bluuebunny/crossref_metadata_2025 huggingface dataset:
Relative Influence of Timing and Accumulation of Snow on Alpine Land Surface Phenology
Authors: Xie Jing , Kneubühler Mathias , Garonna Irene , de Jong Rogier , Notarnicola Claudia , De Gregorio Ludovica , Schaepman Michael E.
Published: February 2018

Timing and accumulation of snow are among the most important phenomena influencing land surface phenology in mountainous ecosystems. However, our knowledge on their influence on alpine land surface phenology is still limited, and much remains unclear as to which snow metrics are most relevant for studying this interaction. In this study, we analyzed five snow and phenology metrics, namely, timing (snow cover duration (SCD) and last snow day), accumulation of snow (mean snow water equivalent, SWEm), and mountain land surface phenology (start of season and length of season) in the Swiss Alps during the period 2003–2014. We examined elevational and regional variations in the relationships between snow and alpine land surface phenology metrics using multiple linear regression and relative weight analyses and subsequently identified the snow metrics that showed strongest associations with variations in alpine land surface phenology of natural vegetation types. We found that the relationships between snow and phenology metrics were pronounced in high‐elevational regions and alpine natural grassland and sparsely vegetated areas. Start of season was influenced primarily by SCD, secondarily by SWEm, while length of season was equally affected by SCD and SWEm across different elevational bands. We conclude that SCD plays the most significant role compared to other snow metrics. Future variations of snow cover and accumulation are likely to influence alpine ecosystems, for instance, their species composition due to changes in the potential growing season. Also, their spatial distribution may change as a response to the new environmental conditions if these prove persistent.
Necromass as a Limited Source of Energy for Microorganisms in Marine Sediments
Authors: Bradley James A. , Amend Jan P. , LaRowe Douglas E.
Published: February 2018

The in situ production of necromass and its role as a power source in sustaining heterotrophic microorganisms in marine sediments has never been quantified. Here we quantify the power availability from necromass oxidation to living microorganisms buried in marine sediments over millions of years, first in the oligotrophic South Pacific Gyre (SPG) and second on a global scale. We calculate that power from autochthonously produced necromass in the upper meter of sediment underlying SPG provides only a small fraction (~0.02%) of the maintenance power demand of the living community (1.9 × 10−19 W cell−1). Power from necromass oxidation diminishes considerably with increasing sediment depth (and thus sediment age). Alternatively, the oxidation of allochthonous organic matter, and of radiolytic H2, provides power equivalent to or in excess of the maintenance demands of living microorganisms at SPG. On a global scale, necromass may support the maintenance power demand of 2 to 13% of the microbial community in relatively young sediments (<10,000 years) when it is oxidized with SO42− and O2, respectively. However, in older sediments, the power supplied by necromass is negligible (<0.01%). Nevertheless, the oxidation of a single dead cell per year provides sufficient power to support the maintenance demands of dozens to thousands of cells in low‐energy marine sediments. This raises the possibility that the production and oxidation of necromass may provide a mechanism for non‐growing microorganisms to endure unfavorable, low‐energy settings over geological timescales.
Seasonal Surface Loading Helps Constrain Short‐Term Viscosity of the Asthenosphere
Authors: Clarke Peter J.
Published: February 2018

Earth materials may display a range of rheological behaviors at different depths and over different timescales. The situation is particularly complex for postseismic relaxation in the uppermost mantle and lower crust, where it can be difficult to distinguish widespread viscous behavior from earthquake afterslip or localized deformation in shear zones over timescales of weeks to decades. By analyzing geodetic observations of seasonal surface mass loads and Earth's surface deformation in response, Chanard et al. (2018, https://doi.org/10.1002/2017GL076451) have established a globally averaged lower bound of 5 × 1017 Pa s for the transient viscosity of a Burgers‐rheology asthenosphere. This implies that lower viscosities inferred by some studies of postseismic relaxation must result from local departures from this global value, or be an artifact of additional afterslip or shear zone deformation.
Peptide Amphiphile Nanostructures for Targeting of Atherosclerotic Plaque and Drug Delivery
Authors: So Miranda M. , Mansukhani Neel A. , Peters Erica B. , Albaghdadi Mazen S. , Wang Zheng , Rubert Pérez Charles M. , Kibbe Melina R. , Stupp Samuel I.
Published: February 2018

Coassembled peptide amphiphile nanofibers designed to target atherosclerotic plaque and enhance cholesterol efflux are shown to encapsulate and deliver a liver X receptor agonist to increase efflux from murine macrophages in vitro. Fluorescence microscopy reveals that the nanofibers, which display an apolipoprotein‐mimetic peptide, localize at plaque sites in low density lipoprotein receptor knockout (LDLR KO) mice with or without the encapsulated molecule, while nanofibers displaying a scrambled, nontargeting peptide sequence do not demonstrate comparable binding. These results show that nanofibers functionalized with apolipoprotein‐mimetic peptides may be effective vehicles for intravascular targeted drug delivery to treat atherosclerosis.
Enhanced Tensile Properties and Fracture Reliability of Cu‐Based Amorphous Wires via Pr‐Doping
Authors: Liu Jingshun , Zhang Yun , Wang Qixiang , Wu Mengjun , Nan Ding , Shen Hongxian , Peng Huaxin
Published: February 2018

