bluuebunny/crossref_metadata_2025 huggingface dataset:
Error probability and channel capacity analysis of wireless system over inverse gamma shadowed fading channel with selection diversity
Authors: Pant Diwaker , Chauhan Puspraj Singh , Soni Sanjay Kumar
Published: September 2019

In this paper, we present an analytical framework to analyse the error probability and the channel capacity of the inverse gamma (I‐Gamma) shadowed fading channel. First, the work discusses the utility of the I‐Gamma over log‐normal (LN) and gamma fading models where the closeness of I‐Gamma with other existing shadowing models is carried out. Utilising the probability density function (PDF) of the I‐Gamma shadowed fading channel, various metrics of the communication system, namely, the average symbol error probability (SEP), the channel capacity under optimal rate adaptation (ORA), channel inversion with fixed rate (CIFR), and truncated CIFR (TIFR) are derived. Further, the work is extended to derive a novel selection combining (SC) PDF, and the analytical results for the SEP and the channel capacity of SC diversity are presented. Furthermore, we also provide simpler asymptotic expressions for the average SEP. In addition, the simplified high and low signal‐to‐noise‐ratio (SNR) solutions to channel capacity are also provided. The derived mathematical formulations have been endorsed by comparing with Monte Carlo simulations.
Development of a mono‐specific anti‐VEGF bivalent nanobody with extended plasma half‐life for treatment of pathologic neovascularization
Authors: Sadeghi Amir , Behdani Mahdi , Muyldermans Serge , Habibi‐Anbouhi Mahdi , Kazemi‐Lomedasht Fatemeh
Published: September 2019

Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis within solid cancers. Thus, targeting VEGF might be part of a feasible therapy for treating pathological neovascularization, and nanobodies − derived from heavy chain‐only antibodies occurring within Camelidae − are a novel class of nanometer‐sized antibodies possessing unique properties that could be developed into a promising therapeutic. However, nanobodies have a very short half‐life in vivo due to their small size. Development of a bivalent nanobody is one way to remediate the half‐life problem of nanobodies. Two identical anti‐VEGF nanobodies were connected using the hinge region of llama IgG2c. The recombinant plasmid (pHEN6c‐bivalent nanobody) was transformed into E.coli WK6 cells and expression of the bivalent nanobody construct was induced with 1mM Isopropyl β‐D‐1‐thiogalactopyranoside (IPTG). Recombinant bivalent nanobody was purified using nickel affinity chromatography and its activity on human endothelial cells was assessed using 3‐(4,5‐Dimethylthiazol‐2‐yr)‐2,5‐diphenyltetrazolium bromide (MTT), tube formation, and cell migration assays. The pharmacokinetic study was performed after intravenous (i.v.) injection of recombinant bivalent nanobody into six‐week‐old C57BL/6 mice. Recombinant bivalent nanobody performed significantly better than monovalent nanobody in inhibiting proliferation, tube formation, and migration of human endothelial cells. Pharmacokinetic results showed a 1.8‐fold longer half‐life of bivalent nanobody in comparison with the monovalent nanobody. These results underscore the potential of recombinant anti‐VEGF bivalent nanobody as a promising tool for development of a novel therapeutic with an extended plasma half‐life for VEGF‐related diseases.
Linking pollen foraging of megachilid bees to their nest bacterial microbiota
Authors: Voulgari‐Kokota Anna , Ankenbrand Markus J. , Grimmer Gudrun , Steffan‐Dewenter Ingolf , Keller Alexander
Published: September 2019

Solitary bees build their nests by modifying the interior of natural cavities, and they provision them with food by importing collected pollen. As a result, the microbiota of the solitary bee nests may be highly dependent on introduced materials. In order to investigate how the collected pollen is associated with the nest microbiota, we used metabarcoding of the ITS2 rDNA and the 16S rDNA to simultaneously characterize the pollen composition and the bacterial communities of 100 solitary bee nest chambers belonging to seven megachilid species. We found a weak correlation between bacterial and pollen alpha diversity and significant associations between the composition of pollen and that of the nest microbiota, contributing to the understanding of the link between foraging and bacteria acquisition for solitary bees. Since solitary bees cannot establish bacterial transmission routes through eusociality, this link could be essential for obtaining bacterial symbionts for this group of valuable pollinators.

Open Research Badges

This article has earned an Open Data Badge for making publicly available the digitally‐shareable data necessary to reproduce the reported results. The data is available at https://www.ebi.ac.uk/ena/data/view/PRJEB27223, https://www.ebi.ac.uk/ena/data/view/PRJEB31610, and https://doi.org/10.5061/dryad.qk36k8q
First record of Oziroë argentinensis (Lillo & Hauman) Speta (Asparagaceae) for Brazil
Authors: de Melo Pablo Hendrigo Alves , Lombardi Julio Antonio
Published: September 2019

We report the first record of Oziroë argentinensis (Asparagaceae) for Brazil, previously known from Paraguay, Bolivia, and Argentina. The plant was collected in the state of Mato Grosso do Sul, growing between limestone rocks, and is the first record of any species of Oziroë on this substrate.
Flexible covariance dynamics, high‐frequency data, and optimal futures hedging
Authors: Lai Yu‐Sheng
Published: September 2019

