bluuebunny/crossref_metadata_2025_split huggingface dataset:
Climatic drivers of pinyon mouse Peromyscus truei population dynamics in a resource‐restricted environment
Authors: Srivathsa Arjun , Tietje William , Rolland Virginie , Polyakov Anne , Oli Madan K. 
Published: January 2019

AbstractHighly variable patterns in temperature and rainfall events can have pronounced consequences for small mammals in resource‐restricted environments. Climatic factors can therefore play a crucial role in determining the fates of small mammal populations. We applied Pradel's temporal symmetry model to a 21‐year capture–recapture dataset to study population dynamics of the pinyon mouse (Peromyscus truei) in a semi‐arid mixed oak woodland in California, USA. We examined time‐, season‐ and sex‐specific variation in realized population growth rate (λ) and its constituent vital rates, apparent survival and recruitment. We also tested the influence of climatic factors on these rates. Overall monthly apparent survival was 0.81 ± 0.004 (estimate ± SE). Survival was generally higher during wetter months (October–May) but varied over time. Monthly recruitment rate was 0.18 ± 0.01, ranging from 0.07 ± 0.01 to 0.63 ± 0.07. Although population growth rate (λ) was highly variable, overall monthly growth rate was close to 1.0, indicating a stable population during the study period (λ ± SE = 0.99 ± 0.01). Average temperature and its variability negatively affected survival, whereas rainfall positively influenced survival and recruitment rates, and thus the population growth rate. Our results suggest that seasonal rainfall and variation in temperature at the local scale, rather than regional climatic patterns, more strongly affected vital rates in this population. Discerning such linkages between species' population dynamics and environmental variability are critical for understanding local and regional impacts of global climate change, and for gauging viability and resilience of populations in resource‐restricted environments.
Markov chain analysis of sessile community dynamics in a degraded Philippine reef to support restoration of coral populations
Authors: Punongbayan Andalus T. 
Published: January 2019

AbstractQuantitative approaches are needed for assessing assisted recovery potential in degraded coral reefs. A lagoonal community (Bolinao, Philippines) that has experienced severe disturbances (overfishing, blast fishing and coral bleaching) in the past was observed for 26 months. Benthic state sequences in 4 × 4 cm patches were used to quantify monthly probabilities of transitions between reef states. Benthic cover distribution was consistent with a spatially heterogeneous Markov process, with high variability in transition probabilities within a subset of four states: crustose algae with cropped turf, the codominant sponge Callyspongia samarensis, articulated coralline algae and fleshy macroalgae (MA). Once a patch is dominated by any of these states, there is high likelihood of cycling within the set before escaping to the rarer invertebrate groups. The assemblage is unlikely to recover naturally given prevailing conditions. Patches dominated by juvenile and adult corals have mean turnover times of about 3 and 5 months, respectively, due to (partial) mortality and competition. Asymmetry was detected for coral–macroalgal competition, despite low fleshy algal cover (9.5%), that was more adverse for coral juveniles than adults. While competition between coral and the mat‐forming C. samarensis was symmetrical, loss of coral cover through this path is relatively higher as a result of the higher interaction frequency. Articulated coralline algae do not appear as a constraint. Complementary strategies for assisted recovery were inferred from successional indices as well as the sensitivity of stationary coral cover to changes in transition probabilities. Results demonstrate that short‐term, fine‐scale observations of state variables can be used to resolve biotic constraints to inform restoration initiatives.
Synchronized expression of FLOWERING LOCUS T between branches underlies mass flowering in Fagus crenata
Authors: Satake Akiko , Kawatsu Kazutaka , Chiba Yukako , Kitamura Keiko , Han Qingmin 
Published: January 2019

