bluuebunny/crossref_metadata_2025 huggingface dataset:
Navigating the Challenges of Home Parenteral Nutrition
Authors: Koenen Brian , Benjamin Richard , Panciu Adriana
Published: February 2019

Providing parenteral nutrition at home has significant challenges for both patients and providers alike. Some of these challenges are systemic and are secondary to the way the healthcare system is designed to deliver care. Others are more practical and require educating patients and their families to ensure success at home. Overall, the nutrition support team was designed to help deal with these challenges in an effective way. The changing realities of the modern health system are challenging the nutrition support team to adapt to new obstacles. Providing patients with the tools to succeed at home requires a significant amount of time and investment but will pay dividends in the future as patients thrive for years to come.
Eight‐node nonconforming hexahedral element based on reverse adjustment to patch test for solids, beams, plates, and shells
Authors: Hu Shengrong , Xu Jingjing , Liu Xinhong , Yan Murong
Published: February 2019

An eight‐node 24‐DOF nonconforming brick element is developed. It contains nine internal modes, including quadratic and cubic forms, wherein each local coordinate component is at most quadratic. The reverse adjustment to patch test is applied to quadratic modes to eliminate shear locking. To rectify the ill‐condition of the element stiffness matrix caused by irregular element shape such as large aspect ratio, a modified regularization method is introduced. It is based on Riley's series expansion of the solution to the ill‐conditioned linear system and is coupled in the condensation procedure of the internal degrees of freedom. With the regularization parameter α = 10−3, the first three terms are enough, which are achieved by two additional refinements in addition to the initial value. To validate the accuracy and robustness, a variety of linear benchmark tests is conducted on solid, beam, plate, and shell structures. The results are in good agreement with the reference solutions, provided the mesh is not too coarse or distorted. The overall performance implies that the new element is competitive with almost all the elements cited, including solid, solid‐shell, and shell elements, and is a potential one‐size‐fits‐all solution to linear structure problems.
Adipose Tissue Mediates Associations of Birth Weight with Glucose Metabolism Disorders in Children
Authors: Wu Yunpeng , Yu Xinting , Li Yu , Li Ge , Cheng Hong , Xiao Xinghua , Mi Jie , Gao Shan , Willi Steven M. , Li Ming
Published: February 2019

Objective

This study aimed to examine the associations between low birth weight (LBW) versus high birth weight (HBW) and dysglycemia, including insulin resistance (IR) and impaired fasting glucose (IFG) in children, and aimed to explore the role of adipose tissue in these relationships.

Methods

A total of 2,935 subjects aged 6 to 18 years were recruited to examine the relationship between birth weight and IR (defined as homeostasis model assessment of IR > 2.3) and IFG. Mediation analyses were conducted to examine the roles of various adipokines and anthropometrics in these relationships.

Results

Children with LBW had a nearly twofold increased risk of IR and IFG compared with children with normal birth weight, even after adjusting for BMI. Decreased circulating adiponectin levels contributed to 21.2% of the LBW–IR relationship, whereas none of the selected adipose markers mediated the LBW–IFG relationship. In contrast, after controlling for current BMI or waist circumference, HBW reduced the risk of IR by 34%, but it was not associated with IFG. The HBW–IR relationship was significantly mediated by reduced leptin levels (21.4%) and fat mass percentage (8.8%), after controlling for BMI.

Conclusions

These findings suggest the potential role of adipose tissue dysfunction as an underlying mechanism for the birth weight–type 2 diabetes relationship.
Novel antibacterial fibers of amphiphilic N‐halamine polymer prepared by electrospinning
Authors: Zhu Chongyi , Chang Dan , Wang Xiao , Chai Danxia , Chen Lili , Dong Alideertu , Gao Ge
Published: February 2019

As a significant role in subcategory of halogen antibacterial field, amphiphilic N‐halamine polymers show a promise as potential antimicrobials having a broad spectrum of microorganisms, long‐term stability, and renewal of their antibacterial properties. By controlling the process parameters, electrospinning has been well recognized as a versatile and effective method being capable of making fibers and could be easily engineered with desired pore size and porosity to enhance the antimicrobial properties. The amphiphilic N‐halamine P (ADMH‐MMA‐HEMA) terpolymer fibers showed efficient antimicrobial properties against both Gram‐positive and Gram‐negative bacteria within brief contact time. The result meant that the polymer fibers of macromolecular architecture with control of structural parameters such as hydrophobicity/hydrophilicity balance achievement improved antimicrobial activities via electrospinning technique. In vitro cytotoxicity study demonstrated that the polymer was biocompatible. As a result, the integration of amphiphilic antibacterial materials and the electrospinning technique provided us a feasible method to fabricate biocompatible antimicrobial products easily with low manufacturing cost and would be applied in many promising application areas.
Non‐ossifying fibroma: A RAS‐MAPK driven benign bone neoplasm
Authors: Bovée Judith VMG , Hogendoorn Pancras CW
Published: February 2019

