoven materials. These have a high fibre content and exploit the excellent natural thermal insulation properties of feathers. The performance of the novel materials developed are tested in order to outline the influence of temperature and density on thermal conductivity and dynamic water sorption. Results are compared to a range of commercially available thermal insulation materials for buildings manufactured from denim, hemp, sheep wool, PET and mineral wool. It was found that air laid feather-fibre fabrics have comparable performance to other fibrous materials and have a thermal conductivity of 0.033 W/(m K) for samples with a density of 59 kg/m3. This is due to the low thermal conductivity of feather fibres and the void structure formed by air-laid processing that effectively traps air. These materials additionally offer improved sustainability credentials as they are derived from a readily available waste that is generally considered to be unavoidable. The paper concludes by highlighting the significant technical and commercial barriers that exist to using waste feathers in thermal insulation products and suggests areas for further research that can exploit the unique properties of feathers.

Graphical Abstract
Exact controllability of semilinear heat equations in spaces of analytic functions
Authors: Laurent Camille , Rosier Lionel
Published: March 2020

It is by now well known that the use of Carleman estimates allows to establish the controllability to trajectories of nonlinear parabolic equations. However, by this approach, it is not clear how to decide whether a given function is indeed reachable. In this paper, we pursue the study of the reachable states of parabolic equations based on a direct approach using control inputs in Gevrey spaces by considering a semilinear heat equation in dimension one. The nonlinear part is assumed to be an analytic function of the spatial variable
x
, the unknown
y
, and its derivative

\partial _{x}y

. By investigating carefully a nonlinear Cauchy problem in the spatial variable and the relationship between the jet of space derivatives and the jet of time derivatives, we derive an exact controllability result for small initial and final data that can be extended as analytic functions on some ball of the complex plane.
Coarctation of Aorta in Turner Mosaicism
Authors: Gorito Vanessa , Baptista Cristina , Santos Paulo , Costa Ana Margarida , Carvalho Joana
Published: March 2020

The prevalence of hypertension in the pediatric age range is estimated at 1–5% worldwide, with higher rates in adolescence. Although primary hypertension is more common, due to the increasing prevalence of obesity and metabolic syndrome among adolescents, secondary hypertension should be always considered and excluded. We present the case of an adolescent with secondary hypertension and a challenging diagnosis associated with coarctation of aorta and Turner Mosaicism.
“Don't Forget that Others Are Watching, Too!” The Effect of Conversational Human Voice and Reply Length on Observers’ Perceptions of Complaint Handling in Social Media
Authors: Javornik Ana , Filieri Raffaele , Gumann Ralph
Published: March 2020

When dissatisfied customers voice their complaints on companies’ social media pages, many other consumers can observe such interactions. Yet, only limited research has investigated how complaint handling is perceived by this online audience. Since the final outcome of the complaint is rarely visible publicly, the message characteristics (e.g., length and style) of company replies can represent signaling cues for observers of how the complaint is handled. The results of two experimental studies show that the use of conversational human voice (CHV) leads to more positive observer perceptions of complaint handling as opposed to when a corporate voice is employed. We found that interactional justice fully mediates this process and that satisfaction with complaint handling positively impacts corporate image and indirectly observers’ WOM intentions. Surprisingly, high CHV can negatively affect procedural justice, but these effects are mainly offset through interactional justice, as the observers focus on the fairness in the communication exchange. Interestingly, our findings show that, in the case of low CHV, other cues such as the length of the company's reply significantly change perceived justice dimensions; however, the length of reply does not lead to such changes when high CHV is employed. Our studies bring novel findings that contribute to justice and signaling theories in the context of complaints management in social media. Managerial implications are discussed.
Nasopharyngeal neuroglial heterotopy ‐ Choristoma: Case report and review of the literature
Authors: Baquero‐Hoyos Maria Monica , Marino José Antonio , Mayorga José Luis
Published: March 2020

We describe the case of a nine‐month‐old patient with a nasopharyngeal choristoma. The case presented includes the retrospective review of the historical, radiological, surgical and histological assessment of this pathology as well as a literature review of this entity. This case was presented in an infant with difficulty feeding, nasal obstruction and failure to thrive, evaluated with flexible nasal endoscopy, CT and MRI. The lesion was then surgically removed without complications. Nasopharyngeal choristoma is a rare congenital non‐malignant mass, which may present within a range of symptoms and severity according to its size, growth and location.
Determinants of Increased Tobacco Consumption Following a Major Disaster
Authors: Koyama Shihoko , Tabuchi Takahiro , Aida Jun , Osaka Ken , Miyashiro Isao
Published: March 2020

Objectives:

Experience of a major disaster can potentially impact on tobacco consumption. Our objective was to explore the determinants of increasing tobacco consumption after the Great East Japan Earthquake (GEJE).

