bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Doping Density and Temperature on the Optoelectronic Properties of Formamidinium Tin Triiodide Thin Films
Authors: Milot Rebecca L. , Klug Matthew T. , Davies Christopher L. , Wang Zhiping , Kraus Hans , Snaith Henry J. , Johnston Michael B. , Herz Laura M.
Published: September 2018

Optoelectronic properties are unraveled for formamidinium tin triiodide (FASnI3) thin films, whose background hole doping density is varied through SnF2 addition during film fabrication. Monomolecular charge‐carrier recombination exhibits both a dopant‐mediated part that grows linearly with hole doping density and remnant contributions that remain under tin‐enriched processing conditions. At hole densities near 1020 cm−3, a strong Burstein–Moss effect increases absorption onset energies by ≈300 meV beyond the bandgap energy of undoped FASnI3 (shown to be 1.2 eV at 5 K and 1.35 eV at room temperature). At very high doping densities (1020 cm−3), temperature‐dependent measurements indicate that the effective charge‐carrier mobility is suppressed through scattering with ionized dopants. Once the background hole concentration is nearer 1019 cm−3 and below, the charge‐carrier mobility increases with decreasing temperature according to ≈T−1.2, suggesting that it is limited mostly by intrinsic interactions with lattice vibrations. For the lowest doping concentration of 7.2 × 1018 cm−3, charge‐carrier mobilities reach a value of 67 cm2 V−1 s−1 at room temperature and 470 cm2 V−1 s−1 at 50 K. Intraexcitonic transitions observed in the THz‐frequency photoconductivity spectra at 5 K reveal an exciton binding energy of only 3.1 meV for FASnI3, in agreement with the low bandgap energy exhibited by this perovskite.
Pairing Toroidal and Magnetic Dipole Resonances in Elliptic Dielectric Rod Metasurfaces for Reconfigurable Wavefront Manipulation in Reflection
Authors: Tsilipakos Odysseas , Tasolamprou Anna C. , Koschny Thomas , Kafesaki Maria , Economou Eleftherios N. , Soukoulis Costas M.
Published: September 2018

A novel approach for reconfigurable wavefront manipulation with gradient metasurfaces based on permittivity‐modulated elliptic dielectric rods is proposed. It is shown that the required 2π phase span in the local electromagnetic response of the metasurface can be achieved by pairing the lowest magnetic dipole Mie resonance with a toroidal dipole Mie resonance, instead of using the lowest two Mie resonances corresponding to fundamental electric and magnetic dipole resonances as customarily exercised. This approach allows for the precise matching of both the resonance frequencies and quality factors. Moreover, the accurate matching is preserved if the rod permittivity is varied, allowing for constructing reconfigurable gradient metasurfaces by locally modulating the permittivity in each rod. Highly efficient tunable beam steering and beam focusing with ultrashort focal lengths are numerically demonstrated, highlighting the advantage of the low‐profile metasurfaces over bulky conventional lenses. Notably, despite using a matched pair of Mie resonances, the presence of an electric polarizability background allows to perform the wavefront shaping operations in reflection, rather than transmission. This has the advantage that any control circuitry necessary in an experimental realization can be accommodated behind the metasurface without affecting the electromagnetic response.
Engineering the Surface/Interface of Horizontally Oriented Carbon Nanotube Macrofilm for Foldable Lithium‐Ion Battery Withstanding Variable Weather
Authors: Liu Ting , Zhang Ming , Wang Yong Long , Wang Qing Yong , Lv Chao , Liu Kai Xi , Suresh Shravan , Yin Yan Hong , Hu Ying Yan , Li Ye Sheng , Liu Xian Bin , Zhong Sheng Wen , Xia Bao Yu , Wu Zi Ping
Published: September 2018

Flexible lithium‐ion batteries attract extensive attention in wearable electronics but are limited by severe capacity loss under extreme weather due to the poor flexible current collector. Herein, a horizontally oriented carbon nanotube macrofilm (HUCNM) with excellent electrical conductivity and tuned electrolyte wettability through engineering the surface/interface of HUCNM is reported for foldable batteries, which exhibits a high capacity of 700 mAh with excellent flexibility and stable charge/discharge rate performance in several extreme conditions. Such amazing results are ascribed to the excellent contact and interaction among the current collector, active material, and electrolyte, which is rising from the surface/interface engineering of carbon nanotube films. This work provides useful insights in the engineering of the surface/interface of carbon current collectors, and revolutionizes the traditional design for wearable electronics, transcending these devices beyond their current limitations.
Community Health Workers and Social Proximity: Implementation of a Parenting Program in Urban Poverty
Authors: Gustafson Erika L. , Atkins Marc , Rusch Dana
Published: September 2018

Community health workers (CHWs) offer a potential means through which to mitigate many of the barriers to mental health services faced by minority youth and their families. The primary aim of the present study was to better understand a core feature of CHWs: their shared community membership with the population served, or social proximity. We conducted qualitative semi‐structured interviews with 16 CHWs implementing a school‐based early intervention program in Latino and African American communities of urban poverty. The program promoted child and parent/caregiver engagement in schooling as a protective factor for children's mental health. Thematic analyses revealed three main themes defining social proximity: (a) experiences of parenthood or caring for children, (b) familiarity with and understanding of culture, and (c) experiences of life hardships and struggles. Additionally, the process of relating with parents/caregivers through shared experiences was the main theme to describe how CHWs leveraged their social proximity. CHWs’ accounts illustrated how their experience of social proximity to the population served was central to how they engaged parents/caregivers in services, highlighting the importance of supporting and promoting CHWs’ natural traits and lived experiences.
Assessing female reproductive status of spectral tarsier (Tarsius tarsier) using fecal steroid hormone metabolite analysis
Authors: Hidayatik Nanik , Agil Muhammad , Heistermann Michael , Iskandar Entang , Yusuf Tuty L. , Sajuthi Dondin
Published: September 2018

