bluuebunny/crossref_metadata_2025 huggingface dataset:
Following the water? Landscape‐scale temporal changes in bat spatial distribution in relation to Mediterranean summer drought
Authors: Amorim Francisco , Jorge Inês , Beja Pedro , Rebelo Hugo
Published: May 2018

Understanding how the spatial distribution of ecological resources shapes species’ diversity and abundance in human‐modified landscapes is a central theme in conservation biology. However, studies often disregard that such patterns may vary over time, thereby potentially missing critical environmental constraints to species persistence. This may be particularly important in highly mobile species such as bats, which are able to track temporal variations in spatial resource distribution. Here we test the hypothesis that bats in Mediterranean landscapes are strongly affected by the progressive reduction in water availability during the seasonal summer drought. We analyzed the effects of landscape composition and structure on bat diversity and activity, during pregnancy, lactation, and postlactation periods, and identified the most influential variables within and across periods. Water bodies showed the strongest positive effect on bats, followed by riparian habitats and areas with steeper (>30%) slopes. However, while during pregnancy, there were only small landscape effects, these increased during lactation and postlactation, highlighting a progressively stronger association with water habitats during the summer drought. The spatial projection of habitat models showed that the landscape distribution of bat diversity and activity hotspots changed markedly over time. During pregnancy, the spatial pattern of hotspot distribution was weakly defined, while during lactation and particularly postlactation, there was a concentration of hotspots along permanently flowing watercourses. Our study highlights that permanently flowing watercourses are critical for bat conservation in Mediterranean landscapes, calling for measures to counteract their ongoing degradation due in particular to climate change, water abstraction and damming. More generally, our study underlines the importance of considering the temporal dimension in habitat selection studies, without which there is the risk of overlooking the importance of habitats that are key for species persistence only at certain times of the year.
Three‐dimensional digitization of the arid land plant Haloxylon ammodendron using a consumer‐grade camera
Authors: Huang Hongyu , Zhang Hao , Chen Chongcheng , Tang Liyu
Published: May 2018

Plant structural parameters are important for ecological studies and for monitoring the environment. Terrestrial laser scanning has become a widely accepted technique for acquiring accurate high‐density three‐dimensional information about plant surfaces; however, this instrument is expensive, technically challenging to operate, heavy, and difficult to transport to hard‐to‐reach areas such as dense forests and undeveloped areas without easy vehicle access. Using Haloxylon ammodendron, a plant widely distributed in arid lands, as an example, we used a consumer‐grade handheld camera to take a series of overlapping images of this plant. Computer vision and photogrammetric software were used to reconstruct highly detailed three‐dimensional data of the plant surface. This surface data was compared to the point cloud of the plant acquired from concomitant terrestrial laser scanning. We demonstrated that the accuracy and degree of completeness of the image‐derived point clouds are comparable to that of laser scanning. Plant structural parameters (such as tree height and crown width) and three‐dimensional models extracted from the point clouds also agree well with a relative difference of less than 5%. Our case study shows that a common camera and image processing software can be an affordable, highly portable, and viable option for acquiring accurate and detailed high‐density and high‐resolution three‐dimensional information about plant structure in the environment. This digitization technique can record the plant and its surrounding environment effectively and efficiently, and it can be applied to many ecological fields and studies.
High‐Temperature Structural and Electrical Characterization of Reduced Oxygen‐Deficient Ruddlesden–Popper Nickelates
Authors: Kravchenko Ekaterina , Neagu Alexandra , Zakharchuk Kiryl , Grins Jekabs , Svensson Gunnar , Pankov Vladimir , Yaremchenko Aleksey A.
Published: May 2018

High‐temperature characterization of oxygen‐deficient Sr‐rich (La1–xSrx)2NiO4–δ (x = 0.5–0.8) solid solutions under mildly reducing conditions with p(O2) ≈ 5 × 10–5 atm was performed by employing structural and thermal analysis, TEM, and electrical conductivity measurements. Oxygen losses from the crystal lattice on reduction were found to result in a reversible transition from the tetragonal (I4/mmm) to the orthorhombic (Immm) structure and shrinkage of the crystal lattice for the compositions with x > 0.5. TEM and thermogravimetric analysis evidenced slow kinetics of the structural transition. The increase in oxygen deficiency under reducing conditions is accompanied by localization of the electronic charge carriers, a drop of the p‐type electronic conductivity, and a transition from metallic‐like to semiconducting behavior. The extent of changes in oxygen nonstoichiometry, unit‐cell dimensions, average Ni oxidation state, electron–hole concentration, and electronic conductivity on reduction is interrelated with the strontium content. The results suggest that the electrical conductivity of (La1–xSrx)2NiO4–δ ceramics depends mainly on the average Ni oxidation state.
“Asian Carp” is Societally and Scientifically Problematic. Let's Replace It
Authors: Kočovský Patrick M , Chapman Duane C , Qian Song
Published: May 2018

