bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new Guatemalan cloud forest endemicOnthophagusLatreille, 1802 (Coleoptera: Scarabaeidae: Scarabaeinae)
Authors: Génier François 
Published: August 2017

AbstractAnew species,Onthophagus contrapositus(Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini), belonging to the New WorldO.dicraniusspecies group is described and illustrated. Photographs of cephalic and pronotal configurations of all known females are presented for the first time to ease identification. A replacement name is proposed,Onthophagus kohlmanninew name, for the secondary junior homonymOnthophagus xiphiasSolís and Kohlmann, 2003.
Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size
Authors: Rodríguez Sara M. , Valdivia Nelson 
Published: August 2017

Background
Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood.

Methods
Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence) and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts’ exposure to the parasite’s dispersive stages.

Results
Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm) than large molecrabs (<15 mm). Independently of seagull density, large molecrabs carried significantly more parasites than small molecrabs. The analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs.

Conclusions
These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation—a characteristic of indirect host-parasite interactions—and subsequent increasing mortality rates over ontogeny underpin size-dependent host-parasite dynamics.
Introduction to Quantum Key Distribution
Authors: Martin Vicente , Martinez‐Mateo Jesus , Peev Momtchil 
Published: August 2017

AbstractQuantum key distribution (QKD) is a cryptographic primitive that allows to exponentially grow a key, initially shared between the end points of a quantum channel–a communications channel over which quantum signals can be transmitted. Its security can be derived from the laws of quantum mechanics, which allow to prove the information‐theoretic security of QKD. In this entry, the process and specific characteristics of QKD are discussed. This includes the meaning of the “absolute security” character that is usually ascribed to QKD, its limitations and practical implementations.
An Overview of Cognitive Radio Networks
Authors: Kusaladharma Sachitha , Tellambura Chintha 
Published: August 2017

AbstractRadio spectrum needed for applications, such as mobile telephony, digital video broadcasting (DVB), wireless local area networks (WiFi), wireless sensor networks (ZigBee), and Internet of things, is enormous and continues to grow exponentially. Since spectrum is limited and the current usage can be inefficient, the cognitive radio paradigm has emerged to exploit the licensed and/or underutilized spectrum much more effectively. In this article, we present the motivation for and details of cognitive radio. A critical requirement for cognitive radio is the accurate, real‐time estimation of spectrum usage. We thus review various spectrum sensing techniques, propagation effects, interference modeling, spatial randomness, upper layer details, and several existing cognitive radio standards.
Elastin‐Like Polymers: Properties, Synthesis, and Applications
Authors: Rodriguez‐Cabello J. Carlos , Ibáñez Fonseca Arturo , Alonso Matilde , Poocza Leander , Cipriani Filippo , González de Torre Israel 
Published: August 2017

Abstract
Elastin‐like recombinamers (ELRs) are biological polymers that due to their flexibility in the design, their self‐assembly properties, easy chemical modification allowing the introduction of many interesting functionalities, versatility to be processed in many forms (aggregates, fibers, layers, nanoparticles, or hydrogels), and excellent cyto‐ and biocompatibility have great potential in many fields, including drug delivery, tissue engineering, protein purification, anticancer gene therapies, and nanovaccines.
In the next pages, we explore the evolution of ELRs from their ancient chemical origin to the most cutting‐edge bioproduction techniques, exploring several hosts that can be used to bioproduce them and their design versatility. We will also discuss several structures formed by ELRs and their potential medical applications.
Nanocelluloses: Science and Technology
Authors: Habibi Youssef 
Published: August 2017