The wild population of spectral tarsier is declining and attempts to breed the species in captivity have been of limited success. One possible reason for this is that information on the reproductive biology of Tarsius tarsier is extremely limited and data on the species reproductive physiology are completely lacking. We validated fecal estrogen (E‐total) and progesterone metabolite (5‐P‐3OH) measurements for monitoring female ovarian activity and pregnancy. We used this approach to provide the first data on cycle and pregnancy length based on endocrine information in this species. We collected regular fecal samples in combination with observations on socio‐sexual behaviors for a maximum of 15 months from three females maintained at Primate Research Center of Bogor Agricultural University, Indonesia. Hormonal profiles indicated that behavioral estrus was associated with marked elevations in fecal E‐total concentrations followed by increases in 5‐P‐3OH levels indicating luteal function. Pregnancy was characterized by low levels of E‐total and 5‐P‐3OH during the first month and markedly rising concentrations thereafter. An ovarian cycle length of 21.7 ± 5.7 days was found. Gestation length was 128d (live infant), 131d (stillbirth), and 164d (death of mother and infant due to dystocia). Despite the small sample size, the study demonstrates the overall validity of fecal sex hormone metabolite measurements for reproductive monitoring in female T. tarsier, as such, the methods described here may ultimately help to improve the breeding management of the species in captivity. They may also offer new opportunities for investigating basic questions of tarsier reproductive biology in the wild by using fecal hormone metabolite analysis to diagnose pregnant animals and determine reproductive rates in relation to ecological and other factors influencing tarsier reproduction. Thus, non‐invasive assessment of female reproductive condition as described here may ultimately contribute to facilitate in and ex situ conservation efforts of this endangered primate species.
Influence of Sulfur‐Containing Diamino Acid Structure on Covalently Crosslinked Copolypeptide Hydrogels
Authors: Raftery Eric D. , Gharkhanian Eric G. , Ricapito Nicole G. , McNamara J. , Deming Timothy J.
Published: September 2018

Biologically occurring non‐canonical di‐α‐amino acids were converted into new di‐N‐carboxyanhydride (di‐NCA) monomers in reasonable yields with high purity. Five different di‐NCAs were separately copolymerized with tert‐butyl‐l‐glutamate NCA to obtain covalently crosslinked copolypeptides capable of forming hydrogels with varying crosslinker density. Comparison of hydrogel properties with residue structure revealed that different di‐α‐amino acids were not equivalent in crosslink formation. Notably, l‐cystine was found to produce significantly weaker hydrogels compared to l‐homocystine, l‐cystathionine, and l‐lanthionine, suggesting that l‐cystine may be a sub‐optimal choice of di‐α‐amino acid for preparation of copolypeptide networks. The di‐α‐amino acid crosslinkers also provided different chemical stability, where disulfide crosslinks were readily degraded by reduction, and thioether crosslinks were stable against reduction. This difference in response may provide a means to fine tune the reduction sensitivity of polypeptide biomaterial networks.
Bericht des Arbeitskreises Kombinierte Spundwände des Ausschusses Ufereinfassungen (EAU)
Authors: Osthoff David
Published: September 2018

In der jüngeren Vergangenheit sind wieder vermehrt Schlosssprengungen bei Stützwandkonstruktionen aus kombinierten Stahlspundwänden aufgetreten. Zur Diskussion und Prüfung der gegenwärtigen Empfehlungen hat der Ausschuss Ufereinfassungen (EAU) im Jahr 2016 einen Arbeitskreis zu Kombinierten Spundwänden berufen, der sich mit der Herstellung von kombinierten Spundwänden unter der Vermeidung von Schlosssprengungen auseinandergesetzt hat. Die abgeschlossene Arbeit des Arbeitskreises wird im vorliegenden Beitrag kurz vorgestellt.
Population-based analysis of the impact of trauma on longer-term functional outcomes
Authors: Uleberg O , Pape K , Kristiansen T , Romundstad P R , Klepstad P
Published: September 2018

Background

Functional outcome measures are important as most patients survive trauma. The aim of this study was to describe the long-term impact of trauma within a healthcare region from a social perspective.

Methods

People active in work or education and admitted to hospitals in Central Norway in the interval 1 June 2007 to 31 May 2010 after sustaining trauma were included in the study. Clinical data were linked to Norwegian national registers of cause of death, sickness and disability benefits, employment and education. Primary outcome measures were receipt of medical benefits and time to return to preinjury work level. Secondary outcome measures were mortality within 30 days or during follow-up.