Bighead Carp Hypophthalmichthys nobilis, Black Carp Mylopharyngodon piceus, Grass Carp Ctenopharyngodon idella, and Silver Carp H. molitrix are considered invasive species in North America and Europe. In North America, they are typically referred to collectively as “Asian carp,” a reference to their native range. The category “Asian carp” fails to acknowledge the cultural value and the ecological differences of these fishes, causes confusion when translated into Chinese, and frequently causes communication problems with the public and occasionally among professionals when some species are intentionally or inadvertently included or excluded when referred to collectively. Herein, we review the long history of aquaculture of these species in China, their human cultural significance, the origin of the category “Asian carp,” and the problems the term “Asian carp” might cause when used in cross-cultural communication. We recommend discontinuing the use of this term and replacing it with individual species names. When a group term is required, there are several more favorable alternatives, including existing Chinese terms that have been used for centuries.
Protein cross‐linking and the Maillard reaction decrease the solubility of milk protein concentrates
Authors: Fan Fengjiao , Liu Meng , Shi Pujie , Xu Xianbing , Lu Weihong , Wang Zhenyu , Du Ming
Published: May 2018

Milk protein concentrate (MPC) is a widely used material in the food industry. However, despite its widespread use, the mechanism underlying the decreased solubility of MPC that occurs during storage has not yet been clarified. In this study, the solubility changes, protein cross‐linking, and Maillard reaction and the relationships between them were investigated in modified MPC powders (MMPC) containing different concentrations of protein and/or lactose stored at 50°C for 15–45 days. The results demonstrated that both the protein and lactose contents affected solubility. The proteins interacted through hydrogen bonding, disulfide bonding, hydrophobic interactions, and nondisulphide covalent bonding, which led to cross‐linking. The Maillard reaction promoted protein cross‐linking and was in turn influenced by protein cross‐linking. The Maillard reaction was slower when the degree of protein cross‐linking was greater. These results improve our understanding of the mechanism leading to poor solubility of MPC powders during storage.
A STATISTICAL MODEL OF CHANGES IN ASSET PRICES EMPLOYING INTRADAY DATA: A RECURSIVE APPROACH
Authors: Fletcher Roy A.
Published: May 2018

This paper develops a statistical model of changes in asset prices employing intraday data. The procedure proposed in this paper is an alternative to the Hausman, Lo, and MacKinlay (1992) ordered probit model. Similar to the ordered probit model, our model also contains the linear regression model as a special case. However, compared to the ordered probit model, our specification is parsimonious. Parsimony does come at a cost, but for certain applications where, for example, a benchmark return is needed in intraday studies, there is value in terms of the computational effort required and the method's robustness to various empirical microstructure phenomena. The parsimony is achieved when statistical implications arising from intraday structural changes, which may due to such factors as concentrated trading patterns, are incorporated into a statistical model.
THE IMPACT FOR STOCKHOLDERS WHEN REGULATED FIRMS REVISE DIVIDEND POLICY
Authors: Shelor Roger M. , Officer Dennis T.
Published: May 2018

This study examines the stock market's response when dividend policy changes are made by firms in a heavily regulated industry. Electric utilities are chosen because these firms are regulated in many ways. Regulatory control covers rates of return, pricing, markets and many other areas. This study focuses on dividend changes which follow a period of dividend stability. The results indicate that electric utility firms' stock prices adjust accordingly at the time of the announcement. The market reaction appears to be greater than that of previous studies which considered many industries.
Treating cachexia using soluble ACVR2B improves survival, alters mTOR localization, and attenuates liver and spleen responses
Authors: Nissinen Tuuli A. , Hentilä Jaakko , Penna Fabio , Lampinen Anita , Lautaoja Juulia H. , Fachada Vasco , Holopainen Tanja , Ritvos Olli , Kivelä Riikka , Hulmi Juha J.
Published: May 2018

Background

Cancer cachexia increases morbidity and mortality, and blocking of activin receptor ligands has improved survival in experimental cancer. However, the underlying mechanisms have not yet been fully uncovered.

Methods

The effects of blocking activin receptor type 2 (ACVR2) ligands on both muscle and non‐muscle tissues were investigated in a preclinical model of cancer cachexia using a recombinant soluble ACVR2B (sACVR2B‐Fc). Treatment with sACVR2B‐Fc was applied either only before the tumour formation or with continued treatment both before and after tumour formation. The potential roles of muscle and non‐muscle tissues in cancer cachexia were investigated in order to understand the possible mechanisms of improved survival mediated by ACVR2 ligand blocking.

Results

Blocking of ACVR2 ligands improved survival in tumour‐bearing mice only when the mice were treated both before and after the tumour formation. This occurred without effects on tumour growth, production of pro‐inflammatory cytokines or the level of physical activity. ACVR2 ligand blocking was associated with increased muscle (limb and diaphragm) mass and attenuation of both hepatic protein synthesis and splenomegaly. Especially, the effects on the liver and the spleen were observed independent of the treatment protocol. The prevention of splenomegaly by sACVR2B‐Fc was not explained by decreased markers of myeloid‐derived suppressor cells. Decreased tibialis anterior, diaphragm, and heart protein synthesis were observed in cachectic mice. This was associated with decreased mechanistic target of rapamycin (mTOR) colocalization with late‐endosomes/lysosomes, which correlated with cachexia and reduced muscle protein synthesis.