Methods:

We conducted a cross-sectional study using data from the Miyagi Prefectural Health Survey 2014: a total of 2632 people were randomly selected from residents aged ≥20 years in Miyagi, Japan. Of 2443 respondents (response rate = 92.8%), 551 current smokers (411 men) were included in the analysis. Odds ratios (OR) and 95% confidence interval (CI) for increasing tobacco consumption were calculated using multivariable logistic regression models including variables of age, sex, disaster-related job status change, education status, self-rated health, and age at smoking initiation.

Results:

After adjustments for all variables, significantly higher ORs for increasing tobacco consumption after the GEJE were observed in women (OR = 1.87; 95% CI = 1.10–3.15), 20–39 years old (OR = 5.18; 95% CI = 2.28–11.75), 40–59 years old (OR = 3.97; 95% CI = 1.76–8.94) and respondents who had lost their jobs (OR = 3.42; 95% CI = 1.06–11.05) than the counterpart categories.

Conclusions:

This study found 3 determinants of increasing tobacco consumption after a major disaster: being a woman, being of working age, and experiencing disaster-related job loss.
Ensuring TB Services During Major Floods – Kerala, India, August 2018
Authors: Sadanandan Rajeev , RL Sarita , Mrithunjayan Sunilkumar , Valamparambil Mathew J. , Balakrishnan Shibu , Suseela Rakesh P.
Published: March 2020

Ensuring the successful treatment of tuberculosis (TB) is an essential public health responsibility of national TB programs. This case study describes how the Department of Health and Family Welfare, Kerala state, successfully prevented the disruptions in TB treatment when an unprecedented massive flood, declared as “a calamity of severe nature,” completely disrupted normal operations in the state during August 2018. Unanticipated floods led to the displacement and relocation of more than 1.5 million citizens. The state has ensured continuity of TB treatment for all notified drug sensitive and drug-resistant TB patients (9608 and 434, respectively), including those who were displaced and relocated. A real-time web-enabled, case-based patient management information system has helped preserve the entire patient information, available at multiple levels. Routine strength of the program, including good rapport with patients, frontline multipurpose health workers and treatment supporters, high literacy rate of general population, and well-integrated primary health care system delivering TB services, enabled ensuring continuity of care during the disaster situation. The success of the post-flood TB control measures in Kerala affirms the importance of maintaining an integrated and strong TB control component with general health system ownership.
Desalambrando: A Nasa Standpoint for Liberation
Authors: Matallana-Peláez Susana E.
Published: March 2020

This article examines the Nasa peoples’ resistance praxis known as “Desalambrar”. Through the analysis of Nasayuwe language, textile art, and ritual dance, the article looks at the idea of ontological continuum at the heart of this praxis, exploring how this concept provides the Nasa with a philosophical standpoint for what they have called “the liberation of Mother Earth”. The article then examines how this idea challenges the Eurocentric divide between Man and Nature/Woman and what it can possibly mean for women, gender, feminism, and the environment.
Protolith nature and P–T evolution of Variscan metamorphic rocks from the Allahyarlu complex, NW Iran
Authors: Moazzen Mohssen , Salimi Zohreh , Rolland Yann , Bröcker Michael , Hajialioghli Robab
Published: March 2020

Metamorphic rocks associated with ophiolitic rocks occur on the eroded surface of a NW–SE-trending anticline in the Allahyarlu area, NW Iran, between the Caucasus and Zagros orogenic belts. Metapelitic rocks consist mainly of quartz, muscovite chlorite, altered biotite and garnet. S1 is the pervasive schistosity, wrapping garnet, which is folded by the second schistosity (S2). The amphibolite records only one phase of deformation as the main lineation. The rocks experienced metamorphism up to the amphibolite facies, then overprinted by greenschist facies condition. Thermobarometry indicates an average pressure of c. 5 kbar and an average temperature of c. 600 °C for the amphibolite facies metamorphism, corresponding to a ∼33 °C km−1 geothermal gradient in response to a thick magmatic arc setting. Greenschist facies metamorphism shows re-equilibration of the rocks during exhumation. Amphibolites whole rock geochemistry shows trace elements patterns similar to both island arc and back-arc basin basalts, suggesting that the protolith-forming magma of the amphibolites was enriched at shallow to medium depth of a subduction system. Negative Nb anomaly and slight enrichment in light rare earth elements (LREE) and large-ion lithophile elements (LILE) of the amphibolites indicate arc-related magmatism for their protolith and a back-arc sialic setting for their formation. 40Ar–39Ar dating on muscovite separated from two gneiss samples, and hornblende separated from three amphibolite samples, documents a Variscan (326–334 Ma) age. The magmatic and metamorphic rock association of the Allahyarlu area suggests the existence of an active continental margin arc during the Variscan orogeny, without clear evidence for a continental collision.
Population assessment of the Endangered Nilgiri tahr Nilgiritragus hylocrius in the Anamalai Tiger Reserve, using the double-observer survey method
Authors: Suryawanshi Kulbhushansingh Ramesh , Mudappa Divya , Khanyari Munib , Raman T. R. Shankar , Rathore Devika , Kumar M. Ananda , Patel Jenis
Published: March 2020