AbstractSince their first isolation in 1940s by Randy, nanocrystalline cellulose attracted the attention of the materials science community. Later during 1980s, the Turbark group succeeded in extracting a new kind of cellulosic nanomaterials in the form of fibrils, stimulating further the interest toward these renewable building blocks. Nowadays, with the emergence of the green portfolio, numerous efforts are being focused on the use of materials from renewable resources, and we are attesting an unprecedented interest for nanocellulose. This interest is due to their renewability and biodegradability, in addition to their appealing intrinsic properties such as low density and outstanding mechanical properties. Moreover, nanocelluloses possess remarkable optical properties originating from their ability to self‐organize into liquid crystalline arrangements. All these notable properties allow the use of nanocelluloses in a wide range of applications. This review, not meant to be exhaustive, collates key up‐to‐date data related to the processing, morphology, and examples of their application in different domains.
Structure of the oceanic lithosphere and upper mantle north of the Gloria Fault in the eastern mid‐Atlantic by receiver function analysis
Authors: Hannemann Katrin , Krüger Frank , Dahm Torsten , Lange Dietrich 
Published: August 2017

AbstractReceiver functions (RF) have been used for several decades to study structures beneath seismic stations. Although most available stations are deployed on shore, the number of ocean bottom station (OBS) experiments has increased in recent years. Almost all OBSs have to deal with higher noise levels and a limited deployment time (∼1 year), resulting in a small number of usable records of teleseismic earthquakes. Here we use OBSs deployed as midaperture array in the deep ocean (4.5–5.5 km water depth) of the eastern mid‐Atlantic. We use evaluation criteria for OBS data and beamforming to enhance the quality of the RFs. Although some stations show reverberations caused by sedimentary cover, we are able to identify the Moho signal, indicating a normal thickness (5–8 km) of oceanic crust. Observations at single stations with thin sediments (300–400 m) indicate that a probable sharp lithosphere‐asthenosphere boundary (LAB) might exist at a depth of ∼70–80 km which is in line with LAB depth estimates for similar lithospheric ages in the Pacific. The mantle discontinuities at ∼410 km and ∼660 km are clearly identifiable. Their delay times are in agreement with PREM. Overall the usage of beam‐formed earthquake recordings for OBS RF analysis is an excellent way to increase the signal quality and the number of usable events.
An explanation of auroral intensification during the substorm expansion phase
Authors: Yao Zhonghua , Rae I. J. , Lui A. T. Y. , Murphy K. R. , Owen C. J. , Pu Z. Y. , Forsyth C. , Grodent D. , Zong Q.‐G. , Du A. M. , Kalmoni N. M. E. 
Published: August 2017

AbstractA multiple auroral onset substorm on 28 March 2010 provides an opportunity to understand the physical mechanism in generating auroral intensifications during a substorm expansion phase. Conjugate observations of magnetic fields and plasma from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft, of field‐aligned currents (FACs) from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) satellites, and from ground‐based magnetometers and aurora are all available. The comprehensive measurements allow us to further our understanding of the complicated causalities among dipolarization, FAC generation, particle acceleration, and auroral intensification. During the substorm expansion phase, the plasma sheet expanded and was perturbed leading to the generation of a slow mode wave, which modulated electron flux in the outer plasma sheet. During this current sheet expansion, field‐aligned currents formed, and geomagnetic perturbations were simultaneously detected by ground‐based instruments. However, a magnetic dipolarization did not occur until about 3 min later in the outer plasma sheet observed by THEMIS‐A spacecraft (THA). We believe that this dipolarization led to an efficient Fermi acceleration to electrons and consequently the cause of a significant auroral intensification during the expansion phase as observed by the All‐Sky Imagers (ASIs). This Fermi acceleration mechanism operating efficiently in the outer plasma sheet during the expansion phase could be a common explanation of the poleward auroral development after substorm onset. These results also show a good agreement between the upward FAC derived from AMPERE measurements and the auroral brightening observed by the ASIs.
Eddy heat flux across the Antarctic Circumpolar Current estimated from sea surface height standard deviation
Authors: Foppert Annie , Donohue Kathleen A. , Watts D. Randolph , Tracey Karen L. 
Published: August 2017