Conclusions

The prolonged survival with continued ACVR2 ligand blocking could potentially be attributed in part to the maintenance of limb and respiratory muscle mass, but many observed non‐muscle effects suggest that the effect may be more complex than previously thought. Our novel finding showing decreased mTOR localization in skeletal muscle with lysosomes/late‐endosomes in cancer opens up new research questions and possible treatment options for cachexia.
Oxazolidine Formation, or Loss of Acid, from Attempted Fluorination of Amide Side‐Chain in 2‐Nitroimidazoles
Authors: Baird Ian R. , Patrick Brian O. , Skov Kirsten A. , James Brian R.
Published: May 2018

Reaction of Etanidazole (a 2‐nitroimidazole derivative with an amide side‐chain containing a hydroxyethyl group) with triflic anhydride gives, depending on conditions, a trifluoromethyl(sulfonyl)oxazolidine via a cyclization reaction, or a fluorine‐free formate derivative; reaction with tosyl chloride gives only a chloroethyl derivative. An attempt to replace a Br‐atom in a related propyl‐containing amide side‐chain by a F‐atom forms instead a propylene derivative via loss of HBr. The studies stem from interest in use of 2‐nitroimidazoles with fluorine‐containing amide side‐chains as hypoxia markers.
Controlled Delivery of Insulin Using Rapidly Separating Microneedles Fabricated from Genipin‐Crosslinked Gelatin
Authors: Chen Bo Zhi , Ashfaq Mohammad , Zhu Dan Dan , Zhang Xiao Peng , Guo Xin Dong
Published: May 2018

Rapidly separating genepin‐crosslinked gelatin (RS‐GC) microneedles (MNs) mounted on the polyvinyl alcohol (PVA)‐coated polylactic acid (PLA) MNs (RS‐PGC‐MNs) are fabricated, in which GC‐MNs deliver insulin within the skin and the PLA supporting array is easily separated by the dissolution of the PVA layer. The release of insulin is controlled by utilizing the virtue of genipin as a crosslinking agent for producing biocompatible GC‐MNs. The degree of crosslinking enhances the mechanical strength as well as humidity resistance. The in vitro and in vivo insulin release tests show significant changes in the release rates in the RS‐PGC‐MNs with different crosslinking degree. The hypoglycemic effect in diabetic mice demonstrate that the higher crosslinking GC‐MNs result in characteristic controlled insulin release compared with other treatments and prolonged effectiveness of the RS‐PGC‐MNs. The proposed RS‐PGC‐MNs is a promising device for effective use as a noninvasive and painless controlled insulin delivery system.
A Robust, Self‐Healable, and Shape Memory Supramolecular Hydrogel by Multiple Hydrogen Bonding Interactions
Authors: Feng Zhanbin , Zuo Hongli , Gao Weisheng , Ning Nanying , Tian Ming , Zhang Liqun
Published: May 2018

A versatile double‐network (DN) hydrogel with two noncovalent crosslinked networks is synthesized by multiple hydrogen bonding (H‐bonding) interactions. The DN hydrogels are synthesized via a heating–cooling photopolymerization process by adding all reactants of agar, N‐acryloyl glycinamide (NAGA) and N‐benzylacrylamide (NBAA) monomers, UV initiators to a single water pot. Poly(N‐acryloyl glycinamide‐co‐N‐benzyl acrylamide) (P(NAGA‐co‐NBAA)) with a triple amide in one side group is synthesized via UV‐light polymerization between NAGA and NBAA, forming a strong intermolecular H‐bonding network. Meanwhile, the intramolecular H‐bonding network is formed between P(NAGA‐co‐NBAA) and agars. The sol–gel phase transition of agars at 86 °C generates the molecular entanglement network. Such a double network enables the hydrogel high self‐healing efficiency (about 95%), good shape memory ability, and high mechanical strength (1.1 MPa). Additionally, the DN hydrogel is completely crosslinked by multiple hydrogen bonds (H‐bonds) and the physical crosslinking of agar without extra potential toxic chemical crosslinker. The DN hydrogels find extensive applications in the biomedical materials due to their excellent biocompatibility.
Differential ability of formononetin to stimulate proliferation of endothelial cells and breast cancer cells via a feedback loop involving MicroRNA‐375, RASD1, and ERα
Authors: Chen Jian , Zhang Xing , Wang Yong , Ye Yu , Huang Zhaoquan
Published: May 2018

For postmenopausal cardiovascular disease, long‐term estrogen therapy may increase the risk of breast cancer. To reduce this risk, estrogen may be replaced with the phytoestrogen formononetin, but how formononetin acts on vascular endothelial cells (ECs) and breast cancer cells is unclear. Here, we show that low concentrations of formononetin induced proliferation and inhibited apoptosis more strongly in cultured human umbilical vein endothelial cells (HUVECs) than in breast cancer cells expressing estrogen receptor α (ERα) (MCF‐7, BT474) or not (MDA‐MB‐231), and that this differential stimulation was associated with miR‐375 up‐regulation in HUVECs. For the first time, we demonstrate the presence of a feedback loop involving miR‐375, ras dexamethasone‐induced 1 (RASD1), and ERα in normal HUVECs, and we show that formononetin stimulated this feedback loop in HUVECs but not in MCF‐7 or BT474 cells. In all three cell lines, formononetin increased Akt phosphorylation and Bcl‐2 expression. Inhibiting miR‐375 blocked these changes and increased proliferation in HUVECs, but not in MCF‐7 or BT474 cells. In ovariectomized rats, formononetin increased uterine weight and caused similar changes in levels of miR‐375, RASD1, ERα, and Bcl‐2 in aortic ECs as in cultured HUVECs. In mice bearing MCF‐7 xenografts, tumor growth was stimulated by 17β‐estradiol but not by formononetin. These results suggest selective action of formononetin in ECs (proliferation stimulation and apoptosis inhibition) relative to breast cancer cells, possibly via a feedback loop involving miR‐375, RASD1, and ERα. This differential effect may explain why formononetin may not increase the risk of postmenopausal breast cancer.
A Novel Clinical Phenotype of Fragile X‐Associated Tremor/Ataxia Syndrome
Authors: Alvarez Bravo Gary , Fernández‐Carril Jose Manuel , López‐Zuazo Ignacio , Yusta Izquierdo Antonio , Abrol Tapan , Alsinaidi Omar
Published: May 2018