AbstractMasting is the intermittent and synchronized production of a large amount of flower and seed in plant populations. This population‐level phenomenon is caused by individual‐level variability in reproduction and its synchrony between individuals. The variability at the individual level is induced by synchronized reproduction between branches within an individual because a tree is an assemblage of branches that are considered as semiautonomous units. However, there have been no empirical studies that quantify the degree of reproductive synchrony at the branch level within the same tree in masting species. Here, we evaluated the reproductive synchrony within individuals by monitoring flowering dynamics and expression level of a flowering‐time gene at the branch‐level in a typical masting species, Fagus crenata Blume. The 4‐year census showed that the branch‐level gene expression was highly variable between years and was strongly synchronized between branches. The branch‐level synchrony in flowering‐time gene expression was followed by coherent flowering cycle at the whole individual. To examine the causal relationship between gene expression and climatic factors, we performed a nonlinear statistical analysis called convergent cross‐mapping using the time course data of gene expression and environmental variables. Our results indicated that the observed gene expression pattern was well cross‐mapped by temperature or precipitation. However, this cross‐mapping skill was lower than that of randomly generated seasonal dynamics, implying a combination of internal and external environmental signals is more likely to regulate gene expression dynamics in F. crenata. Our results provide the first empirical evidence that synchronized expression of a flowering‐time gene between branches underlies integrated flowering behavior at the individual level.
Observer design for neutral‐type neural networks with discrete and distributed time‐varying delays
Authors: Dong Yali , Chen Laijun , Mei Shengwei 
Published: January 2019

SummaryThis paper is concerned with the problem of state estimation for a class of neural networks with discrete and distributed interval time‐varying delays. We propose a new approach of nonlinear estimator design for the class of neutral‐type neural networks. By constructing a newly augmented Lyapunov‐Krasovskii functional, we establish sufficient conditions to guarantee the estimation error dynamics to be globally exponentially stable. The obtained results are formulated in terms of linear matrix inequalities (LMIs), which can be easily verified by the MATLAB LMI control toolbox. Then, the desired estimators gain matrix is characterized in terms of the solution to these LMIs. Three numerical examples are given to show the effectiveness of the proposed design method.
Influence of Pendant Group on Mobility of Organic Thin Film Transistor in Correlation with Reorganization Energy of Molecules
Authors: Patrikar Kalyani , Jain Nakul , Chakraborty Dwaipayan , Johari Priya , Rao Valipe Ramgopal , Kabra Dinesh 
Published: January 2019

AbstractCharge transport properties of common donor copolymers in organic photovoltaics, poly({4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl}{3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thiophenediyl}) (PTB7) and poly([2,6′‐4,8‐di(5‐ethylhexylthienyl)benzo[1,2‐b;3,3‐b]dithiophene]{3‐fluoro‐2[(2‐ethylhexyl) carbonyl]thieno[3,4‐b]thiophenediyl}) (PTB7‐Th), with molecular structures differing only in the pendant group, are studied. This is the first report of field‐effect transistor mobility (µFET) of PTB7‐Th (0.14 cm2 V−1 s−1) and the highest µFET for PTB7 (0.01 cm2 V−1 s−1). µFET of PTB7‐Th is found to be almost one order of magnitude higher than PTB7. To understand the influence of molecular structure on charge transport, hole reorganization energy (λh) is calculated from first‐principles. λh of PTB7‐Th (≈150 meV) is found to be lower than PTB7 (≈346 meV). Further, the ratio of hopping rate versus square of charge transfer integral calculated from Marcus theory using λh for these systems is found to indicate a higher rate of hole transfer across dimers or homojunction interface for PTB7‐Th. These results are supplemented by experimentally determined λ using bulk‐heterojunction organic solar cells, where λPTB7‐Th≈200 meV and λPTB7≈310 meV follow a similar trend. The effective hole‐mobility estimation from BHJ devices correlates well with these λ values. This study provides understanding of charge transport properties via reorganization energy, as a function of pendant group without altering the backbone of the chains.
Pseudoelasticity of Metal Nanoparticles Is Caused by Their Ultrahigh Strength
Authors: Sharma Amit , Gazit Nimrod , Klinger Leonid , Rabkin Eugen 
Published: January 2019