This paper investigates the out‐of‐sample performance of hedged portfolios constructed using a novel rotated ARCH (RARCH) model class, which enables flexible covariance dynamics for spot and futures returns. The model's empirical fit can be significantly improved when it incorporates rotated realized covariance matrix measures. The empirical results suggest that a highly risk‐averse hedger implementing the restricted RARCH model would be willing to pay substantial switching fees to capture the incremental gains generated by the flexible and informative alternative; this thus supports the economic importance of incorporating high‐frequency data into flexible RARCH modeling processes for the construction of optimal hedged portfolios.
Effects of forestry on summertime low flows and physical fish habitat in snowmelt‐dominant headwater catchments of the Pacific Northwest
Authors: Gronsdahl Stefan , Moore R. Dan , Rosenfeld Jordan , McCleary Rich , Winkler Rita
Published: September 2019

Periods of summertime low flows are often critical for fish. This study quantified the impacts of forest clear‐cutting on summertime low flows and fish habitat and how they evolved through time in two snowmelt‐dominant headwater catchments in the southern interior of British Columbia, Canada. A paired‐catchment analysis was applied to July–September water yield, the number of days each year with flow less than 10% of mean annual discharge, and daily streamflow for each calendar day. The postharvest time series were divided into treatment periods of approximately 6–10 years, which were analysed independently to evaluate how the effects of forestry changed through time. An instream flow assessment using a physical habitat simulation‐style approach was used to relate streamflow to the availability of physical habitat for resident rainbow trout. About two decades after the onset of logging and as the extent of logging increased to approximately 50% of the catchments, reductions in daily summertime low flows became more significant for the July–September yield (43%) and for the analysis by calendar day (11–68%). Reductions in summertime low flows were most pronounced in the catchment with the longest postharvest time series. On the basis of the temporal patterns of response, we hypothesize that the delayed reductions in late‐summer flow represent the combined effects of a persistent advance in snowmelt timing in combination with at least a partial recovery of transpiration and interception loss from the regenerating forests. These results indicate that asymptotic hydrological recovery as time progresses following logging is not suitable for understanding the impacts of forest harvesting on summertime low flows. Additionally, these reductions in streamflow corresponded to persistent decreases in modelled fish habitat availability that typically ranged from 20% to 50% during the summer low‐flow period in one of the catchments, suggesting that forest harvest may have substantial delayed effects on rearing salmonids in headwater streams.
Computer‐assisted psychological assessment and psychotherapy for collegians
Authors: Heesacker Martin , Perez Caroline , Quinn Molly S. , Benton Sherry
Published: September 2019

Objective

This article reviews research on computerized and computer‐assisted psychological assessment and psychotherapy for college and university students.

Method

Published reviews of outcome research on the topic are reviewed, along with individual clinical trials and other relevant studies not covered by reviews, as well as reviews of closely‐related research.

Results

Computer‐assisted assessment and psychotherapy have proven effective with collegians across samples, nations, and presenting concerns.

Conclusions

Currently‐available digital technologies can address these mental health service delivery challenges: cost, limited human resources, failure of students to seek help, stigmatization of collegians seeking help, premature termination, inadequate process and outcome data to assess and improve treatment effectiveness, and lack of real‐time data‐based treatment selection.
A promising recovery housing model for American Indian communities
Authors: Jason Leonard A. , Kassanits Jessica , Reilly Angela , Bobak Ted , Guerrero Mayra , Stevens Ed , Light John M. , Doogan Nathan J.
Published: September 2019

In 2016, two Oxford House (OH) recovery homes were established for the Suquamish Tribal reservation. A group of researchers interviewed house members and key individuals responsible for the creation of these two unique OHs. Because American Indians are an at‐risk population for substance use disorders, our study explored whether an OH‐type recovery home model could be successfully adapted to this population, given the specific nature of tribal cultures. Findings indicated that the residents, composed of both American Indians and non‐American Indians, found these OHs to be supportive of recovery in general and with the values of American Indians. The tribal community's positive attitudes toward these recovery homes may have been due to similarities between the Suquamish Tribal Government and OH's democratic structures, with all individuals having a voice in the decision making process. The overall findings suggest that these types of culturally modified recovery settings on American Indian tribal lands could be an important resource for individuals dealing with substance use disorders.
Solid phase microextraction as a powerful alternative for screening of secondary metabolites in actinomycetes
Authors: Acquaro Junior Vinicius Ricardo , Rodrigues Júlia Pereira , Moraes Luiz Alberto Beraldo
Published: September 2019

Actinobacteria are one of the most promising producers of medically and industrially relevant secondary metabolites. However, screening of such compounds in actinobacteria growth demands simple, fast, and efficient extraction procedures that enable detection and precise quantification of biologically active compounds. In this regard, solid phase microextraction (SPME) emerges as an ideal extraction technique for screening of secondary metabolites in bacteria culture due to its non‐exhaustive, minimally invasive, and non‐destructive nature: its integrated sample preparation workflow; balanced coverage feature; metabolism quenching capabilities; and superior cleanup, as well as its versatility in configuration, which enables automation and high throughput applications. The current work provides a comparison of micro‐scale and direct immersion SPME (DI‐SPME) for screening of secondary metabolites, describes the optimization of the developed DI‐SPME method, and introduces the developed technique for mapping of target secondary metabolites as well as its direct coupling to mass spectrometry for such applications. The optimized DI‐SPME method provided higher amounts of extracted ions and intensity signals, yielding superior extraction and desorption efficiency as compared with micro‐scale extraction. Studied compounds presented stability on the coating for 24 h at room temperature. The DI‐SPME mapping approach revealed that lysolipin I and the lienomycin analog are distributed along the center and edges of the colony, respectively. Direct coupling of SPME to MS provided a similar ions profile as SPME‐LC‐MS while enabling a significant decrease in analysis time, demonstrating its suitability for such applications. DI‐SPME is herein presented as an alternative to micro‐scale extraction for screening of secondary metabolites in actinobacteria solid medium, as well as a feasible alternative to DESI‐IMS for mapping of biologic radial distribution of secondary metabolites and cell life cycle studies. Lastly, the direct coupling of DI‐SPME to MS is presented as a fast, powerful technique for high throughput analysis of secondary metabolites in this medium.
Extracellular matrix‐based scaffolding technologies for periodontal and peri‐implant soft tissue regeneration
Authors: Tavelli Lorenzo , McGuire Michael K. , Zucchelli Giovanni , Rasperini Giulio , Feinberg Stephen E. , Wang Hom‐Lay , Giannobile William V.
Published: September 2019