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Assessing Natural Substrates for Restricting Movement of California Sea Cucumbers Parastichopus californicus
Authors: Haddad Colleen A , Cross Stephen F , Davies Hailey L , Duff Stefanie D , Fortune Angela C , Pearce Christopher M
Published: May 2018

California sea cucumbers Parastichopus californicus are reported to prefer hard over soft substrates and can be found associated with shell hash at bivalve farms. We predicted that soft substrates and oyster shells might restrict the movement of sea cucumbers and tested this hypothesis in a laboratory experiment. Small (contracted length, ~4.5 cm) and large (~10 cm) sea cucumbers were placed in the middle of tanks on a uniform, hard substrate (30 × 30-cm PVC sheet) surrounded by various substrates: no substrate (control); silt, fine sand, and very coarse sand (grain sizes: 2–50 μm, 100–250 μm, and 1–2 mm, respectively); and Pacific oyster Crassostrea gigas shells (~10-cm border around the PVC sheet) with or without silt surrounding the shells. Movement of individuals was monitored over 24 h in six replicate trials. The mean percent (±SE) of sea cucumbers remaining on the PVC sheet was not significantly different among the control (22 ± 7%), silt (28 ± 8%), fine sand (37 ± 8%), and very coarse sand (20 ± 7%) treatments. Low percentages (<40%) indicated that the animals were not averse to emigrating to the soft substrates. However, significantly more sea cucumbers remained on the hard substrates (PVC and oyster shells) in the treatments comprised of oyster shell (83 ± 7%) and silt with oyster shell (82 ± 8%) than on the PVC sheet in the soft substrate treatments, indicating an affinity of the sea cucumbers for the oyster shells. Significantly more small individuals (95 ± 5%) than large ones (69 ± 9%) remained on the hard substrates. This study demonstrates that soft substrates do not prevent the movement of sea cucumbers under laboratory conditions, while oyster shells may cause a decrease in movement, which has implications for benthic ranching of commercially-farmed sea cucumbers.
Thermo‐mechanical and adhesive properties of polymeric films based on ZnAl‐hydrotalcite composites for active wound dressings
Authors: Perioli Luana , Dorigato Andrea , Pagano Cinzia , Leoni Matteo , Pegoretti Alessandro
Published: May 2018

Composite films based on sodium carboxymethyl cellulose (Na‐CMC) loaded with a ZnAl(OH)2CO3·yH2O hydrotalcite (ZnAl‐HTlc), were developed and characterized. The composites were mechanically more stable than the matrix alone: the noticeable enhancement of elastic modulus, creep resistance and failure properties, all proportional to the filler content, came at the expenses of a certain embrittlement. The filler tended to aggregate in the composites and the size of the aggregates increased with ZnAl‐HTlc amount. Contact angle measurements highlighted how ZnAl‐HTlc introduction in the polymeric matrix could strongly modify the wettability conditions of the films increasing their hydrophilicity. Bioadhesion tests showed that the adhesion behavior of the composites decreased as ZnAl‐HTlc amount increases, testifying the influence of the filler on the ability of the film to bind skin surface. Therefore, the developed films may find application as active wound dressings since ZnAl‐HTlc can be easily intercalated with an active pharmaceutical ingredient to be progressively released on the wound. POLYM. ENG. SCI., 59:E112–E119, 2019. © 2018 Society of Plastics Engineers
Interaction of N and O atoms with hardwood and softwood surfaces in the flowing afterglow of N2‐O2 microwave plasmas
Authors: Prégent Julien , Robert‐Bigras Germain , Stafford Luc
Published: May 2018

The interaction between hardwood (Sugar Maple) and softwood (Black Spruce) surfaces and N and O atom species produced in the flowing late afterglow of a surface‐wave microwave plasma column in N2‐O2 gas mixtures was investigated using a NO titration method combined with optical emission spectroscopy. Results showed two distinct atom loss regimes following their interaction with wood surfaces: a recombination regime at low oxygen concentrations (<1% O2) and an etching regime by O atoms at higher oxygen concentrations (>1% O2). The etching reaction was confirmed by surface profilometry measurements, with the formation of sub‐millimetre trenches between low‐density early wood and high‐density late wood regions. Recombination dynamics of O and N atoms over smooth and roughened wood regions are also compared.
Enantioselective Addition of Cyanide to CF3‐Substituted Alkylidenemalonates: Construction of Trifluoromethylated All‐Carbon Quaternary Stereocenters
Authors: Jakhar Ajay , Nazish Mohd , Gupta Naveen , Khan Noor‐ul H. , Kureshy Rukhsana I.
Published: May 2018

The construction of a new class of chiral organofluorine compounds with an all‐carbon stereocenter bearing a CF3 group was disclosed. The cinchona alkaloid based phase transfer catalyzed asymmetric conjugated cyanation of CF3 substituted alkylidene malonates have been developed. The nitrile products were achieved in excellent yield with good enantioselectivity. The chirality of product increased up to 98% by recrystallization.
Metal‐Free Epoxidation of Internal and Terminal Alkenes with tert‐Butyl Hydroperoxide/Isobutyraldehyde/Oxygen System
Authors: Hong Mei , Min Jie , Wang Shifa
Published: May 2018