This paper proposed a novel wire‐preparation technique integrated Pr‐doping to improve the tensile properties of rotation‐dipped Cu‐based amorphous wires, and systematically investigates the fracture reliability and fracture mechanism of them. Meanwhile, the mechanical properties are evaluated through tensile tests, and their fracture reliability is estimated by using two‐ and three‐parameter Weibull statistics and lognormal plotting. Experimental results indicate that the Cu‐based wires have entirely amorphous microstructure, a smooth surface and circular cross‐section, and exhibit a relatively higher working temperature. Both the Cu–Zr–Ti and Cu–Zr–Ti–Pr wires represent the higher tensile strengths. In comparison with Cu–Zr–Ti wires, Cu–Zr–Ti–Pr wires possess a maximum tensile strength and ductility of 2.07 GPa and 0.92%, respectively. Meanwhile, Cu–Zr–Ti–Pr wires also exhibit a larger Weibull modulus, which stand for the fracture reliability in Weibull statistics, and higher fracture threshold stress (≈1.42 GPa). Essentially, both fracture of two types of Cu‐based wires take on a brittle fracture characteristic with crack extension region and shear deformation region, and the improved tensile property after Pr‐doping is probably attributed to the strengthened interaction of shear bands and micropore gathering (vein‐shaped pattern forming). Therefore, it can be concluded that the Cu‐based microwires with enhanced tensile property as the ideal candidates including miniaturized components are used for potential electronics engineering and biomedical implantation applications.
Bilayer SiO2 Nanorod Arrays as Omnidirectional and Thermally Stable Antireflective Coating
Authors: Khan Sadaf B. , Wu Hui , Li Jianghao , Chen Limin , Zhang Zhengjun
Published: February 2018

Nature instigates researchers significantly in imitating to engender comparable properties using artificial methods, which unlocks developing trend in material science and engineering progress. Fabricating graded‐index nanostructures is an effective approach to tune and generate similar properties artificially such as the moth's eye antireflectance (AR) or lotus like superhydrophobicity. Herein, Bilayer AR coatings with periodically arranged SiO2 hierarchical nanostructures resembling moth eyes are fabricated on dense SiO2 matrix base layer using the versatile route of glancing angle deposition technique (GLAD). The refractive indices of monolayer SiO2 are tuned from 1.46 to 1.08 by changing the deposition angle (α) from 0 to 88°. The fabricated bilayer SiO2 AR (BSAR) film possess high optical omnidirectional broadband transparency and tunability at a desired wavelength range showing <1% reflectance. The present AR design is flexible and practically applicable to various supporting substrate materials (η varies from 1.45 to 1.9). Furthermore, the omnidirectional BSAR films show multiple functions including enhanced mechanical strength, the thermal stability (up to 300 °C), and hydrophobic capability with a water contact angle (CA) of 147° to withstand under humid environment. This multipurpose coating provides an intriguing route in optics field for imminent research.
Room‐Temperature Electrochemical Conversion of Metal–Organic Frameworks into Porous Amorphous Metal Sulfides with Tailored Composition and Hydrogen Evolution Activity
Authors: He Wenhui , Ifraemov Raya , Raslin Arik , Hod Idan
Published: February 2018

The conversion of metal–organic frameworks (MOFs) into inorganic nanomaterials is considered as an attractive means to produce highly efficient electrocatalysts for alternative‐energy related applications. Yet, traditionally employed MOF‐conversion conditions (e.g., pyrolysis) commonly involve multiple complex high‐temperature reaction processes, which often make it challenging to control the composition, pore structure, and active‐sites of the MOF‐derived catalysts. Herein, a general, simple, room‐temperature method is presented for a controlled electrochemical conversion of MOF (EC‐MOF) films into porous, amorphous metal sulfides (a‐MSx). Detailed X‐ray photoelectron spectroscopy analysis and control over independent EC‐MOF parameters (e.g., scan‐rate and potential window) enable to gain insights on the MOF‐conversion mechanisms, and in turn to fine‐tune the porosity and composition of the obtained MSx. As a result, a highly active amorphous cobalt sulfide (a‐CoSx) electrocatalyst can be designed for hydrogen evolution reaction in neutral pH. Furthermore, the adjustable nature of the EC‐MOF method allows to draw conclusions about the correlation between the concentration of catalytically active species ( sites) and the hydrogen evolution properties of the a‐CoSx. Given the method's generality and the diversity of available MOF structures, EC‐MOF provides a compelling platform for a rational design of a wide variety of active electrocatalytic materials.
Excitation‐Dependent Theranostic Nanosheet for Cancer Treatment
Authors: Guan Shanyue , Yang Di , Weng Yangziwan , Lu Heng , Meng Xiangmin , Qu Xiaozhong , Zhou Shuyun
Published: February 2018

In this work, a novel ruthenium complex loaded monolayer layered double hydroxide (LDH) (denoted as Ru(C‐bpy)2/mLDH) as supramolecular nanosensor is synthesized, which is greatly exclusive to the hypoxic tumor microenvironment. The Ru(C‐bpy)2/mLDH ultrathin sheet displays not only enhanced luminescence lifetime compared to the parent Ru(C‐bpy)2 alone, but also improved oxygen responsibility under an excitation of 488 or 800 nm. Moreover, the Ru(C‐bpy)2/mLDH is possessed of two‐photon fluorescence imaging ability under the 800 nm irradiation. In addition, the Ru(C‐bpy)2/mLDH can generate singlet oxygen with a high yield (φ∆) of 0.28 under the 520 nm irradiation, while the φ∆ of Ru(C‐bpy)2 is 0.19. Therefore, the Ru(C‐bpy)2/mLDH can be applied as a supramolecular theranostic agent with light‐switchable cancer imaging and photodynamic therapy properties.
Uncovering the Circular Polarization Potential of Chiral Photonic Cellulose Films for Photonic Applications
Authors: Zheng Hongzhi , Li Wanru , Li Wen , Wang Xiaojun , Tang Zhiyong , Zhang Sean Xiao‐An , Xu Yan
Published: February 2018