The present article focuses on the properties and indications of scaffold‐based extracellular matrix (ECM) technologies as alternatives to autogenous soft tissue grafts for periodontal and peri‐implant plastic surgical reconstruction. The different processing methods for the creation of cell‐free constructs resulting in preservation of the extracellular matrices influence the characteristics and behavior of scaffolding biomaterials. The aim of this review is to discuss the properties, clinical application, and limitations of ECM‐based scaffold technologies in periodontal and peri‐implant soft tissue augmentation when used as alternatives to autogenous soft tissue grafts.
Analysis of cold spray‐coated boiler‐tube material in a chlorine‐based corrosive environment at 900°C
Authors: Singh Harminder , Kalsi Sukhminderbir Singh , Sidhu Tejinder Singh
Published: September 2019

Energy generation, especially through waste incinerators is the need of the hour, as it serves the dual purpose of waste management and enhances the energy bank. However, mainly because of the presence of chlorine elements in the waste, there is an extensive corrosive failure of incinerator components utilized for energy generation. Therefore, there is need to work on enhancing the material life in these or similar plants, which will further increase plant efficiency. In this study, a corrosion‐resistant coating of 75%Cr3C2–25%NiCr is tested in a Na2SO4–10%NaCl environment at 900°C under cyclic conditions. The 289‐μm‐thick cold spray‐coating was dense (porosity, 0.925%), hard (average, 866 HV) and smooth with a surface roughness of 6.07 μm. Tribology tests on the pin‐on‐disc machine gave an average mean friction coefficient of 0.071 ± 0.006. The coating microstructure developed shows corrosion protective ability under chlorine‐containing high‐temperature conditions, with an overall weight gain of 10.235 mg/cm2, which is 60.9% less in comparison to the 26.177 mg/cm2 shown by the bare alloy. The coating acts as a shield to the substrate against corrosion attack.
Electrochemical assessment of laser heat treatment of an Al–Zn–Mg–Cu alloy
Authors: Wang Kaining , Su Ruiming , Liu Tong , Qu Yingdong , Li Rongde
Published: September 2019

The effect of laser heat treatment on the corrosion properties of the 7075 aluminum alloy was studied electrochemically. Laser retrogression and re‐aging (LRRA) is proposed to replace the retrogression treatment of retrogression and re‐aging. Transmission electron microscopy was used to analyze the microstructure of the alloy. The corrosion of the alloy treated using different LRRA parameters was analyzed by scanning electron microscopy. Using the polarization and electrochemical impedance spectroscopy measurements, it was concluded that the best corrosion resistance was obtained by the alloy treated at 2 mm/s with a laser power of 650 W. The spacing between the precipitate‐free zone and grain boundary precipitates increased. It is proved that the laser process can effectively improve the corrosion resistance of the 7075 alloy.
SET‐LRP Synthesis of Well‐Defined Light‐Responsible Block Copolymer Micelles
Authors: Sedlacek Ondrej , Filippov Sergey K. , Svec Pavel , Hruby Martin
Published: September 2019

Herein, the synthesis of well‐defined light‐sensitive amphiphilic diblock copolymers consisting of UV‐responsive poly(2‐nitrobenzyl acrylate) (PNBA) and hydrophilic poly(ethylene oxide) (PEO) blocks is reported. This is achieved by a single electron transfer living radical polymerization (SET‐LRP) of 2‐nitrobenzyl acrylate monomer initiated by PEO‐containing macroinitiator. Despite several reports on PEO‐b‐PNBA copolymers, this is the first time the PNBA block is synthesized by a controlled radical polymerization leading to the copolymers with low dispersity (Ð = 1.10). In water, the copolymers self‐assemble into well‐defined micelles with a hydrodynamic diameter of 25 nm. Upon irradiation with UV‐light, the PNBA units degrade to hydrophilic poly(acrylate) resulting in disassembly of the micelles. Considering the robustness of the reported synthetic protocol, the prepared polymers represent an interesting platform for the construction of new stimuli‐responsive drug delivery systems.
Influence of validating the parental origin on the clinical interpretation of fetal copy number variations in 141 core family cases
Authors: Shi Panlai , Li Rui , Wang Conghui , Kong Xiangdong
Published: September 2019

Background

The sources and variants types of the copy number variations (CNVs) in prenatal fetal, and the critical role of parental origin on the interpretation of fetal CNVs are unclear.

Methods

One hundred and forty‐one prenatal core families with abnormal CNVs were selected and performed by low‐coverage massively parallel CNV sequencing (CNV‐seq).