AbstractEddy heat flux (EHF) is a predominant mechanism for heat transport across the zonally unbounded mean flow of the Antarctic Circumpolar Current (ACC). Observations of dynamically relevant, divergent, 4 year mean EHF in Drake Passage from the cDrake project, as well as previous studies of atmospheric and oceanic storm tracks, motivates the use of sea surface height (SSH) standard deviation, H*, as a proxy for depth‐integrated, downgradient, time‐mean EHF (
) in the ACC. Statistics from the Southern Ocean State Estimate corroborate this choice and validate throughout the ACC the spatial agreement between H* and
seen locally in Drake Passage. Eight regions of elevated
are identified from nearly 23.5 years of satellite altimetry data. Elevated cross‐front exchange usually does not span the full latitudinal width of the ACC in each region, implying a hand‐off of heat between ACC fronts and frontal zones as they encounter the different
hot spots along their circumpolar path. Integrated along circumpolar streamlines, defined by mean SSH contours, there is a convergence of
in the ACC: 1.06 PW enters from the north and 0.02 PW exits to the south. Temporal trends in low‐frequency [EHF] are calculated in a running‐mean sense using H* from overlapping 4 year subsets of SSH. Significant increases in downgradient [EHF] magnitude have occurred since 1993 at Kerguelen Plateau, Southeast Indian Ridge, and the Brazil‐Malvinas Confluence, whereas the other five
hot spots have insignificant trends of varying sign.
Neurite dispersion: a new marker of multiple sclerosis spinal cord pathology?
Authors: Grussu Francesco , Schneider Torben , Tur Carmen , Yates Richard L. , Tachrount Mohamed , Ianuş Andrada , Yiannakas Marios C. , Newcombe Jia , Zhang Hui , Alexander Daniel C. , DeLuca Gabriele C. , Gandini Wheeler‐Kingshott Claudia A. M. 
Published: August 2017

AbstractObjectiveConventional magnetic resonance imaging (MRI) of the multiple sclerosis spinal cord is limited by low specificity regarding the underlying pathological processes, and new MRI metrics assessing microscopic damage are required. We aim to show for the first time that neurite orientation dispersion (i.e., variability in axon/dendrite orientations) is a new biomarker that uncovers previously undetected layers of complexity of multiple sclerosis spinal cord pathology. Also, we validate against histology a clinically viable MRI technique for dispersion measurement (neurite orientation dispersion and density imaging,NODDI), to demonstrate the strong potential of the new marker.MethodsWe related quantitative metrics from histology and MRI in four post mortem spinal cord specimens (two controls; two progressive multiple sclerosis cases). The samples were scanned at high field, obtaining maps of neurite density and orientation dispersion from NODDI and routine diffusion tensor imaging (DTI) indices. Histological procedures provided markers of astrocyte, microglia, myelin and neurofilament density, as well as neurite dispersion.ResultsWe report from both NODDI and histology a trend toward lower neurite dispersion in demyelinated lesions, indicative of reduced neurite architecture complexity. Also, we provide unequivocal evidence that NODDI‐derived dispersion matches its histological counterpart (P < 0.001), while DTI metrics are less specific and influenced by several biophysical substrates.InterpretationNeurite orientation dispersion detects a previously undescribed and potentially relevant layer of microstructural complexity of multiple sclerosis spinal cord pathology. Clinically feasible techniques such as NODDI may play a key role in clinical trial and practice settings, as they provide histologically meaningful dispersion indices.
Space‐Confined Chemical Vapor Deposition Synthesis of Ultrathin HfS2 Flakes for Optoelectronic Application
Authors: Yan Chaoyi , Gan Lin , Zhou Xing , Guo Jun , Huang Wenjuan , Huang Jianwen , Jin Bao , Xiong Jie , Zhai Tianyou , Li Yanrong 
Published: August 2017