Non‐ossifying fibroma (NOF) has been an intriguing entity since its first description. It is the most common bone tumour, is usually asymptomatic affecting children and adolescents, is composed of a heterogeneous cell population, and undergoes spontaneous regression after puberty. In a recent article in The Journal of Pathology, Baumhoer and colleagues demonstrate mutations activating the RAS‐MAPK pathway (KRAS, FGFR1 and NF1) in ∼80% of the tumours. Activation of the RAS‐MAPK pathway by somatic mutations is found in a plethora of tumour types, both benign and malignant, while germline mutations cause a wide range of syndromes collectively termed the RASopathies. Their findings indicate that NOF, for long thought to be reactive, should be considered a true neoplasm. Moreover, their data suggest that only a subset of cells in the lesion contain the mutation. A second cell population consisting of histiocytes and osteoclast‐like giant cells appears to be reactive. This intimate relation between WT and mutant cells is also frequently encountered in other benign and locally aggressive bone tumours and seems essential for tumourigenesis. The spontaneous regression remains enigmatic and it is tempting to speculate that pubertal hormonal signalling, especially increased oestrogen levels, affect the balance between mutant and WT cells. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
All sub‐nanosecond laser monolithic interconnection of OPV modules
Authors: Kubis Peter , Winter Jan , Gavrilova Anna , Hennel Markus , Schlosser Susanne , Richter Isabel , Distler Andreas , Heyder Madeleine , Kery Stefan , Lenk Peter , Geiger Stephan , Brabec Christoph J. , Huber Heinz P. , Egelhaaf Hans‐Joachim
Published: February 2019

Although green femtosecond lasers provide outstanding quality and wide processing windows for monolithic interconnection of the individual cells in organic photovoltaic (OPV) modules, they are hardly used in commercial applications, due to cost reasons. In this work, a process has been developed that allows the monolithic interconnection in OPV modules with an infrared sub‐nanosecond laser exclusively, without compromising the performance of the modules. While the photoactive layer is removed easily by green femtosecond pulses without damaging the bottom electrode, this is not possible for infrared nanosecond pulses, due to their much larger optical penetration length, which significantly exceeds the thickness of the active layer and is well absorbed by the indium tin oxide (ITO) layer. This leads to damage of the ITO bottom electrode, which in turn compromises the functionality of the module. By systematically varying single‐pulse laser fluence and spatial pulse overlap, the laser parameters are optimized in such a way that the contact area between the residues of the metal oxide bottom electrode and the silver nanowire top electrode is maximized so that the electrical resistances of the contacts are sufficiently small not to affect device performance. This is demonstrated by presenting large‐area OPV modules based on the well‐characterized reference system P3HT:PCBM that show efficiencies of up to 2.4%. This achievement opens up the way towards reliable roll‐to‐roll (R2R) laser patterning processes with sub‐nanosecond lasers and thus represents a breakthrough with respect to cost‐effective R2R manufacturing of OPV modules, due to grossly reduced investment and maintenance costs for laser sources.
New strategies for inhibition of non‐adrenergic prostate smooth muscle contraction by pharmacologic intervention
Authors: Yu Qingfeng , Gratzke Christian , Wang Yiming , Wang Xiaolong , Li Bingsheng , Strittmatter Frank , Herlemann Annika , Wang Ruixiao , Tamalunas Alexander , Waidelich Raphaela , Stief Christian G. , Hennenberg Martin
Published: February 2019

Background

Inhibition of prostate smooth muscle contraction by α1‐adrenoceptor antagonists (α1‐blockers) is a first‐line medical treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia. Increased smooth muscle tone in the hyperplastic prostate may drive urethral obstruction, resulting in bladder outlet obstruction and voiding symptoms. However, efficacy of α1‐blockers is limited, as non‐adrenergic mediators including endothelin‐1 and thromboxane A2 (TXA2) increase prostate smooth muscle tension in parallel to α1‐adrenoceptors. This may maintain urethral obstruction despite therapy with α1‐blockers. Consequently, future treatment options with higher efficacy need to target α1‐adrenergic and non‐adrenergic contractions simultaneouly. Recently, several compounds were reported to inhibit adrenergic or neurogenic prostate contractions, however, their effects on non‐adrenergic contraction are unknown. Here, we examined effects of inhibitors for Rac‐GTPase, Src family kinases (SFKs), and p21‐activated kinases (PAKs) on non‐adrenergic prostate contractions.

Methods

Prostate tissues were obtained from radical prostatectomy. Contractions were studied in an organ bath. Viability of cultured stromal cells was assessed by CCK‐8 assay.

Results

Inhibition of α1‐adrenergic contractions by Rac inhibitors EHT1864 (100 μM) and NSC23766 (100 μM), and SFK inhibitors AZM475721 (10 μM) and PP2 (10 μM) was confirmed by inhibition of methoxamine‐induced contractions. No effects of the PAK inhibitors FRAX486 (30 μM) and IPA3 (300 μM) on α1‐adrenergic contraction were confirmed by absent effects on methoxamine‐inuced contractions. EHT1864 caused inhibition of endothelin‐1‐ and U46619‐induced contractions. EHT1864 reduced the viability of stromal cells concentration‐ and time‐dependently. EHT1864 attenuated KCl‐induced contractions of prostate strips only slightly, so that toxic effects may not account alone for inhibition of agonist‐induced contractions. NSC23766 inhibited U46619‐induced contractions, but not endothelin‐1‐induced contractions. AZM475271 had no effects on endothelin‐1‐ or U46619‐induced contractions, while PP2 inhibited U46619‐ but not endothelin‐1‐induced contractions. FRAX486 caused inhibition of U46619‐induced contractions. IPA3 inhibited U46619‐, but not endothelin‐1‐induced contractions.

Conclusions

Of all six inhibitors, EHT1864 seems to be most promising from a translational point of view, as it inhibited TXA2‐ and endothelin‐1‐induced besides α1‐adrenergic prostate contractions. This reflects divergent pharmacologic profiles of EHT1864 and NSC23766, although both are Rac‐GTPase inhibitors. In vivo, urodynamic effects of EHT1864 and possibly of FRAX486 may exceed those of α1‐blockers.
Evolution of cnidarian trans‐defensins: Sequence, structure and exploration of chemical space
Authors: Mitchell Michela L. , Shafee Thomas , Papenfuss Anthony T. , Norton Raymond S.
Published: February 2019

Many of the small, cysteine‐rich ion‐channel modulatory peptides found in Cnidaria are distantly related to vertebrate defensins (of the trans‐defensin superfamily). Transcriptomic and proteomic studies of the endemic Australian speckled sea anemone (Oulactis sp.) yielded homologous peptides to known defensin sequences. We extended these data using existing and custom‐built hidden Markov models to extract defensin‐like families from the transcriptomes of seven endemic Australian cnidarian species. Newly sequenced transcriptomes include three species of Actiniaria (true sea anemones); the speckled anemone (Oulactis sp.), Oulactis muscosa, Dofleinia cf. armata and a species of Corallimorpharia, Rhodactis sp. We analyzed these novel defensin‐like sequences along with published homologues to study the evolution of their physico‐chemical properties in vertebrate and invertebrate fauna. The cnidarian trans‐defensins form a distinct cluster within the chemical space of the superfamily, with a unique set of motifs and biophysical properties. This cluster contains identifiable subgroups, whose distribution in chemical space also correlates with the divergent evolution of their structures. These sequences, currently restricted to cnidarians, form an evolutionarily distinct clade within the trans‐defensin superfamily.
Molecular Doping of a Water‐Soluble Polythiophene Derivative
Authors: Zessin Johanna , Bittrich Eva , Zessin Jakob , Malanin Mikhail , Posseckardt Juliane , Voit Brigitte , Eichhorn Klaus‐Jochen , Kiriy Anton , Mertig Michael
Published: February 2019

Intrinsic conducting polymers are promising candidates for bioelectronic devices due to their structural kinship to biological matter combined with electronic functionality. For sophisticated nano‐scaled bioelectronic devices, P3RT‐type polythiophene derivatives bearing water‐soluble, biocompatible sidechains are particularly appealing due to their well‐defined molecular structure and controllable end‐group composition. However, their employment in bioelectronic devices is not as straightforward as expected. Challenging is their poor performance due to, e.g., the low charge carrier concentration in the native state. Partial oxidation of these polymers by strong electron acceptors, so‐called p‐type doping, can increase the charge carrier concentration, and thus, the conductivity. The solution‐based molecular p‐type doping of such a water‐soluble polythiophene derivative by the dopant tetrafluoro‐tetracyano‐quinodimethane is reported. The mechanism of the doping process is thoroughly investigated by a combination of spectroscopic techniques covering the UV‐VIS and IR regions. Furthermore, the morphological and electronic properties of polymer thin films are examined as a dependence on the dopant concentration.
The construction of robust mixture‐process experimental designs via genetic algorithm
Authors: Limmun Wanida , Chomtee Boonorm , Borkowski John J.
Published: February 2019

Mixture experiments with the presence of process variables are commonly encountered in the manufacturing industry. The experimenter who plans to conduct mixture experiments in which a process involves the combination of machines, methods, and other resources will try to find condition of design factors which make the product/process insensitive or robust to the variability transmitted into the response variable. We propose the genetic algorithm (GA) for generating robust mixture‐process experimental designs involving control and noise variables. When the noise variables, which are extremely difficult to control or not routinely controlled during the manufacturing process and may change without warning, are considered in a mixture experiment, we propose the robust design setting. When considering a robust design, the design that has a lower and flatter faction of design space curves for all levels of the controllable process variables at varying noise interaction is preferable. We evaluate the designs with respect to these criteria for both the mean model and the slope model. The evaluation demonstrates that the proposed GA designs are robust to the contribution of the interactions involving the noise variables.
Time‐Domain Spectroscopy of Mesoscopic Conductors Using Voltage Pulses
Authors: Burset Pablo , Kotilahti Janne , Moskalets Michael , Flindt Christian
Published: February 2019

The development of single‐electron sources is paving the way for a novel type of experiment in which individual electrons are emitted into a quantum‐coherent circuit. However, to facilitate further progress toward fully coherent on‐chip experiments with electrons, a detailed understanding of the quantum circuits is needed. Here, it is proposed to perform time‐domain spectroscopy of mesoscopic conductors by applying Lorentzian‐shaped voltage pulses to an input contact. Specifically, it is shown how characteristic timescales of a quantum‐coherent conductor can be extracted from the distribution of waiting times between charge pulses propagating through the circuit. To illustrate the idea, Floquet scattering theory is employed to evaluate the electron waiting times for an electronic Fabry–Pérot cavity and a Mach–Zehnder interferometer. The perspectives for an experimental realization of the proposal are discussed and possible avenues for further developments are identified.
Design of motion trajectory and tracking control for underactuated cart‐pendulum system
Authors: Zhang Ancai , She Jinhua , Qiu Jianlong , Yang Chengdong , Alsaadi Fawaz
Published: February 2019

A cart‐pendulum system is a nonlinear underactuated mechanical system with two degrees of freedom. This paper addresses the motion trajectory design and tracking control problems for this underactuated system. First, a friction‐like control law is designed for the system. Then, the characteristics of the closed‐loop control system are analyzed. Second, a new method of constructing an optimal trajectory for the system is developed. Then, a tracking control law is designed to quickly track the constructed trajectory. It guarantees that the motion control of the cart‐pendulum system is achieved along a reference trajectory. Finally, a numerical example is presented to demonstrate the effectiveness of the theoretical results. This study constructs an optimal trajectory for the cart‐pendulum system in its whole motion space and solves the motion control objective by tracking the constructed trajectory. It has many advantages compared with other motion control methods, eg, the optimal motion control objective of the system is achieved by a single control law; and the motion process and transient characteristics (eg, the settling time) of the control system can be accurately predicted.
Google QUIC performance over a public SATCOM access
Authors: Thomas Ludovic , Dubois Emmanuel , Kuhn Nicolas , Lochin Emmanuel
Published: February 2019

Google Quick UDP Internet Connections (QUIC) accounts for almost 10 % of the Internet traffic, and the protocol is not standardized at the Internet Engineering Task Force (IETF) yet. We distinguish Google QUIC (GQUIC) and IETF QUIC (IQUIC) since there may be differences between the two. Both Google and IETF versions run over UDP and cannot be split the way satellite systems usually do with TCP connections. The need for adapting any‐QUIC parameters needs to be evaluated. Since GQUIC is available, we analyze its behavior over a satellite communication system. In our evaluations, GQUIC quick connection establishment does not compensate an inappropriate congestion control. The resulting page downloading time doubles when using GQUIC as opposed to the performance with optimized split TCP connections. This paper concludes that specific tuning are required when any‐QUIC runs over a high bandwidth delay product (BDP) network.
A Carbon‐Dot‐Based Fluorescent Probe for the Sensitive and Selective Detection of Copper(II) Ions
Authors: Zheng Xiaochun , Liu Wenjun , Gai Qixiao , Tian Zhaoshuo , Ren Shoutian
Published: February 2019

Fluorescent carbon dots (CDs) are widely applied for the detection of heavy metal ions due to their nontoxicity, high sensitivity and stability. In this work, CDs were synthesized by a simple and green pyrolysis method without complicated post‐processing procedures and characterized by transmission electron microscope, X‐ray diffraction, fourier transform infrared spectroscopy, UV‐visible spectrophotometer and fluorescence spectroscopy. The CDs exhibited a relatively narrow size distribution of 3.5‐8.6 nm with an average size of 6.1 nm and their surface was decorated with abundant functional groups such as hydroxy and amino groups. They exhibited a strong fluorescent peak at 468 nm with a quantum yield of 25% under 365 nm UV irradiation. The CDs exhibited a strong fluorescence response to 70 μM Cu2+ with the sensitivity up to 77% due to the complexation between the amino groups decorated on the CD surface and the adsorbed copper ions. They also exhibited short response times of less than 1 min, high response selectivity and good stability.
Eu3+ Photoluminescence in LiGd(WO4)2 with Scheelite‐Related Structure
Authors: Tiwari Hansnath , Naidu Salla Asiri , Varadaraju Upadhyayula Venkata
Published: February 2019

A comparative study of Eu3+ photoluminescence in the Scheelite‐type oxides LiGd(WO4)2 and LiGd(MoO4)2 is made. From the emission results, it is observed that the 5D0→7F2 electric dipole transition at 615 nm is predominant in both cases. The critical concentration of Eu3+ is found to be x=0.3 in both LiGd1‐xEux(WO4)2 as well as LiGd1‐xEux(MoO4)2 . The emission intensity of Eu3+ is higher in the tungstate host lattice vis a vis the molybdate. In addition, the emission intensity of Eu3+ in LiGd0.7Eu0.3(WO4)2 is 3.3 times higher compared to that of Y2O3:0.05Eu3+ commercial red phosphor.
Series Resistance Measurements of Perovskite Solar Cells Using Jsc–Voc Measurements
Authors: Mundhaas Noemi , Yu Zhengshan J. , Bush Kevin A. , Wang Hsin‐Ping , Häusele Jakob , Kavadiya Shalinee , McGehee Michael D. , Holman Zachary C.
Published: February 2019

The fill factor (FF) of perovskite solar cells is considerably lower than that of gallium arsenide and silicon cells, though they have similar open‐circuit voltage deficits. To probe the FF loss, which mainly comes from series resistance, the Jsc–Voc characterization technique is applied to perovskite solar cells. A continuous‐lamp solar simulator with an array of neutral density filters is used instead of the quasi‐steady‐state photoconductance technique commonly employed for silicon cells, which allows us to tune sweep parameters to accommodate the complex behavior of perovskites such as hysteresis. It is found that, for Cs0.25FA0.75Pb(Br0.2I0.8)3 (CsFA) perovskite cells, sweeping from positive to negative voltage yields the same series resistance regardless of sweep speed, whereas this is not the case if the sweep is reversed. However, for CH3NH3PbI3 perovskite cells, the series resistance is independent of the sweep speed in both sweep directions. It is also found that, for a poly[bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine] (PTAA) hole contact, increasing the PTAA thickness barely changes the recombination‐limited pseudo‐FF, but reduces the FF due to increased series resistance. A maximum FF of 80.9% was achieved with the PTAA hole contact on a CsFA perovskite absorber.
Flash Reduction Behavior of Magnetite Concentrate Particles in Methane–Nitrogen Atmospheres
Authors: Wang Xingnan , Fu Guiqin , Qu Yingxia , Zhu Miaoyong
Published: February 2019

In this work, the flash reduction behavior of magnetite concentrate particles with CH4–N2 gas mixture is investigated in a drop furnace reactor at 1450–1550 K. Based on the thermodynamic equilibrium compositions, the reaction path of Fe3O4–CH4 system and the influence of the addition of H2 and CO are revealed. The influences of methane concentration and temperature on the reduction degree and phase of reduced particles are investigated. The evolutions of external and internal morphology of reduced particles are observed. It is found that the increase of temperature from 1450 to 1550 K and methane concentration from 2.5 to 7.5 vol% have a positive impact on reduction process. Excessive methane (>7.5 vol%) causes the accumulation of solid carbon on the surface of particles and then weakens the reaction progress. The phase transformation of magnetite during the reduction process can be described as follows: Fe3O4 → FeO → Fe → Fe–C. With the increase of temperature, the microstructure of reduced particles transforms from irregular to sphere due to the dissolution of carbon into iron layer. Furthermore, the critical carbon content in Fe for FeO reduction is analyzed.
Effect of Intercritical Austenitizing Temperature during Quenching–Intercritical Quenching–Tempering Process on Toughness of 25Mn2Si2Cr Bainitic Steel
Authors: Li Ji , Tan Zhunli , Zhang Min , Gao Guhui , Misra Raja Devesh Kumar , Bai Bingzhe
Published: February 2019

An intercritical quenching process is introduced between conventional water quenching and tempering to 25Mn2Si2Cr bainitic steel. The study suggests that the quenching–intercritical quenching–tempering (Q–IQ–T) process effectively improves mechanical properties compared with conventional air cooling and tempering (Q–T). When the intercritical austenitizing temperature is 860 °C, as‐treated steel's tensile strength, yield strength, impact energy (U‐notch) is 1453 MPa, 1141 MPa, and 99 J cm−2, respectively, which is enhancement of 5.4%, 3.2%, and 20.7% compared with the conventional Q–T process. The increase of toughness is achieved without compromising strength. The improvement of toughness arises from refinement of grain size and microstructure.
Barrier contactless dielectrophoresis: A new approach to particle separation
Authors: Podoynitsyn Sergey N. , Sorokina Olga N. , Klimov Maksim A. , Levin Igor I. , Simakin Sergey B.
Published: February 2019

Barrier contactless dielectrophoresis is proposed as a method for microbiological particle separation. Design of a separation device for barrier contactless dielectrophoresis is discussed. The principle of separation device is based on formation of barriers of gradient fields in the volume of separation chamber by electrodes with passivation dielectric coating of silicon carbide. A feature of the method is absence of contact between separated samples and conductive elements of electrode structure. The proposed method is highly efficient and easy to use in comparison with dielectrophoresis on isolated structures and conventional planar systems. Computer simulation of electric field distribution over dielectrophoretic barriers is carried out, and effect of the thickness of the passivation coating on dielectrophoretic properties of barriers is shown. Forces acting on a particle (a yeast cell with a diameter of 7 μm) in separation chamber are evaluated using computer simulation data. Ability of the cell to be captured by the method of contactless barrier dielectrophoresis is theoretically predicted and confirmed experimentally, using yeast cells. The yeast cells subjected to positive dielectrophoresis can be effectively captured (up to 90%) by the separation device at the applied voltage of 20 V and 100 kHz and at flow rate of 20 mL/h.
Magnetic ionic liquids as an efficient tool for the multiresidue screening of organic contaminants in river water samples
Authors: da Silva Ana Cristine , Mafra Gabriela , Spudeit Daniel , Merib Josias , Carasek Eduardo
Published: February 2019

In this study, a multiresidue analytical methodology based on magnetic ionic liquid as extraction phase and dispersive liquid‐liquid microextraction, was developed for the determination of organic contaminants in river water samples by high‐performance liquid chromatography with diode array detection (HPLC‐DAD). Experimental conditions were carefully optimized using univariate and multivariate designs. A simplex‐lattice design was adopted for the optimization of disperser solvent, univariate planning was applied to pH optimization and a central composite design was used for the optimization of magnetic ionic liquid mass, extraction time and NaCl concentration added to the samples. The optimal extraction conditions were a mixture of acetonitrile/methanol 50:50 v/v as disperser solvent, pH adjusted to 6.0, 10 mg of magnetic ionic liquid, and extraction time of 180 s. The analytical parameters of merit were determined under the optimized conditions, and very acceptable results were achieved, with limits of detection ranging from 1.5 to 15 μg L−1 and determination coefficients (R2) higher than 0.992 for all 15 analytes. Precision varied from 8.6 to 17.8% and from 0.4 to 19.3% for interday (n = 9) and intraday (n = 3) assays, respectively. Relative recoveries varied from 56 to 123% in two aqueous samples, both collected in Camboriú city, Santa Catarina, Brazil.
A general framework for multivariate functional principal component analysis of amplitude and phase variation
Authors: Happ Clara , Scheipl Fabian , Gabriel Alice‐Agnes , Greven Sonja
Published: February 2019

Functional data typically contain amplitude and phase variation. In many data situations, phase variation is treated as a nuisance effect and is removed during preprocessing, although it may contain valuable information. In this note, we focus on joint principal component analysis (PCA) of amplitude and phase variation. As the space of warping functions has a complex geometric structure, one key element of the analysis is transforming the warping functions to
. We present different transformation approaches and show how they fit into a general class of transformations. This allows us to compare their strengths and limitations. In the context of PCA, our results offer arguments in favour of the centred log‐ratio transformation. We further embed two existing approaches from the literature for joint PCA of amplitude and phase variation into the framework of multivariate functional PCA, where we study the properties of the estimators based on an appropriate metric. The approach is illustrated through an application from seismology.
Examining the yields of growth feedback from science teachers and students' intrinsic valuing of science: Implications for student‐ and school‐level science achievement
Authors: Burns Emma C. , Martin Andrew J. , Collie Rebecca J.
Published: February 2019

Students' science knowledge and skills are considered critical to growing the intellectual capital on which societies rely to innovate and prosper. However, recent research has documented notable declines in students' intrinsic valuing of science and science achievement in Australia and other western countries. As a result, there have been calls to investigate factors at both the student‐ and school‐level that can improve intrinsic valuing of and achievement in science. Growth feedback from science teachers to students has been identified as one such factor. Growth feedback, which specifically targets individual student growth and improvement, is considered an effective form of teacher feedback. Because recent research has demonstrated the benefits of effective teacher feedback on intrinsic valuing of science and the positive link between intrinsic valuing of science and science achievement, the present investigation examined (at both the student‐ and school‐level) the extent to which growth feedback in science predicts intrinsic valuing of science and the extent to which intrinsic valuing predicts science achievement and mediates the relationship between growth feedback and achievement. This study examined this hypothesized process with the 2015 Australian PISA sample (N = 14,530 students in N = 758 schools) via a multilevel structural equation model. Findings indicated that at both the student‐ and school‐level, growth feedback significantly predicted intrinsic valuing, and intrinsic valuing significantly predicted achievement; growth feedback also had significant indirect effects of achievement via intrinsic valuing. Taken together, our findings indicate that there are personal and whole‐school yields for science achievement from the experiences of growth feedback in and intrinsic valuing of science.
Negotiation of meaning by mixed‐proficiency dyads in face‐to‐face and synchronous computer‐mediated communication
Authors: Moradi Arezoo , Farvardin Mohammad Taghi
Published: February 2019

Few studies have compared the nature of negotiation of meaning across face‐to‐face (FTF) and synchronous computer‐mediated communication (SCMC) modes with mixed‐proficiency dyads. Such comparisons can help identify important strengths and weaknesses of each mode. Therefore, this study explored whether FTF and SCMC modes differ in terms of frequency and quality of negotiations of meaning in English as a foreign language (EFL) learners’ interaction in mixed‐proficiency dyads. To this end, 32 EFL learners at elementary and upper‐intermediate levels were assigned to 16 mixed‐proficiency dyads to perform two information gap tasks (i.e., spot the differences task and jigsaw task). The participants’ interactions in both modes were coded based on Varonis and Gass's (1985) model of negotiation routines and Long's (1980) negotiation moves. The participants’ interactions in each mode were coded. The results show no significant differences between the frequency of negotiations in both modes. However, the results were controversial regarding the quality of negotiations. The quality of negotiation routines was examined by the number of indicators leading to modified output, which revealed that mode of interaction influenced the quality of negotiations and more modified output was produced in the SCMC mode than the FTF mode.
Knowing Without Having The Competence to Do So
Authors: Hirvelä Jaakko ,   Philosophy Documentation Center
Published: February 2019

According to all varieties of virtue reliabilism, knowledge is always gained through the exercise of epistemic competences.These competences can be conceived as competences to form true beliefs, or as competences to know. I will present a short but decisive argument against the idea that knowledge is always gained through the exercise of competences to know.The competence to know isn’t necessary for gaining knowledge.
Frontiers in data analytics for adaptation research: Topic modeling
Authors: Lesnikowski Alexandra , Belfer Ella , Rodman Emma , Smith Julie , Biesbroek Robbert , Wilkerson John D. , Ford James D. , Berrang‐Ford Lea
Published: February 2019

Rapid growth over the past two decades in digitized textual information represents untapped potential for methodological innovations in the adaptation governance literature that draw on machine learning approaches already being applied in other areas of computational social sciences. This Focus Article explores the potential for text mining techniques, specifically topic modeling, to leverage this data for large‐scale analysis of the content of adaptation policy documents. We provide an overview of the assumptions and procedures that underlie the use of topic modeling, and discuss key areas in the adaptation governance literature where topic modeling could provide valuable insights. We demonstrate the diversity of potential applications for topic modeling with two examples that examine: (a) how adaptation is being talked about by political leaders in United Nations Framework Convention on Climate Change; and (b) how adaptation is being discussed by decision‐makers and public administrators in Canadian municipalities using documents collected from 25 city council archives.

This article is categorized under:

Vulnerability and Adaptation to Climate Change > Institutions for Adaptation
Institutional and environmental effectiveness: Will the Paris Agreement work?
Authors: Dimitrov Radoslav , Hovi Jon , Sprinz Detlef F. , Sælen Håkon , Underdal Arild
Published: February 2019

The 2015 Paris Agreement (PA) has been widely hailed as a diplomatic triumph and a breakthrough in global climate cooperation. However, it is commonly accepted that the PA's collective goal—keeping global warming “well below” 2°C above preindustrial levels—remains ambitious. Making matters even more challenging, in 2017, global CO2emissions resumed growth after 3 years of near standstill. In 2018, this growth accelerated. It is therefore extremely important that the PA's institutional architecture meet expectations concerning its ability to induce member countries to promise and deliver emissions reductions. This study offers a review of the rapidly growing literature on the PA, to assess its strengths and weaknesses, its significance, and its prospects. We focus on evaluations of its institutional structure and its ability to induce member countries to implement policies. We frame the issues as a trilemma: the challenge of simultaneously satisfying all three main conditions for effectiveness—broad participation, deep commitments, and satisfactory compliance rates. Based on our review, we conclude that the key challenge for the PA will likely be to facilitate sufficiently fast ratcheting‐up of nationally determined contributions, while keeping compliance rates high.

This article is categorized under:

Policy and Governance > Multilevel and Transnational Climate Change Governance
Higgs stability-bound and fermionic dark matter
Authors: Held Aaron , Sondenheimer René
Published: February 2019

Abstract

Higgs-portal interactions of fermionic dark matter — in contrast to fermions coupled via Yukawa interactions — can have a stabilizing effect on the standard-model Higgs potential. A non-perturbative renormalization-group analysis reveals that, similar to higher-order operators in the Higgs potential itself, the fermionic portal coupling can increase the metastability scale by only about one order of magnitude. Assuming a thermal freeze-out via the Higgs-portal coupling, this regime of very weakly coupled dark matter is in conflict with relic-density constraints. Conversely, fermionic dark matter with the right relic abundance requires either a low cutoff scale of the effective field theory or a strongly interacting scalar sector. This results in a triviality problem in the scalar sector which persists at the non-perturbative level. The corresponding breakdown of the effective field theory suggests a larger dark sector to be present not too far above the dark-fermion mass-scale.
On OSp(N |2) superconformal mechanics
Authors: Chernyavsky Dmitry
Published: February 2019

Abstract

Superparticle models with OSp(N |2) supersymmetry group are studied. We first consider the N = 4 case and construct the models with κ-symmetry on the coset spaces of the OSp(N |2) supergroup. In addition, within the canonical formalism we present an OSp(4|2) superparticle model with semi-dynamical angular variables. For generic N we construct a superparticle model on AdS
2 × S

N −1 with the reduced κ-symmetry. It is demonstrated that the Hamiltonian of this model has the same structure as the one for the N = 4 casebecauseadditionalfermionscontributetothesecond-classconstraintsonly.
Effect of High Postoperative Body Temperature on Long‐Term Prognosis in Patients with Gastric Cancer After Radical Resection
Authors: Zheng Hua‐Long , Lu Jun , Li Ping , Xie Jian‐Wei , Wang Jia‐Bin , Lin Jian‐Xian , Chen Qi‐Yue , Cao Long‐Long , Lin Mi , Tu Ru‐Hong , Huang Ze‐Ning , Lin Ju‐Li , Zheng Chao‐Hui , Huang Chang‐Ming
Published: February 2019

Background

There is a lack of data on the effect of high postoperative body temperature on disease‐free survival (DFS) in patients who underwent radical gastrectomy.

Methods

Patients who underwent radical gastrectomy from January 2006 to December 2011 were selected. The highest body temperature within 1 week after operation was used to establish diagnostic thresholds for high and low body temperature through X‐tile software.

Results

A total of 1396 patients were included in the analysis. The diagnostic threshold for high body temperature was defined as 38 °C; 370 patients were allocated to the high‐temperature group (HTG), while another 1026 patients were allocated to the low‐temperature group (LTG). For all patients, survival analysis showed that 5‐year DFS in the HTG was significantly lower than that for the LTG (55.6% vs 63.9%, P = 0.007). Multivariate analysis revealed that high postoperative body temperature was an independent prognostic risk factor for 5‐year DFS (HR = 1.288 (1.067–1.555), P = 0.008). For patients without complications, survival analysis showed that the 5‐year DFS rate in the HTG was lower than that for the LTG (57.5% vs 64.4%, P = 0.051), especially in patients with stage III gastric cancer (31.3% vs 41.7%, P = 0.037). For patients with complications or infectious complications, there were no significant differences between the HTG and LTG regarding 5‐year DFS (49.3% vs 58.2%, P = 0.23 and 49.4% vs 55.1%, P = 0.481, respectively).

Conclusion

For stage III gastric cancer patients without complications, high postoperative body temperature can significantly reduce the 5‐year DFS. These patients may benefit from more aggressive adjuvant therapy and postoperative surveillance regimens.
Predicting time to dementia using a quantitative template of disease progression
Authors: Bilgel Murat , Jedynak Bruno M. ,   Alzheimer's Disease Neuroimaging Initiative
Published: February 2019

Introduction

Characterization of longitudinal trajectories of biomarkers implicated in sporadic Alzheimer's disease (AD) in decades before clinical diagnosis is important for disease prevention and monitoring.

Methods

We used a multivariate Bayesian model to temporally align 1369 Alzheimer's disease Neuroimaging Initiative participants based on the similarity of their longitudinal biomarker measures and estimated a quantitative template of the temporal evolution of cerebrospinal fluid A, p‐, and t‐tau and hippocampal volume, brain glucose metabolism, and cognitive measurements. We computed biomarker trajectories as a function of time to AD dementia and predicted AD dementia onset age in a disjoint sample.

Results

Quantitative template showed early changes in verbal memory, cerebrospinal fluid Aβ1–42 and p‐tau181p, and hippocampal volume. Mean error in predicted AD dementia onset age was years.

Discussion

Our method provides a quantitative approach for characterizing the natural history of AD starting at preclinical stages despite the lack of individual‐level longitudinal data spanning the entire disease timeline.
Supplier dependence and R&D intensity: The moderating role of network centrality and interconnectedness
Authors: Kim Dong‐Young , Zhu Pengcheng
Published: February 2019

This study examines whether financial dependence upon a few customers is negatively related to the allocation of innovation resources of supplier firms. Furthermore, this study investigates whether these negative effects of supplier dependence on research and development (R&D) intensity are reduced when the supplier leverages social capital conceptualized in terms of eigenvector centrality and interconnectedness. Using panel data, we find that a supplier firm's dependence upon major customers has a negative relationship with the supplier firm's R&D intensity. Our results, however, reveal that a dependent supplier having high eigenvector centrality or working with other companies that are densely connected to each other mitigates the negative effects of supplier dependence on R&D intensity. These findings highlight the importance of external information or resources being available in supply networks when suppliers that are dependent upon major customers explore and exploit opportunities for new product development.
Effect of a weak ion collisionality on the dynamics of kinetic electrostatic shocks
Authors: Sundström Andréas , Juno James , TenBarge Jason M. , Pusztai István
Published: February 2019

In strictly collisionless electrostatic shocks, the ion distribution function can develop discontinuities along phase-space separatrices, due to partial reflection of the ion population. In this paper, we depart from the strictly collisionless regime and present a semi-analytical model for weakly collisional kinetic shocks. The model is used to study the effect of small but finite collisionalities on electrostatic shocks, and they are found to smooth out these discontinuities into growing boundary layers. More importantly, ions diffuse into and accumulate in the previously empty regions of phase space, and, by upsetting the charge balance, lead to growing downstream oscillations of the electrostatic potential. We find that the collisional age of the shock is the more relevant measure of the collisional effects than the collisionality, where the former can become significant during the lifetime of the shock, even for weak collisionalities.
Elephants and mammoths: the effect of an imperfect legal substitute on illegal activity
Authors: Farah Naima , Boyce John R.
Published: February 2019

In response to the CITES ban on trade in elephant ivory, mammoth ivory began to be produced in post-Soviet Russia. We investigate how this substitute to elephant ivory has affected the poaching of elephants. We argue that the early success of the 1989 ivory ban at increasing the African elephant population was driven in part by increasing supply of mammoth ivory. The more recent increases in poaching appear to be driven by increasing demand and falling African institutional quality. We find that absent the 80 tonnes of Russian mammoth ivory exports per annum 2010–2012, elephant ivory prices would have doubled from their $ 100 per kilogram level and that the current poaching level of 34,000 elephants per year may have increased by as many as 55,000 elephants per year on a population of roughly half a million animals.
Who knows best? Older people’s and practitioner contributions to understanding and preventing avoidable hospital admissions
Authors: Glasby Jon , Littlechild Rosemary , Le Mesurier Nick , Thwaites Rachel
Published: February 2019

Whenever there are well-publicised pressures on acute care, there is a tendency for policy makers and the media to imply that a significant number of older people may be taking up hospital beds when they do not really need the services provided there. However, evidence to back up such claims is often lacking, and existing research tends to fail to engage meaningfully with older people themselves. In contrast, this research explores the emergency hospital admissions of older people in three English case study sites, drawing on the lived experience of older people and the practice wisdom of front-line staff to explore the appropriateness of each admission and scope for alternatives to hospital. Contrary to popular opinion, the study did not find evidence of large numbers of older people being admitted to hospital inappropriately. Indeed, some of the older people concerned delayed seeking help and only ended up at hospital as a very last resort, possibly due to concerns about being seen as a burden on scarce public resources. While older people and front-line staff identified a number of suggestions to improve services in future, there seemed few clear cut, easy answers to the longstanding dilemma of how best to reduce emergency admissions. Seeking to understand and potentially reduce emergency hospital admissions is complex, and it is important to consider the experiences and expertise of older people and front-line staff.