Results

The data showed that 72.3% of fetal CNVs were derived from parents, and 27.7% were new variations. Sixty‐three cases were heterozygous deletion, 70 cases were threefold duplication, six cases were complex deletion and duplication, and two cases were fourfold repeats. That means the rate of heterozygous deletion and duplication was approximate one. In addition, in parental‐derived fetal abnormal CNVs reports, before validating parental origin, 62 CNVs were variants of uncertain significance (VUS), 15 CNVs were likely benign, 20 CNVs were likely pathogenic, and 5 CNVs were pathogenic. However, after validating parental origin, the total clinical significance changed into 12 VUS, 89 likely benign, 1 likely pathogenic, and 0 pathogenic. The clinical interpretation of 78.4% fetal CNVs was changed and tended to be benign after parental CNVs were detected. Besides, we followed up all families. 93.3% parental‐derived fetal and 30.3% fetus in new mutation group were born healthy.

Conclusion

Parental origin verification has an important significance for interpretation on the clinical significance of fetal CNVs.
Usefulness of comprehensive targeted multigene panel sequencing for neuromuscular disorders in Korean patients
Authors: Park Jihye , Oh Hyun Mi , Park Hye Jung , Cho Ah‐Ra , Lee Dong‐Woo , Jang Ja‐Hyun , Jang Dae‐Hyun
Published: September 2019

Background

Multigene panel sequencing (MGPS) is the first‐line option in diagnostic testing for genetically heterogeneous but clinically similar conditions, such as neuromuscular disorders (NMDs). In this study, we aimed to assess the utility of comprehensive NMD MGPS and the need for updated panels.

Methods

All patients were analyzed by either of two versions of the NMD MGPS and by chromosomal microarray and karyotype testing. Four patients with negative NMD MGPS results underwent whole exome sequencing.

Results

In total, 91 patients were enrolled, and a genetic diagnosis was made in 36 (39.6%); of these, 33 were diagnosed by the comprehensive NMD MGPS, two were confirmed by chromosomal microarray, and one was diagnosed by whole exome sequencing. For MGPS, the diagnostic yield of Version 2 (19/52; 36.5%) was a little higher than that of Version 1 (14/39; 35.9%), and one gene identified in Version 2 was not included in Version 1. A total of 36 definitive and nine possible causative variants were identified, of which 17 were novel.

Conclusion

A more comprehensive panel for NMD MGPS can improve the diagnostic efficiency in genetic testing. The rapid discovery of new disease‐causing genes over recent years necessitates updates to existing gene panels.
One‐bump positive solutions for the Kirchhoff equations with perturbation in
Authors: Liu Weiming
Published: September 2019

In this paper, we study the Kirchhoff equations with perturbation in
. Applying the finite reduction method, we prove that the equation has one‐bump positive solutions under some suitable conditions that are given in Section 1.
Could circRNA be a new biomarker for pre‐eclampsia?
Authors: Shafabakhsh Rana , Mirhosseini Naghmeh , Chaichian Shala , Moazzami Bahram , Mahdizadeh Zahra , Asemi Zatollah
Published: September 2019

Pre‐eclampsia is a devastating complication of pregnancy which is characterized by hypertension and proteinuria in pregnant women. Pre‐eclampsia is important as it is the leading cause of death. Moreover, untreated pre‐eclampsia might lead to other lethal complications, for both fetus and mother. Pre‐eclampsia can also affect the quality of life in affected women. Despite a large number of risk factors for pre‐eclampsia, these risk factors are able to detect just 30% of women who are susceptible to pre‐eclampsia. Heterogeneous manifestations of pre‐eclampsia necessitate the discovery of potential biomarkers required for its early detection. Circular RNAs (circRNAs) are a type of RNA which are more abundant, specific, and highly organized compared with other types of RNA. Accordingly, circRNAs have been suggested as one of the potential biomarkers for different diseases. Recently, researchers have shown interest in the effects of circRNAs in pre‐eclampsia, although the current evidence is limited. The majority of obstetricians are probably not aware of circRNAs as a useful biomarker. Here, we aimed to summarize recent supporting evidence and assess the mechanisms by which circRNAs are involved in pre‐eclampsia.
Kunststoffindustrie: schwächeres Wachstum, mehr Kreislaufwirtschaft
Authors: Busching Johanna
Published: September 2019

Die Weltwirtschaft entwickelte sich im Jahr 2018 langsamer als zuvor. Der Abschwung der Abnehmerbranchen beeinträchtigte deutsche Unternehmen. Das Thema Kreislaufwirtschaft wurde infolge der Diskussionen um Klima‐ und Ressourcenschutz sowie angesichts vermüllter Meere bedeutender.
Trendbericht Lebensmittelchemie
Authors: Wefers Daniel
Published: September 2019

a‐Glucane sind in Form von Stärke Bestandteil vieler Lebensmittel, sie beeinflussen unter anderem deren Textur. In den letzten Jahren hat das Interesse an den a‐Glucanen zugenommen, die von Milchsäurebakterien gebildet werden. Vor allem die für die Glucansynthese verantwortlichen Enzyme werden verstärkt erforscht.
Umweltchemie in ihren Anfängen
Authors: Gröger Martin
Published: September 2019

Alexander von Humboldt ist den meisten Menschen als Astronom, Geologe, Kunst‐ und Kulturgeschichtler sowie Zoologe bekannt. Dabei galt er als einer der geschicktesten Chemiker seiner Zeit.
Neue Aromaten auf die Überwachungsliste
Authors: Andersson Jan T.
Published: September 2019

