bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnesiumoxid, unlöslich (Sintermagnesia) (alveolengängige Fraktion) [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: April 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has reevaluated Magnesium oxide. Magnesium oxide, sintermagnesite [
1309‐48‐4
], is a biopersistent granular dust. Therefore, the respirable fraction of magnesium oxide dust has been classified in Carcinogen Category 4 and a MAK value of 0.3 mg/m³ × material density was established for the respirable fraction in analogy to the other biopersistent granular dusts. Additionally for this fraction the Peak Limitation Category II with an excursion factor of 8 was established. Since magnesium oxide is not systemically distributed and accumulates only locally in the lungs, no developmental effects due to this dust are expected to occur at the MAK value of 0.3 mg/m³ × material density (respirable, R‐fraction). Magnesium oxide has accordingly been classified in Pregnancy Risk Group C. Magnesium oxide is not designated with either “Sa” or “Sh” or “H”.
n
‐Butyl acrylate [MAK Value Documentation, 2017]
Authors: Hartwig A. ,   MAK Commission
Published: April 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) of 2 ml/m
3
for n‐butyl acrylate. The critical effect in a two‐year inhalation study with rats was reserve cell hyperplasia with loss of ciliated or olfactory cells at the lowest concentration of 15 ml/m
3
. The lower confidence limit of the benchmark dose for an extra risk of 5% increase of the critical effect incidence (BMDL
05
) of about 3 ml/m
3
, which had been calculated in the previous evaluations, was confirmed. Since 2014, the Commission uses an empirical approach to set MAK values for substances with critical effects on the upper respiratory tract or the eyes. Based on this approach, the equivalent concentration at the workplace is 1.5 ml/m
3
. However, studies in humans to investigate the sensory irritation of n‐butyl acrylate are lacking. As the structurally related ethyl acrylate possesses a RD
50
value as well as subchronic and chronic NOAECs similar to those of n‐butyl acrylate, the NOAEC of 2.5 ml ethyl acrylate/m
3
for sensory irritation in volunteers was used as a read‐across. As the MAK value for ethyl acrylate has been set at 2 ml/m
3
, the MAK value of 2 ml/m
3
for n‐butyl acrylate could be confirmed. In analogy to ethyl acrylate, the assignment of n‐butyl acrylate to Peak Limitation Category I and the excursion factor of 2 were confirmed. The NOAECs for developmental toxicity in rats and mice are sufficiently high so that damage to the embryo or foetus is unlikely when the MAK value is observed. Thus, n‐butyl acrylate continues to be classified in Pregnancy Risk Group C. The substance is marginally clastogenic in vitro but not in vivo and was not carcinogenic in a 2‐year inhalation study in rats. There are only a few cases of contact sensitization in humans but there are positive results in local lymph node assays. Data on airway sensitization are still not available. n‐Butyl acrylate continues to be designated with “Sh”. Skin absorption was calculated to contribute significantly to the systemic toxicity and n‐butyl acrylate is designated with an “H”.
1,3‐Dioxolan [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: April 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) and the Pregnancy Risk Group of 1,3‐dioxolane [
646‐06‐0
].

1,3‐Dioxolane causes a reduction in white blood cell count and in relative spleen weight at 1000 ml/m
3
and above in female rats after 13 weeks whole body inhalation. The NOAEC is 298 ml/m
3
. As the percentage of white blood cell count reduction is the same after four and 13 weeks, no decrease of the NOAEC after chronic exposure is expected. The former MAK value of 100 ml/m
3
was derived from the NOAEC. The MAK value is now lowered to 50 ml/m
3
which takes into account the increased respiratory volume at the workplace because the blood:air partition coefficient of 1,3‐dioxolane is > 5 (see List of MAK‐ and BAT values chapters I b and I c). Since a systemic effect is critical, Peak Limitation Category II is retained. The default excursion factor of 2 is retained as well, as no half‐life in blood is known.

In a prenatal toxicity study in rats with gavage application, 1,3‐dioxolane results in reduced fetal body weights and gross external, soft tissue and skeletal malformations or variations at 1000 mg/kg body weight and day. The NOAEL for developmental toxicity is 500 mg/kg body weight and day. After toxicokinetic scaling this dose corresponds to a concentration of 875 mg/m
3
(285 ml/m
3
) at the workplace. The difference to the MAK value of 50 ml/m
3
is not sufficient. Therefore, the assignment to Pregnancy Risk Group B, for substances, for which damage to the embryo or foetus must be expected even when the MAK value is observed, is confirmed.
N‐Vinyl‐2‐pyrrolidon [MAK Value Documentation in German language, 2018]
Authors: Hartwig A. ,   MAK Commission
Published: April 2018

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated the maximum concentration at the workplace (MAK value) and the Pregnancy Risk Group of N‐vinyl‐2‐pyrrolidone [
88‐12‐0
].

N‐Vinyl‐2‐pyrrolidone is a non‐genotoxic carcinogen in liver, nose and larynx of rats. In 28‐day inhalation studies it was shown that cell proliferation in liver and hyperplasia in the nasal epithelia of rats is increased at 0.5 ml/m
3
with a NOAEC of 0.2 ml/m
3
. The former MAK value of 0.02 ml/m
3
was derived from this concentration, the MAK value is now lowered to 0.01 ml/m
3
. This takes into account the increased respiratory volume at the workplace, because the blood:air partition coefficient of N‐vinyl‐2‐pyrrolidone is > 5 (see List of MAK‐ and BAT values chapters I b and I c). Since a systemic effect is critical, Peak Limitation Category II is retained. As the critical metabolite is not known, the default excursion factor of 2 for systemically acting compounds is confirmed.