The epoxidation of several alkenes was studied using oxygen as green oxidant, isobutyraldehyde (IBA) as co‐reagent and tert‐butyl hydroperoxide (TBHP) as radical initiator at mild conditions (60 oC, atmospheric pressure with an oxygen balloon). TBHP could accelerate the production of carbonyl radical and its peroxidation, without using a metal catalyst. The factors influencing the conversion of the substrates and selectivity of the epoxides have been well investigated. Under optimized reaction conditions, the epoxidation of linear terminal, cyclic and aromatic alkenes was evaluated. Most performed reactions were high selectivity for production of the corresponding epoxides.
Construction of Novel Kojic Acid Fused Furans by Domino Reactions of a Kojic Acid Derivative with (Z)‐Bromonitroalkenes
Authors: Yu Shuo‐Wen , Zhao Si‐Han , Chen Hui , Xu Xiao‐Ying , Yuan Wei‐Cheng , Zhang Xiao‐Mei
Published: May 2018

A series of novel kojic acid fused furans have been synthesized by domino cyclization‐elimination reactions of a kojic acid derivative with (Z)‐bromonitroalkenes. In the presence of a bifunctional thiourea‐tertiary amine organocatalyst and sodium bicarbonate, the reactions provided the products in up to quantitative yields.
A Quest towards Eccentric Piedfort Pairs
Authors: Mehrotra Sonam , Raje Sakthi , Jain Anant Kumar , Jain Ankit , Kandasamy Parameswaran , Butcher Ray J. , Angamuthu Raja
Published: May 2018

A group of symmetrically‐trisubstituted‐1,3,5‐triazine‐based molecules have been studied extensively in order to create Piedfort pairs that are intended to be employed in sequestration of small molecules. Extensive inter and intramolecular interactions observed in the solid‐state of the studied triazine molecules lead to the formation of one‐dimensional ribbon and two‐dimensional sheet motifs. Koneramine formation was applied as a new strategy to increase the bulkiness of the substituents on 1,3,5‐triazine ring that prevented the formation of ribbons and sheets yet yielded hydrogen‐bonded dimer. The protonated forms of one of the triazine compound showed that the triazine ring nitrogens are more basic than amine nitrogens on the periphery; protonated N2,N4,N6‐triphenyl‐1,3,5‐triazine‐2,4,6‐triamine resulted in eccentric Piedfort pairs that displayed aesthetic structural patterns possessing variety of inter and intramolecular interactions including stacking between electron deficient triazine ring of one member and electron rich aryl ring of another member.
Hierarchically Porous Co and N‐Codoped Carbon Hollow Structure Derived from PS@ZIF‐67 as an Electrocatalyst for Oxygen Reduction
Authors: Lin Xiangjun , Wang Yameng , Liu Ting , Chen Heng , Jiang Zhongjie , Chen Yan , Liu Jiang , Huang. Jianlin , Liu Meilin
Published: May 2018

The development of low‐cost, highly efficient, and durable electrocatalysts for oxygen reduction reaction (ORR) is vital to commercialization of a new generation of rechargeable metal‐air batteries and fuel cells. Here we report a facile, efficient, template‐assisted strategy for fabrication of hierarchically porous Co, N‐codoped carbon hollow structures as ORR eletrocatalysts. The unique architecture of the catalyst was constructed through in situ growth of Co‐based zeolitic imidazolate framework (ZIF‐67) on the surface of carboxylated polystyrene (PS) nanosphere and pyrolysis for removal of PS and carbonization of ZIF‐67. The resulting catalyst exhibited outstanding ORR activity in both alkaline and acidic electrolyte solution, comparable to that of a commercial Pt/C catalyst, and better than those reported for most Co, N‐codoped carbon catalysts. Such superior performance is attributed to the unique features of the catalyst: large specific surface area, openly exposed active sites, high content of the pyridinic‐N and graphitic‐N active sites, and fast transfer of electrons and ions. Moreover, the catalyst also displayed much better tolerance to methanol and durability than the commercial Pt/C catalyst, ascribed to strong coupling of active sites and highly graphitic carbon sheets. Further, the simple, effective and low‐cost synthesis strategy for creation of hierarchically porous electrodes is applicable to fabrication of other energy storage and conversion devices as well.
The rise of two‐dimensional van der Waals ferroelectrics
Authors: Wu Menghao , Jena Puru
Published: May 2018

Recent research on ferroelectrics based on two‐dimensional (2D) materials may lead to a technological revolution, offering much higher density for integration as well as a better combination of semiconductor properties and non‐volatile memories at the nanoscale compared with traditional ferroelectrics. In addition, ferroelectricity can be much more robust than ferromagnetism in 2D. In this study, we review the studies on 2D ferroelectricity starting from 2013, which are mainly first‐principles predictions, including functionalization‐induced 2D ferroelectricity in prevalent non‐polar 2D materials as well as 2D intrinsic ferroelectricity, which are either in‐plane or vertical. Although the number of reports on 2D ferroelectricity is still small compared to the large amount of research on 2D ferromagnetism, the potential of these materials to unravel new science and technology has stimulated considerable interest in 2D ferroelectricity, making it a fast developing field. It is interesting to note that 2D ferroelectricity was experimentally realized a year before 2D ferromagnetism, and the large difference in the Curie temperatures of these materials has further demonstrated that 2D ferroelectricity could be much more robust than 2D ferromagnetism.