Seit über 40 Jahren werden in Umweltproben fast immer die gleichen 16 polycylischen aromatischen Kohlenwasserstoffe (PAK) bestimmt, um PAK‐Belastungen abzuschätzen. Diese Substanzen sind allerdings nicht für alle Untersuchungsgebiete aussagekräftig.
Liste besorgniserregender Stoffe erweitert
Authors: Bulmahn Maren
Published: September 2019

Die europäische Chemikalienagentur Echa hat die Liste besonders besorgniserregender Stoffe, die Kandidatenliste, im Juli erweitert.
Kreativ per Mausklick
Authors: Osterath Brigitte
Published: September 2019

Im Juni kam in Brasilien das erste Parfüm auf den Markt, das vollständig von einer Künstlichen Intelligenz entwickelt wurde. Das Computersystem kombinierte Inhaltsstoffe in einer Art, an die ein Mensch zuvor nicht gedacht hatte.
8. Symposium Forschung der chemischen Industrie
Authors: Serrano Eloisa , Sandfort Frederik
Published: September 2019

Am 6. Juni tauschten sich beim Symposium „Forschung der Chemischen Industrie“ (FoChIn) über 200 Wissenschaftler aus der Universität, vom Studienanfänger bis zum Professor, mit Forschern der Industrie aus. Die Veranstaltung fand bereits zum achten Mal im Fachbereich Chemie und Pharmazie an der Universität Münster statt. Organisiert wurde die von der Industrie und vom SFB 858 unterstützte Veranstaltung von Frank Glorius und seiner Arbeitsgruppe.
22. Steinheimer Gespräche – Chemie und Automatisierung
Authors: Lissel Franziska , Steinberg Simon
Published: September 2019

Unter dem Rahmenthema „Chemie und Automatisierung“ fanden vom 16. bis 18. Mai die 22. Steinheimer Gespräche in Mainz statt. Die vom Fonds der Chemischen Industrie (FCI) ausgerichtete Veranstaltung lieferte einen Einblick in aktuelle Entwicklungen in chemischer Industrie und Forschung. Zudem ermöglichten die Steinheimer Gespräche einen Dialog zwischen Industrievertretern, Hochschullehrern und Liebig‐Stipendiaten, insbesondere zu Fragen der Digitalisierung in der Chemie und den Herausforderungen der Industrie 4.0.
Mit der GDCh zu Tagungen im In‐ und Ausland
Authors: Schmitz Karin
Published: September 2019

Studierende, die ihre Bachelor‐ oder Masterarbeit auf einem Kongress vorstellen, können Reisestipendien beantragen. Geld gibt die GDCh selbst oder eine bei ihr angesiedelte Stiftung.
A particle mechanics approach for the dynamic strength model of the jointed rock mass considering the joint orientation
Authors: Zhou Changtai , Xu Chaoshui , Karakus Murat , Shen Jiayi
Published: September 2019

In nature, there exist several forms of anisotropy in rock masses due to the presence of bedding planes, joints, and weak layers. It is well understood that the anisotropic properties of jointed rock masses significantly affect the stability of surface and underground excavations. However, these critical anisotropic characteristics are often ignored in existing uniaxial dynamic failure criteria. This study investigates the effect of a pre‐existing persistent joint on the rate‐dependent mechanical behaviours of a rock mass using a particle mechanics approach, namely, bonded particle model (BPM), to realistically replicate the mechanical response of the rock mass. Firstly, in order to capture the rate‐dependent response of the jointed rock mass, the BPM model is validated using published experimental data. Then, a dynamic strength model is proposed based on the Jaeger criterion and simulation results. To further investigate the dynamic behaviours, the dynamic uniaxial compressive strength (UCS) for anisotropic rock masses with various joint orientations is investigated by subjecting the BPM models to uniaxial compression numerical tests with various strain rate. The proposed dynamic strength model is validated based on numerical simulation results. Finally, the fragmentation characteristics of the jointed rock masses are analysed, which demonstrate that the failure mode affects the dynamic UCS. This is further confirmed by the analysis of the orientations of microscopic cracks generated by the compression loading.
In vivo 13C and 1H‐[13C] MRS studies of neuroenergetics and neurotransmitter cycling, applications to neurological and psychiatric disease and brain cancer
Authors: Rothman Douglas L. , de Graaf Robin A. , Hyder Fahmeed , Mason Graeme F. , Behar Kevin L. , De Feyter Henk M.
Published: September 2019

In the last 25 years 13C MRS has been established as the only noninvasive method for measuring glutamate neurotransmission and cell specific neuroenergetics. Although technically and experimentally challenging 13C MRS has already provided important new information on the relationship between neuroenergetics and neuronal function, the high energy cost of brain function in the resting state and the role of altered neuroenergetics and neurotransmitter cycling in disease. In this paper we review the metabolic and neurotransmitter pathways that can be measured by 13C MRS and key findings on the linkage between neuroenergetics, neurotransmitter cycling, and brain function. Applications of 13C MRS to neurological and psychiatric disease as well as brain cancer are reviewed. Recent technological developments that may help to overcome spatial resolution and brain coverage limitations of 13C MRS are discussed.
When is a matrix unitary or Hermitian plus low rank?
Authors: Del Corso Gianna M. , Poloni Federico , Robol Leonardo , Vandebril Raf
Published: September 2019