Results

Some 1191 patients were included in the study, of whom 193 (16·2 per cent) were severely injured (Injury Severity Score greater than 15). Five years after injury, the prevalence of medical benefits was 15·6 per cent among workers with minor injuries, 22·3 per cent in those with moderate injuries and 40·5 per cent among workers with severe injuries. The median time after injury until return to work was 1, 4 and 11 months for patients with minor, moderate and severe injuries respectively. Twelve patients died within 30 days and an additional 17 (1·4 per cent) during follow-up.

Conclusion

Patients experiencing minor or major trauma received high levels of medical benefits; however, most recovered within the first year and resumed preinjury work activity. Patients with severe trauma were more likely to receive medical benefits and have a delayed return to work. Registration number: NCT02602405 (http://www.clinicaltrials.gov).
Inhibiting Pneumococcal Surface Antigen A (PsaA) with Small Molecules Discovered through Virtual Screening: Steps toward Validating a Potential Target for Streptococcus pneumoniae
Authors: Obaidullah Ahmad J. , Ahmed Mostafa H. , Kitten Todd , Kellogg Glen E.
Published: September 2018

The pneumococcal surface antigen A (PsaA) metal transporter protein provides manganese to bacterial cells. The X‐ray crystal structures of PsaA, in both closed (Mn bound) and open (metal free) conformations, were explored with virtual screening to identify potential inhibitors of manganese transport. We pursued three strategies for inhibition: i) targeting a cavity close to the bound Mn to keep the metal in place; ii) targeting the metal‐free Mn site to prevent metal uptake; and iii) targeting a potentially druggable allosteric site involving loops that translate between the conformations. Tiered assays were used to test the resulting 170 acquired hits: i) assay 1 tested the compounds’ growth inhibition of the TIGR4 S. pneumoniae strain (ΔPsaA mutant control), yielding 80 compounds (MIC≤250 μm); ii) assay 2 tested if the addition of 20 μm Mn to inhibited cell cultures restored growth, yielding 21 compounds; and iii) assay 3 confirmed that the restored bacterial growth was Mn concentration dependent, as was the restoration of ΔPsaA growth, yielding 12 compounds with MICs of 125 μm or greater. It may be possible for a small molecule to inhibit PsaA, but we have not yet identified a compound with exemplary properties.
Splinting and mechanical disruption of the mitral valve apparatus by an endocardial left ventricular lead while delivering cardiac resynchronization therapy
Authors: Behar Jonathan M. , Ranjan Kula , Bhattacharyya Sanjeev , Sporton Simon , Dhinoja Mehul
Published: September 2018

Key Clinical Message

Splinting and mechanical disruption of the mitral valve apparatus is an important limitation of an endocardial left ventricular (LV) pacing lead. Further, long‐term data are required before this approach is more widely adopted.
Integration of Heuristic and Automated Parametrization of Three Unresolved Two‐Electron Surface‐Confined Polyoxometalate Reduction Processes by AC Voltammetry
Authors: Robinson Martin , Ounnunkad Kontad , Zhang Jie , Gavaghan David , Bond Alan
Published: September 2018

The thermodynamic and electrode kinetic parameters that describe each of the three unresolved proton‐coupled two‐electron transfer processes of surface‐confined Keggin‐type phosphomolybdate, [PMo12O40]3− adsorbed onto glassy carbon electrode in 1.0 M H2SO4 have been elucidated by comparison of experimental and simulated AC voltammmetric data. Modelling of this problem requires the introduction of over 30 parameters, although this may be reduced to about half this number when intelligent forms of data analysis are introduced. Heuristic (i. e., an experimenter based trial and error method) and automated data optimization approaches are integrated in this very extensive parameter estimation exercise. However, obtaining a unique solution remains challenging for reasons that are outlined. In the final analysis and using the automated strategy, estimates of six reversible potentials, lower limits of the six electron transfer rate constants, the double layer capacitance, uncompensated resistance and surface coverage are reported, with others (such as the charge transfer co‐efficient) present in the model being unobtainable for reasons that are provided. The fit to experimental data using parameters obtained by automated data optimisation is excellent and slightly superior to that obtained by heuristic analysis. The parameters obtained by either method account for differences in shapes and current magnitudes of each of the overall two electron processes.
Effective CoxSy HER Electrocatalysts Fabricated by In‐Situ Sulfuration of a Metal‐Organic Framework
Authors: Sun Xiaowen , Huang Hui , Wang Chaopeng , Liu Yingying , Hu Tong‐Liang , Bu Xian‐He
Published: September 2018

A sulfur and nitrogen containing cobalt metal‐organic framework (Co−MOF) was chosen as a precursor to prepare cobalt sulfides as HER electrocatalysts. Cobalt sulfides with different stoichiometries, CoS1.097, Co9S8, Co9S8/CoS1.097, and Co9S8/CoS1.097/rGO, were obtained through a phase control method and in‐situ sulfuration of the MOF precursor. Co9S8/CoS1.097/rGO shows excellent HER performance, with an overpotential of 50 mV at a current density (j) of 1 mA cm−2 (η0), and 188 mV at a current density of 10 mA cm−2 (η10), stemming from the synergistic effect of Co9S8, CoS1.097, high specific surface area and the nitrogen and sulfur doped carbon matrix.
Recent Progress of Hybrid Solid‐State Electrolytes for Lithium Batteries
Authors: Liu Xiaoyan , Li Xinru , Li Hexing , Wu Hao Bin
Published: September 2018