This article is categorized under:

Structure and Mechanism > Computational Materials Science
Out‐compute drug side effects: Focus on cytochrome P450 2D6 modeling
Authors: Don Charleen G. , Smieško Martin
Published: May 2018

Understanding the way in which drugs are metabolized by cytochrome P450 2D6 (CYP2D6) and hence the underlying mechanisms that define potential toxicity is crucial to avoid adverse reactions. The high occurrence of CYP2D6 polymorphs enhances the complexity of the toxicity assessment of a drug candidate and should be tackled from early drug discovery phase on. The recent increase in available mammalian CYP2D6 X‐ray structures opens the gateway to the development of in silico three‐dimensional CYP2D6 toxicity prediction techniques that address also the major clinically relevant allelic variants. This review presents the basic principles needed for comprehending the enzyme particularities, gives a concise overview of several clinical relevant allelic CYP2D6 variants, and explores the state‐of‐the‐art CYP2D6 research field to accelerate the development and use of such integrative in silico modeling technologies.

This article is categorized under:

Structure and Mechanism > Computational Biochemistry and Biophysics

Structure and Mechanism > Molecular Structures

Software > Molecular Modeling
Axisymmetric indentation of an elastic thin plate by a rigid sphere revisited
Authors: Li Min , Ru C.Q. , Gao Cun‐Fa
Published: May 2018

A simple analytical model based on a Kerr‐type differential relation is proposed to study the indentation problem of a circular elastic thin plate indented by a rigid sphere. Unlike some existing methods which matched two solutions inside and outside the contact zone, the present method is based on a simple differential relation between contact pressure and the normal deflection of the pressured surface of elastic plate, which holds both inside and outside the contact zone and makes it possible to analyze both zones by a single governing differential equation. Explicit relations between the contact‐zone radius, indentation displacement and indentation load are derived for different boundary conditions. The proposed model is validated by good agreement between the predicted results and some known data available in existing literature. In particular, the present model confirms that the indenter will lose contact with the plate around the center of the plate as the indentation load exceeds a certain critical value, and then the contact zone becomes to an annular zone. Detailed analytical and numerical results beyond existing literature are demonstrated for the annular contact zone regarding the critical contact‐zone radius, the width of annular contact zone and the associated contact pressure distribution.
Automatic Bayes Factors for Testing Equality- and Inequality-Constrained Hypotheses on Variances
Authors: Böing-Messing Florian , Mulder Joris
Published: May 2018

In comparing characteristics of independent populations, researchers frequently expect a certain structure of the population variances. These expectations can be formulated as hypotheses with equality and/or inequality constraints on the variances. In this article, we consider the Bayes factor for testing such (in)equality-constrained hypotheses on variances. Application of Bayes factors requires specification of a prior under every hypothesis to be tested. However, specifying subjective priors for variances based on prior information is a difficult task. We therefore consider so-called automatic or default Bayes factors. These methods avoid the need for the user to specify priors by using information from the sample data. We present three automatic Bayes factors for testing variances. The first is a Bayes factor with equal priors on all variances, where the priors are specified automatically using a small share of the information in the sample data. The second is the fractional Bayes factor, where a fraction of the likelihood is used for automatic prior specification. The third is an adjustment of the fractional Bayes factor such that the parsimony of inequality-constrained hypotheses is properly taken into account. The Bayes factors are evaluated by investigating different properties such as information consistency and large sample consistency. Based on this evaluation, it is concluded that the adjusted fractional Bayes factor is generally recommendable for testing equality- and inequality-constrained hypotheses on variances.
Gabbro-peridotite sills of the Late Riphean Dovyren plutonic complex (northern Baikal area, Russia)
Authors: Orsoev D.A. , Mekhonoshin A.S. , Kanakin S.V. , Badmatsyrenova R.A. , Khromova E.A.
Published: May 2018

We report data on the geology, mineralogy, petrography, and chemistry of 733 Ma gabbro-peridotite sills from the Late Riphean Dovyren plutonic complex. Thick sills were differentiated into plagiolherzolite to olivine gabbronorite compositions by fractional crystallization of the K–Na series high-Mg low-alkali low-Ti picritic parental magma. The magma already contained up to 5% of intratelluric olivine crystals when entering the reservoir. The sills emplaced before the whole complex, judging by the presence of their fragments as plagiolherzolite xenoliths in the gabbro zone of the Yoko-Dovyren layered pluton. The gabbro-peridotite sills are products of high-temperature within-plate magmatism. High heat flow during the generation of the magma, evident from its high-Mg composition, was likely maintained by the activity of a mantle plume associated with the Neoproterozoic Franklin large igneous province.
THE ARCHAEOLOGY OF HOME:QIAOXIANGAND NONSTATE ACTORS IN THE ARCHAEOLOGY OF THE CHINESE DIASPORA
Authors: Voss Barbara L. , Kennedy J. Ryan , Tan Jinhua (Selia) , Ng Laura W.
Published: May 2018