For rats, the NOAEC for developmental toxicity after inhalation is 5 ml N‐vinyl‐2‐pyrrolidone/m
3
, where reduced maternal body weight gain occurred. At 20 ml/m
3
reduced foetal bodyweight and an increase of variations were observed. Taking into account the increased respiratory volume at the work place the NOAEC for developmental toxicity is 250 times higher than the MAK‐value. Therefore, N‐vinyl‐2‐pyrrolidone remains assigned to Pregnancy Risk Group C.
Synthesis of 2D Metal Chalcogenide Thin Films through the Process Involving Solution‐Phase Deposition
Authors: Giri Anupam , Park Gyeongbae , Yang Heeseung , Pal Monalisa , Kwak Junghyeok , Jeong Unyong
Published: April 2018

2D metal chalcogenide thin films have recently attracted considerable attention owing to their unique physicochemical properties and great potential in a variety of applications. Synthesis of large‐area 2D metal chalcogenide thin films in controllable ways remains a key challenge in this research field. Recently, the solution‐based synthesis of 2D metal chalcogenide thin films has emerged as an alternative approach to vacuum‐based synthesis because it is relatively simple and easy to scale up for high‐throughput production. In addition, solution‐based thin films open new opportunities that cannot be achieved from vacuum‐based thin films. Here, a comprehensive summary regarding the basic structures and properties of different types of 2D metal chalcogenides, the mechanistic details of the chemical reactions in the synthesis of the metal chalcogenide thin films, recent successes in the synthesis by different reaction approaches, and the applications and potential uses is provided. In the last perspective section, the technical challenges to be overcome and the future research directions in the solution‐based synthesis of 2D metal chalcogenides are discussed.
Melanoma, thyroid cancer, and gynecologic cancers in a cohort of female flight attendants
Authors: Pinkerton Lynne E. , Hein Misty J. , Anderson Jeri L. , Christianson Annette , Little Mark P. , Sigurdson Alice J. , Schubauer‐Berigan Mary K.
Published: April 2018

Background

Flight attendants may have an increased risk of some cancers from occupational exposure to cosmic radiation and circadian disruption.

Methods

The incidence of thyroid, ovarian, and uterine cancer among ∼6000 female flight attendants compared to the US population was evaluated via life table analyses. Associations of these cancers, melanoma, and cervical cancer with cumulative cosmic radiation dose and metrics of circadian disruption were evaluated using Cox regression.

Results

Incidence of thyroid, ovarian, and uterine cancer was not elevated. No significant, positive exposure‐response relations were observed. Weak, non‐significant, positive relations were observed for thyroid cancer with cosmic radiation and time zones crossed and for melanoma with another metric of circadian disruption.

Conclusions

We found little evidence of increased risk of these cancers from occupational cosmic radiation or circadian disruption in female flight attendants. Limitations include few observed cases of some cancers, limited data on risk factors, and misclassification of exposures.
Association of copy number variation across the genome with neuropsychiatric traits in the general population
Authors: Guyatt Anna L. , Stergiakouli Evie , Martin Joanna , Walters James , O'Donovan Michael , Owen Michael , Thapar Anita , Kirov George , Rodriguez Santiago , Rai Dheeraj , Zammit Stan , Gaunt Tom R.
Published: April 2018

Copy number variants (CNVs) are associated with psychiatric conditions in clinical populations. The relationship between rare CNV burden and neuropsychiatric traits in young, general populations is underexplored. A total of 6,807 children from the Avon Longitudinal Study of Parents and Children (ALSPAC) were studied. CNVs were inferred from single nucleotide polymorphism‐array data using PennCNV. After excluding children with known candidate CNVs for schizophrenia (SCZ), rare (<1%) CNV burden (total number of genes affected by CNVs, total length of CNVs, and largest CNV carried) was analyzed in relation to: psychotic experiences (PEs) and anxiety/depression in adolescence; autism spectrum disorder (ASD) and attention‐deficit hyperactivity disorder (ADHD), ASD and ADHD traits, and cognitive measures during childhood. Outcomes were also assessed in relation to known SCZ CNVs. The number of genes affected by rare CNVs was associated with a continuous measure of ASD: the standardized mean difference [SMD] per gene affected was increased by 0.018 [95%CI 0.011,0.025], p = 3e‐07 for duplications and by 0.021 [95%CI 0.010, 0.032], p = 1e‐04 for deletions. In line with our published results on educational attainment in ALSPAC, intelligence quotient (IQ) was associated with CNV burden: the SMD per gene affected was −0.017 [95%CI −0.025, −0.008] p = 1e‐04 for duplications and −0.023 [95%CI −0.037, −0.009], p = .002 for deletions. Associations were also observed for measures of coherence, attention, memory, and social cognition. SCZ‐associated deletions were associated with IQ (SMD: −0.617 [95%CI −0.936, −0.298], p = 2e‐04), but not with PEs or other traits. We found that rare CNV burden and known SCZ candidate CNVs are associated with neuropsychiatric phenotypes in a nonclinically ascertained sample of young people.
Fucose‐Migration in intakten protonierten Glykan‐Ionen – ein universelles Phänomen in der Massenspektrometrie
Authors: Mucha Eike , Lettow Maike , Marianski Mateusz , Thomas Daniel A. , Struwe Weston B. , Harvey David J. , Meijer Gerard , Seeberger Peter H. , von Helden Gert , Pagel Kevin
Published: April 2018