Conventional liquid electrolytes for lithium batteries usually suffer from irreversible decomposition and safety concerns. Solid state electrolytes (SSEs) have been considered as the key for advanced lithium batteries with improved energy density and safety, whereas challenges remain for polymer and inorganic SSEs. Recently, hybrid solid‐state electrolytes (HSSEs) that integrate the merits of different electrolyte systems have been under intensive study. Herein, we summarize the recent progress of HSSEs with different compositions and structures. The design principle of each type of HSSEs are discussed, as well as their ionic conducting mechanism, electrochemical performance and effects of compositional/structural control. Finally, challenges and perspectives are provided for the future development of HSSEs and solid‐state lithium batteries.
Stimuli‐Responsive Properties of Aggregation‐Induced‐Emission Compounds Containing a 9,10‐Distyrylanthracene Moiety
Authors: Jia Xiang‐Rui , Yu Hui‐Juan , Chen Jian , Gao Wei‐Jie , Fang Jing‐Kun , Qin Yuan‐Shou , Hu Xiao‐Kai , Shao Guang
Published: September 2018

Two 9,10‐distyrylanthracene‐based luminophores exhibiting aggregation‐induced emission and stimuli‐responsive properties were synthesized. Seven‐ or five‐color luminescence switching based on a single organic molecule was achieved for the first time. These phase transitions can be induced by physical stimuli such as grinding by mortar and pestle, heating, and exposure to the vapors of organic solvents. Moreover, a strategy for the design of new mechanoresponsive materials with π‐conjugated luminophores is proposed.
From Photoinduced to Dark Cytotoxicity through an Octahedral Cluster Hydrolysis
Authors: Svezhentseva Ekaterina V. , Vorotnikov Yuri A. , Solovieva Anastasiya O. , Pozmogova Tatiana N. , Eltsov Ilia V. , Ivanov Anton A. , Evtushok Darya V. , Miroshnichenko Svetlana M. , Yanshole Vadim V. , Eling Charlotte J. , Adawi Ali M. , Bouillard Jean‐Sebastien G. , Kuratieva Natalia V. , Fufaeva Maria S. , Shestopalova Lidiya V. , Mironov Yuri V. , Efremova Olga A. , Shestopalov Michael A.
Published: September 2018

Octahedral molybdenum and tungsten clusters have potential biological applications in photodynamic therapy and bioimaging. However, poor solubility and hydrolysis stability of these compounds hinder their application. The first water‐soluble photoluminescent octahedral tungsten cluster [{W6I8}(DMSO)6](NO3)4 was synthesised and demonstrated to be at least one order of magnitude more stable towards hydrolysis than its molybdenum analogue. Biological studies of the compound on larynx carcinoma cells suggest that it has a significant photoinduced toxicity, while the dark toxicity increases with the increase of the degree of hydrolysis. The increase of the dark toxicity is associated with the in situ generation of nanoparticles that clog up the cisternae of rough endoplasmic reticulum.
Compressed sensing: Reconstruction of non‐uniformly sampled multidimensional NMR data
Authors: Bostock Mark , Nietlispach Daniel
Published: September 2018

Nuclear magnetic resonance (NMR) spectroscopy is widely used across the physical, chemical, and biological sciences. A core component of NMR studies is multidimensional experiments, which enable correlation of properties from one or more NMR‐active nuclei. In high‐resolution biomolecular NMR, common nuclei are 1H, 15N, and 13C, and triple resonance experiments using these three nuclei form the backbone of NMR structural studies. In other fields, a range of other nuclei may be used. Multidimensional NMR experiments provide unparalleled information content, but this comes at the price of long experiment times required to achieve the necessary resolution and sensitivity. Non‐uniform sampling (NUS) techniques to reduce the required data sampling have existed for many decades. Recently, such techniques have received heightened interest due to the development of compressed sensing (CS) methods for reconstructing spectra from such NUS datasets. When applied jointly, these methods provide a powerful approach to dramatically improve the resolution of spectra per time unit and under suitable conditions can also lead to signal‐to‐noise ratio improvements. In this review, we explore the basis of NUS approaches, the fundamental features of NUS reconstruction using CS and applications based on CS approaches including the benefits of expanding the repertoire of biomolecular NMR experiments into higher dimensions. We discuss some of the recent algorithms and software packages and provide practical tips for recording and processing NUS data by CS.
SOGC: Implementing surrogate object garbage collector management for a Mobile Cloud Environment
Authors: Gnana Jeevan A.N. , Maluk Mohamed M.A.
Published: September 2018

The aim of an ideal distributed Mobile Cloud environment, the surrogate object, is an agent for a particular Mobile Host in the wired or wireless network with specific data structures and methods. The Surrogate object is a software entity that is hosted on mobile support station and acts on behalf of a mobile host during the disconnection operation. The mobile hosts are registered with their own unique identifier in their cloud environment with their mobile support system. If the registered Mobile host is migrated from one cloud to another, the surrogate object handovers the data or resource management to another cloud with a new object with the same entities of old surrogate object, which leads inefficient. The granularity of object migration the old object is useless after the old object switched over into the new object. The collection of unused surrogate object is a big challenge. This problem will be achieved through the garbage collector technique in Mobile Cloud computing. In this research, we propose the Surrogate Object Garbage Collector (SOGC) model with new middleware consists in detecting the unused surrogate object by Mark‐Compact Garbage Collection technique to recycle their object resources. SOGC periodically recycles the idle object and automatically reuses it; whenever it is needed to manage cloud environment, it results in quality‐of‐execution, low latency, and cost optimization in data management.
Origin of Color Centers in the Perovskite Oxide CeAlO3
Authors: Zhang Su , Lv Lingling , Jiang Lihong , Li Huimin , Li Da , Feng Jing , Luo Yanqing , Pang Ran , Li Chengyu , Zhang Hongjie
Published: September 2018