AbstractDue to the predicted excellent electronic properties superior to group VIB (Mo and W) transition metal dichalcogenides (TMDs), group IVB TMDs have enormous potential in nanoelectronics. Here, the synthesis of ultrathin HfS2 flakes via space‐confined chemical vapor deposition, realized by an inner quartz tube, is demonstrated. Moreover, the effect of key growth parameters including the dimensions of confined space and deposition temperature on the growth behavior of products is systematically studied. Typical as‐synthesized HfS2 is a hexagonal‐like flake with a smallest thickness of ≈1.2 nm (bilayer) and an edge size of ≈5 µm. The photodetector based on as‐synthesized HfS2 flakes demonstrates excellent optoelectronic performance with a fast photoresponse time (55 ms), which is attributed to the high‐quality crystal structure obtained at a high deposition temperature and the ultraclean interface between HfS2 and the mica substrate. With such properties HfS2 holds great potential for optoelectronics applications.
Functional Hybrid Nanopaper by Assembling Nanofibers of Cellulose and Sepiolite
Authors: González del Campo M. Mar , Darder Margarita , Aranda Pilar , Akkari Marwa , Huttel Yves , Mayoral Alvaro , Bettini Jefferson , Ruiz‐Hitzky Eduardo 
Published: August 2017

AbstractFunctional heterofibrous hybrid materials are prepared in an integrative approach from aqueous dispersions of nanofibrillated cellulose and sepiolite by applying high shear homogenization and ultrasound irradiation. Both types of nanofibers remain physically cross‐linked forming homogeneous and very stable high‐viscosity gels that can be shaped as films and considered as “hybrid nanopapers” as well. The presence of sepiolite modifies the surface roughness of the films resulting from the casting process, which can be rendered hydrophobic, as the hydrophilic characteristics of both components resulted modulated. In addition, these fibrous hybrid systems can benefit from the properties provided by the two components, such as mechanical behavior, surface properties, and chemical reactivity. Moreover, further assembly of these hybrid nanopapers to other particulate solids, such as carbon nanotubes, magnetite, or ZnO nanoparticles, results in multifunctional hybrid nanopapers, opening a versatile way for developing other numerous organic–inorganic materials of interest in diverse applications.
Gold Layers on Elastomers near the Critical Stress Regime
Authors: Osmani Bekim , Deyhle Hans , Töpper Tino , Pfohl Thomas , Müller Bert 
Published: August 2017

AbstractSoft electrodes are essential components of soft robotics, tunable optics, microfluidics, flexible electronics, neuroprosthetics, and dielectric elastomeric transducers (DET). The two main paths employed to increase an electrode's compliance involve the manipulation of either its intrinsic material properties or its structural features, such as the introduction of wrinkles, which arise above the critical stress of metal films on elastomeric substrates. Herein, this study demonstrates that the interplay between functionalized oxygen‐plasma‐treated polydimethylsiloxane (PDMS) films and sputter‐deposited metal electrodes allows for conserving compressive stress within the electrode. Insulator–metal transition already occurs for 10 nm thin Au electrodes, and below this electrode thickness, atomic force microscopy nanoindentations with sub‐micrometer resolutions reveal no stiffening of the Au/PDMS heterostructure. These DETs exhibit reduced electrocreasing, which is a significant contributor to structural failure, while their enhanced dielectric breakdown field of up to 120 V µm–1 enables calculated strains above 10% — a crucial requirement for thin‐film DETs such as those used for artificial muscles.
Photothermally Triggered Shape‐Adaptable 3D Flexible Electronics
Authors: Du Xuemin , Cui Huanqing , Sun Bin , Wang Juan , Zhao Qilong , Xia Kai , Wu Tianzhun , Humayun Mark S. 
Published: August 2017

AbstractEffective contact between flexible electronics and soft biological tissues, which may have different surface curvatures, for medical applications has long been a challenge. Here, this study reports a strategy for preparing shape‐adaptable 3D flexible electronics by combining photothermally responsive poly(N‐isopropylacrylamide)/gold nanorods (PNIPAM@AuNRs) composite hydrogels with conventional flexible microelectrode arrays (fMEAs). The fMEAs‐functionalized composite hydrogels are shape‐adaptable and can accommodate different surface geometries. Triggered remotely in seconds by near‐infrared (NIR) light at a wavelength of 808 nm, the composite hydrogel layer is grafted on the back side of the fMEAs shrinks to induce a desirable shape transformation in the fMEAs. By patterning the responsive hydrogel layer, the fMEAs can exhibit planar‐to‐twisted structural transformations in response to an external stimulus as a result of differential shrinkage and their elastic moduli. This strategy not only enables fMEAs to modify their shape to remotely accommodate unpredictable shapes of different surfaces by irradiation with NIR but also provides multiple architectures of 3D fMEAs upon stimulation. These photothermally responsive composite‐hydrogel‐based fMEAs may provide new methods for achieving wearable and implantable devices and facilitate deeper investigations into biological systems.
Decarbonylative Phosphorylation of Amides by Palladium and Nickel Catalysis: The Hirao Cross‐Coupling of Amide Derivatives
Authors: Liu Chengwei , Szostak Michal 
Published: August 2017