Hermitian and unitary matrices are two representatives of the class of normal matrices whose full eigenvalue decomposition can be stably computed in quadratic computing complexity once the matrix has been reduced, for instance, to tridiagonal or Hessenberg form. Recently, fast and reliable eigensolvers dealing with low‐rank perturbations of unitary and Hermitian matrices have been proposed. These structured eigenvalue problems appear naturally when computing roots, via confederate linearizations, of polynomials expressed in, for example, the monomial or Chebyshev basis. Often, however, it is not known beforehand whether or not a matrix can be written as the sum of a Hermitian or unitary matrix plus a low‐rank perturbation. In this paper, we give necessary and sufficient conditions characterizing the class of Hermitian or unitary plus low‐rank matrices. The number of singular values deviating from 1 determines the rank of a perturbation to bring a matrix to unitary form. A similar condition holds for Hermitian matrices; the eigenvalues of the skew‐Hermitian part differing from 0 dictate the rank of the perturbation. We prove that these relations are linked via the Cayley transform. Then, based on these conditions, we identify the closest Hermitian or unitary plus rankkmatrix to a given matrixA, in Frobenius and spectral norm, and give a formula for their distance fromA. Finally, we present a practical iteration to detect the low‐rank perturbation. Numerical tests prove that this straightforward algorithm is effective.
Heiße Quellen im Wärmebild
Authors: Vollmer Michael , Shaw Joseph A. , Nugent Paul W. , Harris Wilson
Published: September 2019

Gute Infrarotkameras werden immer günstiger, inzwischen gibt es sie auch als Smartphone‐Aufsätze. Besonders spannend wird es, wenn man damit den Yellowstone‐Park besucht. Heiße Thermalquellen und Geysire bieten perfekte Motive. Neben dem ästhetischen Reiz ist auch die physikalische Interpretation der Wärmebilder spannend. Wegen der relativ geringen räumlichen Auflösung von IR‐Kameras empfiehlt es sich, vom Stativ aus aufgenommene Einzelbilder zu Panoramen zusammenzusetzen. Interessant sind zudem Infrarotvideos dynamischer Vorgänge, zum Beispiel der Mischung von heißem Thermalwasser in kaltem Flusswasser.
Validation of pediatric health‐related quality of life instruments for primary ciliary dyskinesia (QOL‐PCD)
Authors: Behan Laura , Leigh Margaret W. , Dell Sharon D. , Quittner Alexandra L. , Hogg Claire , Lucas Jane S.
Published: September 2019

Rationale

Having developed the first disease‐specific, health‐related quality of life (HRQoL) instruments for children with primary ciliary dyskinesia (PCD), we aimed to assess the psychometric performance of quality of life (QOL)‐PCD child, adolescent, and parent‐proxy versions in terms of reliability and validity across cross‐cultural settings and caring for patients with this rare disease.

Methods

Children (n = 71), adolescents (n = 85), and parents (n = 68) from multiple centers in the UK and North America completed age‐appropriate QOL‐PCD and generic QOL measures: pediatric QOL inventory, COPD assessment test (CAT), and Sino‐Nasal Outcome Test 20. Total of 13 children, 13 parents, and 17 adolescents repeated QOL‐PCD 10 to 14 days later to assess test‐retest reliability. Multitrait analysis evaluated how the items loaded to hypothesized scales: physical, emotional & social functioning, treatment burden, role, vitality, upper and lower respiratory symptoms, and ears and hearing symptoms. Examination of item‐to‐total correlations led to removal of three, five, and six items, respectively in the prototype child, adolescent and parent‐proxy versions; the validated measures now comprise between 34 and 38 items.

Results

The QOL‐PCD scales had good internal consistency; Cronbach's α for QOL‐PCD parent‐proxy ranged 0.62 to 0.86. Test‐retest reliability demonstrated stability across all scales; for example QOL‐PCD adolescent intraclass correlation coefficients ranged 0.71 to 0.89. Significant relationships were found between QOL‐PCD scales and similar constructs on generic questionnaires, for example, QOL‐PCD adolescent lower respiratory symptoms and the CAT score (r = .64, P < .01); weaker correlations were found between different constructs.

Conclusion

Age‐specific QOL‐PCD demonstrated good internal consistency, test‐retest reliability, and validity. QOL‐PCD offers promising outcome measures for multicenter clinical trials, as well as monitoring symptoms, functioning, and QOL during routine care.
Stronger Reductive Environment in Solvothermal Synthesis Leads to Improved Ga Doping Efficiency in ZnO Nanocrystals and Enhanced Plasmonic Absorption
Authors: Šutka Andris , Zukuls Anzelms , Eglītis Raivis , Käämbre Tanel , Kook Mati , Vlassov Sergei , Rubenis Kristaps , Ignatans Reinis
Published: September 2019

The key parameter for degenerated semiconductor oxide plasmonic nanocrystals is the doping level. Hydrothermal and solvothermal approaches are considered to be less effective toward achieving high concentration of aliovalent donor dopants in a host oxide when compared to other synthesis methods that use long chain hydrocarbon solvents, fatty acids, and fatty amines as precursors. Because of this, although they have several advantages such as sustainability, ease of use, relatively inexpensive reagents and apparatus, and reduced environmental impact, they are excluded from the list of potential synthesis methods. Herein, an effective Zn2+ substitution with aliovalent Ga3+ in the ZnO host lattice is demonstrated, and it is achieved by increasing the reductive power of the solvothermal synthesis conditions by either solvent substitution or the addition of reducing agents. This increase results in an increased oxidation affinity of the medium. This in turn promotes Ga3+ incorporation into the ZnO lattice, by skewing the reaction equilibrium toward oxygen evolution.
Formation of Few‐ and Monolayered WS2 Sheets Using Plasma‐Treated Dimethyl‐Sulfoxide Solvent‐Based Exfoliation
Authors: Esfandiari Mehrnaz , Kamaei Sadegh , Rajabali Mona , Mohajerzadeh Shams
Published: September 2019