Fucose ist ein essenzieller Desoxyzucker, der in einer Vielzahl biologisch relevanter Glykane und ihrer Konjugate vorkommt. Ein verbreitetes Problem in massenspektrometrischen Analysen von fucosylierten Glykanen ist der intramolekulare Transfer von Fucoseeinheiten, der zu fehlerhaften Sequenzzuordnungen führen kann. Diese Migrationsreaktion wird typischerweise der Aktivierung während der kollisionsinduzierten Dissoziation in der Tandem‐Massenspektrometrie (Tandem‐MS) zugeordnet. Hier wird erstmals mit Kaltionen‐Spektroskopie gezeigt, dass Fucose‐Migration nicht auf Fragmente beschränkt ist, die in der Tandem‐MS erhalten werden, sondern auch in intakten Glykan‐Ionen beobachtet werden kann. Diese Beobachtung lässt auf eine mögliche niedrige Energiebarriere für diese Transferreaktion schließen und verallgemeinert die Fucose‐Migration zu einem Problem, das bei jeder Art von Massenspektrometrie‐Experiment auftreten kann.
Asymmetrische reduktive Carbocyclisierung durch modifizierte En‐Reduktasen
Authors: Heckenbichler Kathrin , Schweiger Anna , Brandner Lea Alexandra , Binter Alexandra , Toplak Marina , Macheroux Peter , Gruber Karl , Breinbauer Rolf
Published: April 2018

En‐Reduktasen der “Old Yellow Enzyme”(OYE)‐Familie reduzieren die C=C‐Doppelbindung in α,β‐ungesättigten Verbindungen, die eine elektronenziehende Gruppe (z. B. eine Carbonyl‐Gruppe) tragen. Diese asymmetrische Reduktion hat in der Biokatalyse Anwendung gefunden. Es konnte gezeigt werden, dass Mitglieder dieser Enzymfamilie außerdem noch die Bildung von C‐C‐Bindungen katalysieren können. Mit α,β‐ungesättigten Aldehyden und Ketonen, die eine zusätzliche elektrophile Gruppe enthalten, kann eine reduktive Cyclisierung erfolgen. Dabei überträgt der durch zwei Elektronen reduzierte Enzymcofaktor FMN ein Hydrid. Das entstandene Enolat kann danach mit einem internen Elektrophil unter Ringbildung reagieren. Ortsgerichteter Austausch des entscheidenden Tyr‐Rests gegen ein nichtprotisches Phe oder Trp begünstigt die reduktive Cyclisierung über die natürliche Reduktionsreaktion. Diese neue Transformation ermöglicht die enantioselektive Synthese von chiralen Cyclopropanen mit bis zu >99 % ee.
Smart DNA Hydrogel Integrated Nanochannels with High Ion Flux and Adjustable Selective Ionic Transport
Authors: Wu Yafeng , Wang Dianyu , Willner Itamar , Tian Ye , Jiang Lei
Published: April 2018

Nanochannels based on smart DNA hydrogels as stimulus‐responsive architecture are presented for the first time. In contrast to other responsive molecules existing in the nanochannel in monolayer configurations, the DNA hydrogels are three‐dimensional networks with space negative charges, the ion flux and rectification ratio are significantly enhanced. Upon cyclic treatment with K+ ions and crown ether, the DNA hydrogel states could be reversibly switched between less stiff and stiff networks, providing the gating mechanism of the nanochannel. Based on the architecture of DNA hydrogels and pH stimulus, cation or anion transport direction could be precisely controlled and multiple gating features are achieved. Meanwhile, G‐quadruplex DNA in the hydrogels might be replaced by other stimulus‐responsive DNA molecules, peptides, or proteins, and thus this work opens a new route for improving the functionalities of nanochannel by intelligent hydrogels.
Ein rein organisches Tricarbanion
Authors: Höfler Denis , Goddard Richard , Lingnau Julia B. , Nöthling Nils , List Benjamin
Published: April 2018

Wie viele Carbanionen kann ein organisches Molekül tragen? Die Bildung von rein organischen Carbanionen mit mehreren Ladungen ist eine anspruchsvolle Aufgabe, da eine Ladungsstabilisierung nicht durch Metallkoordination erreicht werden kann. Bisher wurden nur Salze von quartären Ammoniumdicarbanionen beschrieben. Mit stark elektronenarmen Trifluormethansulfonylgruppen konnte jetzt erstmals die Bildung eines rein organischen Tricarbanions erzielt werden.
Asymmetric Reductive Carbocyclization Using Engineered Ene Reductases
Authors: Heckenbichler Kathrin , Schweiger Anna , Brandner Lea Alexandra , Binter Alexandra , Toplak Marina , Macheroux Peter , Gruber Karl , Breinbauer Rolf
Published: April 2018