AbstractConsidering the ubiquity of organophosphorus compounds in organic synthesis, pharmaceutical discovery agrochemical crop protection and materials chemistry, new methods for their construction hold particular significance. A conventional method for the synthesis of C−P bonds involves cross‐coupling of aryl halides and dialkyl phosphites (the Hirao reaction). We report a catalytic deamidative phosphorylation of a wide range of amides using a palladium or nickel catalyst giving aryl phosphonates in good to excellent yields. The present method tolerates a wide range of functional groups. The reaction constitutes the first example of a transition‐metal‐catalyzed generation of C−P bonds from amides. This redox‐neutral protocol can be combined with site‐selective conventional cross‐coupling for the regioselective synthesis of potential pharmacophores. Mechanistic studies suggest an oxidative addition/transmetallation pathway. In light of the importance of amides and phosphonates as synthetic intermediates, we envision that this Pd and Ni‐catalyzed C−P bond forming method will find broad application.
Dimethyltin(IV) complexes derived from hydroxamic acid and acylhydrazone ligands: Synthesis, DNA/bovine serum albumin interaction and cytotoxicity
Authors: Liu Kai , Chang Guoliang , Yan Hui , Li Zhen , Hong Min , Niu Meiju 
Published: August 2017

Two novel dimethyltin(IV) complexes, Me2SnL1(PyCOO)(MeOH) (1) and Me2SnL2 (2) (HL1 = 4‐pyridinehydroxamic acid and H2L2 = 2‐hydroxy‐N′‐[(2‐hydroxy‐5‐chlorophenyl)methylidene]benzoylhydrazone), were synthesized and characterized using elemental analyses, Fourier transform infrared and NMR (1H, 13C) spectroscopies and single‐crystal X‐ray diffraction. In complex 1 the geometry around the tin atom is a six‐coordinated distorted octahedral configuration, while complex 2 exhibits five‐coordinated distorted trigonal bipyramid geometry. Preliminary in vitro cytotoxicity studies with two human cancer cell lines (HeLa and A549) using MTT assay show that complex 1 is more potent than complex 2. The interactions of the two complexes with calf thymus DNA and bovine serum albumin were also investigated using UV–visible absorption spectral, thermal denaturation and viscosity measurements and docking analysis. Investigations indicate that the structures of the mixed ligands play an important role in the properties of the dimethyltin(IV) complexes, and, to some extent, the antitumor activities of the complexes are partly related to interactions with DNA and some proteins in cancer cells.
Dynamic Self‐Assembly of Gold/Polymer Nanocomposites: pH‐Encoded Switching between 1D Nanowires and 3D Nanosponges
Authors: Zhang Qi , Xu Tian‐Yi , Zhao Cai‐Xin , Jin Wei‐Hang , Wang Qian , Qu Da‐Hui 
Published: August 2017

AbstractThe design of tunable dynamic self‐assembly of nanoparticles with switchable assembled dimensions and morphologies is a challenging goal whose realization is vital for the evolution of smart nanomaterials. Herein, we report on chitosan polymer as an effective supramolecular “glue” for aldehyde‐modified Au nanoparticles to reversibly modulate the states of self‐assembled nanocomposites. By simultaneous integration of dynamic covalent Schiff base interactions and noncovalent hydrogen bonds, the chitosan/Au nanocomposites could reversibly transform their assembled morphologies from one‐dimensional nanowires to three‐dimensional nanosponges in response to the variation of pH value. Moreover, the obtained nanosponges could be used as an efficient pH‐controlled cargo release system.