Circularly polarized light (CPL) is central to photonic technologies. A key challenge lies in developing a general route for generation of CPL with tailored chiroptical activity using low‐cost raw materials suitable for scale‐up. This study presents that cellulose films with photonic bandgaps (PBG) and left‐handed helical sense have an intrinsic ability for circular polarization leading to PBG‐based CPL with extraordinary |g | values, well‐defiend handedness, and tailorable wavelength by the PBG change. Using such cellulose films, incident light ranging from near‐UV to near‐IR can be transformed to passive L‐CPL and R‐CPL with viewing‐side‐dependent handedness and |g | values up to 0.87, and spontaneous emission transformed to R‐CPL emission with |g | values up to 0.68. Unprecedented evidence is presented with theoretical underpinning that the PBG effect can stimulate the R‐CPL emission. The potential of cellulose‐based CPL films for polarization‐based encryption is illustrated. The evaporation‐induced self‐assembly coupled with nanoscale mesogens of cellulose nanocrystals opens new venues for technological advances and enables a versatile strategy for rational design and scalable manufacturing of organic and inorganic CPL films for photonic applications.
Liquid‐Crystalline Dynamic Networks Doped with Gold Nanorods Showing Enhanced Photocontrol of Actuation
Authors: Lu Xili , Zhang Hu , Fei Guoxia , Yu Bing , Tong Xia , Xia Hesheng , Zhao Yue
Published: February 2018

A near‐infrared‐light (NIR)‐ and UV‐light‐responsive polymer nanocomposite is synthesized by doping polymer‐grafted gold nanorods into azobenzene liquid‐crystalline dynamic networks (AuNR‐ALCNs). The effects of the two different photoresponsive mechanisms, i.e., the photochemical reaction of azobenzene and the photothermal effect from the surface plasmon resonance of the AuNRs, are investigated by monitoring both the NIR‐ and UV‐light‐induced contraction forces of the oriented AuNR‐ALCNs. By taking advantage of the material's easy processability, bilayer‐structured actuators can be fabricated to display photocontrollable bending/unbending directions, as well as localized actuations through programmed alignment of azobenzene mesogens in selected regions. Versatile and complex motions enabled by the enhanced photocontrol of actuation are demonstrated, including plastic “athletes” that can execute light‐controlled push‐ups or sit‐ups, and a light‐driven caterpillar‐inspired walker that can crawl forward on a ratcheted substrate at a speed of about 13 mm min‐1. Moreover, the photomechanical effects arising from the two types of light‐triggered molecular motion, i.e., the trans–cis photoisomerization and a liquid‐crystalline–isotropic phase transition of the azobenzene mesogens, are added up to design a polymer “crane” that is capable of performing light‐controlled, robot‐like, concerted macroscopic motions including grasping, lifting up, lowering down, and releasing an object.
Reversible and Precisely Controllable p/n‐Type Doping of MoTe2 Transistors through Electrothermal Doping
Authors: Chang Yuan‐Ming , Yang Shih‐Hsien , Lin Che‐Yi , Chen Chang‐Hung , Lien Chen‐Hsin , Jian Wen‐Bin , Ueno Keiji , Suen Yuen‐Wuu , Tsukagoshi Kazuhito , Lin Yen‐Fu
Published: February 2018

Precisely controllable and reversible p/n‐type electronic doping of molybdenum ditelluride (MoTe2) transistors is achieved by electrothermal doping (E‐doping) processes. E‐doping includes electrothermal annealing induced by an electric field in a vacuum chamber, which results in electron (n‐type) doping and exposure to air, which induces hole (p‐type) doping. The doping arises from the interaction between oxygen molecules or water vapor and defects of tellurium at the MoTe2 surface, and allows the accurate manipulation of p/n‐type electrical doping of MoTe2 transistors. Because no dopant or special gas is used in the E‐doping processes of MoTe2, E‐doping is a simple and efficient method. Moreover, through exact manipulation of p/n‐type doping of MoTe2 transistors, quasi‐complementary metal oxide semiconductor adaptive logic circuits, such as an inverter, not or gate, and not and gate, are successfully fabricated. The simple method, E‐doping, adopted in obtaining p/n‐type doping of MoTe2 transistors undoubtedly has provided an approach to create the electronic devices with desired performance.
High‐Performance n‐Channel Organic Transistors Using High‐Molecular‐Weight Electron‐Deficient Copolymers and Amine‐Tailed Self‐Assembled Monolayers
Authors: Wang Yang , Hasegawa Tsukasa , Matsumoto Hidetoshi , Mori Takehiko , Michinobu Tsuyoshi
Published: February 2018