Ene reductases from the Old Yellow Enzyme (OYE) family reduce the C=C double bond in α,β‐unsaturated compounds bearing an electron‐withdrawing group, for example, a carbonyl group. This asymmetric reduction has been exploited for biocatalysis. Going beyond its canonical function, we show that members of this enzyme family can also catalyze the formation of C−C bonds. α,β‐Unsaturated aldehydes and ketones containing an additional electrophilic group undergo reductive cyclization. Mechanistically, the two‐electron‐reduced enzyme cofactor FMN delivers a hydride to generate an enolate intermediate, which reacts with the internal electrophile. Single‐site replacement of a crucial Tyr residue with a non‐protic Phe or Trp favored the cyclization over the natural reduction reaction. The new transformation enabled the enantioselective synthesis of chiral cyclopropanes in up to >99 % ee.
A Purely Organic Tricarbanion
Authors: Höfler Denis , Goddard Richard , Lingnau Julia B. , Nöthling Nils , List Benjamin
Published: April 2018

How many carbanions can an organic molecule accommodate? The formation of purely organic carbanions with multiple charges is challenging as charge stabilization cannot be achieved through metal coordination. Previously, only quaternary ammonium dicarbanion salts had been reported. By using highly electron‐deficient trifluoromethanesulfonyl (triflyl or Tf) groups, the formation of a purely organic tricarbanion has been realized for the first time.
The size effect to O2−–Ce4+ charge transfer emission and band gap structure of Sr2CeO4
Authors: Wang Wenjun , Pan Yu , Zhang Wenying , Liu Xiaoguang , Li Ling
Published: April 2018

Sr2CeO4 phosphors with different crystalline sizes were synthesized by the sol–gel method or the solid‐state reaction. Their crystalline size, luminescence intensity of O2−−Ce4+ charge transfer and energy gaps were obtained through the characterization by X‐ray diffraction, photoluminescence spectra, as well as UV–visible diffuse reflectance measurements. An inverse relationship between photoluminescence (PL) spectra and crystalline size was observed when the heating temperature was from 1000°C to 1300°C. In addition, band energy calculated for all samples showed that a reaction temperature of 1200°C for the solid‐state method and 1100°C for sol–gel method gave the largest values, which corresponded with the smallest crystalline size. Correlation between PL intensity and crystalline size showed an inverse relationship. Band structure, density of states and partial density of states of the crystal were calculated to analyze the mechanism using the cambrige sequential total energy package (CASTEP) module integrated with Materials Studio software.
Hollow Nickel–Cobalt Layered Double Hydroxide Supported Palladium Catalysts with Superior Hydrogen Evolution Activity for Hydrolysis of Ammonia Borane
Authors: Zhou Ying‐Hua , Wang Suqin , Zhang Zhiyan , Williams Nicholas , Cheng Yong , Gu Jing
Published: April 2018

Although ammonia borane (NH3BH3, AB) has been identified as an excellent hydrogen‐storage medium, the development of a highly active catalyst that can function under mild conditions for controllable hydrogen release is still a great challenge. The synergistic effect induced by interactions between metal nanoparticles and a support has been widely applied in thermocatalytic conversion processes. In this work, Pd nanoparticles (NPs) highly dispersed on hollow NiCo layered double hydroxide (LDH) were designed for efficient hydrogen generation from AB at room temperature. During the hydrolytic dehydrogenation of AB, Pd/α‐LDH and Pd/β‐LDH exhibited catalytic activities with total turnover frequency (TOF) values of 49.5 and 28.1 min−1 with activation energy (Ea) values of 20.56 and 37.56 kJ mol−1, respectively, at 298 K; thus, these catalysts outperform most Pd‐based catalysts. The improved catalytic effect was attributed to the controllable size and fine distribution of the Pd NPs and the collaborative effect provided by the hydroxide of α‐LDH and the intercalated anions (HO−). This catalysts design principle can be easily transferred to other catalyst research fields for energy‐conversion and ‐storage purposes.
Transition‐Metal‐Catalyzed C−H Functionalization for Construction of Quaternary Carbon Centers
Authors: Li Yang , Xu Silong
Published: April 2018

Efficient construction of quaternary carbon centers represents one of the most challenging goals in organic synthesis, and it has drawn tremendous research interest from organic chemist community. The past decade has witnessed a significant advancement of direct C−H functionalization, which delivers various synthetic tools for assembling structurally diversified architectures with the advantage of step‐ and atom‐economy, operational simplicity, and readily available substrates. In this Minireview, synthetic methods based on transition‐metal‐catalyzed C−H functionalization as efficient tools for the construction of quaternary carbon centers are summarized.
DFT Studies on the Reactions of Boroles with Alkynes
Authors: Wang Zheng , Zhou Yu , Zhang Jing‐Xuan , Krummenacher Ivo , Braunschweig Holger , Lin Zhenyang
Published: April 2018

DFT calculations were performed to investigate the reactions of boroles with alkynes, in which boranorbornadiene, borepin and/or boracyclohexadiene can be formed depending on the substituents on the borole and alkyne. Our computational results indicated that formation of boranorbornadiene and borepin is generally kinetically favoured and that the products can interconvert. Formation of boracyclohexadiene is kinetically unfavourable in most reactions. However, certain substituents can promote the formation of boracyclohexadiene by stabilizing an energetically high‐lying zwitterionic transition state that leads to boracyclohexadiene. Borafluorene reacted with most alkynes to give borepin exclusively due to its propensity to maintain its aromaticity. However, when it reacted with silyl‐substituted alkyne(s), a novel product, different from boranorbornadiene, borepin and boracyclohexadiene was generated, which can be attributed to the well‐known ability of silyl groups to migrate.
CHA2DS2‐VASc score and clinical outcomes of patients with chest pain discharged from internal medicine wards following acute coronary syndrome rule‐out
Authors: Topaz Guy , Haisraely Ory , Shacham Yacov , Beery Gil , Shilo Lotan , Kassem Nuha , Pereg David , Kitay‐Cohen Yona
Published: April 2018

Background

Chest‐pain patients deemed safe for discharge from internal medicine wards might still be at risk for adverse outcomes.