Tungsten disulfide is an emerging 2D material with unique electrical and optical properties. Although chemical vapor deposition and mechanical exfoliation lead to large‐area layers, sonication solvent‐based exfoliation is a convenient method to realize mono‐ and few‐layer flakes. Herein, a mixture of dimethyl‐sulfoxide (DMSO) and water as a safe, facile, and user‐friendly exfoliation solvent for the synthesis of large‐scale WS2 sheets is investigated. While water molecules weaken the Van der Waals force between the stacked layers, DMSO molecules facilitate the exfoliation process. To improve exfoliation and achieve large‐area sheets, plasma pretreatment is exploited on bulk WS2 prior to the exfoliation process. For this purpose, O2 and H2 gases are used to carry out the plasma pretreatment. The oxygen plasma treatment is shown to be an effective strategy, leading to large‐area features. Moreover, inert gases as He and Ar are used to obtain small sheets. Transmission electron microscopy, atomic force microscopy, Raman spectroscopy, and dynamic light scattering analyses are used to understand the mechanism of exfoliation and study the effects of various parameters as water temperature, plasma power, and duration.
A mixed PI/VI design method for nonlinear H∞ Control
Authors: Liu Lijun , Zhu Chunhui , Wei Fang , Yu Zhen
Published: September 2019

This paper proposes a new mixed policy iteration and value iteration (PI/VI) design method for nonlinear H∞ control based on the theories of polynomial optimization and Lasserre's hierarchy. The design of a mixed PI/VI controller can be carried out in four steps: firstly, initialize design parameters and expand nonlinear system matrices; secondly, obtain a polynomial matrix inequality for policy improvement; thirdly, obtain the Lasserre's hierarchy of a global polynomial optimization problem for value improvement; fourthly, perform the mixed PI/VI algorithm to approximate the optimal nonlinear H∞ control law. The novelty of this work lies in that the problem of designing a nonlinear H∞ controller is translated into a polynomial global optimization problem, which can be solved by Lasserre's hierarchy directly, and then, the mixed PI/VI algorithm is presented to approximate the optimal nonlinear H∞ control law by updating global optimizers iteratively. The main results of this paper consist of the mixed PI/VI algorithm and the related three theorems, which guarantee robust stability and performance of the closed‐loop nonlinear system. Numerical simulations show that the mixed PI/VI algorithm converges very fast and achieves good robust stability and performance in transient behavior, disturbance rejection, and enlarging the domain of attraction of the close‐loop system.
Effect of amino, hydroxyl, and carboxyl terminal groups of alkyl chains of self‐assembled monolayers on the adsorption pattern of gold nanoparticles
Authors: Zahid Ali A.S.M. , Hanif Md.A. , Lee Insup , Islam Md. Akherul , Hahn Jae R.
Published: September 2019

The adsorption pattern of gold nanoparticles (AuNPs) on functionalized self‐assembled monolayers (SAMs) produced on a Au(111) surface was characterized. The Au(111) was modified with 11‐amino‐1‐undecanethiol hydrochloride (AUT), 11‐mercapto‐1‐undecanol (MUT), or 11‐mercaptoundecanoic acid (MUA) at an elevated temperature and pressure. The AuNPs aggregated on the AUT‐SAM surface, whereas they were well dispersed on the MUT‐SAM surface and localized on the MUA‐SAM surface. The results suggest that interactions between AuNPs differ according to the degree of peeling of citrate‐layer‐capped AuNPs. The degree of peeling, which is related to both the surface randomness of the SAMs and the functional characteristics of the terminal group of each SAM, was discussed on the basis of scanning tunneling microscopy observations, X‐ray photoelectron spectroscopic analyses, and contact angle measurements. Our study shows that AuNP patterns can be controlled by changing the terminal group of the alkyl thiol SAM on a Au(111) surface.
Surface treatment of magnesium oxysulfate whiskers through plasma polymerization
Authors: Lan Shengjie , Zhu Donghai , Dang Li , Huang Ziyang , Yang Linbo , Xu Ziyu
Published: September 2019

The surface of magnesium oxysulfate (MOS) whiskers was treated through plasma polymerization to increase the compatibility between the MOS whiskers and a polymer matrix. Different plasma parameters were chosen to determine the most hydrophobic coating. The surface structure of the plasma‐treated MOS whiskers was examined. The MOS whiskers retained their crystal structure after plasma treatment, as shown by X‐ray powder diffraction (XRD) analyses. X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT‐IR) spectroscopy analyses revealed that a polymer sheath was formed on the surface of the MOS whiskers, and interfacial chemical bonds were generated between the polymer sheath and the MOS whiskers. The thin‐layer polymer sheath was uniform around the entire surface of the MOS whiskers and exhibited a typical amorphous structure, as determined by transmission electron microscopy (TEM) combined with selected area electron diffraction (SAED) analyses. The possible reaction mechanism on the surface of the MOS whiskers under plasma treatment was then proposed. Finally, the effect of surface treatment was evaluated by scanning electron microscopy (SEM), measurement of the contact angle and contact angle hysteresis, and torque rheometer. Results showed that plasma treatment could markedly increase the hydrophobicity of the MOS whiskers' surface, effectively reducing the agglomeration and improving the dispersibility of the MOS whiskers in the matrix, which results in the improved compatibility between the MOS whiskers and the polyvinyl matrix, as well as the processability of the composites.
Effect decomposition through multiple causally nonordered mediators in the presence of exposure‐induced mediator‐outcome confounding
Authors: Mittinty Murthy N. , Lynch John W. , Forbes Andrew B. , Gurrin Lyle C.
Published: September 2019