The Nilgiri tahr Nilgiritragus hylocrius is an Endangered species of mountain ungulate endemic to the Western Ghats of India, a biodiversity hotspot. Habitat fragmentation, hunting and a restricted range are the major threats to this species. Although several surveys have assessed the species’ status, a population estimate based on a scientifically robust method is needed. We used the double-observer method to estimate the population of the Nilgiri tahr in the Anamalai Tiger Reserve, a protected area in the Western Ghats. We walked 257 km of transects across the Reserve, covering 36 grassland blocks (i.e. clusters of montane grasslands that were relatively separate from each other). We counted a minimum of 422 individuals in 28 groups, and estimated the tahr population in the study area to be 510 individuals (95% CI 300–858) in 35 groups. The male:female ratio was 0.71 and the young:female ratio was 0.56. Comparing our estimate with previous surveys suggests that the Nilgiri tahr population in Anamalai Tiger Reserve is stable. We found the double-observer survey method to be appropriate for population estimation and long-term monitoring of this species, and make recommendations for improved field protocols to facilitate the implementation of the method in the tropical mountains of the Western Ghats. Our findings suggest that the Reserve harbours 20–25% of the global population of the Nilgiri tahr, highlighting the area's importance for the conservation of this species.
Which is worse for the red-billed curassow: habitat loss or hunting pressure?
Authors: Rios Elaine , McGowan Philip J. K. , Collar Nigel J. , Benchimol Maíra , Canale Gustavo R. , Olmos Fabio , Santos-Filho Manoel , Bernardo Christine S. S.
Published: March 2020

Large ground-dwelling Neotropical gamebirds are highly threatened by habitat loss and hunting, but conservationists rarely attempt to distinguish between these two threats in the management of populations. We used three different types of species records to determine the status (i.e. persistence level) of the Endangered red-billed curassow Crax blumenbachii in 14 forest remnants in north-east Brazil, as either persistent, precarious or extirpated. We related these persistence levels to variables measured in a 2-km buffer radius, including variables associated with habitat quality (proportion of forest cover, length of rivers, patch density, distance from rivers) and hunting pressure (proportion of cacao agroforests and farmlands, length of roads, total area occupied by settlements, distance from roads and from settlements). Curassows were more persistent in forest patches located (1) more distant from settlements, (2) in landscapes with few settlements, (3) in landscapes with a high incidence of roads, (4) in a mosaic with a high proportion of forest, shaded cacao agroforest and farmland, and (5) more distant from other forest patches. Hunting pressure potentially exerts more influence on persistence than habitat quality: (1) hunting pressure submodels had a higher explanatory power than habitat quality submodels, (2) final models comprised four hunting pressure variables but only two habitat quality variables, and (3) hunting pressure variables appeared in all models whereas habitat quality variables appeared in only one final model. If hunting pressure is driving declines in curassows, regions with low human presence and a high proportion of forest cover are recommended for establishing new reserves.
Particle Filter-Based Inter-System Positioning Model for Non-Overlapping Frequency Code Division Multiple Access Systems
Authors: Shang Rui , Meng Xiaolin , Gao Chengfa , Pan Shuguo , Gao Wang , Peng Zihan
Published: March 2020

In the process of composing a double-differenced positioning model, it is difficult to separate different frequency signals between code division multiple access (CDMA) systems, the single-difference ambiguity of the pivot satellite and phase differential inter-system biases (PDISBs). Hence it is difficult to calibrate in advance the bias between systems in order to build an inter-system model which only needs one pivot satellite. Based on analysis of the stability of PDISB parameters for non-overlapping frequency CDMA systems, this study adopts a particle filter to estimate the fractional part of the PDISBs (F-PDISBs) between the systems and proposes a particle filter-based inter-system positioning model. Results show that the F-PDISBs and code DISBs for the baselines with the same receiver types and some with different receiver types are rather stable over time and for these baselines it is feasible to use a particle filter to estimate the F-PDISB parameters in the initial stage. Having attained the F-PDISBs, the inter-system model can be constructed to improve positioning accuracy in complex operational environments.
Rate of inappropriate energy and micronutrient intake among the Korean working population
Authors: Lee Wanhyung , Jung Jiyoun , Ahn Joonho , Kim Hyoung-Ryoul
Published: March 2020

Objective:

Adequate energy and nutrient intakes are important for workers who spend at least one-third of their day working. We investigated differences in these intakes among Korean workers because few studies have reported on energy or nutrient intakes, related to working conditions (long working hours, shift work and non-standard work).