Hypothesis

CHA2DS2‐VASc score improves risk stratification of low‐risk chest‐pain patients discharged after acute coronary syndrome (ACS) rule‐out.

Methods

We accessed medical records of patients who were admitted to internal medicine wards at a single medical center during 2010–2016 and discharged following an ACS rule‐out. Patients were classified according to CHA2DS2‐VASc score: 0–1 (low), 2–3 (intermediate), >3 (high). Primary endpoint was occurrence of ACS at 1 year; 30‐day and 1‐year all‐cause mortality (ACM) were secondary outcomes.

Results

Of 12 449 patients, 7057 (57%) had low, 3781 (30%) intermediate, and 1611 (13%) high CHA2DS2‐VASc scores. Compared with a low score, intermediate and high scores were associated with significantly increased risk for 1‐year ACS during the first year (OR: 2.89, 95% CI: 1.91–4.37, P < 0.01 and OR: 4.84, 95% CI: 3.02–7.74, P < 0.01, respectively). Each 1‐point increase in CHA2DS2‐VASc was associated with a 37% increased risk for 1‐year ACS. A higher CHA2DS2‐VASc score was associated with significantly higher 30‐day ACM. Hazard ratios for 30‐day ACM were 1.9 (95% CI: 1.1–3.4, P = 0.03) and 4.4 (95% CI: 2.4–7.9, P < 0.01) for intermediate and high CHA2DS2‐VASc scores, respectively, compared with a low score. Each 1‐point increase in CHA2DS2‐VASc score was associated with 43% increased risk for 30‐day mortality.

Conclusions

High CHA2DS2‐VASc score (>3) was associated with adverse outcomes among chest‐pain patients discharged from internal medicine wards following ACS rule‐out.
A novel adaptive radio map for RSS‐based indoor positioning
Authors: Ye Ayong , Yang Xiaoliang , Li Qing , Chen Aimin
Published: April 2018

Fingerprinting positioning is used for indoor location estimation because of low cost and open access properties, in which a radio map is built by calibrating signal‐strength values at several training locations in the offline phase. However, due to the sophisticated propagation of radio signals, the received signal strength (RSS) in wireless network change as the environment changes, and the radio map built in the offline phase may be out of date. Furthermore, the recalibration of signal‐strength values for each environment change is laborious and time consuming. In this paper, we present a novel algorithm to reconstruct a radio map using real‐time signal‐strength readings received at some reference points. We first demonstrate that different features of signal propagation are obtained in different regions of indoor environment. Then, the indoor environment is divided into several regions by clustering the path‐loss parameters of each reference point. In addition, the relationship between the RSS of reference points and calibration nodes is established with robust linear regression. Finally, the real‐time radio map is updated dynamically according to robust regression and the real‐time RSSs of the calibration nodes. The experimental results show the usefulness of the proposed method and the accuracy of the localization can be improved.
Evaluation of dataflow programming models for electronic structure theory
Authors: Jagode Heike , Danalis Anthony , Hoque Reazul , Faverge Mathieu , Dongarra Jack
Published: April 2018

Dataflow programming models have been growing in popularity as a means to deliver a good balance between performance and portability in the post‐petascale era. In this paper, we evaluate different dataflow programming models for electronic structure methods and compare them in terms of programmability, resource utilization, and scalability. In particular, we evaluate two programming paradigms for expressing scientific applications in a dataflow form: (1) explicit dataflow, where the dataflow is specified explicitly by the developer, and (2) implicit dataflow, where a task scheduling runtime derives the dataflow using per‐task data‐access information embedded in a serial program. We discuss our findings and present a thorough experimental analysis using methods from the NWChem quantum chemistry application as our case study, and OpenMP, StarPU, and PaRSEC as the task‐based runtimes that enable the different forms of dataflow execution. Furthermore, we derive an abstract model to explore the limits of the different dataflow programming paradigms.
Preparing and Presenting a Poster
Authors: Torigoe Sharon E.
Published: April 2018

A poster is one method of informing the world about results from a research project. Whether serving as an aid for a presentation or standing alone, it should provide information about a project. Both substantive and stylistic qualities should contribute to effectively communicating one's conclusions. This article gives general guidelines and suggestions for poster content, layout, and design to assist in preparing an effective poster. © 2018 by John Wiley & Sons, Inc.
Radiation Safety and Measurement
Authors: Meisenhelder Jill , Bursik Steve
Published: April 2018

Scientific knowledge has been considerably advanced by the use of biochemical molecules which incorporate radioisotopes at specific sites. This unit provides an overview of the use of radioisotopes in the biochemical laboratory. It begins with a discussion of the principles of radioactivity in order to provide the reader/user with knowledge on which to base a common sense approach to the safe use of isotopes. The characteristics of isotopes most commonly used in a biochemical laboratory are then detailed, as well as the safety precautions and monitoring methods peculiar to each one. Detection and imaging methods used in experimental analysis are reviewed. Finally, an outline of an orderly, proper response to a spill of radioactive material is presented. © 2018 by John Wiley & Sons, Inc.
Modeling Quantum Kinetics in Ion Traps: State‐changing Collisions for OH+() Ions with He as a Buffer Gas
Authors: González‐Sánchez L. , Wester R. , Gianturco F.A.
Published: April 2018