While high‐performance p‐type semiconducting polymers are widely reported, their n‐type counterparts are still rare in terms of quantity and quality. Here, an improved Stille polymerization protocol using chlorobenzene as the solvent and palladium(0)/copper(I) as the catalyst is developed to synthesize high‐quality n‐type polymers with number‐average molecular weight up to 105 g mol−1. Furthermore, by sp2‐nitrogen atoms (sp2‐N) substitution, three new n‐type polymers, namely, pBTTz, pPPT, and pSNT, are synthesized, and the effect of different sp2‐N substitution positions on the device performances is studied for the first time. It is found that the incorporation of sp2‐N into the acceptor units rather than the donor units results in superior crystalline microstructures and higher electron mobilities. Furthermore, an amine‐tailed self‐assembled monolayer (SAM) is smoothly formed on a Si/SiO2 substrate by a simple spin‐coating technique, which can facilitate the accumulation of electrons and lead to more perfect unipolar n‐type transistor performances. Therefore, a remarkably high unipolar electron mobility up to 5.35 cm2 V−1 s−1 with a low threshold voltage (≈1 V) and high on/off current ratio of ≈107 is demonstrated for the pSNT‐based devices, which are among the highest values for unipolar n‐type semiconducting polymers.
A Printing‐Centric Approach to the Electrostatic Modification of Polymer/Clay Composites for Use in 3D Direct‐Ink Writing
Authors: Rauzan Brittany M. , Lehman Sean E. , McCracken Joselle M. , Lee Jonghun , Lin Xiao‐Min , Sandy Alec , Narayanan Suresh , Rogers Simon A. , Nuzzo Ralph G.
Published: February 2018

Polymer/clay composite inks are exceptionally useful materials for fabrication processes based on 3D direct‐ink writing, however, there remains an insufficient understanding of how their physiochemical dynamics impact printability. Using a model system, N‐isopropylacrylamide/Laponite, the electrostatic interactions between Laponite platelets are modified to tune critical rheological properties in order to improve printability. Rheological measurements and X‐ray scattering experiments are carried out to monitor the nano/micro‐structural dynamics and complex physicochemical interactions of Laponite as it impacts complex modulus in the linear region, flow behavior, thixotropy, and yield stress of the composite ink. Modification of the electrostatic interactions between platelets reduces the yield stress of the material, while maintaining a complex microstructure that allows for sufficient recovery times upon removal of stress to form stable, and thus printable, filaments. A printing‐centric approach is established based on a fundamental understanding of electrostatic inter‐particle interactions, harnessing the innate microstructure of Laponite in 3D direct‐ink writing of composites.
Fabrication of Nearly‐Hyperuniform Substrates by Tailored Disorder for Photonic Applications
Authors: Piechulla Peter M. , Muehlenbein Lutz , Wehrspohn Ralf B. , Nanz Stefan , Abass Aimi , Rockstuhl Carsten , Sprafke Alexander
Published: February 2018

Disordered optical substrates play a key role in photonic applications. Furthermore, structures of correlated, in particular hyperuniform, disorder are an emerging new class of photonic material enabling new ways of k‐space engineering. Yet, there are little to no feasible technologies that allow fabrication of tailored disordered structures to facilitate a tailored optical response. This work reports on a scalable method to fabricate substrates of tailored correlated disorder by self‐stabilized colloid deposition. Easy‐to‐access experimental parameters allow to tune lateral and vertical statistics of the disordered patterns. In addition, a model is presented that allows accurate prediction of mono‐ as well as polydisperse particle patterns. Correlation of disorder of the prepared patterns is investigated by means of the structure factor and optical measurements.
The Nature of Ion‐Pair Recognition by Tetra‐phosphonate Calix[4]pyrroles
Authors: Wang Teng , Liu Jingjing
Published: February 2018

The tetra‐phosphonate calix[4]pyrroles can function as multitopic receptors for ion‐pair recognition, and this process is mainly driven by noncovalent interactions (NCIs). In the present contribution, the NCIs in ion‐pair recognition by two representative receptors iiii and oooo, which differ in the relative orientation of the phosphonate groups, were explored by density functional theory calculations. The decomposition of the interaction energy suggests that electrostatic plays a dominant role in ion‐pair recognition, and it dictates that contact and separated arrangements are the favorable binding modes for iiii and oooo receptors, respectively. Furthermore, the calculation results predict that iiii receptors show superior binding affinities for organic chloride salts compared to oooo receptors. This study reveals the nature of ion‐pair recognition by tetra‐phosphonate calix[4]pyrroles, while providing valuable insights into the design of novel calix[4]pyrrole‐based ion‐pair receptors.
Boosting the Potassium Storage Performance of Alloy‐Based Anode Materials via Electrolyte Salt Chemistry
Authors: Zhang Qing , Mao Jianfeng , Pang Wei Kong , Zheng Tian , Sencadas Vitor , Chen Yuanzhen , Liu Yajie , Guo Zaiping
Published: February 2018

Potassium‐ion batteries (PIBs) are promising energy storage systems because of the abundance and low cost of potassium. The formidable challenge is to develop suitable electrode materials and electrolytes for accommodating the relatively large size and high activity of potassium. Herein, Bi‐based materials are reported as novel anodes for PIBs. Nanostructural design and proper selection of the electrolyte salt have been used to achieve excellent cycling performance. It is found that the potassiation of Bi undergoes a solid‐solution reaction, followed by two typical two‐phase reactions, corresponding to Bi ↔ Bi(K) and Bi(K) ↔ K5Bi4 ↔ K3Bi, respectively. By choosing potassium bis(fluorosulfonyl)imide (KFSI) to replace potassium hexafluorophosphate (KPF6) in carbonate electrolyte, a more stable solid electrolyte interphase layer is achieved and results in notably enhanced electrochemical performance. More importantly, the KFSI salt is very versatile and can significantly promote the electrochemical performance of other alloy‐based anode materials, such as Sn and Sb.
Tuning Electronic Structure of NiFe Layered Double Hydroxides with Vanadium Doping toward High Efficient Electrocatalytic Water Oxidation
Authors: Li Pengsong , Duan Xinxuan , Kuang Yun , Li Yaping , Zhang Guoxin , Liu Wen , Sun Xiaoming
Published: February 2018