AbstractAn assembly of hemispherical Ag nanoparticles is prepared by solid‐state dewetting of thin Ag film deposited on the sapphire substrate. The in situ nanomechanical compression testing of the particles with a flat diamond punch inside the scanning electron microscope demonstrates the deformation behavior typical for the nucleation‐controlled plasticity: high elastic deformation followed by an abrupt particles collapse. The latter is associated with the dislocations nucleation in otherwise pristine particle. The average contact pressure in the contact zone at the onset of dislocation‐controlled plasticity is about 8 GPa, and does not depend on particle size. This observation supports the hypothesis that the pseudoelasticity of much smaller Ag nanoparticles is intrinsically related to their ultrahigh strength. A stress‐induced diffusion along the particle–substrate and particle–punch interfaces is identified as a factor controlling the pseudoelastic deformation. The corresponding diffusion model allows estimating the room‐temperature self‐diffusion coefficient of Ag along the Ag–W and Ag–zirconia interfaces, which is quite close to the estimated value of the grain boundary self‐diffusion coefficient in Ag. Based on this finding, the map of pseudoelastic deformation of crystalline materials is proposed.
Designing Next‐Generation Local Drug Delivery Vehicles for Glioblastoma Adjuvant Chemotherapy: Lessons from the Clinic
Authors: Tabet Anthony , Jensen Melanie P. , Parkins Christopher C. , Patil Parag G. , Watts Colin , Scherman Oren A. 
Published: January 2019

AbstractTo date, the clinical outcomes and survival rates for patients with glioblastoma (GB) remain poor. A promising approach to disease‐modification involves local delivery of adjuvant chemotherapy into the resection cavity, thus circumventing the restrictions imposed by the blood–brain barrier. The clinical performance of the only FDA‐approved local therapy for GB [carmustine (BCNU)‐loaded polyanhydride wafers], however, has been disappointing. There is an unmet medical need in the local treatment of GB for drug delivery vehicles that provide sustained local release of small molecules and combination drugs over several months. Herein, key quantitative lessons from the use of local and systemic adjuvant chemotherapy for GB in the clinic are outlined, and it is discussed how these can inform the development of next‐generation therapies. Several recent approaches are highlighted, and it is proposed that long‐lasting soft materials can capture the value of stiff BCNU‐loaded wafers while addressing a number of unmet medical needs. Finally, it is suggested that improved communication between materials scientists, biomedical scientists, and clinicians may facilitate translation of these materials into the clinic and ultimately lead to improved clinical outcomes.
Simultaneous Production and Functionalization of Boron Nitride Nanosheets by Sugar‐Assisted Mechanochemical Exfoliation
Authors: Chen Shaohua , Xu Runzhang , Liu Jiaman , Zou Xiaolong , Qiu Ling , Kang Feiyu , Liu Bilu , Cheng Hui‐Ming 
Published: January 2019

AbstractDue to their extraordinary properties, boron nitride nanosheets (BNNSs) have great promise for many applications. However, the difficulty of their efficient preparation and their poor dispersibility in liquids are the current factors that limit this. A simple yet efficient sugar‐assisted mechanochemical exfoliation (SAMCE) method is developed here to simultaneously achieve their exfoliation and functionalization. This method has a high actual exfoliation yield of 87.3%, and the resultant BNNSs are covalently grafted with sugar (sucrose) molecules, and are well dispersed in both water and organic liquids. A new mechanical force–induced exfoliation and chemical grafting mechanism is proposed based on experimental and density functional theory investigations. Thanks to the good dispersibility of the nanosheets, flexible and transparent BNNS/poly(vinyl alcohol) (PVA) composite films with multifunctionality is fabricated. Compared to pure PVA films, the composite films have a remarkably improved tensile strength and thermal dissipation capability. Noteworthy, they are flame retardant and can effectively block light from the deep blue to the UV region. This SAMCE production method has proven to be highly efficient, green, low cost, and scalable, and is extended to the exfoliation and functionalization of other two‐dimensional (2D) materials including MoS2, WS2, and graphite.
Bismuth Sulfide Nanorods with Retractable Zinc Protoporphyrin Molecules for Suppressing Innate Antioxidant Defense System and Strengthening Phototherapeutic Effects
Authors: Cheng Yan , Chang Yun , Feng Yanlin , Jian Hui , Wu Xiaqing , Zheng Runxiao , Xu Keqiang , Zhang Haiyuan 
Published: January 2019