We present quantum scattering calculations for rotational state‐changing cross sections and rates, up to about 50 K of ion translational temperatures, for the OH+ molecular ion in collision with He atoms as the buffer gas in the trap. The results are obtained both by using the correct spin‐rotation coupling of angular momenta and also within a recoupling scheme that treats the molecular target as a pseudo‐(
) state, and then compares our findings with similar data for the OH−(
) molecular partner under the same conditions. This comparison intends to link the cation behaviour to the one found earlier for the molecular anion. The full calculations including the spin‐rotation angular momenta coupling effects have been recently reported (L. González‐Sánchez and R. Wester and F.A. Gianturco, Mol.Phys.2018, DOI 10.1080/00268976.2018.1442597) with the aim of extracting specific propensity rules controlling the size of the cross sections. The present study is instead directed to modelling trap cooling dynamics by further obtaining the solutions of the corresponding kinetics equations under different trap schemes so that, using the presently computed rates can allow us to indicate specific optimal conditions for the experimental setup of the collisional rotational cooling in an ion trap for the system under study.
The Evolution of Growth, Crystal Orientation, and Grain Boundaries Disorientation Distribution in Gold Thin Films
Authors: Parajuli Prakash , Mendoza‐Cruz Rubén , Santiago Ulises , Ponce Arturo , Yacamán Miguel José
Published: April 2018

Herein, the growth and annealing effect of gold thin films are systematically studied by using an automated crystal orientation mapping (ACOM–TEM) technique. The crystallographic redistribution and structural changes in grain and boundaries due to recrystallization and grain kinetic processes are followed and described. The as‐grown films show a dominant <111> texture followed by <110>, <100>, <112>, <102>, and <212> orientations; having a noticeable reorientation of the grains after annealing along the <111> direction parallel to the electron beam, as well as the expected grain size enlargement. Moreover, the random high angle grain boundaries observed in as‐grown film transform towards low coincidence site lattice (CSL) boundaries after annealing. The consequences of recrystallization and grain kinetic processes, primarily grain rotation and coupled grain boundary migration on the evolution of the film structural properties are discussed based on the experimental results.
A novel leader election algorithm based on resources for ring networks
Authors: Biswas Tarun , Bhardwaj Rajat , Ray Anjan Kumar , Kuila Pratyay
Published: April 2018

The leader node in a distributed computing system is responsible to establish coordination among all other nodes that are situated apart geographically. Selection of a suitable leader is one of the major and challenging problems. In this paper, a novel leader election algorithm is proposed based on resources of each node in a ring network. All the nodes compute resource strength values by considering available resources like CPU, memory capacity, and residual energy. A node with the highest resource strength over the network is elected as the leader. The proposed algorithm has also considered sudden failure of the nodes particularly when it is the leader node. Moreover, addition of new nodes is also considered. The proposed algorithm shows improvement on message complexity over the network and resource‐based priority generation, which helps in efficient election of the leader. To validate, the proposed algorithm is extensively simulated as well as real‐life hardware experiment is also done. In the experiment, 2 cases are considered with different weight of the resources, and consequent effects are shown. The results are also compared with the existing algorithms, and it is observed that the proposed work comparably performs better that the existing related algorithms.
Stable routing protocol based on fuzzy logic system in vehicular ad hoc networks
Authors: Marzak Bouchra , El Moumni Soufiane , Benlahmar Elhabib , Ait‐Mlouk Addi , Talea Mohamed
Published: April 2018

Vehicular ad‐hoc networks have several roles in alert messages dissemination between vehicles in danger, the most important role is to provide helpful information for drivers (eg, road traffic state). But, some performance improvements are frequently needed in terms of routing. Hence, several clustering approaches have been proposed to optimize the network services. These approaches are based on increasing data delivery, reducing data congestion, and dividing the traffic into clusters. However, a stable clustering algorithm is always required in order to ensure the data dissemination in a dense, mobile, or a large‐scale environment. Therefore, in this paper, we have proposed a stable routing protocol based on the fuzzy logic system, which can deliver alert messages with minimum delay and improve the stability of clusters structure by generating only a small number of clusters in the network. In this work, the fuzzy logic system has been used to create the clusters and select a cluster head for each cluster. We have used the network simulator (NS2) to generate the results. As a result, we could reduce the cluster head changes and increase the cluster member lifetime compared with recent approaches.
Performance analysis on DPSK modulation using symbol repetition and interleaving
Authors: Han Sungmin , Lee Jaeseok , Kwon Taesoo , Choi Ji‐Woong
Published: April 2018