Binary NiFe layer double hydroxide (LDH) serves as a benchmark non‐noble metal electrocatalyst for the oxygen evolution reaction, however, it still needs a relatively high overpotential to achieve the threshold current density. Herein the catalyst's electronic structure is tuned by doping vanadium ions into the NiFe LDHs laminate forming ternary NiFeV LDHs to reduce the onset potential, achieving unprecedentedly efficient electrocatalysis for water oxidation. Only 1.42 V (vs reversible hydrogen electrode (RHE), ≈195 mV overpotential) is required to achieve catalytic current density of 20 mA cm−2 with a small Tafel slope of 42 mV dec−1 in 1 m KOH solution, which manifests the best of NiFe‐based catalysts reported till now. Electrochemical analysis and density functional theory +U simulation indicate that the high catalytic activity of NiFeV LDHs mainly attributes to the vanadium doping which can modify the electronic structure and narrow the bandgap thereby bring enhanced conductivity, facile electron transfer, and abundant active sites.
Heat/mass transfer from a neutrally buoyant sphere by mixed natural and forced convection in a simple shear flow
Authors: Yuan Bing , Yang Chao , Mao Zai‐Sha , Yin Xiaolong , Koch Donald L.
Published: February 2018

Building on the work of Yang et al. in 2011, the finite difference method and the Boussinesq approximation were applied to solve the time‐dependent Navier‐Stokes, convection diffusion and continuity equations in spherical coordinates. An idealized condition, the mass transfer from a neutrally buoyant sphere in a horizontal simple shear flow with natural convection was numerically simulated for the first time in this work. In the hybrid transfer case, the outwardly spiraling streamlines enhanced the transfer process, but the counter‐gravity spiraling streamlines near the sphere hindered the natural convection and the spatial dilution action weakened the natural convection transfer process. These competing effects led to nonmonotonic behavior of the Nusselt number with Reynolds number. Results from these previously undocumented cases were summarized into correlations for predicting Nusselt numbers at finite Reynolds numbers for various Grashof and Prandtl numbers. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2816–2827, 2018
Total duplication of the small single copy region in the angiosperm plastome: Rearrangement and inverted repeat instability in Asarum
Authors: Sinn Brandon T. , Sedmak Dylan D. , Kelly Lawrence M. , Freudenstein John V.
Published: February 2018

Premise of the Study

As more plastomes are assembled, it is evident that rearrangements, losses, intergenic spacer expansion and contraction, and syntenic breaks within otherwise functioning plastids are more common than was thought previously, and such changes have developed independently in disparate lineages. However, to date, the magnoliids remain characterized by their highly conserved plastid genomes (plastomes).

Methods

Illumina HiSeq and MiSeq platforms were used to sequence the plastomes of Saruma henryi and those of representative species from each of the six taxonomic sections of Asarum. Sequenced plastomes were compared in a phylogenetic context provided by maximum likelihood and parsimony inferences made using an additional 18 publicly available plastomes from early‐diverging angiosperm lineages.

Key Results

In contrast to previously published magnoliid plastomes and the newly sequenced Saruma henryi plastome published here, Asarum plastomes have undergone extensive disruption and contain extremely lengthy AT‐repeat regions. The entirety of the small single copy region (SSC) of A. canadense and A. sieboldii var. sieboldii has been incorporated into the inverted repeat regions (IR), and the SSC of A. delavayi is only 14 bp long. All sampled Asarum plastomes share an inversion of a large portion of the large single copy region (LSC) such that trnE‐UUC is adjacent to the LSC‐IR boundary.

Conclusions

Plastome divergence in Asarum appears to be consistent with trends seen in highly rearranged plastomes of the monocots and eudicots. We propose that plastome instability in Asarum is due to repetitive motifs that serve as recombinatory substrates and reduce genome stability.
Herbarium specimens show patterns of fruiting phenology in native and invasive plant species across New England
Authors: Gallinat Amanda S. , Russo Luca , Melaas Eli K. , Willis Charles G. , Primack Richard B.
Published: February 2018

Premise of the Study

Patterns of fruiting phenology in temperate ecosystems are poorly understood, despite the ecological importance of fruiting for animal nutrition and seed dispersal. Herbarium specimens represent an under‐utilized resource for investigating geographical and climatic factors affecting fruiting times within species, patterns in fruiting times among species, and differences between native and non‐native invasive species.

Methods

We examined over 15,000 herbarium specimens, collected and housed across New England, and found 3159 specimens with ripe fruits, collected from 1849–2013. We examined patterns in fruiting phenology among 37 native and 18 invasive woody plant species common to New England. We compared fruiting dates between native and invasive species, and analyzed how fruiting phenology varies with temperature, space, and time.

Key Results

Spring temperature and year explained a small but significant amount of the variation in fruiting dates. Accounting for the moderate phylogenetic signal in fruiting phenology, invasive species fruited 26 days later on average than native species, with significantly greater standard deviations.

Conclusions

Herbarium specimens can be used to detect patterns in fruiting times among species. However, the amount of intraspecific variation in fruiting times explained by temporal, geographic, and climatic predictors is small, due to a combination of low temporal resolution of fruiting specimens and the protracted nature of fruiting. Later fruiting times in invasive species, combined with delays in autumn bird migrations in New England, may increase the likelihood that migratory birds will consume and disperse invasive seeds in New England later into the year.
A new commelinid monocot seed fossil from the early Eocene previously identified as Solanaceae
Authors: Särkinen Tiina , Kottner Sören , Stuppy Wolfgang , Ahmed Farah , Knapp Sandra
Published: February 2018

Premise of the Study

Fossils provide minimum age estimates for extant lineages. Here we critically evaluate Cantisolanum daturoides Reid & Chandler and two other early putative seed fossils of Solanaceae, an economically important plant family in the Asteridae.

Methods

Three earliest seed fossil taxa of Solanaceae from the London Clay Formation (Cantisolanum daturoides) and the Poole and Branksome Sand Formations (Solanum arnense Chandler and Solanispermum reniforme Chandler) were studied using x‐ray microcomputed tomography (MCT) and scanning electron microscopy (SEM).

Key Results

The MCT scans of Cantisolanum daturoides revealed a high level of pyrite preservation at the cellular level. Cantisolanum daturoides can be clearly excluded from Solanaceae and has more affinities to the commelinid monocots based on a straight longitudinal axis, a prominent single layer of relatively thin‐walled cells in the testa, and a clearly differentiated micropyle surrounded by radially elongated and inwardly curved testal cells. While the MCT scans show no internal preservation in Solanum arnense and Solanispermum reniforme, SEM images show the presence of several characteristics that allow the placement of these taxa at the stem node of Solanaceae.

Conclusions

Cantisolanum daturoides is likely a member of commelinid monocots and not Solanaceae as previously suggested. The earliest fossil record of Solanaceae is revised to consist of fruit fossil with inflated calyces from the early Eocene of Patagonia (52 Ma) and fossilized seeds from the early to mid‐Eocene of Europe (48–46 Ma). The new identity for Cantisolanum daturoides does not alter a late Cretaceous minimum age for commelinids.
How High Schools Become Empowering Communities: A Mixed‐Method Explanatory Inquiry into Youth‐Adult Partnership and School Engagement
Authors: Zeldin Shepherd , Gauley Josset Sky , Barringer Alexandra , Chapa Brie
Published: February 2018

Educational reform efforts emphasize empowerment and engagement, but these concepts are rarely translated into policy or classroom practice. This inquiry explores how schools can become places where students take ownership over their own learning. Phase 1 of this inquiry, a survey of students from diverse high schools, examines pathways to school engagement. Results indicated that youth voice in decision‐making, particularly when the experience is situated within supportive adult relationships and a sense of safety, significantly predicts emotional and cognitive engagement. Phase 2, a case study of an exemplary high school, sought to explain these pathways. Grounded in the theoretical perspectives of “empowered community settings” and “youth‐adult partnership,” analyses highlighted the importance of a shared belief system and core instructional activities that were student‐centered, affirmative, and strength‐based. Within this context, the opportunity role structure allowed students to exercise voice in creating their own educational program. The relational environment offered partnership and safety for academic risk‐taking. Teachers broke down traditional roles and power hierarchies in ways that helped students discover their own sources of engagement. The article identifies ways that community psychologists, as policy framers and as researchers, can help schools become places of empowerment and engagement.
Spectroscopic Evidence for Aminomethylene (H−C̈−NH2)—The Simplest Amino Carbene
Authors: Eckhardt André K. , Schreiner Peter R.
Published: February 2018

Although N‐heterocyclic carbenes have been well‐studied, the simplest aminocarbene, aminomethylene H−C̈−NH2, has not been spectroscopically identified to date. Herein we report the gas‐phase preparation of aminomethylene by high‐vacuum flash pyrolysis of cyclopropylamine and subsequent trapping of the pyrolysate in an inert argon matrix at 12 K. Aminomethylene was characterized by matching matrix IR and UV/Vis spectroscopic data with ab initio coupled cluster computations. After UV irradiation of the matrix aminomethylene rearranges to its isomer methanimine (formaldimine) H2C=NH. Based on our experimental results and computations aminomethylene has a singlet ground state with a reaction barrier of almost 46 kcal mol−1 to methanimine so that H‐tunneling is excluded.
Microtubule Inner Proteins: A Meshwork of Luminal Proteins Stabilizing the Doublet Microtubule
Authors: Ichikawa Muneyoshi , Bui Khanh Huy
Published: February 2018

Motile eukaryotic cilia and flagella are hair‐like organelles responsible for cell motility and mucociliary clearance. Using cryo‐electron tomography, it has been shown that the doublet microtubule, the cytoskeleton core of the cilia and flagella, has microtubule inner protein structures binding periodically inside its lumen. More recently, single‐particle cryo‐electron microscopy analyses of isolated doublet microtubules have shown that microtubule inner proteins form a meshwork inside the doublet microtubule. High‐resolution structures revealed new types of interactions between the microtubule inner proteins and the tubulin lattice. In addition, they offered insights into the potential roles of microtubule inner proteins in the stabilization and assembly of the doublet microtubule. Herein, we review our new insights into microtubule inner proteins from the doublet microtubule together with the current body of literature on microtubule inner proteins.
Measurement selection in assessing outcomes of the Bradley Hospital Children's Partial Hospital Program
Authors: Yaptangco Mona , Musella Katharine , Preddy Teri , Parade Stephanie , Parent Justin
Published: February 2018

Mental health disorders are a prevalent health concern in the United States, with approximately 20% of children suffering from a mental health disorder. Given the impact of mental health disorders in children (e.g., poor outcomes in academic achievement, lower income, reduced cognitive abilities, etc.), it is increasingly important to determine whether the services and treatment provided are effective. In fact, a dramatic increase in health care costs has subsequently led to the need for formal evaluation of patients and reporting their progress to insurance providers.
Microporous Polymers as Macroligands for Pentamethylcyclopentadienylrhodium Transfer‐Hydrogenation Catalysts
Authors: Wisser Florian M. , Mohr Yorck , Quadrelli Elsje Alessandra , Farrusseng David , Canivet Jérôme
Published: February 2018

Herein, we report the synthesis of two bipyridine‐based porous polymers and their use as platforms for the heterogenization of pentamethylcyclopentadienylrhodium catalytic species. These highly stable heterogeneous catalysts demonstrate their efficiency in the transfer hydrogenation of α‐aryl ketones. Moreover, we show that their catalytic activity is similar to that of homogeneous analogues, highlighting the absence of diffusion limitations in the solids. We rationalize the differences in the measured activities by using the Hammett parameter as a descriptor of the electronic environment of the catalytic site in both homogeneous and heterogeneous systems.
How Does a Container Affect Acidity of its Content: Charge‐Depletion Bonding Inside Fullerenes
Authors: Jaroš Adam , Badri Zahra , Bora Pankaj Lochan , Bonab Esmaeil Farajpour , Marek Radek , Straka Michal , Foroutan‐Nejad Cina
Published: February 2018

A recent study (Sci. Adv.2017,3, e1602833) has shown that FH⋅⋅⋅OH2hydrogen bond in a HF⋅H2O pair substantially shortens, and the H−F bond elongates upon encapsulation of the cluster in C70fullerene. This has been attributed to compression of the HF⋅H2O pair inside the cavity of C70. Herein, we present theoretical evidence that the effect is not caused by a mere compression of the H2O⋅HF pair, but it is related to a strong lone‐pair–π (LP–π) bonding with the fullerene cage. To support this argument, a systematic electronic structure study of selected small molecules (HF, H2O, and NH3) and their pairs enclosed in fullerene cages (C60, C70, and C90) has been performed. Bonding analysis revealed unique LP–πcageinteractions with a charge‐depletion character in the bonding region, unlike usual LP–π bonds. The LP–πcageinteractions were found to be responsible for elongation of the H−F bond. Thus, the HF appears to be more acidic inside the cage. The shortening of the FH⋅⋅⋅OH2contact in (HF⋅H2O)@C70originates from an increased acidity of the HF inside the fullerenes. Such trends were also observed in other studied systems.
Binary FeCo Oxyhydroxide Nanosheets as Highly Efficient Bifunctional Electrocatalysts for Overall Water Splitting
Authors: Nguyen Trang‐Thi Hong , Lee Jooyoung , Bae Joonwon , Lim Byungkwon
Published: February 2018

Bifunctional catalysts that are highly active toward both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are attractive for efficient electrochemical water splitting. Herein, we report a bifunctional FeCoOOH nanosheet catalyst for highly efficient electrochemical water splitting in an alkaline electrolyte. The FeCoOOH nanosheet arrays were grown directly on the surface of a porous Ni foam by using a simple hydrothermal method. Because of their binary oxyhydroxide structure and high electrical conductivity intrinsic to direct growth, these FeCoOOH nanosheets exhibited excellent activities toward both the HER and OER. With the use of this bifunctional FeCoOOH catalyst, an alkaline water electrolyzer in a two‐electrode configuration achieved 10 mA cm−2 only at a cell voltage of 1.62 V without iR compensation in 1 m KOH, which outperformed that based on the combination of commercial IrO2 and Pt/C catalysts.
One‐Step Low‐Temperature Synthesis of Syringe‐Shaped ZnO Nanorod Arrays, Growth Mechanism and Optical Properties
Authors: He Guannan , Huang Bo , He Qinyu , Li Lunxiong
Published: February 2018

The syringe‐shaped ZnO nanorod arrays (ZNAs) are synthesized by one‐step aqueous solution method. The SiNx/Si substrate with this structure exhibits rather lower surface reflectance over a wide range of wavelengths than the samples without it or with round top ZNAs. The theoretical reflectance simulated by three‐dimensional finite‐difference time‐domain method also reveals that the ZnO nanorods with ultrasharp tips can effectively suppress the surface reflectance, which attributes to the effective refractive index gradual increasing from air to the bottom of syringe‐shaped ZNAs. Also, from the room‐temperature PL spectra, the UV emission peak is found at around 380 nm, and the intensity is much higher than other two broad visible peaks (at around 460 nm and 540 nm respectively), indicating ZNAs synthesized in solution have high crystal quality. Furthermore, the possible growth mechanism of syringe‐shaped ZNAs is proposed.
Clinical relevance of smartphone apps for diabetes management: A global overview
Authors: Huang Zhilian , Soljak Michael , Boehm Bernhard Otto , Car Josip
Published: February 2018

Background

We assessed the number, proportion, and clinical relevance of diabetes self‐management apps in major languages spoken by 10 countries with the highest number of people with diabetes.