Avin et al (2005) showed that, in the presence of exposure‐induced mediator‐outcome confounding, decomposing the total causal effect (TCE) using standard conditional exchangeability assumptions is not possible even under a nonparametric structural equation model with all confounders observed. Subsequent research has investigated the assumptions required for such a decomposition to be identifiable and estimable from observed data. One approach was proposed by VanderWeele et al (2014). They decomposed the TCE under three different scenarios: (1) treating the mediator and the exposure‐induced confounder as joint mediators; (2) generating path‐specific effects albeit without distinguishing between multiple distinct paths through the exposure‐induced confounder; and (3) using so‐called randomised interventional analogues where sampling values from the distribution of the mediator within the levels of the exposure effectively marginalises over the exposure‐induced confounder. In this paper, we extend their approach to the case where there are multiple mediators that do not influence each other directly but which are all influenced by an exposure‐induced mediator‐outcome confounder. We provide a motivating example and results from a simulation study based on from our work in dental epidemiology featuring the 1982 Pelotas Birth Cohort in Brazil.
Regioselective Synthesis of Carbazole‐Grafted Dispirothiapyrrolizine Derivatives via 1,3‐Dipolar Cycloaddition Strategy
Authors: Murali Karunanidhi , Sparkes Hazel A. , Prasad Karnam Jayarampillai Rajendra
Published: September 2019

A library of dispirooxindole‐thiapyrrolizine derivatives have been prepared via 1,3‐dipolar cycloaddition of azomethine ylide, generated in situ from the reaction of isatin and thiaproline with a series of 2‐arylidene/heteroarylidene‐2,3,4,9‐tetrahydrocarbazol‐1‐ones. Moderate to good yields were obtained for these reactions and also for spiro compounds of acenaphthenequinone obtained using the same optimized reaction condition. The structures of the spiro compounds were established by FTIR, 1H NMR, 13C NMR and elemental analysis. The regio‐ and stereo‐chemistry of the spiranic adducts were ascertained by single crystal X‐ray diffraction studies.
Identifying general trends and patterns in complex systems research: An overview of theoretical and practical implications
Authors: Preiser Rika
Published: September 2019

Research on complex systems is becoming more prolific, and there is a need to provide some point of orientation to researchers and practitioners that are drawing on the body of literature that informs the field of complexity research. In this paper, I aim to give an overview of the development of the field and offer some overarching trends and patterns that are recognizable in research on complex systems. The paper then draws on the work to provide six organizing principles of complex systems to inform practical implications and methods for studying and understanding complex systems.
Optimum design of tuned mass dampers for different earthquake ground motion parameters and models
Authors: Greco Rita , Morga Mariantonietta
Published: September 2019

Tuned mass dampers are frequently used for passive control of vibrations in civil structures subject to seismic and wind actions. Their efficiency depends on selection of their mechanical properties in relation to main system and excitation characteristics. This paper proposes an optimum design strategy of single tuned mass dampers to control vibrations of principal mode of structures excited by earthquake ground motion. The main purpose of the paper is to investigate the influence of the time modulation of earthquake excitation upon the optimal tuned mass dampers design parameters: frequency and damping ratio. The study is based on numerical analyses carried out with different stochastic models for earthquakes: a simple filtered white noise model and two time modulated filtered white noise models. The numerical analyses are carried out to solve an optimization problem with a performance index defined by the reduction of the standard deviation of either the structure displacement or its inertial acceleration as objective function. To complete the work, the influence of the bandwidth excitation over the values of the optimal tuned mass damper parameters is investigated, as well the optimum mass ratio and the structure frequency. The results of the numeral analyses carried out infer that the earthquake excitation characteristics, including its modulation in time domain, highly affect the optimum tuned mass damper design parameters values.
Wind farm generation forecast and optimal maintenance schedule model
Authors: Pelajo Jonas C. , Brandão Luiz E.T. , Gomes Leonardo L. , Klotzle Marcelo C.
Published: September 2019

Wind farms must periodically take their turbines offline in order to perform scheduled maintenance repairs. Given that these interruptions impact energy generation and that under Power Purchase Agreements productions shortfalls must be replaced by energy purchases in the spot market, the optimal time to begin maintenance work in a wind farm is a function of both the expected wind speeds and electricity spot prices. In this article, we develop a model to determine the optimal maintenance schedule of a wind farm based on forecasted wind speeds and energy prices. We analyze a window of opportunity in the most likely period of the year and perform weekly updates of expected wind speeds and energy price forecasts. Wind speeds are forecasted with an ARMAX model, where monthly dummies are used as exogenous variables to capture the seasonality of wind speeds, while spot prices are simulated under a standard dual stochastic programing model. The decision to defer maintenance to a future date is modeled in a probabilistic model and also under the real options approach. We test these models with actual data from a wind farm in the Brazilian Northeast and provide comparisons with current practice in order to determine the benefits of the model. The results suggest that this model may provide advantages over a stopping decision that randomly chooses a week to begin maintenance within the opportunity window and is close to the optimal stopping date considering perfect information on future wind speeds and electricity prices.