bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulsed EPR Dipolar Spectroscopy on Spin Pairs with one Highly Anisotropic Spin Center: The Low‐Spin FeIII Case
Authors: Abdullin Dinar , Brehm Philipp , Fleck Nico , Spicher Sebastian , Grimme Stefan , Schiemann Olav
Published: August 2019

Pulsed electron paramagnetic resonance (EPR) dipolar spectroscopy (PDS) offers several methods for measuring dipolar coupling constants and thus the distance between electron spin centers. Up to now, PDS measurements have been mostly applied to spin centers whose g‐anisotropies are moderate and therefore have a negligible effect on the dipolar coupling constants. In contrast, spin centers with large g‐anisotropy yield dipolar coupling constants that depend on the g‐values. In this case, the usual methods of extracting distances from the raw PDS data cannot be applied. Here, the effect of the g‐anisotropy on PDS data is studied in detail on the example of the low‐spin Fe3+ ion. First, this effect is described theoretically, using the work of Bedilo and Maryasov (Appl. Magn. Reson. 2006, 30, 683–702) as a basis. Then, two known Fe3+/nitroxide compounds and one new Fe3+/trityl compound were synthesized and PDS measurements were carried out on them using a method called relaxation induced dipolar modulation enhancement (RIDME). Based on the theoretical results, a RIDME data analysis procedure was developed, which facilitated the extraction of the inter‐spin distance and the orientation of the inter‐spin vector relative to the Fe3+ g‐tensor frame from the RIDME data. The accuracy of the determined distances and orientations was confirmed by comparison with MD simulations. This method can thus be applied to the highly relevant class of metalloproteins with, for example, low‐spin Fe3+ ions.
N‐Heterocyclic Carbenes as Key Intermediates in the Synthesis of Fused, Mesoionic, Tricyclic Heterocycles
Authors: Benaissa Idir , Pallova Lenka , Morantin Marie‐Emilie , Lafitte Thomas , Huynh Mathieu , Barthes Cécile , Vendier Laure , Lugan Noël , Bastin Stéphanie , César Vincent
Published: August 2019

Coupling between 5‐bromoimidazo[1,5‐a]pyridinium salts and malonate or arylacetate esters leads to a facile and straightforward access to the new mesoionic, fused, tricyclic system of imidazo[2,1,5‐cd]indolizinium‐3‐olate. Mechanistic studies show that the reaction pathway consists of nucleophilic aromatic substitution on the cationic, bicyclic heterocycle by an enolate‐type moiety and in the nucleophilic attack of a transient free N‐heterocyclic carbene (NHC) species on the ester group; the relative order of these two steps depends on the nature of the starting ester. This work highlights the valuable implementation of free NHC species as key intermediates in synthetic chemistry, beyond their classical use as stabilizing ligands or organocatalysts.
Correlating Oxygen Reduction Reaction Activity and Structural Rearrangements in MgO‐Supported Platinum Nanoparticles
Authors: Rossi Kevin , Asara Gian Giacomo , Baletto Francesca
Published: August 2019

We develop a multi‐scale approach towards the design of metallic nanoparticles with applications as catalysts in electrochemical reactions. The here discussed method exploits the relationship between nanoparticle architecture and electrochemical activity and is applied to study the catalytic properties of MgO(100)‐supported Pt nanosystems undergoing solid‐solid and solid‐liquid transitions. We observe that a major increment in the activity is associated to the reconstruction of the interface layers, supporting the need for a full geometrical characterisation of such structures also when in‐operando.
A comprehensive circuit model for evaluating the response of silicon photomultipliers in continuous wave light regime
Authors: Siminfar Amir Reza , Shoaei Omid
Published: August 2019

In this paper, a comprehensive dynamic model for silicon photomultiplier (SiPM) detectors is proposed to investigate their response when exposed to the light of any wavelength and relatively high intensity. Also, a procedure is proposed to perform reliable circuit‐level simulations to predict the response of these detectors under various photon rates. The approach of dynamic model is based on the state of microcells in terms of overvoltage, elapsed recharging time, and their effect on the triggering probability with which the detector current and voltage can be accurately simulated. Using the proposed model, the SiPM behaviour is examined under various continuous illumination power in simulation. The effectiveness of the proposed model and the simulation method are verified by experimental results extracted from two SiPM detectors.
Comparative analysis to determine the accuracy of fractional derivatives in modeling supercapacitors
Authors: Carreño C.A. , Rosales J.J. , Merchan L.R. , Lozano J.M. , Godínez F.A.
Published: August 2019

In this paper, we study a supercapacitor model represented by an equivalent RC circuit considering five different types of derivatives: Caputo, Caputo‐Fabrizio, and Atangana‐Baleanu fractional derivatives and the conformable and integer‐order derivatives. A set of experimental data from six commercial supercapacitors are used to estimate the parameter values for each derivative model by applying interior point optimization. The results show that the most accurate approach is achieved with the conformable derivative followed by the Caputo fractional derivative.
Link quality estimation for arbitrary packet sizes over wireless links using packet reception events
Authors: Jacobsson Martin , Rohner Christian
Published: August 2019

The packet error rate of wireless links is known to increase with the length of packets. Yet, packet length is rarely taken into account in protocols and algorithms estimating the packet error rate. Still, it is an important factor that higher layer protocols need to be aware of. In this article, we systematically measure the relationship between packet length and packet error rate over a wide range of wireless links and technologies. On the basis of our measurements, we propose a simple empirical model that can capture this behavior. Using this model, multiple methods are proposed that can estimate the packet error rate for any packet length by sampling the link. We consider methods based on hello packets with controlled packet lengths as well as data packets, where the transmitted packet lengths cannot be controlled. We investigate the accuracy of the different estimation methods in various situations and show how they are able to predict the delivery ratio for different packet sizes.
Factors determining species richness patterns of breeding birds along an elevational gradient in the Horn of Africa region
Authors: Abebe Ahunim Fenitie , Cai Tianlong , Wale Melaku , Song Gang , Fjeldså Jon , Lei Fumin
Published: August 2019

Aim

To document the species richness patterns of breeding birds along elevational gradients and explore its drivers in the Horn of Africa region.

Location

Horn of Africa region.

Taxon

Breeding birds.

Methods

Distributional data for breeding birds were collected. Elevational distribution data were extracted, interpolated, and assembled for all birds, passerines, and nonpasserines. In order to tease apart how different environmental factors contributed to the variation in species richness, we found it is necessary to divide the area into four subregions with different climatic regimes and topographic structure, namely western slope, eastern slope, wet side, and dry side. Then, the species richness in each 100‐m elevational band was counted along the elevational gradients of each subregion. Pearson's correlation analyses and ordinary least squares (OLS) regressions were used to examine the relationships between species richness and factors.

Results

The variation in species richness followed hump‐shaped patterns for all subregions, although with peak values at different elevations. The bird species groups on the western and eastern slopes showed low and high plateaus with mid‐elevation peaks, respectively, but very low species diversities at the highest elevations. Species richness was significantly correlated with temperature range and productivity in each subregion. The temperature range, area, and productivity explained 82% of the species richness variations for all birds on the western slope.

Main conclusions

The separate analyses of four area subdivisions provide strong indications of how various factors interact. Productivity and temperature range were the major driving factors for shaping the richness patterns, but deviations from expected patterns suggest modifying roles of mist formation zones in the valleys that deeply intersect the large highlands in the west and rich riparian vegetation where water from cool and humid environments at high elevation reaches lower elevations in the arid east. Conservation is recommended in each subregion based on the elevational richness scenarios.
Fine‐scale hierarchical genetic structure and kinship analysis of the ascidianPyura chilensisin the southeastern Pacific
Authors: Morales‐González Sarai , Giles Emily C. , Quesada‐Calderón Suany , Saenz‐Agudelo Pablo
Published: August 2019

Studying population structure and genetic diversity at fine spatial scales is key for a better understanding of demographic processes that influence population connectivity. This is particularly important in marine benthic organisms that rely on larval dispersal to maintain connectivity among populations. Here, we report the results of a genetic survey of the ascidianPyura chilensisfrom three localities along the southeastern Pacific. This study follows up on a previous report that described a genetic break in this region among localities only 20 km apart. By implementing a hierarchical sampling design at four spatial levels and using ten polymorphic microsatellite markers, we test whether differences in fine‐scale population structure explain the previously reported genetic break. We compared genetic spatial autocorrelations, as well as kinship and relatedness distributions within and among localities adjacent to the genetic break. We found no evidence of significant autocorrelation at the scale up to 50 m despite the low dispersal potential ofP. chilensisthat has been reported in the literature. We also found that the proportion of related individuals in close proximity (<1 km) was higher than the proportion of related individuals further apart. These results were consistent in the three localities. Our results suggest that the spatial distribution of related individuals can be nonrandom at small spatial scales and suggests that dispersal might be occasionally limited in this species or that larval cohorts can disperse in the plankton as clustered groups. Overall, this study sheds light on new aspects of the life of this ascidian as well as confirms the presence of a genetic break at 39°S latitude. Also, our data indicate there is not enough evidence to confirm that this genetic break can be explained by differences in fine‐scale genetic patterns among localities.
Intraspecific facilitation explains the persistence of Phragmites australis in modified coastal wetlands
Authors: Reijers Valérie C. , van den Akker Marloes , Cruijsen Peter M. J. M. , Lamers Leon P. M. , van der Heide Tjisse
Published: August 2019

Coastal exploitation and human‐mediated modifications have markedly altered the community composition and functioning of coastal wetlands worldwide. Although recent work has shown that harnessing positive density‐dependent feedbacks can greatly enhance the recovery of habitat‐modifying species in degraded wetlands, the role of these intraspecific feedbacks in explaining the persistence of altered, unfavorable plant communities remains largely unexplored. Here, we experimentally tested whether intraspecific facilitation may explain the persistence of common reed (Phragmites australis) in human‐modified coastal wetlands. We performed a full‐factorial mesocosm experiment crossing low‐density pioneer versus high‐density established development stages with saline (20 psu) versus freshwater conditions. Results showed a clear shift in plant growth response from intraspecific competition under freshwater conditions to self‐facilitation in saline treatments. We identified two positive feedback mechanisms enabling the established treatment to overcome salinity stress: (1) Enhanced root oxygenation of the sediment at higher plant density decreased accumulation and intrusion of phytotoxic sulfide, and (2) density‐dependent rainwater infiltration into the soil lowered salinity in the dense root mat, preventing salt stress. Our study demonstrates that intraspecific facilitation can be an important factor in explaining the persistence of Phragmites australis in coastal wetlands. We emphasize the importance of integrating positive interactions in coastal restoration but argue that they should either be harnessed when restoring vegetation or broken when eradication of nontarget species is the management objective.
One‐Pot and Reducible‐Functional‐Group‐Tolerant Synthesis of α‐Aryl‐ and α‐Heteroaryl‐α‐Trifluoromethyl Alcohols via Tandem Trifluoroacetylation and MPV Type Reduction
Authors: Funabiki Kazumasa , Hayakawa Ayaka , Kani Ryunosuke , Inuzuka Toshiyasu , Kubota Yashuhiro
Published: August 2019

We have developed a new one‐pot synthesis of α‐aryl‐ and α‐heteroaryl‐α‐trifluoromethyl alcohols carrying not only arenes with electron‐withdrawing groups but also electron‐deficient nitrogen‐containing heteroarenes, which are of increasing interest because these compounds are some of the most important units in current fluorine‐containing inhibitors or antagonists. This new method includes three tandem reactions in a one‐pot synthesis: (1) the in situ generation of functionalized aromatic and electron‐deficient heteroaromatic Grignard reagents, (2) trifluoroacetylation of the generated Grignard reagents with diphenylmethyl trifluoroacetate, and (3) successive Meerwein–Ponndorf–Verley type reduction. It offers several advantages, including no need for expensive transition metals and gaseous trifluoromethylating reagents, toleration of not only reducible functional groups on the aryl groups but also electron‐deficient nitrogen‐containing heterocycles, easy scalability, and the ability to suppress the formation of the bis‐aldol product as a by‐product by changing the ester moiety of the trifluoroacetate from an isopropyl to a diphenylmethyl group.
Response surface optimization of acid pretreatment of cassava stem for bioethanol production
Authors: Sivamani Selvaraju , Baskar Rajoo , Chandrasekaran Arun P.
Published: August 2019

Agricultural waste, cassava stem was found to contain about 25 and 40% of hemicellulose and cellulose, respectively. Bioethanol is produced from cassava stem by dilute acid pretreatment followed by alkali delignification, cellulase digestion, and fermentation by Fusarium oxysporum. Dilute acid pretreatment was optimized by response surface methodology based Box–Behnken design. The optimum xylose concentration obtained by the experiment was 11.24 g/L and the model was sulfuric acid concentration of 2.02% (v/v), solid to liquid ratio of 0.05 g/ml and 79 min. After alkali delignification and cellulase hydrolysis of pretreated cassava stem, the glucose content was 18.1 g/L and the bioethanol concentration obtained through co‐fermentation of xylose and glucose by F. oxysporum was 13.62 g/L. The optimum values indicated that 91.1% yield was achieved with cassava stem using dilute sulfuric acid pretreatment. Hence, the dilute acid pretreatment of cassava stem was found to be the promising method for bioethanol production.
Numerical and experimental study of a novel aerodynamic foam breaker for foam drilling fluid
Authors: Cao Pinlu , Chen Zhuo , Liu Miaomiao , Cao Hongyu , Chen Baoyi
Published: August 2019

Defoaming is a key technology for increasing the efficiency of foam drilling in petroleum engineering. To enhance the performance of a mechanical foam breaker in foam drilling, a novel aerodynamic foam breaker with two annular slits was investigated in this study. The computational fluid dynamics code of ANSYS Fluent was used to simulate the velocity and pressure distribution inside the foam breaker, and the optimum distance between the two annular slits was determined based on the simulation methods. Meanwhile, a series of experiments were conducted to test the actual performance of the foam breaker. The results demonstrate that various factors may affect the efficiency of the foam breaker, including the foam gas‐liquid ratio, basic liquid viscosity, and air supply method. A higher gas‐liquid ratio of the foam and air supply pressure result in a superior foam breaker performance. The viscosity of the foam liquid phase exhibits exactly the opposite behavior, meaning that the foam breaker more effectively destroys foam from a lower‐viscosity liquid. This study verifies the practicability of this novel aerodynamic foam breaker and discusses the effects of different parameters on the defoaming percentage, and this study can act as a reference and guidance for subsequent defoaming research.
An integrated heat recovery and storage system for a residential building
Authors: Bolt Andre A , Dincer Ibrahim , Agelin‐Chaab Martin
Published: August 2019

In this article, a novel multigeneration system is proposed which can produce four useful outputs for a small residential building located in Ottawa, Ontario (Canada). The residential building has a total of six floors, 24 units, and houses ~96 residents. The system uses parabolic solar collectors to superheat steam, which then provides energy to the remainder of the cycle. During the nighttime or poor weather conditions, the system can still function effectively by using hot and cold molten salt storage tanks. The molten salt storage tanks contain mixtures of NaNO3 and KNO3, at 45% and 55%, respectively. The proposed system has an overall energetic and exergetic efficiencies of 43.33% and 60.55% during the heating process, and 38.42% and 70.87% during the cooling process, respectively. To effectively operate, the system must consume 2256 kW of solar energy. The high and low‐pressure turbines have a combined power output of 713.8 kW, at an isentropic efficiency of 90%. The heating and cooling loads output from the condenser and the evaporator were calculated to be 471.7 and 316 kW, respectively. The load produced from this system can adequately satisfy the peak load conditions. The cascade system added to the evaporator will enable it to act more effectively compared to the condenser in terms of the coefficient of performance (COP). Also, the desalination system is capable of meeting the daily water requirements of 654.12 m3/day, by consuming untreated water at a flow rate of 84.71 kg/s and releasing distilled water at 7.55 kg/s.
A multivariant secure framework for smart mobile health application
Authors: Butt Shariq Aziz , Jamal Tauseef , Azad Muhammad Ajmal , Ali Arshad , Safa Nader Sohrabi
Published: August 2019

Wireless sensor network enables remote connectivity of technological devices such as smart mobile with the internet. Due to its low cost as well as easy availability of data sharing and accessing devices, the Internet of Things (IoT) has grown exponentially during the past few years. The availability of these devices plays a remarkable role in the new era of mHealth. In mHealth, the sensors generate enormous amounts of data and the context‐aware computing has proven to collect and manage the data. The context aware computing is a new domain to be aware of context of involved devices. The context‐aware computing is playing a very significant part in the development of smart mobile health applications to monitor the health of patients more efficiently. Security is one of the key challenges in IoT‐based mHealth application development. The wireless nature of IoT devices motivates attackers to attack on application; these vulnerable attacks can be denial of service attack, sinkhole attack, and select forwarding attack. These attacks lead intruders to disrupt the application's functionality, data packet drops to malicious end and changes the route of data and forwards the data packet to other location. There is a need to timely detect and prevent these threats in mobile health applications. Existing work includes many security frameworks to secure the mobile health applications but all have some drawbacks. This paper presents existing frameworks, the impact of threats on applications, on information, and different security levels. From this line of research, we propose a security framework with two algorithms, ie, (i) patient priority autonomous call and (ii) location distance based switch, for mobile health applications and make a comparative analysis of the proposed framework with the existing ones.
The evolution of intergroup tolerance in nonhuman primates and humans
Authors: Pisor Anne C. , Surbeck Martin
Published: August 2019

Primate individuals use a variety of strategies in intergroup encounters, from aggression to tolerance; however, recent focus on the evolution of either warfareorpeace has come at the cost of characterizing this variability. We identify evolutionary advantages that may incentivize tolerance toward extra‐group individuals in humans and nonhuman primates, including enhanced benefits in the domains of transfer, mating, and food acquisition. We highlight the role these factors play in the flexibility of gorilla, chimpanzee, bonobo, and human behavior. Given humans have an especially broad range of intergroup behavior, we explore how the human foraging ecology, especially large spatial and temporal fluctuations in resource availability, may have selected for a greater reliance on tolerant between‐community relationships—relationships reinforced by status acquisition and cultural institutions. We conclude by urging careful, theoretically motivated study of behavioral flexibility in intergroup encounters in humans and the nonhuman great apes.
Comparing flow resistance law for fixed and mobile bed rills
Authors: Di Stefano Costanza , Nicosia Alessio , Palmeri Vincenzo , Pampalone Vincenzo , Ferro Vito
Published: August 2019

Rills caused by run‐off concentration on erodible hillslopes have very irregular profiles and cross‐section shapes. Rill erosion directly depends on the hydraulics of flow in the rills, which may differ greatly from hydraulics of flow in larger and regular channels. In this paper, a recently theoretically deduced rill flow resistance equation, based on a power–velocity profile, was tested experimentally on plots of varying slopes (ranging from 9% to 26%) in which mobile and fixed bed rills were incised. Initially, measurements of flow velocity, water depth, cross‐section area, wetted perimeter, and bed slope, carried out in 320 reaches of mobile bed rills and in 165 reaches of fixed rills, were used for calibrating the theoretical flow resistance equation. Then the relationship between the velocity profile parameter Γ, the channel slope, and the flow Froude number was separately calibrated for the mobile bed rills and for the fixed ones. The measurements carried out in both conditions (fixed and mobile bed rills) confirmed that the Darcy–Weisbach friction factor can be accurately estimated using the proposed theoretical approach. For mobile bed rills, the data were supportive of the slope independence hypothesis of velocity, due to the feedback mechanism, stated by Govers. The feedback mechanism was able to produce quasicritical flow conditions. For fixed bed rills, obtained by fixing the rill channel, by a glue, at the end of the experimental run with a mobile bed rill, the slope independence of the flow velocity measurements was also detected. Therefore, an experimental run carried out by a rill bed fixed after modelling flow action is useful to detect the feedback mechanism. Finally, the analysis showed that, for the investigated conditions, the effect of sediment transport on the flow resistance law can be considered negligible respect to the grain roughness effect.
Exosomal long noncoding RNAs in aging and age‐related diseases
Authors: Cao Qidong , Guo Ziyuan , Yan Youyou , Wu Jiuping , Song Chunli
Published: August 2019

Molecules secreted by cells into the internal environment during aging, including those secreted in exosomes, have long been a matter of concern. Those cells that absorb exosomes, also known as recipient cells, exhibit certain phenotypic changes because of the regulatory role of functional molecules (including proteins and nucleic acids) released in exosomes. Involvement of noncoding RNAs (ncRNAs) in the regulation of aging has received increasing attention, and long ncRNAs (lncRNAs) have become one of the research hotspots in recent years. LncRNAs carried by exosomes play a role in intercellular communication between adjacent and distant cells. Moreover, exosomal lncRNAs promote the decline of organ functions and the development of age‐related diseases, including atherosclerosis, Type 2 diabetes, osteoporosis, osteoarthritis, rheumatoid arthritis, Parkinson's disease, multiple sclerosis, and cancer. Here, we review the regulatory roles of exosomal lncRNAs in aging and age‐related diseases.
Estimating and accounting for the output gap with large Bayesian vector autoregressions
Authors: Morley James , Wong Benjamin
Published: August 2019

We consider how to estimate the trend and cycle of a time series, such as real gross domestic product, given a large information set. Our approach makes use of the Beveridge–Nelson decomposition based on a vector autoregression, but with two practical considerations. First, we show how to determine which conditioning variables span the relevant information by directly accounting for the Beveridge–Nelson trend and cycle in terms of contributions from different forecast errors. Second, we employ Bayesian shrinkage to avoid overfitting in finite samples when estimating models that are large enough to include many possible sources of information. An empirical application with up to 138 variables covering various aspects of the US economy reveals that the unemployment rate, inflation, and, to a lesser extent, housing starts, aggregate consumption, stock prices, real money balances, and the federal funds rate contain relevant information beyond that in output growth for estimating the output gap, with estimates largely robust to substituting some of these variables or incorporating additional variables.
Generalized spectral light scatter models of diverse bacterial colony morphologies
Authors: Doh Iyll‐Joon , Sturgis Jennifer , Sarria Zuniga Diana V. , Pruitt Robert E. , Robinson J. Paul , Bae Euiwon
Published: August 2019

An optical forward‐scatter model was generalized to encompass the diverse nature of bacterial colony morphologies and the spectral information. According to the model, the colony shape and the wavelength of incident light significantly affect the characteristics of a forward elastic‐light‐scattering pattern. To study the relationship between the colony morphology and the scattering pattern, three‐dimensional colony models were generated in various morphologies. The propagation of light passing through the colony model was then simulated. In validation of the theoretical modeling, the scattering patterns of three bacterial genera, Staphylococcus, Exiguobacterium and Bacillus, which grow into colonies having convex, crateriform and flat elevations, respectively, were qualitatively compared to the simulated scattering patterns. The strong correlations observed between simulated and experimental patterns validated the scatter model. In addition, spectral effect on the scattering pattern was studied using the scatter model, and experimentally investigated using Staphylococcus, whose colony has circular form and convex elevation. Both simulation and experiment showed that changes in wavelength affected the overall pattern size and the number of rings.
Age differences in public stigma, self‐stigma, and attitudes toward seeking help: A moderated mediation model
Authors: Mackenzie Corey S. , Heath Patrick J. , Vogel David L. , Chekay Richelle
Published: August 2019

Objective

Stigma is commonly identified as a key reason that older adults are especially unlikely to seek mental health services, although few studies have tested this assumption. Our objectives were to: (a) examine age differences in public and self‐stigma of seeking help, and attitudes toward seeking help, and (b) see whether age moderates an internalized stigma of seeking help model.

Methods

A total of 5,712 Canadians ranging in age from 18 to 101 completed self‐report measures of public stigma of seeking help, self‐stigma of seeking help, and help‐seeking attitudes.

Results

Older participants had the lowest levels of stigma and the most positive help‐seeking attitudes. Age also moderated the mediation model, such that the indirect effect of public stigma on help‐seeking attitudes through self‐stigma was strongest for older participants.

Conclusion

Our findings have implications for the influence of stigma and attitudes as barriers to treatment across the adult lifespan, and for stigma reduction interventions.
MicroRNA‐326 decreases tau phosphorylation and neuron apoptosis through inhibition of the JNK signaling pathway by targeting VAV1 in Alzheimer's disease
Authors: He Bin , Chen Wei , Zeng Jingsong , Tong Wusong , Zheng Ping
Published: August 2019

Alzheimer's disease (AD) is a progressive and age‐related neurological dysfunction. Abundant data have profiled microRNA (miR) patterns in healthy, aging brain, and in the moderate and late‐stages of AD. Herein, this study aimed to explore whether miR‐326 could influence neuron apoptosis in AD mice and how miR‐326 functions in this process. The candidate differentially expressed gene VAV1 was obtained by microarray analysis, and miRNAs that could regulate VAV1 candidate gene were predicted. Luciferase activity determination confirmed VAV1 as a target gene of miR‐326. AD mice models were established for investigating the effect of miR‐326 on AD mice. The overexpression of miR‐326 contributed to decreased time of the mice to find the platform and the escape latency and increased residence time on the target area. Besides, elevation of miR‐326 decreased Aβ deposition and contents of Aβ1–40 and Aβ1–42. Moreover, miR‐326 overexpression increased neuron cell ability, mediated cell entry, and inhibited neuron apoptosis via JNK signaling pathway. Of crucial importance, miR‐326 negatively regulated the expression of VAV1, inhibited tau phosphorylation, and blocked the activation of the JNK signaling pathway. Taken together these observations, we demonstrate that miR‐326 improves cognitive function of AD mice and inhibits neuron apoptosis in AD mice through inactivation of the JNK signaling pathway by targeting VAV1. Based on those findings, miR‐326 might exert promise as target for the treatment of AD.
An implementation of punishment in the evolutionary theory of behavior dynamics
Authors: McDowell J. J , Klapes Bryan
Published: August 2019

An implementation of punishment in the evolutionary theory of behavior dynamics is proposed, and is applied to responding on concurrent schedules of reinforcement with superimposed punishment. In this implementation, punishment causes behaviors to mutate, and to do so with a higher probability in a lean reinforcement context than in a rich one. Computational experiments were conducted in an attempt to replicate three findings from experiments with live organisms. These are (1) when punishment is superimposed on one component of a concurrent schedule, response rate decreases in the punished component and increases in the unpunished component, (2) when punishment is superimposed on both components at equal scheduled rates, preference increases over its no‐punishment baseline, and (3) when punishment is superimposed on both components at rates that are proportional to the scheduled rates of reinforcement, preference remains unchanged from the baseline preference. Artificial organisms animated by the theory, and working on concurrent schedules with superimposed punishment, reproduced all of these findings. Given this outcome, it may be possible to discover a steady‐state mathematical description of punished choice in live organisms by studying the punished choice behavior of artificial organisms animated by the evolutionary theory.
Genre maps as a method to visualize engineering writing and argumentation patterns
Authors: Berdanier Catherine G. P.
Published: August 2019

Background

Graduate engineering students are required to write for academic audiences; however, very few engineering programs teach engineering academic writing, and similarly, little research has been conducted on graduate engineering student writing.

Purpose/Hypothesis

The purposes of this study were to investigate the argumentation patterns employed in the research statements of graduate engineering students who won NSF Graduate Research Fellowship Program (GRFP) awards as an example of authentic graduate engineering student academic writing and to introduce visual genre maps as a method of analyzing argument structure.

Design/Method

This study employed genre analysis methods to investigate the argumentation patterns of a corpus of 50 winning engineering NSF GRFP research proposals, using a rhetorical move‐step coding framework modified from prior genre work in English research.

Results

The genre analysis resulted in nine rhetorical moves and subcategorical steps. The argumentation codes were graphed as a function of progress through the document to create maps of argumentation that can be compared across the corpus. Four resulting categories of genre maps emerged from the findings, indicating major patterns in argumentation structure.

Conclusions

The study of rhetorical moves of engineering graduate student research proposals offers students and instructors a way to present engineering writing from a genre lens. Genre maps may be an effective way for writers to envision the shape of written arguments and craft stronger technical messages.
New Biphenyl‐Based Bispyrazolines: Synthesis, Antimicrobial, and Docking Studies
Authors: Yusuf Mohamad , Nisa Shehneela , Paul Kamaldeep
Published: August 2019

In this study, a series of new bispyrazolines 8(a–f) have been prepared from the cyclization reactions of bischalcones 7(a–f) with phenyl hydrazine by refluxing under the alkaline alcoholic (KOH/EtOH) conditions. The O‐alkylation reactions of hydroxyl substituted chalcone 6 with different 1,ω‐dibromoalkanes in the presence of anhydrous potassium carbonate, tetrabutylammonium iodide, and dry acetone afforded the symmetrical new bischalcones 7(a–f) in good yields. Chalcone 6 was realized by using the Claisen–Schmidt reaction of m‐hydroxyacetophenone with bipheny‐4‐carboxaldehyde. The various spectroscopic parameters such as IR, 1H‐NMR, 13C‐NMR, and ESI‐MS have been thoroughly used for the structural interpretations of the newly prepared products. The in vitro antibacterial and antifungal activities of these compounds have been examined with the help of serial tube dilution method, and many of the tested products were found to be revealing the promising antimicrobial properties, which were evident from their minimum inhibitory concentration values. The molecular docking simulations of the synthesized substances have also been achieved to observe the structural association into the active site of the Escherichia coli FabH (PdB: 3IL9). Docking results of these compounds suggested that bispyrazoline 8b demonstrated the lowest binding energy that describes its higher stability into the pocket of E. coli. The excellent inhibitory activity of this bisheterocycle against E. coli FabH may be ascribed on the basis of hydrophobic and van der Waals interactions.
One‐pot Two‐step Reaction for Synthesis of Poly‐substituted Pyrano[3,2‐c]pyridones and Spiro[indoline‐3,4′‐pyrano[3,2‐c]pyridine]‐2,5′(6′H)‐diones in Water
Authors: Xu Zhenhang , Du Yijun , Wang Songxiang , Wu Zeru , Lou Yuhao , Zhang Furen
Published: August 2019

An efficient four‐component approach for the synthesis poly‐substituted pyrano[3,2‐c]pyridones and spiro[indoline‐3,4′‐pyrano[3,2‐c]pyridine]‐2,5′(6′H)‐diones in water has been established. During the reaction, the products were readily achieved through one‐pot two‐step reaction using solid acid as catalyst. The advantages of atom and step economy, the recyclability of heterogeneous solid acid catalyst, easy workup procedure, and the wide scope of substrates make the reaction a powerful tool for assembling pyrano[3,2‐c]pyridone skeletons of chemical and medical interest.
Feeding kinematics and morphology of the alligator gar (Atractosteus spatula, Lacépède, 1803)
Authors: Lemberg Justin B. , Shubin Neil H. , Westneat Mark W.
Published: August 2019

Living gars are a small clade of seven species that occupy an important position on the actinopterygian phylogenetic tree as members of Holostei, sister‐group to teleosts, and exhibit many plesiomorphic traits used to interpret and reconstruct early osteichthyan feeding mechanisms. Previous studies of gar feeding kinematics have focused on the ram‐based, lateral‐snapping mode of prey capture found in the narrow‐snouted Lepisosteus genus, whereas this study focuses on a member of the broad‐snouted Atractosteus sister‐genus, the alligator gar (Atractosteus spatula, Lacépède, 1803). High‐speed videography reveals that the feeding system of alligator gars is capable of rapid expansion from anterior to posterior, timed in a way to generate suction, counteract the effects of a bow‐wave during ram‐feeding, and direct a unidirectional flow of water through the feeding system. Reconstructed contrast‐enhanced μCT‐based cranial anatomy and three‐dimensional modeling of linkage mechanics show that a lateral‐sliding palatoquadrate, flexible intrasuspensorial joint, pivoting interhyal, and retractable pectoral girdle increase the range of motion and expansive capabilities of the alligator gar feeding mechanism. Reconstructions of muscular anatomy, inferences from in vivo kinematics, and in situ manipulations show that input from the hyoid constrictors and hypaxials play an important role in decoupling and modulating the dual roles of the sternohyoideus during feeding: hyoid retraction (jaw opening) and hyoid rotation (pharyngeal expansion). The alligator gar possesses an intricate feeding mechanism, capable of precise control with plesiomorphic muscles that represent one of the many ways the ancestral osteichthyan feeding mechanism has been modified for prey capture.
Application of the normalized relative error distribution analysis for non‐destructive quality control of drugs by Raman spectroscopy
Authors: Galeev Roman R. , Saveliev Anatoly A. , Galeeva Ekaterina V. , Falaleeva Tatyana S. , Aryslanov Ilshat R. , Semanov Dmitry A. , Davletshin Rustam R.
Published: August 2019

Development of drug quality control methods using non‐invasive methods, in particular Raman spectroscopy, is an important task in the pharmaceutical industry. This paper presents a new approach to the analysis of drug spectra obtained with portable Raman spectrometers. It represents a normalized relative error distribution analysis (nReDA). The proposed method uses the Pearson residuals distribution statistics and, compared with the correlation method, allows increasing the screening sensitivity to foreign components that are not contained in the original sample, with the same resistance to changes in the noise distribution and the peak ratios. On the basis of the statistical data, the nReDA in some way is similar to the techniques such as principal component analysis, however, it requires a considerably less spectra to build a representative model and is suitable for comparing Raman spectra, having a noise other than the Gaussian one. The paper shows the prospects of the algorithm for creating a spectral library and solving the problem of transferring Raman libraries to a large number of spectrometers of the same type.
Preparation of a high‐performance thermally shrinkable polystyrene SERS substrate via Au@Ag nanorods self‐assembled to detect pesticide residues
Authors: Zhao Hang , Hasi Wuliji , Li Nan , Sha Xuanyu , Han Siqingaowa
Published: August 2019

This paper reports a “bottom‐up” substrate preparation method using a two‐phase interface self‐assembly technology that combines silver‐coated gold core–shell nanorods with the thermally shrinkable polystyrene (TSP) support material for surface‐enhanced Raman spectroscopy (SERS), that is, TSP‐SERS substrate. The gold nanorods with long absorption wavelength were used as the core, and the silver shells were coated to obtain the core–shell nanostructures with a stronger resonance with the wavelength of the light source. The density of the nanostructures and numbers of “hot spots” within the light spot increased via the three‐dimensional folding feature formed by thermal shrinkage. The combined effect of the two factors increases the enhancement factor by an order of magnitude to 107 after thermal contraction. The detection concentration of 4‐mercaptobenzoic acid can reach 10−9 M, and the maximum relative standard deviation is only 8.9%. In fact, the detection limit of benzimidazole on the surface of apple can reach 0.5 mg/L, and the recovery deviation is controlled within the range of 11.7%. The practical detection of benzimidazole pesticide residues showed that this method has wide application prospects in the detection of pesticide residues.
Phenolic compounds and antioxidant activity in sweet potato after heat treatment
Authors: Kim Min Young , Lee Byong Won , Lee Hyeong‐Un , Lee Yu Young , Kim Mi Hyang , Lee Jin Young , Lee Byoung Kyu , Woo Koan Sik , Kim Hyun‐Joo
Published: August 2019

BACKGROUND

The ability of heat treatment with a soaking solvent to increase soluble phenolic compounds due to the liberation or breakdown of the cell matrix has been investigated in various plants. This study investigated the changes in phenolic compounds and antioxidant activities of 12 sweet potato cultivars after heat treatment with distilled water or prethanol A.

RESULTS

The highest total polyphenol content (134.67 mg gallic acid equivalents/g extract residue) and flavonoid content (65.43 mg catechin equivalents/g extract residue) was observed in the ‘Jami’ (JM) cultivar after heat treatment with prethanol A. Higher polyphenol and flavonoid content was generally observed in the purple sweet potato cultivars. Salicylic acid was the major phenolic acid, followed by protocatechuic acid or chlorogenic acid in almost all untreated sweet potato cultivars. The salicylic acid, vanillic acid, gallic acid, and caffeic acid content of the sweet potatoes increased after the heat treatment, whereas the protocatechuic acid and chlorogenic acid content decreased. The highest 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2‐azinobis(3‐ethyl benzothiazoline)‐6‐sulfonic acid (ABTS) radical scavenging activity levels were observed in the JM cultivar subjected to heat treatment with prethanol A (48.15 and 80.00 mg TE/g extract residue, respectively).

CONCLUSION

These results suggest that heat treatment with a soaking solvent is an efficient method to enhance the antioxidant characteristics of Korean sweet potato cultivars. © 2019 Society of Chemical Industry
Effect of high levels of CO2on the electrochemical behavior and the enzymatic and non‐enzymatic antioxidant systems in black and white table grapes stored at 0 °C
Authors: Romero Irene , Domínguez Irene , Doménech‐Carbó Antonio , Gavara Rafael , Escribano Maria Isabel , Merodio Carmen , Sanchez‐Ballesta Maria Teresa
Published: August 2019

BACKGROUND

In this study, we analyzed the effect of the application of high levels of CO2 (20 kPa CO2 + 20 kPa O2 + 60 kPa N2) for 3 days at low temperature on a white table‐grape cultivar (Superior Seedless) in comparison with a black one (cv. