bluuebunny/crossref_metadata_2025 huggingface dataset:
Dinitroaniline herbicide resistance in a multiple‐resistant Lolium rigidum population
Authors: Chen Jinyi , Yu Qin , Owen Mechelle , Han Heping , Powles Stephen
Published: November 2017

BACKGROUND

The pre‐emergence dinitroaniline herbicides (such as trifluralin and pendimethalin) are vital to Australian no‐till farming systems. A Lolium rigidum population collected from the Western Australian grain belt with a 12‐year trifluralin use history was characterised for resistance to dinitroaniline, acetyl CoA carboxylase (ACCase)‐ and acetolactate synthase (ALS)‐inhibiting herbicides. Target‐site resistance mechanisms were investigated.

RESULTS

This L. rigidum population exhibited 32‐fold resistance to trifluralin, as compared with the susceptible population. It also displayed 12‐ to 30‐fold cross‐resistance to other dinitroaniline herbicides (pendimethalin, ethalfluralin and oryzalin). In addition, this population showed multiple resistance to commonly used post‐emergence ACCase‐ and ALS‐inhibiting herbicides. Two target‐site α‐tubulin gene mutations (Val‐202‐Phe and Thr‐239‐Ile) previously documented in other dinitroaniline‐resistant weed species were identified, and some known target‐site mutations in ACCase (Ile‐1781‐Leu, Asp‐2078‐Gly and Cys‐2088‐Arg) and ALS (Pro‐197‐Gln/Ser) were found in the same population. An agar‐based Petri dish screening method was established for the rapid diagnosis of resistance to dinitroaniline herbicides.

CONCLUSION

Evolution of target‐site resistance to both pre‐ and post‐emergence herbicides was confirmed in a single L. rigidum population. The α‐tubulin mutations Val‐202‐Phe and Thr‐239‐Ile, documented here for the first time in L. rigidum, are likely to be responsible for dinitroaniline resistance in this population. Early detection of dinitroaniline herbicide resistance and integrated weed management strategies are needed to maintain the effectiveness of dinitroaniline herbicides. © 2017 Society of Chemical Industry
Monitoring resistance of Cydia pomonella (L.) Spanish field populations to new chemical insecticides and the mechanisms involved
Authors: Bosch Dolors , Rodríguez Marcela A , Avilla Jesús
Published: November 2017

BACKGROUND

Widespread resistance of Cydia pomonella to organophosphates was demonstrated in populations from the Spanish Ebro Valley area which showed high levels of enzymatic detoxification. To determine the efficacy of new insecticides, neonate larval bioassays were carried out on 20 field codling moth populations collected from three different Spanish apple production areas. Synergist bioassays were performed to determine the enzymatic mechanisms involved.

RESULTS

The least active ingredients were methoxyfenozide, with 100% of the populations showing significantly lower mortality than the susceptible strain, and lambda‐cyhalothrin, with very high resistance ratios (872.0 for the most resistant field population). Approximately 50% of the populations were resistant or tolerant to thiacloprid. By contrast, tebufenozide was very effective in all the field populations, as was chlorpyrifos‐ethyl despite its widespread use during the last few years. Indoxacarb, spinosad and chlorantraniliprole also provided high efficacy, as did emamectin and spinetoram, which are not yet registered in Spain.

CONCLUSION

The resistant Spanish codling moth populations can be controlled using new reduced‐risk insecticides. The use of synergists showed the importance of the concentration applied and the difficulty of interpreting results in field populations that show multiple resistance to different active ingredients. © 2017 Society of Chemical Industry
Ambrosia artemisiifolia as a potential resource for management of golden apple snails, Pomacea canaliculata (Lamarck)
Authors: Ding Wenbing , Huang Rui , Zhou Zhongshi , He Hualiang , Li Youzhi
Published: November 2017

BACKGROUND

Ambrosia artemisiifolia, an invasive weed in Europe and Asia, is highly toxic to the golden apple snail (GAS; Pomacea canaliculata) in laboratory tests. However, little is known about the chemical components of A. artemisiifolia associated with the molluscicidal activity or about its potential application for GAS control in rice fields. This study evaluated the molluscicidal activities of powders, methanol extracts, and individual compounds from A. artemisiifolia against GAS in rice fields and under laboratory conditions.

RESULTS

Ambrosia artemisiifolia powders did not negatively affect the growth and development of rice but they reduced damage to rice caused by GAS. Extracts had moderate acute toxicity but potent chronic toxicity. The 24‐h 50% lethal concentration (LC50) of the extracts against GAS was 194.0 mg L–1, while the weights, lengths and widths of GAS were significantly affected by exposure to a sublethal concentration (100 mg/mL). Psilostachyin, psilostachyin B, and axillaxin were identified as the most active molluscicide components in the aerial parts of A. artemisiifolia, and the 24‐h LC50 values of these purified compounds were 15.9, 27.0, and 97.0 mg/L, respectively.

CONCLUSION

The results indicate that chemical compounds produced by A. artemisiifolia may be useful for population management of GAS in rice fields. © 2017 Society of Chemical Industry
Criteria to define interruption of transmission of human cytomegalovirus from organ donor to recipient
Authors: Baraniak Ilona Anna , Reeves Matthew B. , Griffiths Paul D.
Published: November 2017

In this review article, we consider results suggesting that transmission of human cytomegalovirus (HCMV) from a donor of a solid organ to an immunologically naive individual can be reduced. Two randomized controlled trials have been conducted recently, one of active immunization of recipients pretransplant and another of passive immunization with monoclonal antibodies specific for HCMV given at the time of transplant. Although the available data are encouraging—providing evidence of a reduction in the incidence of HCMV viraemia—they fall short of what would be required to prove definitively that transmission has been completely prevented. Here, we reflect on these studies and propose a set of 5 criteria, which, if satisfied in the future, could be taken as proof that active and/or passive immunization against HCMV effectively interrupts transmission of virus from the donor. We suggest that these criteria are considered when designing future randomized controlled trials.
A novel SON2‐based similarity index and its application for the rationalization of river water quality monitoring network
Authors: Antanasijević D. , Pocajt V. , Antanasijević J. , Perić‐Grujić A. , Ristić M.
Published: November 2017

In this paper, a novel self‐organizing network (SON) based similarity index and its application for the optimization of sampling locations in an existing river water quality monitoring network (WQMN) is presented. A rationalization of the River Danube WQMN on its stretch through Serbia was performed using the proposed SON2‐based similarity index. A high‐dimensional dataset was used, which is composed of 18 water quality parameters that were collected during the period 2002–2010 at 17 monitoring locations. The SON‐based seasonal classification that divides 12 months into the cold, moderate, and warm seasons was employed, whereas its second application on each seasonal class yielded subclasses that were used to compare the monitoring locations. The obtained SON2‐based similarity index can be utilized for analysing seasonal variations, as well as overall similarities among neighbouring sites. Based on the calculated similarities of locations and characteristics of the River Danube basin a rationalized WQMN, which uses 30% less monitoring sites, has been proposed.
To swim or to jump? Passage behaviour of a potamodromous cyprinid over an experimental broad‐crested weir
Authors: Amaral S.D. , Branco P. , Katopodis C. , Ferreira M.T. , Pinheiro A.N. , Santos J.M.
Published: November 2017

Physical stressors, such as man‐made obstacles, are considered one of the main causes that negatively affect freshwater fish. Even small weirs may impact fish populations, including potamodromous cyprinids, by partially or totally blocking upstream migratory movements. Some studies have addressed the effect of key hydraulic parameters on upstream movements past small weirs, but little is known on how these parameters interact to induce swimming or jumping behaviour in negotiating such obstacles. This study aims to evaluate the passage behaviour (swimming vs. jumping) of Iberian barbel (Luciobarbus bocagei), a potamodromous species, over an experimental small broad‐crested weir, considering the effect of different plunge pool depths (D), waterfall heights (H), and weir discharges (Q). Results revealed that passage behaviour was highly dependent on combinations of plunge pool depths and waterfall heights. Barbel navigated most configurations by swimming (overall outcomes: 81.5% swimming vs. 18.5% jumping), except the ones with the higher waterfall heights (25 cm) tested. Therefore, higher waterfalls proved to be preponderant in the switching of passage behaviour from swimming to jumping. Regarding the discharge over the 1‐m‐wide weir (overall outcomes: 85% swimming vs. 15% jumping), contrary to what was expected, there was no evidence that passage behaviour was discharge‐related, for the range of discharges tested (25–100 L/s). These results are useful to identify potential migration obstacles and should be taken into consideration in river restoration projects and when designing fishways for potamodromous cyprinids.
Design, Synthesis and Biological Evaluation of Novel 2‐Phenylthiazole Derivatives for the Treatment of Alzheimer's Disease
Authors: Shi Da‐Hua , Tang Zong‐ming , Liu Yu‐Wei , Harjani Jitendra R. , Zhu Hui‐Long , Ma Xiao‐Dong , Song Xiao‐Kai , Liu Wei‐Wei , Lu Chen , Yang Wen‐Tao , Song Meng‐Qiu
Published: November 2017

A new series of 2‐phenylthiazole derivatives were designed, synthesized, characterized and evaluated as potential candidates to treat Alzheimer's disease. Most of these compounds exhibited significant acetylcholinesterase inhibitory activities. Among them, compound ethyl 2‐[4‐(4‐{[2‐(pyrrolidin‐1‐yl)ethyl]amino}butoxy)phenyl]thiazole‐4‐carboxylate (5 b–8) exhibited the best acetylcholinesterase inhibition activity with IC50 values of 4.8 μM. Moreover, the compound ethyl 2‐(4‐{[5‐(cyclohexylamino)pentyl]oxy}phenyl)thiazole‐4‐carboxylate (5 c–6) had the best butyrylcholinesterase inhibitory activity, with an IC50 value of 0.16 μM. The docking studies demonstrated that compound 5 b–8 could interact with both the catalytic active site (CAS) and the peripheral anionic site (PAS) of acetylcholinesterase. Compound 5 b–8 also showed biometal chelating abilities. These attributes highlight 5 b–8 as a promising candidate for further studies directed to the development of novel drugs against Alzheimer's disease.
A Combined Experimental and Theoretical Study to Explore the Importance of σ‐Hole Carbon Bonding Interactions in Stabilizing Molecular Assemblies
Authors: Roy Sourav , Drew Michael G. B. , Bauzá Antonio , Frontera Antonio , Chattopadhyay Shouvik
Published: November 2017

Two new hetero‐dinuclear nickel(II)/cadmium(II) complexes, [(DMF)1.78(DMSO)0.22NiL1Cd(Cl)(NCS)] (1) and [(DMF)(H2O)NiL2CdCl2]⋅DMF (2) with compartmental Schiff bases, H2L1=N,N′‐bis(3‐ethoxysalicylidene)‐2,2‐dimethylpropane‐1,3‐diamine and H2L2 = N,N′‐bis(5‐bromo‐3‐methoxysalicylidene)‐2,2‐dimethylpropane‐1,3‐diamine, have been prepared and characterized by single crystal X‐ray diffraction analysis. In each complex, nickel(II) and cadmium(II) are placed in the N2O2 and O2O2' compartments of the Schiff base respectively. Both complexes form interesting supramolecular assemblies in the solid state. Energy associated with conventional C−H⋅⋅⋅π interaction in complex 1 and unconventional σ‐hole carbon bonding interaction in complex 2 in the solid state of these complexes are estimated by DFT calculation and characterized by Natural Bond Orbital analysis and molecular electrostatic potential surface analysis as well.
Guanidine Cellulose for Biocompatible Nanoparticles Phase Transfer
Authors: Xie Haibo , Cao Xuefeng , Shan Shuang , Chen Qin , Xu Qinqin , Guo Yuanlong , Tan Mingqian
Published: November 2017

The introduction of 1, 1, 3, 3‐tetramethyl guanidine groups with degree of substitution of 0.18 into cellulose can tailor the solubility of cellulose in water, which leads to a general and robust development of biopolymer‐based biodegradable and biocompatible material for phase‐transfer of hydrophobic biocompatible nanoparticles to aqueous solution. Fourier transform infrared spectroscopy shows the successful ligand exchange between small molecules and 1, 1, 3, 3‐tetramethyl guanidine functionalized cellulose during the phase transfer. Transmission electron microscope images of the original and transferred nanoparticles confirm the success of the phase transfer without obvious agglomeration occurred. The transferred nanoparticles possessed their own unique properties such as surface plasmon resonance, magnetism, up‐conversion fluorescence.
Nested identities as cognitive drivers of strategy
Authors: Irwin Jennifer , Lahneman Brooke , Parmigiani Anne
Published: November 2017

Research Summary: Organizations face tensions to conform to industry norms for legitimacy yet differentiate for competitive advantage when implementing strategies. We suggest this tension is due to and resolved through organizations’ cognitive negotiations of multiple levels of identity. Through an inductive study in the recreational vehicle industry, we find that organizations concurrently draw on identities at the organizational, industry, and strategic group levels to formulate and enact specific competitive actions. Specifically, we find that organizational identity relates to decisions on product offerings; industry identity relates to downstream strategy; and strategic group identity relates to upstream strategy, firm boundaries, and expansion mode. Our findings highlight the importance of strategic group identity and inform a grounded model describing how organizations draw upon different levels of identity to influence strategy.

Managerial Summary: Many managers experience tensions of differentiating their firms’ competitive actions from rivals, while conforming with industry norms and practices. In this article, we argue that a manager can navigate these tensions by understanding their firm, strategic group, and industry identities and how these identities interrelate. Through a qualitative case study of the U.S. recreational vehicle industry, we show that each level of identity influences different competitive actions, with firm identity connected to product offerings, industry identity related to managing downstream distribution, and strategic group identity related to firm boundary and acquisition strategies. Overall, strategic group identity is the most critical for managers as this level filters how they view competitors and provides the rules of competition.
Molten Salt Assisted Self‐Assembly: Synthesis of Mesoporous LiCoO2 and LiMn2O4 Thin Films and Investigation of Electrocatalytic Water Oxidation Performance of Lithium Cobaltate
Authors: Saat Gülbahar , Balci Fadime Mert , Alsaç Elif Pınar , Karadas Ferdi , Dag Ömer
Published: November 2017

Mesoporous thin films of transition metal lithiates (TML) belong to an important group of materials for the advancement of electrochemical systems. This study demonstrates a simple one pot method to synthesize the first examples of mesoporous LiCoO2 and LiMn2O4 thin films. Molten salt assisted self‐assembly can be used to establish an easy route to produce mesoporous TML thin films. The salts (LiNO3 and [Co(H2O)6](NO3)2 or [Mn(H2O)4](NO3)2) and two surfactants (10‐lauryl ether and cethyltrimethylammonium bromide (CTAB) or cethyltrimethylammonium nitrate (CTAN)) form stable liquid crystalline mesophases. The charged surfactant is needed for the assembly of the necessary amount of salt in the hydrophilic domains of the mesophase, which produces stable metal lithiate pore‐walls upon calcination. The films have a large pore size with a high surface area that can be increased up to 82 m2 g−1. The method described can be adopted to synthesize other metal oxides and metal lithiates. The mesoporous thin films of LiCoO2 show promising performance as water oxidation catalysts under pH 7 and 14 conditions. The electrodes, prepared using CTAN as the cosurfactant, display the lowest overpotentials in the literature among other LiCoO2 systems, as low as 376 mV at 10 mA cm–2 and 282 mV at 1 mA cm–2.
Scalable Fabrication of Highly Active and Durable Membrane Electrodes toward Water Oxidation
Authors: Li Yu , Chen Shuangming , Xi Dawei , Bo Yanan , Long Ran , Wang Chengming , Song Li , Xiong Yujie
Published: November 2017

The electrocatalytic oxygen evolution reaction (OER) is a highly important reaction that requires a relatively high overpotential and determines the rate of water splitting—a process for producing hydrogen. The overall OER performance is often largely limited by uncontrollable interface when active catalysts are loaded on conductive supports, for which polymer binders are widely used, but inevitably block species transportation channels. Here, a scalable fabrication approach to freestanding graphitized carbon nanofiber networks is reported, which provides abundant sites for in situ growing Fe/Ni catalysts with the improved interface. The fabricated hybrid membrane exhibits high activity and durability toward OER, with an overpotential of 280 mV at a geometrical current density of 10 mA cm−2 and a Tafel slope of 30 mV dec−1 in alkaline medium. As implemented as a freestanding electrode, the 3D hybrid structure achieves further enhanced OER performance with an overpotential down to 215 mV at 10 mA cm−2. This work provides fresh insights into rationally fabricating OER electrocatalysts from the angle of electrode design.
Dual Roles of Protein as a Template and a Sulfur Provider: A General Approach to Metal Sulfides for Efficient Photothermal Therapy of Cancer
Authors: Sheng Jianping , Wang Liqiang , Han Yajing , Chen Wansong , Liu Hong , Zhang Min , Deng Liu , Liu You‐Nian
Published: November 2017

Fabrication of clinically translatable nanoparticles (NPs) as photothermal therapy (PTT) agents against cancer is becoming increasingly desirable, but still challenging, especially in facile and controllable synthesis of biocompatible NPs with high photothermal efficiency. A new strategy which uses protein as both a template and a sulfur provider is proposed for facile, cost‐effective, and large‐scale construction of biocompatible metal sulfide NPs with controlled structure and high photothermal efficiency. Upon mixing proteins and metal ions under alkaline conditions, the metal ions can be rapidly coordinated via a biuret‐reaction like process. In the presence of alkali, the inert disulfide bonds of S‐rich proteins can be activated to react with metal ions and generate metal sulfide NPs under gentle conditions. As a template, the protein can confine and regulate the nucleation and growth of the metal sulfide NPs within the protein formed cavities. Thus, the obtained metal sulfides such as Ag2S, Bi2S3, CdS, and CuS NPs are all with small size and coated with proteins, affording them biocompatible surfaces. As a model material, CuS NPs are evaluated as a PTT agent for cancer treatment. They exhibit high photothermal efficiency, high stability, water solubility, and good biocompatibility, making them an excellent PTT agent against tumors. This work paves a new avenue toward the synthesis of structure‐controlled and biocompatible metal sulfide NPs, which can find wide applications in biomedical fields.
Internal quality assurance for external contributions in GitHub: An empirical investigation
Authors: Lu Yao , Mao Xinjun , Li Zude , Zhang Yang , Wang Tao , Yin Gang
Published: November 2017

For popular open‐source software projects, there are always a large number of worldwide developers who have been glued to making code contributions, while most of these developers play the role of casual contributors because of their very limited code commits. The frequent turnover of such a group of developers and the wide variations in their coding experiences challenge the project management on code and quality. This paper aims to investigate the status quo of internal quality assurance for external contributions in social coding sites. We first conducted a case study of 21 popular GitHub projects to estimate the code quality of the casual contributors. The quantitative results show that the casual contributors introduced greater quantity and severity of code quality issues than the main contributors; the developers who contribute to different projects as main and casual contributors did not perform significantly differently in terms of their code quality. On the basis of these findings, we further conducted a survey of 81 developers on GitHub to understand their practices on internal quality assurance. The qualitative results expose some limitations of present internal quality control for external contributions in GitHub. Finally, we discuss an alternative quality management paradigm: Continuous Inspection for industrial practices.
Recent Progress in Oxygen Electrocatalysts for Zinc–Air Batteries
Authors: Yang Dongjiang , Zhang Lijie , Yan Xuecheng , Yao Xiangdong
Published: November 2017

Zinc–air batteries (ZABs) have attracted extensive attention due to their remarkable high theoretical energy output. They represent one of the most promising future power sources. However, many barriers restrict their application on a large scale. One of the main challenges is the sluggish rates of the oxygen‐reduction reaction (ORR) and oxygen‐evolution reaction (OER), which govern the discharging and charging processes of the battery, respectively. Here, recent advances related to oxygen electrocatalyst materials for ZABs are discussed. Detailed discussions will focus on unifunctional ORR electrocatalysts and bifunctional ORR and OER electrocatalysts. Pt‐based nanomaterials, as the best ORR electrocatalysts, possess the virtue of high activity, but have the disadvantages of high cost, scarcity, and poor stability. Thus, materials based on transition metals (alloys, metal oxides, metal nitrides, and spinel oxides) and metal‐free materials are widely investigated as nonprecious ORR catalysts owing to their promising catalytic activities. As for bifunctional ORR and OER electrocatalysts, the following two categories are introduced: (i) metal‐based materials, including single metal/metal‐oxides‐based materials and mixed‐metal/metal‐oxides‐based materials; and (ii) metal‐free materials. Finally, perspectives on the continuous research and limitation of the current ZAB technology are provided.
General and Scalable Solid‐State Synthesis of 2D MPS3 (M = Fe, Co, Ni) Nanosheets and Tuning Their Li/Na Storage Properties
Authors: Liang Qinghua , Zheng Yun , Du Chengfeng , Luo Yubo , Zhang Jianli , Li Bing , Zong Yun , Yan Qingyu
Published: November 2017

The scalable preparation of 2D nanomaterials is challenging and highly desirable for fundamental interest and practical applications. Herein, an efficient solid‐state method is developed for producing emerging 2D ternary layered metal phosphorus trichalcogenide (MPS3, M = Fe, Co, Ni) nanosheets on a large scale. The high‐quality MPS3 single‐crystal nanosheets are exposed with (00l) facets and have an average lateral size of ≈200 nm and an average thickness of ≈18 nm. Moreover, their interlayer spacing can be expanded by intercalating propylamine at room temperature. For Li/Na storage applications, such MPS3 nanosheets can achieve: i) high specific capacity owing to the intrinsic composition, realizing a theoretical specific capacity higher than the corresponding metal oxides, and ii) superior rate capability due to the large extrinsic pseudocapacitive contribution from surface redox reactions. Remarkably, the propylamine‐intercalated samples show improved Li/Na storage performance due to the better electrical conductivity and enlarged interlayer distance to allow easier ion accessibility and faster ion diffusion. Impressively, the Na‐ion batteries based on the intercalated NiPS3 nanosheets deliver 1090 and 536 mA h g−1 at 0.05 and 5.0 A g−1, respectively. This work paves the way for developing MPS3 nanosheets for energy storage and conversion, catalysis, and so on.
Antitumor and anti‐metastatic mechanisms of Rhizoma paridis saponins in Lewis mice
Authors: Man Shuli , Chai Hongyan , Cui Jingxia , Yao Jingwen , Ma Long , Gao Wenyuan
Published: November 2017

Lung cancer is one of the most common causes of death in the world. Rhizoma paridis saponins (RPS) have been found to show inhibition of pulmonary adenoma in previous research. However, the detailed mechanisms of RPS from a holistic view have not been established. In this study, Lewis pulmonary adenoma mice were successfully established to analyze the pathways involved in RPS intervening tumor formation and progression. As a result, RPS inhibited levels of cytokines or receptors such as VEGFD, VEGFR3, RAGE, IL6R, IL17BR, and CXCL16 which were regarded as the initiators induced tumor cell proliferation, adhesion, angiogenesis, and invasion. Meanwhile, RPS raised the content of SOD and CAT enzymes and thereby inhibited the aberrantly active NF‐κB, and phosphorylation of PI3K/Akt and MAPK (including p38, Erk1/2, and JNK) signaling pathways. Soon after, RPS changed mRNA expression of nuclear factors containing NF‐κB, HIF‐1A, STAT3, and Jun, and consequentially suppressed the expression of angiogenesis, lymphangiogenesis, adhesion, inflammation, and invasion enzymes. In conclusion, this research provided a holistic view to understand the multi‐target antitumor mechanisms of RPS which promoted the application of RPS in the future.
The sensing mechanism studies of the fluorescent probes with electronically excited state calculations
Authors: Li Guang‐Yue , Han Ke‐Li
Published: November 2017

Recent research has indicated that fluorescent probes have tremendous potential for the selective detection of chemical and biological species. Over the past decade, researchers have proposed a series of fluorescence‐based sensing mechanisms of such probes by the calculation of their electronic excited states. Investigations of sensing mechanisms have been based on deep insights into the interactions between probe molecules and their target species, as well as their fluorescence properties. Advances in calculation methods, modeling software, and computational power have enabled researchers to use excited‐state theoretical calculations to reproduce experimental fluorescence phenomena and then provide molecular‐level explanations thereof. In this advanced review, we describe the evolution of theoretical studies on excited‐state sensing mechanisms for fluorescent probes that respond to target species. Focusing on calculation methods that facilitate investigation of the photophysical properties and excited‐state dynamics of probes, we emphasize sensing mechanisms mainly reported by our group. Most of these studies have been supported by theoretical predictions based on time‐dependent density functional theory. For this most popular excited‐state calculation method, vertical excitation energy, excited‐state geometrical optimization and a scan of the excited‐state potential energy surface should be noted in the calculation of electronic and molecular differences between the excited‐state probe and its reaction product with the target analyte. These state‐of‐the‐art calculations are of great importance for unraveling details of fluorescence‐based sensing mechanisms, including photochemical reactions (such as twist intramolecular charge transfer and excited‐state proton transfer) and excited‐state electronic processes (such as intramolecular charge transfer and photoinduced electron transfer). These studies have generated new and inspirational mechanistic proposals and have provided a systematic approach for the development of efficient fluorescent sensors. WIREs Comput Mol Sci 2018, 8:e1351. doi: 10.1002/wcms.1351

This article is categorized under:

Structure and Mechanism > Computational Biochemistry and Biophysics

Theoretical and Physical Chemistry > Spectroscopy
Large‐eddy simulations of wind‐farm wake characteristics associated with a low‐level jet
Authors: Na Ji Sung , Koo Eunmo , Jin Emilia Kyung , Linn Rodman , Ko Seung Chul , Muñoz‐Esparza Domingo , Lee Joon Sang
Published: November 2017

In this study, we performed a suite of flow simulations for a 12‐wind‐turbine array with varying inflow conditions and lateral spacings, and compared the impacts of the flow on velocity deficit and wake recovery. We imposed both laminar inflow and turbulent inflows, which contain turbulence for the Ekman layer and a low‐level jet (LLJ) in the stable boundary layer. To solve the flow through the wind turbines and their wakes, we used a large‐eddy simulation technique with an actuator‐line method. We compared the time series for the velocity deficit at the first and rear columns to observe the temporal change in velocity deficit for the entire wind farm. The velocity deficit at the first column for LLJ inflow was similar to that for laminar inflow. However, the magnitude of velocity deficit at the rear columns for the case with LLJ inflow was 11.9% greater because of strong wake recovery, which was enhanced by the vertical flux of kinetic energy associated with the LLJ. To observe the spatial transition and characteristics of wake recovery, we performed statistical analyses of the velocity at different locations for both the laminar and LLJ inflows. These studies indicated that strong wake recovery was present, and a kurtosis analysis showed that the probability density function for the streamwise velocity followed a Gaussian distribution. In a quadrant analysis of the Reynolds stress, we found that the ejection and sweep motions for the LLJ inflow case were greater than those for the laminar inflow case.
Bayesian multiple comparisons and model selection
Authors: Neath Andrew A. , Flores Javier E. , Cavanaugh Joseph E.
Published: November 2017

The testing of multiple hypotheses is an important consideration in many statistical analyses. A theme for multiple comparisons problems under a frequentist paradigm is the need for an adjustment to control the overall error probability for the false detection of null effects. Our review will focus on Bayesian approaches to multiple comparisons problems. Under a Bayesian paradigm, multiplicity adjustments arise from a concern that many of the effects to be tested are null. We will discuss how Bayesian models provide a multiplicity adjustment through a prior placing increased probability on null effects, or through hierarchical modeling. We will also show how the Bayesian information criterion for model selection fits naturally into the study of multiple comparisons problems. WIREs Comput Stat 2018, 10:e1420. doi: 10.1002/wics.1420

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Bayesian Methods and Theory

Statistical and Graphical Methods of Data Analysis > Modeling Methods and Algorithms

Data: Types and Structure > Traditional Statistical Data
Is pressurized exhaust an effective tool against burrowing rodents?
Authors: Baldwin Roger A. , Kavermann Matt , Meinerz Ryan , Orloff Steve B.
Published: November 2017

Burrow fumigants are lethal tools for mitigating rodent damage, but until recently, only gas cartridges and aluminum phosphide were registered for use in California, USA. In 2012, pressurized exhaust machines that emit carbon monoxide were legalized for use, although their efficacy was unknown. From 2014 through 2015, we assessed the efficacy of the Pressurized Exhaust Rodent Controller (PERC) for managing California ground squirrels (Otospermophilus spp.) and pocket gophers (Thomomys bottae) across various localities in California. The PERC machine proved effective for California ground squirrels (efficacy = 83%), although results were variable across the 2 study areas (efficacy = 66–100%), potentially due to differences in soil moisture or injection time across study sites. The PERC machine was moderately effective at controlling pocket gophers (efficacy = 68%), but performed better than in previous studies. Pressurized exhaust machines show promise as a tool for managing burrowing rodents. © 2017 The Wildlife Society.
Keeping and breeding the rescued Sunda pangolins (Manis javanica) in captivity
Authors: Zhang Fuhua , Yu Jiaming , Wu Shibao , Li Shaoshan , Zou Cuiyun , Wang Qiaoyun , Sun Ruyong
Published: November 2017

The Sunda pangolin (Manis javanica Desmarest, 1822) is a Critically Endangered species. Given that this species lacks effective policies for in situ conservation and prevention of poaching in the wild, ex situ conservation and a captive breeding program are urgently needed to save this species from extinction. However, techniques for the maintenance and captive breeding of pangolins have not been well developed. In June 2010, we established the Pangolin Research Base for Artificial Rescue and Conservation Breeding of South China Normal University (PRB‐SCNU). To date, a total of 34 Sunda pangolin cubs have been born at PRB‐SCNU, 26 of which were captive bred, indicating great progress in keeping and breeding the Sunda pangolin. The techniques for maintenance—including housing, transitioning to an artificial diet, husbandry, and captive breeding—are described in this paper. The purpose of this manuscript is to share our successful experiences and techniques in the maintenance, management, and captive breeding of Sunda pangolins, and to provide guidance and a reference for the captive care and management of Sunda pangolins and other pangolin species.
Gauge backgrounds and zero-mode counting in F-theory
Authors: Bies Martin , Mayrhofer Christoph , Weigand Timo
Published: November 2017

Abstract

Computing the exact spectrum of charged massless matter is a crucial step towards understanding the effective field theory describing F-theory vacua in four dimensions. In this work we further develop a coherent framework to determine the charged massless matter in F-theory compactified on elliptic fourfolds, and demonstrate its application in a concrete example. The gauge background is represented, via duality with M-theory, by algebraic cycles modulo rational equivalence. Intersection theory within the Chow ring allows us to extract coherent sheaves on the base of the elliptic fibration whose cohomology groups encode the charged zero-mode spectrum. The dimensions of these cohomology groups are computed with the help of modern techniques from algebraic geometry, which we implement in the software gap. We exemplify this approach in models with an Abelian and non-Abelian gauge group and observe jumps in the exact massless spectrum as the complex structure moduli are varied. An extended mathematical appendix gives a self-contained introduction to the algebro-geometric concepts underlying our framework.
Donaldson-Witten theory and indefinite theta functions
Authors: Korpas Georgios , Manschot Jan
Published: November 2017

Abstract

We consider partition functions with insertions of surface operators of topologically twisted$$ \mathcal{N}=2 $$N=2, SU(2) supersymmetric Yang-Mills theory, or Donaldson-Witten theory for short, on a four-manifold. If the metric of the compact four-manifold has positive scalar curvature, Moore and Witten have shown that the partition function is completely determined by the integral over the Coulomb branch parametera, while more generally the Coulomb branch integral captures the wall-crossing behavior of both Donaldson polynomials and Seiberg-Witten invariants. We show that after addition of a$$ \overline{\mathcal{Q}} $$Q¯-exact surface operator to the Moore-Witten integrand, the integrand can be written as a total derivative to the anti-holomorphic coordinateāusing Zwegers’ indefinite theta functions. In this way, we reproduce Göttsche’s expressions for Donaldson invariants of rational surfaces in terms of indefinite theta functions for any choice of metric.
Sterile neutrinos or flux uncertainties? — Status of the reactor anti-neutrino anomaly
Authors: Dentler Mona , Hernández-Cabezudo Álvaro , Kopp Joachim , Maltoni Michele , Schwetz Thomas
Published: November 2017

Abstract

The ∼ 3σ discrepancy between the predicted and observed reactor anti-neutrino flux, known as the reactor anti-neutrino anomaly, continues to intrigue. The recent discovery of an unexpected bump in the reactor anti-neutrino spectrum, as well as indications that the flux deficit is different for different fission isotopes seems to disfavour the explanation of the anomaly in terms of sterile neutrino oscillations. We critically review this conclusion in view of all available data on electron (anti)neutrino disappearance. We find that the sterile neutrino hypothesis cannot be rejected based on global data and is only mildly disfavored compared to an individual rescaling of neutrino fluxes from different fission isotopes. The main reason for this is the presence of spectral features in recent data from the NEOS and DANSS experiments. If state-of-the-art predictions for reactor fluxes are taken at face value, sterile neutrino oscillations allow a consistent description of global data with a significance close to 3σ relative to the no-oscillation case. Even if reactor fluxes and spectra are left free in the fit, a 2σ hint in favour of sterile neutrinos remains, with allowed parameter regions consistent with an explanation of the anomaly in terms of oscillations.
The influence of cervical movement on eye stabilization reflexes: a randomized trial
Authors: Ischebeck Britta K. , de Vries Jurryt , van Wingerden Jan Paul , Kleinrensink Gert Jan , Frens Maarten A. , van der Geest Jos N.
Published: November 2017

To investigate the influence of the amount of cervical movement on the cervico-ocular reflex (COR) and vestibulo-ocular reflex (VOR) in healthy individuals. Eye stabilization reflexes, especially the COR, are changed in neck pain patients. In healthy humans, the strength of the VOR and the COR are inversely related. In a cross-over trial the amplitude of the COR and VOR (measured with a rotational chair with eye tracking device) and the active cervical range of motion (CROM) was measured in 20 healthy participants (mean age 24.7). The parameters were tested before and after two different interventions (hyperkinesia: 20 min of extensive active neck movement; and hypokinesia: 60 min of wearing a stiff neck collar). In an additional replication experiment the effect of prolonged (120 min) hypokinesia on the eye reflexes were tested in 11 individuals. The COR did not change after 60 min of hypokinesia, but did increase after prolonged hypokinesia (median change 0.220; IQR 0.168, p = 0.017). The VOR increased after 60 min of hypokinesia (median change 0.155, IQR 0.26, p = 0.003), but this increase was gone after 120 min of hypokinesia. Both reflexes were unaffected by cervical hyperkinesia. Diminished neck movements influences both the COR and VOR, although on a different time scale. However, increased neck movements do not affect the reflexes. These findings suggest that diminished neck movements could cause the increased COR in patients with neck complaints.
Score-Based Tests of Differential Item Functioning via Pairwise Maximum Likelihood Estimation
Authors: Wang Ting , Strobl Carolin , Zeileis Achim , Merkle Edgar C.
Published: November 2017

Measurement invariance is a fundamental assumption in item response theory models, where the relationship between a latent construct (ability) and observed item responses is of interest. Violation of this assumption would render the scale misinterpreted or cause systematic bias against certain groups of persons. While a number of methods have been proposed to detect measurement invariance violations, they typically require advance definition of problematic item parameters and respondent grouping information. However, these pieces of information are typically unknown in practice. As an alternative, this paper focuses on a family of recently proposed tests based on stochastic processes of casewise derivatives of the likelihood function (i.e., scores). These score-based tests only require estimation of the null model (when measurement invariance is assumed to hold), and they have been previously applied in factor-analytic, continuous data contexts as well as in models of the Rasch family. In this paper, we aim to extend these tests to two-parameter item response models, with strong emphasis on pairwise maximum likelihood. The tests’ theoretical background and implementation are detailed, and the tests’ abilities to identify problematic item parameters are studied via simulation. An empirical example illustrating the tests’ use in practice is also provided.
Two-Step Estimation of Models Between Latent Classes and External Variables
Authors: Bakk Zsuzsa , Kuha Jouni
Published: November 2017

We consider models which combine latent class measurement models for categorical latent variables with structural regression models for the relationships between the latent classes and observed explanatory and response variables. We propose a two-step method of estimating such models. In its first step, the measurement model is estimated alone, and in the second step the parameters of this measurement model are held fixed when the structural model is estimated. Simulation studies and applied examples suggest that the two-step method is an attractive alternative to existing one-step and three-step methods. We derive estimated standard errors for the two-step estimates of the structural model which account for the uncertainty from both steps of the estimation, and show how the method can be implemented in existing software for latent variable modelling.
Detecting Multiple Random Changepoints in Bayesian Piecewise Growth Mixture Models
Authors: Lock Eric F. , Kohli Nidhi , Bose Maitreyee
Published: November 2017

Piecewise growth mixture models are a flexible and useful class of methods for analyzing segmented trends in individual growth trajectory over time, where the individuals come from a mixture of two or more latent classes. These models allow each segment of the overall developmental process within each class to have a different functional form; examples include two linear phases of growth, or a quadratic phase followed by a linear phase. The changepoint (knot) is the time of transition from one developmental phase (segment) to another. Inferring the location of the changepoint(s) is often of practical interest, along with inference for other model parameters. A random changepoint allows for individual differences in the transition time within each class. The primary objectives of our study are as follows: (1) to develop a PGMM using a Bayesian inference approach that allows the estimation of multiple random changepoints within each class; (2) to develop a procedure to empirically detect the number of random changepoints within each class; and (3) to empirically investigate the bias and precision of the estimation of the model parameters, including the random changepoints, via a simulation study. We have developed the user-friendly package BayesianPGMM for R to facilitate the adoption of this methodology in practice, which is available at https://github.com/lockEF/BayesianPGMM. We describe an application to mouse-tracking data for a visual recognition task.
Optimal portfolio selection under vanishing fixed transaction costs
Authors: Christensen Sören , Irle Albrecht , Ludwig Andreas
Published: November 2017

In this paper asymptotic results in a long-term growth rate portfolio optimization model under both fixed and proportional transaction costs are obtained. More precisely, the convergence of the model when the fixed costs tend to 0 is investigated. A suitable limit model with purely proportional costs is introduced and the convergence of optimal boundaries, asymptotic growth rates, and optimal risky fraction processes is rigorously proved. The results are based on an in-depth analysis of the convergence of the solutions to the corresponding Hamilton–Jacobi–Bellman equations.
Exponential ergodicity of an affine two-factor model based on the α-root process
Authors: Jin Peng , Kremer Jonas , Rüdiger Barbara
Published: November 2017

We study an affine two-factor model introduced by Barczy et al. (2014). One component of this two-dimensional model is the so-called α-root process, which generalizes the well-known Cox–Ingersoll–Ross process. In the α = 2 case, this two-factor model was used by Chen and Joslin (2012) to price defaultable bonds with stochastic recovery rates. In this paper we prove exponential ergodicity of this two-factor model when α ∈ (1, 2). As a possible application, our result can be used to study the parameter estimation problem of the model.
Reducing PTSD symptoms through a gender norms and economic empowerment intervention to reduce intimate partner violence: a randomized controlled pilot study in Côte D'Ivoire
Authors: Annan J. , Falb K. , Kpebo D. , Hossain M. , Gupta J.
Published: November 2017

Background.

Women living in war-affected contexts face high levels of gender-based violence, including intimate partner violence (Stark & Ager, 2011). Despite well-documented negative consequences, including posttraumatic stress disorder (PTSD) (Garcia-Moreno et al. 2006; Steel et al. 2009), evidence remains thin regarding intervention effectiveness to mitigate consequences in these settings.

Methods.

This study used a two-armed parallel pilot randomized controlled trial to compare the impact of a group savings only (control) to gender dialogue groups added to group savings (treatment) on women's symptoms of PTSD in northwestern Côte d'Ivoire. Eligible Ivorian women (18+ years, no prior experience with group savings) were invited to participate and 1198 were randomized into treatment groups.

Results.

In the ITT analyses, women in the treatment arm had significantly fewer PTSD symptoms relative to the control arm (β: −0.12; 95% CI: −0.20 to −0.03; p = 0.005). Partnered women in the treatment arm who had not experienced intimate partner violence (IPV) at baseline had significantly fewer PTSD symptoms than the control arm (β = −0.12; 95% CI: −0.21 to −0.03; p = 0.008), while those who had experienced IPV did not show significant differences between treatment and control arms (β = −0.09; 95% CI: −0.29 to 0.11; p = 0.40).

Conclusions.

Adding a couples gender discussion group to a women's savings group significantly reduced women's PTSD symptoms overall. Different patterns emerge for women who experienced IPV at baseline v. those who did not. More research is needed on interventions to improve mental health symptoms for women with and without IPV experiences in settings affected by conflict.