AbstractBismuth (Bi)‐based nanomaterials (NMs) are widely used for computed tomography (CT) imaging guided photothermal therapy, however, the photodynamic property is hardly exhibited by these NMs due to the fast electron–hole recombination within their narrow bandgap. Herein, a sophisticated nanosystem is designed to endow bismuth sulfide (Bi2S3) nanorods (NRs) with potent photodynamic property. Zinc protoporphyrin IX (ZP) is linked to Bi2S3 NRs through a thermoresponsive polymer to form BPZP nanosystems. The stretching ZP could prebind to the active site of heme oxygenase‐1 overexpressed in cancer cells, suppressing the cellular antioxidant defense capability. Upon NIR laser irradiation, the heat released from Bi2S3 NRs could retract the polymer and drive ZP to the proximity of Bi2S3 NRs, facilitating an efficient electron–hole separation in ZP and Bi2S3 NRs, and leading to reactive oxygen species generation. In vitro and in vivo studies demonstrate the promising photodynamic property of BPZP, together with their photothermal and CT imaging performance.
Compositional Engineering for Thermally Stable, Highly Efficient Perovskite Solar Cells Exceeding 20% Power Conversion Efficiency with 85 °C/85% 1000 h Stability
Authors: Matsui Taisuke , Yamamoto Teruaki , Nishihara Takashi , Morisawa Ryosuke , Yokoyama Tomoyasu , Sekiguchi Takashi , Negami Takayuki 
Published: January 2019

AbstractPerovskite solar cells have received great attention because of their rapid progress in efficiency, with a present certified highest efficiency of 23.3%. Achieving both high efficiency and high thermal stability is one of the biggest challenges currently limiting perovskite solar cells because devices displaying stability at high temperature frequently suffer from a marked decrease of efficiency. In this report, the relationship between perovskite composition and device thermal stability is examined. It is revealed that Rb can suppress the growth of PbI2 even under PbI2‐rich conditions and decreasing the Br ratio in the perovskite absorber layer can prevent the generation of unwanted RbBr‐based aggregations. The optimized device achieved by engineering perovskite composition exhibits 92% power conversion efficiency retention in a stress test conducted at 85 °C/85% relative humidity (RH) according to an international standard (IEC 61215) while exceeding 20% power conversion efficiency (certified efficiency of 20.8% at 1 cm2). These results reveal the great potential for the practical use of perovskite solar cells in the near future.
Suppressed Triplet Exciton Diffusion Due to Small Orbital Overlap as a Key Design Factor for Ultralong‐Lived Room‐Temperature Phosphorescence in Molecular Crystals
Authors: Narushima Kaishi , Kiyota Yasuhiro , Mori Takehiko , Hirata Shuzo , Vacha Martin 
Published: January 2019

AbstractPersistent room‐temperature phosphorescence (RTP) under ambient conditions is attracting attention due to its strong potential for applications in bioimaging, sensing, or optical recording. Molecular packing leading to a rigid crystalline structure that minimizes nonradiative pathways from triplet state is often investigated for efficient RTP. However, for complex conjugated systems a key strategy to suppress the nonradiative deactivation is not found yet. Here, the origin of small rates of a nonradiative decay process from triplet states of conjugated molecular crystals showing RTP is reported. Optical microscopy analysis showed that, despite a favorable molecular stacking, an aromatic crystal with strong RTP is characterized by small diffusion length and small values of the diffusion coefficient of triplet excitons. Quantum chemical calculations reveal a large overlap between the lowest unoccupied molecular orbitals but very small overlap between the highest occupied molecular orbitals (HOMOs). Inefficient electron exchange caused by the small overlap of HOMOs prevents triplet excitons from diffusing over long distances and consequently from quenching at defect sites inside the crystal or at the crystal surface. These results will allow design of comprehensive molecular structures to obtain molecular solids with more efficient RTP.
Ab Initio Design of Graphene Block Enables Ultrasensitivity, Multimeter‐Like Range Switchable Pressure Sensor
Authors: Zang Xiaoling , Wang Xusheng , Xia Jiahao , Chai Yuqiao , Ma Xinlei , Li Rui , Ji Junhui , Xu Huaping , Xue Mianqi 
Published: January 2019

AbstractIn pursuit of the next‐generation pressure sensors, the fabrication of graphene‐based devices is considered to be one of the most promising approaches to address the unsatisfied sensitivity within a wide pressure range. Here, an ab initio design based on the graphene block is proposed to realize a high‐performance and multimeter‐like range switchable pressure sensor. The sensor contains three designed graphene‐based foams with different initial resistances, which enable continuous resistance‐change behavior induced by the pressure. Specifically, the reduced graphene oxide (rGO) foam–based sensor demonstrates a three times resistance change within the pressure range of 0–300 Pa, the rGO/polyurethane (rGO/PU) foam–based sensor presents a six times resistance change within the pressure range of 0.09–30 kPa, and the selenium‐functionalized rGO/PU (SFrGO/PU) foam–based sensor displays a resistance change of more than 1000‐fold within the pressure range of 1–72 kPa. Such different initial resistances and responses endow the device with controllable estimating pressure ranges, offering a switchable multimeter‐like function for various applications. This ab initio design, which is applicable to various 2D materials and operation modes, can provide a facile and feasible approach toward the next‐generation pressure sensors and other application fields related to 2D materials.
Palladium/Unichiral Ligand‐Catalyzed Decarboxylative Asymmetric Protonation of Racemic β‐Oxoallyl Esters
Authors: Muzart Jacques 
Published: January 2019

AbstractThe palladium‐catalyzed decarboxylative asymmetric protonation (DAP) of racemic allyl β‐keto esters using achiral protic species, first disclosed in 2006, is now a mature methodology for applications in asymmetric organic synthesis. In contrast, the mechanism of protonation remains unclear despite experimental and computational studies. The aim of this review is, firstly, to gather together the literature results, observations and proposals and, secondly, to suggest, for the enantioselectivity‐determining step, transition states depending on the substrate and the proton source.magnified image
What makes a weed a weed? A large‐scale evaluation of arable weeds through a functional lens
Authors: Bourgeois Bérenger , Munoz François , Fried Guillaume , Mahaut Lucie , Armengot Laura , Denelle Pierre , Storkey Jonathan , Gaba Sabrina , Violle Cyrille 
Published: January 2019

Premise of the StudyDespite long‐term research efforts, a comprehensive perspective on the ecological and functional properties determining plant weediness is still lacking. We investigated here key functional attributes of arable weeds compared to non‐weed plants, at large spatial scale.MethodsWe used an intensive survey of plant communities in cultivated and non‐cultivated habitats to define a pool of plants occurring in arable fields (weeds) and one of plants occurring only in open non‐arable habitats (non‐weeds) in France. We compared the two pools based on nine functional traits and three functional spaces (LHS, reproductive and resource requirement hypervolumes). Within the weed pool, we quantified the trait variation of weeds along a continuum of specialization to arable fields.Key ResultsWeeds were mostly therophytes and had higher specific leaf area, earlier and longer flowering, and higher affinity for nutrient‐rich, sunny and dry environments compared to non‐weeds, although functional spaces of weeds and non‐weeds largely overlapped. When fidelity to arable fields increased, the spectrum of weed ecological strategies decreased as did the overlap with non‐weeds, especially for the resource requirement hypervolume.ConclusionsArable weeds constitute a delimited pool defined by a trait syndrome providing tolerance to the ecological filters of arable fields (notably, regular soil disturbances and fertilization). The identification of such a syndrome is of great interest to predict the weedy potential of newly established alien plants. An important reservoir of plants may also become weeds after changes in agricultural practices, considering the large overlap between weeds and non‐weeds.
Heartbreak: A case of post‐infarction cardiogenic shock
Authors: Mukherjee Ashes , Fong Jason 
Published: January 2019

AbstractVentricular septal rupture is a rare but catastrophic complication of acute myocardial infarction. Although it has declined in incidence since the introduction of percutaneous coronary intervention, there hasn't been a significant change of mortality from the condition. In the chain of survival, prompt diagnosis and definitive surgery form the cardinal links. Prolonged medical management is not a feasible option as it is likely to be futile but the aim should be to reduce afterload with the help of intra‐aortic balloon pump or support with ventricular assist devices. Echocardiography sits at the heart of the diagnosis of this time critical condition and will guide accurate therapy and intervention. We present the first reported case from an Australian emergency department, where the echocardiography done by the emergency physician clinched the diagnosis. We emphasise here the paramountcy of emergency physicians being proficient in basic echocardiography to achieve rapid diagnosis. Once diagnosed it is critical to have an individual case‐tailored multi‐disciplinary discussion between emergency medicine, cardiothoracic surgery, cardiology and intensive care as to plan the optimal timing of surgery.