It is well known that the differential phase shift keying (DPSK) transmission does not require a reference phase and reduces the computational complexity and power consumption of the receiver at the cost of the transmission reliability. To improve the reliability of transmission under such scenario, we use a symbol repetition scheme to the DPSK modulation, such as the IEEE 802.15.6 wireless body area network and the ITU‐T G.9903. However, the message symbol repetition with interleaving in conventional manner as in coherent modulation schemes may degrade the receiver performance because of the noise characteristic of the differential demodulation structure. In this work, we analyze the performance of repeated DPSK system with and without the interleaver and demonstrate which scenario is suitable for each modulation order. We propose a proper transmission setting, which achieves noticeable performance improvement at the receiver as well as enhances the energy efficiency of the communication system. Since it can be implemented with very small modification to existing systems, our results are highly applicable with negligible modification of the hardware structure and thus enable substantially low‐cost implementation in future communication systems including wireless body area network internet of things applications.
The emergence of top‐down, sensory prediction during learning in infancy: A comparison of full‐term and preterm infants
Authors: Boldin Alex M. , Geiger Romin , Emberson Lauren L.
Published: April 2018

Prematurity alters developmental trajectories in preterm infants even in the absence of medical complications. Here, we use fNIRS and learning tasks to probe the nature of the developmental differences between preterm and full‐term born infants. Our recent work has found that prematurity disrupts the ability to engage in top‐down sensory prediction after learning. We now examine the neural changes during the learning that precede prediction. In full‐terms, we found modulation of all cortical regions examined during learning (temporal, frontal, and occipital). By contrast, preterm infants had no evidence of neural changes in the occipital lobe selectively. This is striking as the learning task leads to the emergence of visual prediction. Moreover, the shape of individual infants’ occipital lobe trajectories (regardless of prematurity) predicts subsequent visual prediction abilities. These results suggest that modulation of sensory cortices during learning is closely related to the emergence of top‐down signals and further indicates that developmental differences in premature infants may be associated with deficits in top‐down processing.
Privacy‐aware face detection using biological signals in camera images
Authors: Kitajima Toshihiro , Murakami Edwardo Arata Y. , Yoshimoto Shunsuke , Kuroda Yoshihiro , Oshiro Osamu
Published: April 2018

People sensing occurs everywhere, in the Internet of Things (IoT). Cameras are being increasingly used because they provide inexpensive and effective sensing devices. However, the camera acquires the information that identifies an individual, there is a problem that the privacy of the person is invaded. Furthermore, since home appliances are increasingly being connected to the Internet via the IoT, it has become possible for user images to leak out unintentionally. With these concerns in mind, we propose a face detection method that protects user privacy by using intentionally blurred images. In this method, the presence of a human being is determined by dividing an image into several regions and then calculating the heart rate detected in each region. In our performance evaluation, the proposed method showed dominant performance results when compared with an existing face detection method, and was confirmed to be an effective method for detecting faces in both normal and blurred images. We confirmed the influence of the performance in the proposed method when changing the sharpness of the images. The proposed method also showed high accuracy position detection performance results. Furthermore, we confirmed the effectiveness of the proposed method in near‐infrared images and distorted images.
Fog and live fuel moisture in coastal California shrublands
Authors: Emery Nathan C. , D'Antonio Carla M. , Still Christopher J.
Published: April 2018

Across Mediterranean‐type climate regions, seasonal drought desiccates plants, facilitating ignition and the spread of wildfires. Along the California coast, summertime fog has the potential to ameliorate drought conditions and thus reduce plant flammability during a critical time of elevated fire risk. This study investigated the uptake of dry season fog and how it affects live fuel moisture (LFM) in six dominant shrub species from chaparral and sage scrub plant associations. Fog water uptake was evaluated using stable isotopes of hydrogen and oxygen at several field sites in Santa Barbara County, California. Clear evidence of fog water uptake was identified only in Baccharis pilularis, from the sage scrub association. To determine the effects of fog on LFM, meteorological variables and indices including fog deposition were combined into principal components and the scores regressed against the LFM loss rate during the summer drought. Fog deposition slowed rates of LFM loss for all three sage scrub species tested, but it did not affect the chaparral species. Fog is a more regular occurrence in the sage scrub association, and thus, it is likely that fog ameliorates drought for species that experience consistent fog during the summer months. In coastal California, summer fog can be essential to plant water relations and reduce LFM loss rates during the summer drought. Understanding these effects is important in the context of changing climate in southern California and fire‐prone regions around the world.
Formation of litter crusts and its multifunctional ecological effects in a desert ecosystem
Authors: Jia Chao , Liu Yu , He Honghua , Miao Hai‐tao , Huang Ze , Zheng Jiyong , Han Fengpeng , Wu Gao‐Lin
Published: April 2018

Desertification is one of the major issues in global environmental change, and it is of great concern to scientists and policy‐makers in the world. Litter crusts can be of great importance for the restoration and management of desert ecosystems. The formation of litter crusts and its ecological effects on desert surface microhabitats were studied in a wind–water erosion crisscross desert region. It was found that litter crusts, especially the four‐year litter crusts, exhibited a better soil storage capacity and temperature regulating ability when compared to the bare land, biocrusts, and two‐year litter crusts; the four‐year litter crusts significantly increased soil total porosity, soil water storage, and soil organic carbon content, but reduced soil bulk density. Furthermore, species richness, coverage, and plant height of seedlings in litter crusts were significantly greater than those in bare land and biocrusts. Although the bare land had the greatest total number of seedlings, the survival rate of seedlings was lowest there. Our findings revealed that litter crusts had significantly positive effects on soil moisture, soil temperature, soil physicochemical properties, and seedling establishment. The multifunctional ecological effects of litter crusts are more positive than lichen‐ and moss‐dominated biocrusts in desert ecosystems.
The Use of Switchable Polarity Solvents for the Synthesis of 16‐Arylidene Steroids via Claisen–Schmidt Condensation
Authors: Ispán Dávid , Szánti‐Pintér Eszter , Papp Máté , Wouters Johan , Tumanov Nikolay , Zsirka Balázs , Gömöry Ágnes , Kollár László , Skoda‐Földes Rita
Published: April 2018