The archaeology of the nineteenth-century Chinese diaspora is a well-developed archaeological subfield, but research on Chinese migrants’ homelands is lacking. Survey of a qiaoxiang (home village) in China's Pearl River Delta provides the first archaeological evidence from a home village of Chinese migrants. Transnational comparative analysis with collections recovered from Chinese diaspora settlements reveals stark differences in the use of China-produced goods between qiaoxiang and Chinese settlements abroad. Qiaoxiang residents primarily used locally produced ceramics, while residents of Chinese diaspora settlements consumed ceramics produced in Gaobei and Jingdezhen, major pottery centers located in northeast Guangdong Province and Jiangxi Province, hundreds of kilometers to the north. Additionally, qiaoxiang residents were engaged in global networks of consumption, using British refined earthenwares and other products produced in Europe and the United States. These findings challenge the common assumption made in diaspora research that artifacts produced in migrants’ homelands are evidence of tradition, while those produced in migrants’ adopted countries are evidence of culture change. Instead, the results of qiaoxiang archaeology indicate the significance of nonstate actors, especially import-export companies, in shaping the material worlds of both homeland and diaspora communities. (Spanish abstract available as Supplemental Text 1.)
A NOTE ON A COMPLETE SOLUTION OF A PROBLEM POSED BY K. MAHLER
Authors: MARQUES DIEGO , MOREIRA CARLOS GUSTAVO
Published: May 2018

Let $\unicode[STIX]{x1D70C}\in (0,\infty ]$ be a real number. In this short note, we extend a recent result of Marques and Ramirez [‘On exceptional sets: the solution of a problem posed by K. Mahler’, Bull. Aust. Math. Soc.94 (2016), 15–19] by proving that any subset of $\overline{\mathbb{Q}}\cap B(0,\unicode[STIX]{x1D70C})$, which is closed under complex conjugation and contains $0$, is the exceptional set of uncountably many analytic transcendental functions with rational coefficients and radius of convergence $\unicode[STIX]{x1D70C}$. This solves the question posed by K. Mahler completely.
COMMON SLOTS OF BILINEAR AND QUADRATIC PFISTER FORMS
Authors: CHAPMAN ADAM
Published: May 2018

We show that over any field$F$of characteristic 2 and 2-rank$n$, there exist$2^{n}$bilinear$n$-fold Pfister forms that have no slot in common. This answers a question of Becher [‘Triple linkage’,Ann.$K$-Theory, to appear] in the negative. We provide an analogous result also for quadratic Pfister forms.
CONVERGENCE OF MANN’S ALTERNATING PROJECTIONS IN CAT() SPACES
Authors: CHOI BYOUNG JIN
Published: May 2018

We study the convex feasibility problem in$\text{CAT}(\unicode[STIX]{x1D705})$spaces using Mann’s iterative projection method. To do this, we extend Mann’s projection method in normed spaces to$\text{CAT}(\unicode[STIX]{x1D705})$spaces with$\unicode[STIX]{x1D705}\geq 0$, and then we prove the$\unicode[STIX]{x1D6E5}$-convergence of the method. Furthermore, under certain regularity or compactness conditions on the convex closed sets, we prove the strong convergence of Mann’s alternating projection sequence in$\text{CAT}(\unicode[STIX]{x1D705})$spaces with$\unicode[STIX]{x1D705}\geq 0$.
INTERSECTIONS OF MULTICURVES FROM DYNNIKOV COORDINATES
Authors: YURTTAŞ S. ÖYKÜ , HALL TOBY
Published: May 2018

We present an algorithm for calculating the geometric intersection number of two multicurves on the$n$-punctured disk, taking as input their Dynnikov coordinates. The algorithm has complexity$O(m^{2}n^{4})$, where $m$is the sum of the absolute values of the Dynnikov coordinates of the two multicurves. The main ingredient is an algorithm due to Cumplido for relaxing a multicurve.
Workers and the Radical Right in Poland
Authors: Ost David
Published: May 2018

How has the Law and Justice Party in Poland (PiS) been able to get significant labor support to introduce far-right policies that undermine pluralist democracy? We look at PiS in the context of the “left fascist” traditions of the past, when redistributionist policies won wide support among workers who were accepted as part of the favored “nation.” Labor support breaks down along three lines, with industrial labor most closely aligned with PiS, white-collar labor (in education and health) mostly opposed, and the marginalized small-city precariat being mobilized by PiS, but also finding a place in explicitly fascist parties further to the Right. Left alternatives, weakened due to the collapse of class discourse, are slowly reemerging, but the Right will likely command most labor support for the near future.
“Italians First”: Workers on the Right Amidst Old and New Populisms
Authors: Zazzara Gilda
Published: May 2018

This article deals with the Italian working-class attitude to vote right-wing, seen in a long-term perspective, in particular in the northern and more industrialized regions. It stresses the fact that the left-wing parties reached their largest majority among working-class voters only for a short period. The end of the long cycle of factory conflicts of the 1970s on the one side, and the crisis of the “local political subcultures”—Catholic and Communist—in mediating the relationship between the working class and the central State on the other, marked the outbreak of a new political phenomenon: the establishment of the Lega Nord party in the 1980s. This party has been able to shift progressively from identity-based claims and secessionist proposals to xenophobia and the demand that a priority be accorded to Italian workers on the labour market. In the most recent years workers’ support for the Lega Nord has been contended by a new populist competitor, the Five Star Movement, whose ability to intercept a widespread “working-class malaise” will be tested in years to come.
ESTIMATION OF SPATIAL AUTOREGRESSIONS WITH STOCHASTIC WEIGHT MATRICES
Authors: Gupta Abhimanyu
Published: May 2018