Methods

China, India, USA, Brazil, Russian Federation, Mexico, Indonesia, Egypt, Japan, and Pakistan were identified as the 10 countries with the largest number of people with diabetes based on the latest NCD‐RisC survey. Android and iOS apps in the 10 national languages were extracted with a search strategy. App titles and descriptions were systematically screened by trained reviewers, including apps specific for diabetes self‐management and excluding apps for health care providers, general well‐being, health and product promotion, and traditional cure. Eighteen apps in the above languages were then downloaded based on availability and popularity and assessed for clinical relevance to diabetes self‐management with reference to current clinical guidelines.

Results

The diabetes‐related search terms identified 3374 Android and 4477 iOS apps, where 1019 Android and 1303 iOS apps were screened as being relevant for diabetes self‐management. Chinese and English language apps constitute above 80% of the diabetes apps, have more downloads, and more comprehensive clinically relevant functions compared with other languages. None of the apps assessed met all criteria for information provision and app functionalities nor provided information cited from accredited sources.

Conclusions

Our study showed that apps could play an important role in complementing multifaceted diabetes care, but should preferably be regulated, context specific, and more tailored to users' needs with clear guidance for patients and clinicians about the choices.
Effect of denosumab on fasting glucose in women with diabetes or prediabetes from the FREEDOM trial
Authors: Napoli Nicola , Pannacciulli Nicola , Vittinghoff Eric , Crittenden Daria , Yun Jang , Wang Andrea , Wagman Rachel , Schwartz Ann V.
Published: February 2018

Background

RANKL is a key regulator of bone resorption that may also modulate glucose metabolism. Denosumab (DMAb) is a fully human monoclonal antibody that binds RANKL and was associated with fracture risk reduction in the FREEDOM trial. We hypothesized that DMAb treatment decreased fasting serum glucose (FSG) relative to placebo in women with diabetes or prediabetes enrolled in FREEDOM trial.

Methods

Post hoc analysis of FREEDOM, in which 7808 postmenopausal osteoporotic women were randomized to receive DMAb or placebo every 6 months for 36 months. All diabetes group included subjects with a self‐report of diabetes, use of antidiabetic medication (ADM), or an FSG ≥ 126 mg/dL at baseline. The diabetes group without prior ADM use included subjects with a self‐reported history of diabetes or FSG level ≥ 126 mg/dL at baseline. Prediabetes was defined as an FSG of 100 to 125 mg/dL on no ADM. Average postbaseline FSG across visits was estimated and compared between DMAb and placebo. Main outcome measures are the difference in average postbaseline FSG across follow‐up visits between DMAb and placebo.

Results

Estimated average postbaseline FSG across visits was not different between DMAb and placebo in either all diabetes group (P = .20) or those with prediabetes (P = .42); in diabetic women not on ADM, estimated average postbaseline FSG across visits was lower with DMAb than placebo (−6.8 mg/dL; 95% CI, −12.6 to −1.0; P = .02).

Conclusions

DMAb did not affect FSG in postmenopausal osteoporotic women with prediabetes or diabetes. There was evidence of modest FSG lowering with DMAb in those with diabetes who were not on ADM. It remains to be determined whether blockade of RANKL has a clinically important effect on glucose metabolism.
Management of a stage‐structured insect pest: an application of approximate optimization
Authors: Hackett Sean C. , Bonsall Michael B.
Published: February 2018

Ecological decision problems frequently require the optimization of a sequence of actions over time where actions may have both immediate and downstream effects. Dynamic programming can solve such problems only if the dimensionality is sufficiently low. Approximate dynamic programming (ADP) provides a suite of methods applicable to problems of arbitrary complexity at the expense of guaranteed optimality. The most easily generalized method is the look‐ahead policy: a brute‐force algorithm that identifies reasonable actions by constructing and solving a series of temporally truncated approximations of the full problem over a defined planning horizon. We develop and apply this approach to a pest management problem inspired by the Mediterranean fruit fly,Ceratitis capitata. The model aims to minimize the cumulative costs of management actions and medfly‐induced losses over a single 16‐week season. The medfly population is stage‐structured and grows continuously while management decisions are made at discrete, weekly intervals. For each week, the model chooses between inaction, insecticide application, or one of six sterile insect release ratios. Look‐ahead policy performance is evaluated over a range of planning horizons, two levels of crop susceptibility to medfly and three levels of pesticide persistence. In all cases, the actions proposed by the look‐ahead policy are contrasted to those of a myopic policy that minimizes costs over only the current week. We find that look‐ahead policies always out‐performed a myopic policy and decision quality is sensitive to the temporal distribution of costs relative to the planning horizon: it is beneficial to extend the planning horizon when it excludes pertinent costs. However, longer planning horizons may reduce decision quality when major costs are resolved imminently. ADP methods such as the look‐ahead‐policy‐based approach developed here render questions intractable to dynamic programming amenable to inference but should be applied carefully as their flexibility comes at the expense of guaranteed optimality. However, given the complexity of many ecological management problems, the capacity to propose a strategy that is “good enough” using a more representative problem formulation may be preferable to an optimal strategy derived from a simplified model.