Switchable polarity recyclable solvent mixtures were applied as reaction medium and catalyst to replace the conventional base catalysts in the Claisen–Schmidt condensation of 17‐oxo steroids with aromatic aldehydes. Reversibility between ionic and nonionic forms of the new 2‐n‐butyl‐1,1,3,3‐tetramethylguanidine (nBu‐TMG)/ethylene glycol/CO2 and 2‐tert‐butyl‐1,1,3,3‐tetramethylguanidine (tBu‐TMG)/ethylene glycol/CO2 systems were proved by conductivity measurements. The structure of the ionic form was established by 1H NMR and IR measurements and by quantum chemical calculations. The steroidal products with androstane and estrane skeleton were characterised with spectroscopic methods (NMR, IR, MS).
Synthesis and Absolute Configuration of Natural 2‐Pyrones
Authors: Burkhardt Immo , Dickschat Jeroen S.
Published: April 2018

2‐Pyrones are frequently produced by microorganisms and often exhibit interesting bioactivities. Therefore, a short and easy synthetic access to these natural products is desirable. Synthetic routes to nectriapyrone, gibepyrone A, racemic gulypyrone A, (+)‐germicidin C, (ent)‐desoxygermicidin C and (ent)‐prolipyrone A via a modular approach are presented, allowing the assignment of the absolute configurations of the latter three chiral compounds. The method failed for the synthesis of (ent)‐phomapyrone B that was thus synthesized via a different route, resulting in an assignment of the absolute configuration of natural phomapyrone B.
Social attribution in anorexia nervosa
Authors: Oldershaw Anna , DeJong Hannah , Hambrook David , Schmidt Ulrike
Published: April 2018

People with anorexia nervosa (AN) report socioemotional difficulties; however, measurement has been criticised for lacking ecological validity and the state or trait nature of difficulties remains unclear. Participants (n = 122) were recruited across 3 groups: people who are currently ill with AN (n = 40); people who recovered (RecAN, n = 18); healthy‐control participants (n = 64). Participants completed clinical questionnaires and the Social Attribution Task. The Social Attribution Task involves describing an animation of moving shapes, scored for number of propositions offered, accuracy, and social relevance. Groups were compared cross‐sectionally. Those with current AN were assessed prepsychological and postpsychological treatments.

People with AN provided fewer propositions than other groups and fewer salient social attributions than healthy‐control participants. Those who recovered scored intermediately and not significantly different from either group. Following treatment, people with AN demonstrated (nonsignificant) improvements, and no significance between group differences were observed. Findings suggest difficulties for people with AN in providing spontaneous social narrative and in identifying social salience.
Review of atrazine sampling by polar organic chemical integrative samplers and Chemcatcher
Authors: Booij Kees , Chen Sunmao
Published: April 2018

A key success factor for the performance of passive samplers is the proper calibration of sampling rates. Sampling rates for a wide range of polar organic compounds are available for Chemcatchers and polar organic chemical integrative samplers (POCIS), but the mechanistic models that are needed to understand the effects of exposure conditions on sampling rates need improvement. Literature data on atrazine sampling rates by these samplers were reviewed with the aim of assessing what can be learned from literature reports of this well-studied compound and identifying knowledge gaps related to the effects of flow and temperature. The flow dependency of sampling rates could be described by a mass transfer resistance model with 1 (POCIS) or 2 (Chemcatcher) adjustable parameters. Literature data were insufficient to evaluate the temperature effect on the sampling rates. An evaluation of reported sampler configurations showed that standardization of sampler design can be improved: for POCIS with respect to surface area and sorbent mass, and for Chemcatcher with respect to housing design. Several reports on atrazine sampling could not be used because the experimental setups were insufficiently described with respect to flow conditions. Recommendations are made for standardization of sampler layout and documentation of flow conditions in calibration studies. Environ Toxicol Chem 2018;37:1786–1798. © 2018 SETAC
Real World Compromises: Policy and Practice Impacts of Kindergarten Entry Assessment‐Related Validity and Reliability Challenges
Authors: Ackerman Debra J.
Published: April 2018

Kindergarten entry assessments (KEAs) have increasingly been incorporated into state education policies over the past 5 years, with much of this interest stemming from Race to the Top—Early Learning Challenge (RTT‐ELC) awards, Enhanced Assessment Grants, and nationwide efforts to develop common K–12 state learning standards. Drawing on information included in RTT‐ELC annual progress reports, published research, and a variety of other KEA‐relevant documents, in this report, I share the results of case studies of 7 recently implemented state KEAs. The focus of this inquiry was the assessment‐ and teacher‐related validity and reliability challenges that contributed to adjustments to the content of these measures, the policies regarding when they are to be administered, and the training and technical support provided to teachers who are tasked with the role of KEA assessor and data interpreter. Although these 7 KEAs differ, the results of the study suggest that they experienced common validity and reliability issues and subsequent policy and practice revisions. These findings also suggest the value of iterative research as a means for highlighting these issues and informing the policies and practices that can impact KEA validity and reliability.