We examine a higher-order spatial autoregressive model with stochastic, but exogenous, spatial weight matrices. Allowing a general spatial linear process form for the disturbances that permits many common types of error specifications as well as potential ‘long memory’, we provide sufficient conditions for consistency and asymptotic normality of instrumental variables, ordinary least squares, and pseudo maximum likelihood estimates. The implications of popular weight matrix normalizations and structures for our theoretical conditions are discussed. A set of Monte Carlo simulations examines the behaviour of the estimates in a variety of situations. Our results are especially pertinent in situations where spatial weights are functions of stochastic economic variables, and this type of setting is also studied in our simulations.
The Origins of Iconic Depictions: A Falsifiable Model Derived from the Visual Science of Palaeolithic Cave Art and World Rock Art
Authors: Hodgson Derek , Pettitt Paul
Published: May 2018

Archaeologists have struggled for more than a century to explain why the first representational art of the Upper Palaeolithic arose and the reason for its precocious naturalism. Thanks to new data from various sites across Europe and further afield, as well as crucial insights from visual science, we may now be on the brink of bringing some clarity to this issue. In this paper, we assert that the main precursors of the first figurative art consisted of hand prints/stencils (among the Neanderthals and earlyHomo sapiens) and a corpus of geometric marks as well as a hunting lifestyle and highly charged visual system for detecting animals in evocative environments. Unlike many foregoing arguments, the present one is falsifiable in that five critical, but verifiable, points are delineated.
Using Vertically Integrated Ocean Fields to Characterize Greenland Icebergs' Distribution and Lifetime
Authors: Marson Juliana M. , Myers Paul G. , Hu Xianmin , Le Sommer Julien
Published: May 2018

Icebergs represent approximately half of Greenland's yearly mass loss, having important implications for biological productivity, freshwater fluxes in the ocean, and navigation. This study applies an iceberg model that uses integrated ocean fields (from surface to iceberg keel) to simulate the drift and decay of Greenland icebergs. This version of iceberg model (VERT) is compared with a more widely adopted version (SURF) which only uses surface ocean fields in its equations. We show that icebergs in VERT tend to drift along the shelf break, while in SURF they concentrate along the coastline. Additionally, we show that Greenland's southeast coast is the source of ∼60% of the icebergs that cross the interior of the Labrador Sea—a region that stages buoyancy‐driven convection and is, therefore, sensitive to freshwater input.
H I 21‐cm Cosmology and the Bispectrum: Closure Diagnostics in Massively Redundant Interferometric Arrays
Authors: Carilli C. L. , Nikolic Bojan , Thyagarajan Nithyanandan , Gale‐Sides K.
Published: May 2018

New, massively redundant low‐frequency arrays allow for a novel investigation of closure relations in interferometry. We employ commissioning data from the Hydrogen Epoch of Reionization Array to investigate closure quantities in this densely packed grid array of 14‐m antennas operating at 100 to 200 MHz. We investigate techniques that utilize closure phase spectra for redundant triads to estimate departures from redundancy for redundant baseline visibilities. We find a median absolute deviation from redundancy in closure phase across the observed frequency range of about 4.5°. This value translates into a nonredundancy per visibility phase of about 2.6°, using prototype electronics. The median absolute deviations from redundancy decrease with longer baselines. We show that closure phase spectra can be used to identify ill‐behaved antennas in the array, independent of calibration. We investigate the temporal behavior of closure spectra. The Allan variance increases after a 1‐min stride time, due to passage of the sky through the primary beam of the transit telescope. However, the closure spectra repeat to well within the noise per measurement at corresponding local sidereal times from day to day. In future papers in this series we will develop the technique of using closure phase spectra in the search for the H I 21‐cm signal from cosmic reionization.
IL-3 but not monomeric IgE regulates FcεRI levels and cell survival in primary human basophils
Authors: Zellweger Fabian , Buschor Patrick , Hobi Gabriel , Brigger Daniel , Dahinden Clemens Andreas , Villiger Peter Matthias , Eggel Alexander
Published: May 2018

Binding of allergen-specific IgE to its primary receptor FcεRI on basophils and mast cells represents a central event in the development of allergic diseases. The high-affinity interaction between IgE and FcεRI results in permanent sensitization of these allergic effector cells and critically regulates their release of pro-inflammatory mediators upon IgE cross-linking by allergens. In addition, binding of monomeric IgE has been reported to actively regulate FcεRI surface levels and promote survival of mast cells in the absence of allergen through the induction of autocrine cytokine secretion including interleukin-3 (IL-3). As basophils and mast cells share many biological commonalities we sought to assess the role of monomeric IgE binding and IL-3 signaling in FcεRI regulation and cell survival of primary human basophils. FcεRI cell surface levels and survival of isolated blood basophils were assessed upon addition of monomeric IgE or physiologic removal of endogenous cell-bound IgE with a disruptive IgE inhibitor by flow cytometry. We further determined basophil cell numbers in both low and high serum IgE blood donors and mice that are either sufficient or deficient for FcεRI. Ultimately, we investigated the effect of IL-3 on basophil surface FcεRI levels by protein and gene expression analysis. Surface levels of FcεRI were passively stabilized but not actively upregulated in the presence of monomeric IgE. In contrast to previous observations with mast cells, monomeric IgE binding did not enhance basophil survival. Interestingly, we found that IL-3 transcriptionally regulates surface levels of FcεRI in human primary basophils. Our data suggest that IL-3 but not monomeric IgE regulates FcεRI expression and cell survival in primary human basophils. Thus, blocking of IL-3 signaling in allergic effector cells might represent an interesting approach to diminish surface FcεRI levels and to prevent prolonged cell survival in allergic inflammation.