Design:

Dietary intake was assessed using 1-d 24-h recall. Energy and nutrient intakes were evaluated using age- and sex-specific dietary reference intakes for Korean citizens. Occupational characteristics were obtained from self-reported Korean National Health and Nutritional Examination Survey (KNHANES) data (occupational classification, working hours, shift work and non-standard workers). An age, education and household income-adjusted logistic regression model was applied to investigate differences in inappropriate energy and nutrient intakes, by sex and occupation.

Setting:

Cross-sectional study.

Participants:

From KNHANES (2007–2016), 11 145 participants (5401 males; 5744 females) were included, finally.

Results:

Males with long working hours had higher inappropriate carbohydrate, protein, water, vitamin B2 and phosphate intakes than those who worked ≤60 h/week. Long working hours among females were significantly associated with total energy and nutrient ‘under-intake’. Male shift and non-standard workers had higher inappropriate protein, water, mineral and vitamin intakes. Multivariate logistic regression revealed that white- and male pink-collar workers had significantly increased risks of water and vitamins A, C, B1 and niacin ‘under-intake’.

Conclusions:

We found different rates of inappropriate energy and micronutrient intakes according to working conditions. Younger workers with long hours and shift work schedules were vulnerable to inappropriate energy and nutrient intakes.
SMALL-BOUND ISOMORPHISMS OF FUNCTION SPACES
Authors: RONDOŠ JAKUB , SPURNÝ JIŘÍ
Published: March 2020

Let $\mathbb{F}=\mathbb{R}$ or $\mathbb{C}$. For $i=1,2$, let $K_{i}$ be a locally compact (Hausdorff) topological space and let ${\mathcal{H}}_{i}$ be a closed subspace of ${\mathcal{C}}_{0}(K_{i},\mathbb{F})$ such that each point of the Choquet boundary $\operatorname{Ch}_{{\mathcal{H}}_{i}}K_{i}$ of ${\mathcal{H}}_{i}$ is a weak peak point. We show that if there exists an isomorphism $T:{\mathcal{H}}_{1}\rightarrow {\mathcal{H}}_{2}$ with $\left\Vert T\right\Vert \cdot \left\Vert T^{-1}\right\Vert <2$, then $\operatorname{Ch}_{{\mathcal{H}}_{1}}K_{1}$ is homeomorphic to $\operatorname{Ch}_{{\mathcal{H}}_{2}}K_{2}$. We then provide a one-sided version of this result. Finally we prove that under the assumption on weak peak points the Choquet boundaries have the same cardinality provided ${\mathcal{H}}_{1}$ is isomorphic to ${\mathcal{H}}_{2}$.
PROPAGATION OF SINGULARITIES ON AdS SPACETIMES FOR GENERAL BOUNDARY CONDITIONS AND THE HOLOGRAPHIC HADAMARD CONDITION
Authors: Gannot Oran , Wrochna Michał
Published: March 2020

We consider the Klein–Gordon equation on asymptotically anti-de-Sitter spacetimes subject to Neumann or Robin (or Dirichlet) boundary conditions and prove propagation of singularities along generalized broken bicharacteristics. The result is formulated in terms of conormal regularity relative to a twisted Sobolev space. We use this to show the uniqueness, modulo regularizing terms, of parametrices with prescribed $\text{b}$-wavefront set. Furthermore, in the context of quantum fields, we show a similar result for two-point functions satisfying a holographic Hadamard condition on the $\text{b}$-wavefront set.
Correlation of Quaternary Volcano Clusters With Partial Melting of Mantle Wedge, Northeast Japan: A Numerical Model Study
Authors: Yoo Soohwan , Lee Changyeol
Published: March 2020

The Quaternary volcano clusters in Northeast Japan and the no‐volcano zones between them imply extensive and scarce melting, respectively, in the mantle wedge, but no quantitative study on the heterogeneous melting has been conducted. Here, we constructed two‐dimensional numerical models by considering along‐arc temperature variations in the mantle wedge expressed as high‐ (hot fingers) and low‐temperature anomalies (deterred corner flow) with the slab dehydration, porous flow of aqueous fluid, and partial melting of the mantle wedge. The results show that the high‐ and low‐temperature anomalies in the mantle wedge result in extensive and negligible melting beneath the volcano clusters and no‐volcano zones, respectively, consistent with geochemical and geophysical estimations. Contrary to the near‐complete slab dehydration beneath the volcano clusters, the partially dehydrated subducting slab beneath the no‐volcano zones transports the remaining water into the mantle transition zone, which has implications for intraplate volcanoes in Northeast Asia.
Strong Precipitation Suppression by Aerosols in Marine Low Clouds
Authors: Fan Chongxing , Wang Minghuai , Rosenfeld Daniel , Zhu Yannian , Liu Jihu , Chen Baojun
Published: March 2020

The adjustment of cloud amount to aerosol effects occurs to a large extent in response to the aerosol effect on precipitation. Here the marine boundary layer clouds were studied by analyzing the dependence of rain intensity measured by Global Precipitation Measurement on cloud properties. We showed that detectable rain initiates when the drop effective radius at the cloud top (re) exceeds 14 μm, and precipitation is strongly suppressed with increasing cloud drop concentration (Nd), which contributes to the strong dependence of cloud amount on aerosols. The rain rate increases sharply with cloud thickness (CGT) and re when re > 14 μm. The dependence of rain rate on re and CGT presents a simple framework for precipitation susceptibility to aerosols, which explains other previously observed relationships. We showed that sorting data by CGT and using alternative cloud condensation nuclei proxy rather than aerosol optical depth are critical for studying aerosol‐cloud‐precipitation interactions.
The 3D Seismic Azimuthal Anisotropies and Velocities in the Eastern Tibetan Plateau Extracted by an Azimuth‐Dependent Dispersion Curve Inversion Method
Authors: Liang Chuntao , Liu Zhiqiang , Hua Qian , Wang Liang , Jiang Ningbo , Wu Jing
Published: March 2020

An azimuth‐dependent dispersion curve inversion (ADDCI) method is applied to Rayleigh waves to extract 3D velocity and azimuthal anisotropy. The synthetic tests show that the ADDCI method is able to extract azimuthal anisotropy at different depths. The errors of the fast propagation direction (FPD) and the magnitude of the anisotropy (MOA) are less than 10° and 1–2%, respectively. The 3D anisotropic model shows large variations in the FPDs and MOAs with depth and blocks; strong contrasts are observed across major faults, and the average MOA in the crust is approximately 3%. The FPDs are positively correlated with the GPS velocity direction and the strikes of regional faults in most of the blocks. The low‐velocity zones (LVZs) in middle to lower crust are widely observed in the Songpan‐Ganze terrane, the north Chuan‐Dian block, and surprisingly in the Huayingshan thrust and fold belt. The LVZs in middle crust are also positively correlated with a region of low velocities in the uppermost mantle. These observations may suggest that large‐scale deformation is coupled vertically from surface to uppermost mantle. Crust shortening by the pure shearing process, which involves the thrusting and folding of the upper crust and the lateral extrusion of blocks, may be the major mechanism causing the growth of the eastern Tibetan Plateau.
Revision of the Chinese Altai‐East Junggar Terrane Accretion Model Based on Geophysical and Geological Constraints
Authors: Guy Alexandra , Schulmann Karel , Soejono Igor , Xiao Wenjiao
Published: March 2020

Potential field data analysis, geology, and geochemistry are used to revise the terrane accretion model of the Chinese Altai and East Junggar. Major gradients of potential field data demarcate significant crustal structures and their continuity in depth. These data demonstrate that the distribution of geophysical anomalies does not match with terranes boundaries defined previously. Instead, heterogeneously developed NE/SW‐trending gravity and NW‐SE magnetic anomalies in both units correlate with Devonian and Permian tectonometamorphic zones, respectively. Geophysical data also indicate a dense lower crust of the East Junggar confirmed by previous igneous petrology studies and seismic experiment. The northern tip of this dense crust coincides with the main gravity gradient beneath the Chinese Altai and a prominent magnetic high located above a NW/SE‐trending zone of Permian granulites. This zone forms a boundary between north‐ and south‐dipping gravity and magnetic anomalies that are interpreted as reflecting quasi‐symmetrical extrusion of the Chinese Altai crust. In contrast, all geophysical data show the absence of a prominent deep‐seated discontinuity which can be correlated with the Erqis Zone. These data are compared with corresponding data sets from southern Mongolia allowing the proposition of a new geodynamic model for the studied area. This model involves (1) accretionary stage characterized by Late Devonian joint evolution of the East Junggar and Chinese Altai characterized by N‐S trending orogenic fabrics and (2) Early Permian oroclinal bending associated with underthrusting of the dense Junggar basement beneath the Chinese Altai and the development of NW‐SE trending deformation zones in both units.
Subduction Reversal in a Divergent Double Subduction Zone Drives the Exhumation of Southern Qiangtang Blueschist‐Bearing Mélange, Central Tibet
Authors: Li D. , Wang G. H. , Bons P. D. , Zhao Z. B. , Du J. X. , Wang S. L. , Yuan G. L. , Liang X. , Zhang L. , Li C. , Fang D. R. , Tang Y. , Hu Y. L. , Fu Y. Z.
Published: March 2020

(Ultra) high‐pressure (HP) rocks can be exhumed rapidly by subduction reversal or divergent plate motion. Recent studies show that subduction reversal can in particular occur in a divergent double subduction zone when the slab pull of one slab exceeds that of the other, shorter one, which then experiences a net upward pull. This recent hypothesis, first proposed for Triassic HP‐rocks exposed in the central Qiangtang mélange belt in central Tibet, can explain the exhumation of (ultra) HP rocks through upward slab movement. However, this model lacks the support of kinematic evidence. In this study, based on the recognition of multiple deformational phases, we analyze the kinematics of the HP‐bearing mélange in central Qiangtang. Based on new 40Ar‐39Ar geochronology data and those collected from the literature, we present a temporal framework for the new observations. We recognize a switch in sense of shear between the prograde (D1) and exhumation (D2‐3) paths. The change of shear sense reflects the reversal from downward to upward movement of the oceanic slab below. Early D2 represents the early exhumation stage that caused retrograde metamorphism from eclogite to blueschist facies. No magmatism occurred during this period. Continued exhumation from blueschist facies to greenschist facies resulted in D2‐D3 structures. Voluminous igneous activity occurred during this stage. We suggest that subduction reversal in a divergent double subduction zone can best explain the kinematic evolution and temporal framework above. This exhumation model may provide a new perspective on the exhumation mechanism for other HP rocks around the world.
Continuity of Ice Sheet Mass Loss in Greenland and Antarctica From the GRACE and GRACE Follow‐On Missions
Authors: Velicogna Isabella , Mohajerani Yara , A Geruo , Landerer Felix , Mouginot Jeremie , Noel Brice , Rignot Eric , Sutterley Tyler , van den Broeke Michiel , van Wessem Melchior , Wiese David
Published: March 2020

We examine data continuity between the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow‐On (FO) missions over Greenland and Antarctica using independent data from the mass budget method, which calculates the difference between ice sheet surface mass balance and ice discharge at the periphery. For both ice sheets, we find consistent GRACE/GRACE‐FO time series across the data gap, at the continental and regional scales, and the data gap is confidently filled with mass budget method data. In Greenland, the GRACE‐FO data reveal an exceptional summer loss of 600 Gt in 2019 following two cold summers. In Antarctica, ongoing high mass losses in the Amundsen Sea Embayment of West Antarctica, the Antarctic Peninsula, and Wilkes Land in East Antarctica cumulate to 2130, 560, and 370 Gt, respectively, since 2002. A cumulative mass gain of 980 Gt in Queen Maud Land since 2009, however, led to a pause in the acceleration in mass loss from Antarctica after 2016.
Pushing periodic-disorder-induced phase matching into the deep-ultraviolet spectral region: theory and demonstration
Authors: Shao Mingchuan , Liang Fei , Yu Haohai , Zhang Huaijin
Published: March 2020

Nonlinear frequency conversion is a ubiquitous technique that is used to obtain broad-range lasers and supercontinuum coherent sources. The phase-matching condition (momentum conservation relation) is the key criterion but a challenging bottleneck in highly efficient conversion. Birefringent phase matching (BPM) and quasi-phase matching (QPM) are two feasible routes but are strongly limited in natural anisotropic crystals or ferroelectric crystals. Therefore, it is in urgent demand for a general technique that can compensate for the phase mismatching in universal nonlinear materials and in broad wavelength ranges. Here, an additional periodic phase (APP) from order/disorder alignment is proposed to meet the phase-matching condition in arbitrary nonlinear crystals and demonstrated from the visible region to the deep-ultraviolet region (e.g., LiNbO3 and quartz). Remarkably, pioneering 177.3-nm coherent output is first obtained in commercial quartz crystal with an unprecedented conversion efficiency above 1‰. This study not only opens a new roadmap to resuscitate those long-neglected nonlinear optical crystals for wavelength extension, but also may revolutionize next-generation nonlinear photonics and their further applications.
Fiber reinforced GelMA hydrogel to induce the regeneration of corneal stroma
Authors: Kong Bin , Chen Yun , Liu Rui , Liu Xi , Liu Changyong , Shao Zengwu , Xiong Liming , Liu Xianning , Sun Wei , Mi Shengli
Published: March 2020

Regeneration of corneal stroma has always been a challenge due to its sophisticated structure and keratocyte-fibroblast transformation. In this study, we fabricate grid poly (ε-caprolactone)-poly (ethylene glycol) microfibrous scaffold and infuse the scaffold with gelatin methacrylate (GelMA) hydrogel to obtain a 3 D fiber hydrogel construct; the fiber spacing is adjusted to fabricate optimal construct that simulates the stromal structure with properties most similar to the native cornea. The topological structure (3 D fiber hydrogel, 3 D GelMA hydrogel, and 2 D culture dish) and chemical factors (serum, ascorbic acid, insulin, and β-FGF) are examined to study their effects on the differentiation of limbal stromal stem cells to keratocytes or fibroblasts and the phenotype maintenance, in vitro and in vivo tissue regeneration. The results demonstrate that fiber hydrogel and serum-free media synergize to provide an optimal environment for the maintenance of keratocyte phenotype and the regeneration of damaged corneal stroma.
Elastic conducting polymer composites in thermoelectric modules
Authors: Kim Nara , Lienemann Samuel , Petsagkourakis Ioannis , Alemu Mengistie Desalegn , Kee Seyoung , Ederth Thomas , Gueskine Viktor , Leclère Philippe , Lazzaroni Roberto , Crispin Xavier , Tybrandt Klas
Published: March 2020

The rapid growth of wearables has created a demand for lightweight, elastic and conformal energy harvesting and storage devices. The conducting polymer poly(3,4-ethylenedioxythiophene) has shown great promise for thermoelectric generators, however, the thick layers of pristine poly(3,4-ethylenedioxythiophene) required for effective energy harvesting are too hard and brittle for seamless integration into wearables. Poly(3,4-ethylenedioxythiophene)-elastomer composites have been developed to improve its mechanical properties, although so far without simultaneously achieving softness, high electrical conductivity, and stretchability. Here we report an aqueously processed poly(3,4-ethylenedioxythiophene)-polyurethane-ionic liquid composite, which combines high conductivity (>140 S cm−1) with superior stretchability (>600%), elasticity, and low Young’s modulus (<7 MPa). The outstanding performance of this organic nanocomposite is the result of favorable percolation networks on the nano- and micro-scale and the plasticizing effect of the ionic liquid. The elastic thermoelectric material is implemented in the first reported intrinsically stretchable organic thermoelectric module.
Context-dependent dynamics lead to the assembly of functionally distinct microbial communities
Authors: Bittleston Leonora S. , Gralka Matti , Leventhal Gabriel E. , Mizrahi Itzhak , Cordero Otto X.
Published: March 2020

Niche construction through interspecific interactions can condition future community states on past ones. However, the extent to which such history dependency can steer communities towards functionally different states remains a subject of active debate. Using bacterial communities collected from wild pitchers of the carnivorous pitcher plant, Sarracenia purpurea, we test the effects of history on composition and function across communities assembled in synthetic pitcher plant microcosms. We find that the diversity of assembled communities is determined by the diversity of the system at early, pre-assembly stages. Species composition is also contingent on early community states, not only because of differences in the species pool, but also because the same species have different dynamics in different community contexts. Importantly, compositional differences are proportional to differences in function, as profiles of resource use are strongly correlated with composition, despite convergence in respiration rates. Early differences in community structure can thus propagate to mature communities, conditioning their functional repertoire.
Filamentation of the bacterial bi-functional alcohol/aldehyde dehydrogenase AdhE is essential for substrate channeling and enzymatic regulation
Authors: Pony Pauline , Rapisarda Chiara , Terradot Laurent , Marza Esther , Fronzes Rémi
Published: March 2020

Acetaldehyde–alcohol dehydrogenase (AdhE) enzymes are a key metabolic enzyme in bacterial physiology and pathogenicity. They convert acetyl-CoA to ethanol via an acetaldehyde intermediate during ethanol fermentation in an anaerobic environment. This two-step reaction is associated to NAD+ regeneration, essential for glycolysis. The bifunctional AdhE enzyme is conserved in all bacterial kingdoms but also in more phylogenetically distant microorganisms such as green microalgae. It is found as an oligomeric form called spirosomes, for which the function remains elusive. Here, we use cryo-electron microscopy to obtain structures of Escherichia coli spirosomes in different conformational states. We show that spirosomes contain active AdhE monomers, and that AdhE filamentation is essential for its activity in vitro and function in vivo. The detailed analysis of these structures provides insight showing that AdhE filamentation is essential for substrate channeling within the filament and for the regulation of enzyme activity.
Single crystal of a one-dimensional metallo-covalent organic framework
Authors: Xu Hai-Sen , Luo Yi , Li Xing , See Pei Zhen , Chen Zhongxin , Ma Tianqiong , Liang Lin , Leng Kai , Abdelwahab Ibrahim , Wang Lin , Li Runlai , Shi Xiangyan , Zhou Yi , Lu Xiu Fang , Zhao Xiaoxu , Liu Cuibo , Sun Junliang , Loh Kian Ping
Published: March 2020

Although polymers have been studied for well over a century, there are few examples of covalently linked polymer crystals synthesised directly from solution. One-dimensional (1D) covalent polymers that are packed into a framework structure can be viewed as a 1D covalent organic framework (COF), but making a single crystal of this has been elusive. Herein, by combining labile metal coordination and dynamic covalent chemistry, we discover a strategy to synthesise single-crystal metallo-COFs under solvothermal conditions. The single-crystal structure is rigorously solved using single-crystal electron diffraction technique. The non-centrosymmetric metallo-COF allows second harmonic generation. Due to the presence of syntactic pendant amine groups along the polymer chains, the metallopolymer crystal can be further cross-linked into a crystalline woven network.
Antibody response of a particle-inducing, liposome vaccine adjuvant admixed with a Pfs230 fragment
Authors: Huang Wei-Chiao , Deng Bingbing , Seffouh Amal , Ortega Joaquin , Long Carole A. , Suresh Ragavan V. , He Xuedan , Miura Kazutoyo , Lee Shwu-Maan , Wu Yimin , Lovell Jonathan F.
Published: March 2020

Pfs230 is a malaria transmission-blocking antigen candidate, expressed on the surface of Plasmodium falciparum gametocytes. A recombinant, his-tagged Pfs230 fragment (Pfs230C1; amino acids 443–731) formed serum-stable particles upon incubation with liposomes containing cobalt-porphyrin-phospholipid (CoPoP). In mice, immunization with Pfs230C1, admixed with the adjuvants Alum, Montanide ISA720 or CoPoP liposomes (also containing synthetic monophosphoryl lipid A; PHAD), resulted in elicitation of IgG antibodies, but only those induced with CoPoP/PHAD or ISA720 strongly reduced parasite transmission. Immunization with micrograms of Pfs230C1 adjuvanted with identical liposomes lacking cobalt (that did not induce particle formation) or Alum was less effective than immunization with nanograms of Pfs230C1 with CoPoP/PHAD. CoPoP/PHAD and ISA720 adjuvants induced antibodies with similar Pfs230C1 avidity but higher IgG2-to-IgG1 ratios than Alum, which likely contributed to enhanced functional activity. Unlike prior work with another transmission-blocking antigen (Pfs25), Pfs230C1 was found to be effectively taken up by antigen-presenting cells without particle formation. The anti-Pfs230C1 IgG response was durable in mice for 250 days following immunization with CoPoP/PHAD, as were antibody avidity and elevated IgG2-to-IgG1 ratios. Immunization of rabbits with 20 µg Pfs230C1 admixed with CoPoP/PHAD elicited antibodies that inhibited parasite transmission. Taken together, these results show that liposomes containing CoPoP and PHAD are an effective vaccine adjuvant platform for recombinant malaria transmission blocking antigens.
Novel strategies for expansion of tooth epithelial stem cells and ameloblast generation
Authors: Binder Martin , Biggs Leah C. , Kronenberg Mark S. , Schneider Pascal , Thesleff Irma , Balic Anamaria
Published: March 2020

Enamel is secreted by ameloblasts derived from tooth epithelial stem cells (SCs). Humans cannot repair or regenerate enamel, due to early loss of tooth epithelial SCs. Contrarily in the mouse incisors, epithelial SCs are maintained throughout life and endlessly generate ameloblasts, and thus enamel. Here we isolated Sox2-GFP+ tooth epithelial SCs which generated highly cellular spheres following a novelin vitrostrategy. This system enabled analysis of SC regulation by various signaling molecules, and supported the stimulatory and inhibitory roles of Shh and Bmp, respectively; providing better insight into the heterogeneity of the SCs. Further, we generated a novel mouse reporter,Enamelin-tdTomato for identification of ameloblasts in live tissues and cells, and used it to demonstrate presence of ameloblasts in the new 3D co-culture system of dental SCs. Collectively, our results provide means of generating 3D tooth epithelium from adult SCs which can be utilized toward future generation of enamel.