In view of the significant impact of color centers on the physical and chemical properties of materials, studies on the origin of such color centers are needed. In this article, detailed crystal structure analysis and compositional characterization of CeAlO3 was carried out by applying XRD, XPS, HRTEM, STEM‐EDS and ICP‐OES techniques. The results revealed that crystal defects may be the main cause of color centers. The existence of oxygen and aluminum vacancy was proved and confirmed by the application of XPS, ICP‐OES and STEM‐EDS characterization methods. Overall, it unlikely that a single crystal defect would generate the yellow‐green color of CeAlO3 crystals.
RNA‐seq: Basic Bioinformatics Analysis
Authors: Ji Fei , Sadreyev Ruslan I.
Published: September 2018

Quantitative analysis of gene expression is crucial for understanding the molecular mechanisms underlying genome regulation. RNA‐seq is a powerful platform for comprehensive investigation of the transcriptome. In this unit, we present a general bioinformatics workflow for the quantitative analysis of RNA‐seq data and describe a few current publicly available computational tools applicable at various steps of this workflow. These tools comprise a pipeline for quality assessment and quantitation of RNA‐seq data that starts from raw sequencing files and is focused on the identification and analysis of genes that are differentially expressed between biological conditions. © 2018 by John Wiley & Sons, Inc.
Do female directors influence firms' environmental innovation? The moderating role of ownership type
Authors: Liao Zhongju , Zhang Manting , Wang Xiaopeng
Published: September 2018

As more and more females join boards of directors, their decisions concerning environmental innovation have also become the focus of scholars. Based on the upper echelons theory, feminist caring theory, and social role theory, this study constructed a relationship model between female directors and firms' environmental innovations and chose ownership type as the moderating variable. Selecting 688 listed companies in the Chinese manufacturing industry as the research sample and adopting multiple regression analysis methods, the study found that, when the proportion of female directors on the board of directors increased, the level of a firm's environmental innovation also increased significantly. After female directors were divided into independent and nonindependent directors, we found that female independent directors had a significant effect on the firms' environmental innovations. However, female chairpersons had no significant effect on the firms' environmental innovations. In addition, the effect of female directors and female independent directors on a firm's environmental innovation was stronger for state‐owned listed companies.
Building legitimacy and trust between a mining company and a community to earn social license to operate: A Peruvian case study
Authors: Saenz Cesar
Published: September 2018

The purpose of this paper is to understand how a mining company earns social license to operate (SLO) by taking action to gain legitimacy and build trust by presenting a comparative case study analysis of two mining operations in Peru. The analysis was qualitative in nature and was complemented by insights gleaned from supplementary interviews with key informants and the emerging literature on SLO, legitimacy, and trust. The findings revealed a model with a total of five components to earn SLO—three for legitimacy (pragmatic, moral, and cognitive legitimacy) and two for trust (decision‐maker factors and situational factors).
Fluorine‐Free Water‐in‐Salt Electrolyte for Green and Low‐Cost Aqueous Sodium‐Ion Batteries
Authors: Han Jin , Zhang Huang , Varzi Alberto , Passerini Stefano
Published: September 2018

The highly concentrated “water‐in‐salt” electrolyte (WiSE) containing sodium acetate and potassium acetate demonstrates surprising performance (specific capacity of 37 mA h−1 g−1 at the 5th cycle and average discharge voltage of 0.82 V) in aqueous sodium‐ion batteries (SIBs) based on Na2MnFe(CN)6 and NaTi2(PO4)3. The fluorine‐free electrolyte offers a wide electrochemical stability window and compatibility with Al current collector. The electrolyte, current collector, and the electrode materials based on abundant elements make the proposed battery chemistry safe, low‐cost, and environmentally friendly.
Preparation and Reactivity of Biomass‐Derived Dihydro‐Dioxins
Authors: Montgomery James R. D. , Kempf Karl , Miles‐Barrett Daniel M. , Kempf Oxana , Lebl Tomas , Westwood Nicholas J.
Published: September 2018

The depolymerization of the biopolymer lignin can give pure aromatic monomers but selective catalytic approaches remain scarce. Here, an approach was rerouted to deliver an unusual phenolic monomer. This monomer's instability proved challenging, but a degradation study identified strategies to overcome this. Heterocycles and a useful synthetic intermediate were prepared. The range of aromatics available from the β‐O‐4 unit in lignin was extended.
Pest suppression in cultivar mixtures is influenced by neighbor‐specific plant–plant communication
Authors: Dahlin Iris , Rubene Diana , Glinwood Robert , Ninkovic Velemir
Published: September 2018

Increased plant genotypic diversity in crop fields can promote ecosystem services including pest control, but understanding of mechanisms behind herbivore population responses to cultivar mixtures is limited. We studied aphid settling on barley plants exposed to volatiles from different cultivars, aphid population development in monocultures and two‐cultivar mixtures, and differences in volatile composition between studied cultivars. Aphid responses to one cultivar in a mixture were neighbor‐specific and this was more important for pest suppression than the overall mixture effect, aphid colonization patterns, or natural enemy abundance. Aphid populations decreased most in a mixture where both cultivars showed a reduced aphid–plant acceptance after reciprocal volatile exposure in the laboratory, and reduced population growth compared to monocultures in the field. Our findings suggest that herbivore population responses to crop genotypic diversity can depend on plant–plant volatile interactions, which can lead to changes in herbivore response to individual cultivars in a mixture, resulting in slower population growth. The impact of plant–plant interaction through volatiles on associated herbivore species is rarely considered, but improved understanding of these mechanisms would advance our understanding of the ecological consequences of biodiversity and guide development of sustainable agricultural practices. Combining cultivars in mixtures based on how they interact with each other is a promising strategy for sustainable pest management.
Salty fertile lakes: how salinization and eutrophication alter the structure of freshwater communities
Authors: Lind Lovisa , Schuler Matthew S. , Hintz William D. , Stoler Aaron B. , Jones Devin K. , Mattes Brian M. , Relyea Rick A.
Published: September 2018

The quality of freshwater ecosystems is decreasing worldwide because of anthropogenic activities. For example, nutrient over‐enrichment associated with agricultural, urban, and industrial development has led to an acceleration of primary production, or eutrophication. Additionally, in northern areas, deicing salts that are an evolutionary novel stressor to freshwater ecosystems have caused chloride levels of many freshwaters to exceed thresholds established for environmental protection. Even if excess nutrients and road deicing salts often contaminate freshwaters at the same time, the combined effects of eutrophication and salinization on freshwater communities are unknown. Thus by using outdoor mesocosms, we investigated the potentially interactive effects of nutrient additions and road salt (NaCl) on experimental lake communities containing phytoplankton, periphyton, filamentous algae, zooplankton, two snail species (Physa acuta and Viviparus georgianus), and macrophytes (Nitella spp.). We exposed communities to a factorial combination of environmentally relevant concentrations of road salt (15, 250, and 1000 mg Cl−/L), nutrient additions (oligotrophic, eutrophic), and sunlight (low, medium, and high) for 80 d. We manipulated light intensity to parse out the direct effects of road salts or nutrients from the indirect effects via algal blooms that reduce light levels. We observed numerous direct and indirect effects of salt, nutrients, and light as well as interactive effects. Added nutrients caused increases in most producers and consumers. Increased salt (1000 mg Cl−/L) initially caused a decline in cladoceran and copepod abundance, leading to an increase in phytoplankton. Increased salt also reduced the biomass and chl a content of Nitella and reduced the abundance of filamentous algae. Added salt had no effect on the abundance of pond snails, but it caused a decline in banded mystery snails, which led to an increase in periphyton. Low light negatively affected all taxa (except Nitella) and light levels exhibited multiple interactions with road salt, but the combined effects of nutrients and salt were always additive. Collectively, our results indicate that eutrophication and salinization both have major effects on aquatic ecosystems and their combined effects (through different mechanisms) are expected to promote large blooms of phytoplankton and periphyton while causing declines in many species of invertebrates and macrophytes.
Relations of interannual differences in stream litter breakdown with discharge: bioassessment implications
Authors: Yeung Alex C. Y. , Musetta‐Lambert Jordan L. , Kreutzweiser David P. , Sibley Paul K. , Richardson John S.
Published: September 2018

Ecosystem‐level processes are increasingly used by researchers and managers as indicators of ecological integrity for bioassessment, particularly in streams. However, processes like litter breakdown integrate multiple mechanistic pathways, which can vary differentially even under natural, unimpacted conditions. In particular, weather‐driven hydrologic variations may strongly influence invertebrate shredder feeding and physical abrasion, inducing high natural variability of litter breakdown rates, which may obscure the effects of anthropogenic disturbances. Yet, such variability is rarely assessed to refine benchmarks of ecological status. Here, we quantified how interannual hydrologic differences contributed to the spatio‐temporal variability of litter breakdown rate and its components (fragmentation, λF; and dissolution and microbial decomposition, λm), in low‐order unimpacted, perennial streams across three climatically similar regions in temperate Canada. We measured litter breakdown rates in coarse (5 or 10 mm; kc)‐ and fine‐mesh (0.5 mm; kf) leaf bags during fall for 2–4 yr and used variance partitioning to disentangle the variation of kc, λF, and λm, as explained by hydrologic indices (during and prior to leaf bag incubation), decomposer‐related variables, and water chemistry. Contrary to our hypotheses, interannual hydrologic variability was unrelated to λF, and poorly predicted λm and kc within regions. Within‐region spatial (i.e., across sites in a year) and temporal (across years at a site) differences in kc approximated or exceeded the range of natural variability suggested to characterize reference conditions by a popular bioassessment framework. Accordingly, we recommend site‐ and region‐specific modifications of benchmarks for reference conditions that account for interannual variability, while cautioning about their potential non‐stationarity under climate change. Composite parameters such as kc/kf and λF/λm were substantially more variable across sites, and hence are not robust assessment parameters. As the range of natural variability of litter breakdown revealed in this study can overlap with the average impacts of certain anthropogenic disturbances (e.g., nutrient enrichment) on this parameter reported by previous research, we emphasize the need to include other structural and functional indicators to ensure comprehensive stream bioassessments.
An ecoimmunological approach to disease in tortoises reveals the importance of lymphocytes
Authors: Sandmeier Franziska C. , Weitzman Chava L. , Tracy C. Richard
Published: September 2018

We quantified the severity of upper respiratory tract disease (URTD) and immunological metrics (differential white blood cell counts and bacteria‐killing ability of blood plasma) in relation to climatic variables in 20 populations of Mojave desert tortoise (Gopherus agassizii). Prevalence and infection intensity ofMycoplasma agassizii, an etiological agent ofURTD, have previously been quantified for these populations (Weitzman et al.). Immunological variables were reduced by principal component analyses and separated into cells involved in inflammation (PC1) and cellular functions mediated by lymphocytes and basophils (PC2). In population‐level models, the mean number of lymphocytes per individual was associated with mean annual number of days below freezing. Lymphocytes were also positively associated with mean infection intensity ofM. agassizii. Additionally, prevalence ofURTDwas closely associated withPC1 (cells associated with inflammation). This suggests that at least two immunological strategies are involved in responding toM. agassizii, one that involves primarily lymphocytes and one that involves inflammatory mechanisms. Recent studies on immunology in Testudines suggest that a large proportion of lymphocytes in this taxon are similar to B‐1 lymphocytes of mammals and have phagocytic properties. Controlled experiments are needed to understand the disease mitigation of these lymphocytes in desert tortoises.
Evaluation of the Antioxidant Capacity of a Guarana Seed Extract on Canola Oil Lipid Stability Using Accelerated Storage
Authors: Gómez Belen , Strozzi Isabella , Barba Francisco J. , Vargas Flávia Carolina , Saraiva Jorge A. , Marszałek Krystian , Sobral Paulo José do Amaral , Lorenzo Jose M.
Published: September 2018

This study evaluates the antioxidant ability of hydroethanolic (40:60, water:ethanol, v/v) guarana seeds extracts (GSE), compared to the synthetic butylated hydroxytoluene (BHT), in the lipid oxidation evolution of canola oil, using an accelerated storage test (16 days at 60 °C). Canola oil is stabilized by GSE addition (200–1000 ppm) and following the peroxides, p‐anisidine, or conjugated dienes values, a higher stabilization is observed for 800 or 1000 ppm compared to the dose of 200 ppm. Thiobarbituric acid reactive substances increase from 0.57 to 4.56 mg MDA kg−1 after 16 days (control), while no significant differences are observed with GSE (1.51–1.87) compared to BHT (1.57 mg MDA kg−1). The effect of GSE addition to canola oil on individual fatty acids shows that the PUFA contents decrease significantly without GSE, 24.6 versus 28.2 g/100 g of FAMEs, respectively, but not with GSE at 600–1000 ppm. The observed impact of GSE (200–1000 ppm) in stabilizing canola oil is comparable to BHT at 200 ppm, GSE being of great interest as a natural additive with high antioxidant activity over synthetic antioxidants.

Practical Application: The addition of guarana seed extracts (GSE) to canola oil is a useful strategy to reduce lipid oxidation of this oil, as well as to preserve its polyunsaturated fatty acids when antioxidants are not added. Moreover, the utilization of GSE is of great interest as a natural antioxidant over butylated hydroxytoluene (BHT), thus reducing the amount of synthetic antioxidants to be used.

Evaluation of the antioxidant ability of guarana seeds extracts (GSE), compared to the synthetic butylated hydroxytoluene (BHT), in the lipid oxidation evolution of canola oil, using an accelerated storage test (16 days at 60 °C).
Dielectrophoretic separation of microalgae cells in ballast water in a microfluidic chip
Authors: Wang Yanjuan , Wang Junsheng , Wu Xudong , Jiang Zong , Wang Wei
Published: September 2018

The composition of the ship's ballast water is complex and contains a large number of microalgae cells, bacteria, microplastics, and other microparticles. To increase the accuracy and efficiency of detection of the microalgae cells in ballast water, a new microfluidic chip for continuous separation of microalgae cells based on alternating current dielectrophoresis was proposed. In this microfluidic chip, one piece of 3‐dimensional electrode is embedded on one side and eight discrete electrodes are arranged on the other side of the microchannel. An insulated triangular structure between electrodes is designed for increasing the inhomogeneity of the electric field distribution and enhancing the dielectrophoresis (DEP) force. A sheath flow is designed to focus the microparticles near the electrode, so as to increase the suffered DEP force and improve separation efficiency. To demonstrate the performance of the microfluidic separation chip, we developed two species of microalgae cells (Platymonas and Closterium) and a kind of microplastics to be used as test samples. Analyses of the related parameters and separation experiments by our designed microfluidic chip were then conducted. The results show that the presented method can separate the microalgae cells from the mixture efficiently, and this is the first time to separate two or more species of microalgae cells in a microfluidic chip by using negative and positive DEP force simultaneously, and moreover it has some advantages including simple operation, high efficiency, low cost, and small size and has great potential in on‐site pretreatment of ballast water.
Fan‐Shaped Flexible Radioisotope Thermoelectric Generators Based on BixTeyand BixSb2‐xTeyFabricated Through Electrochemical Deposition
Authors: Li Junqin , Tang Xiaobin , Liu Yunpeng , Yuan Zicheng , Xu Zhiheng , Liu Kai
Published: September 2018

This article employs electrochemical deposition to prepare thermoelectric film materials to achieve a miniaturized radioisotope thermoelectric generator (RTG). First, the optimal composition and material properties are obtained by optimizing the deposition potential and the concentration of the electrolyte. The n‐type material can reach the highest thermoelectric power factor of 812.34 μW m−1 K−2at a deposition potential of 0 V vs Ag/AgCl, and its composition is Bi1.92Te3.08. The highest power factor of 137.18 μW m−1 K−2of the p‐type material is obtained when the ratio of the concentration of SbO+to Bi3+ions in the electrolyte solution is set to 6 with the deposition potential of −0.12 V vs Ag/AgCl. The composition is Bi0.68Sb1.24Te3.08. Then, a principle fan‐shaped RTG (FRTG) with an overall size of 11 mm (height) × 33.8 mm (diameter) is manufactured and tested. The FRTG generates an open‐circuit voltage of 170.21 mV, a maximum output power of 247.55 nW, and a temperature difference of 57.8 K at 1.5 W heat source. Compared with the RTG prepared by mechanical cutting in previous research, the FRTG exhibits a volume that is reduced by 12.45 times and a voltage that is increased by 60.71%.
Optimization‐based profitability management tool for cloud broker
Authors: Becker Denis M. , Gaivoronski Alexei A. , Nesse Per Jonny
Published: September 2018

This paper represents a model that supports the choice of efficient service portfolios at a cloud service broker. Among the many types of different cloud service brokers, we focus on a firm that offers service bundles that are composed from different services of different internet software providers. The necessary integration, aggregation, and customization of services can be time consuming and costly. Whenever the cloud broker can choose from many service combinations, but has limited human resources with critical time to market, it is essential to prioritize some of the service bundles, markets, services, and internet software providers. The purpose of this paper is to facilitate this kind of decision. Moreover, both the time and resources required for creating service offerings and the customers' demand for these service bundles are subject to uncertainty. Because of this uncertainty, a cloud broker needs to be guided to potential service portfolios that give the best trade‐off between risk and profitability. Our model helps the decision maker to identify efficient service portfolios, ie, service portfolios that for a given risk have the highest profitability or for a given profitability have the lowest risk. Our paper shows the application of this model to a cloud broker that mediates mainly software as a service bundled with mobile subscriptions for telephony (calling and messaging) and internet access. The model is inspired by the ideas from financial portfolio optimization and product‐mix decisions under scarce resources. The model corresponds to a linear stochastic optimization problem with an objective function that balances risk and profitability.
Genetic association analysis with pedigrees: Direct inference using the composite likelihood ratio
Authors: Baskurt Zeynep , Strug Lisa J.
Published: September 2018

The likelihood function represents statistical evidence given data and a model. The evidential paradigm (EP), an alternative to Bayesian and Frequentist paradigms, provides considerable theory demonstrating evidence strength for different parameter values via the ratio of likelihoods at different parameter values; thus, enabling inference directly from the likelihood function. The likelihood function, however, can be difficult to compute; for example, in genetic association studies with a binary outcome in large pedigrees. Composite likelihood (CL) is an alternative when the real likelihood is intractable. We show CLs have the two large sample properties of the EP for reliable evidence interpretation: (1) CL supports the true value over a false value by an arbitrarily large factor; and (2) the probability of favouring a false value over the true value is small and bounded. Using simulation, and in a genetic association analysis of reading disability (RD) in large rolandic epilepsy pedigrees, we show that the CL approach yields valid statistical inference and identifies RD associated variants. When compared to analyses using generalized estimating equations, results show a similar prioritization of SNPs, although the CL approach provides additional complementary information, and more intuitive solutions to the multiple hypothesis testing problem.
Use of an at‐home multilevel pregnancy test and an automated call‐in system to follow‐up the outcome of medical abortion
Authors: Anger Holly , Dabash Rasha , Peña Melanie , Coutiño Dolores , Bousiéguez Manuel , Sanhueza Patricio , Winikoff Beverly
Published: September 2018

Objective

To assess the feasibility of using an at‐home multilevel pregnancy test (MLPT) and interactive voice response (IVR) call‐in system for remote follow‐up of medical abortion.

Methods

A prospective pilot study was conducted among women who had a medical abortion at up to 70 days at a clinic in Mexico City, Mexico, between June 1, 2015, and January 30, 2016. Participants took an MLPT at the initial clinic visit and another MLPT at home 2 weeks later. They were requested to report their MLPT results via the IVR system and attend the clinic for follow‐up evaluation.

Results

Of 200 women considered for inclusion, 163 (81.5%) were included in the analysis. Only 10 (6.6%) of the 152 women who had a medical abortion on or before 63 days from last menstrual period reported MLPT results to the IVR system that required clinical evaluation to assess medical abortion outcome. The remaining 142 (93.4%) women in this group reported MLPT results that ruled out ongoing pregnancy (confirmed at clinical evaluation). Reported MLPT results ruled out ongoing pregnancy among the 11 women who had a medical abortion after 63 days; however, 1 (9%) had an ongoing pregnancy at clinical evaluation.

Conclusion

Use of MLPTs and the IVR system provided a streamlined approach to follow‐up after medical abortion.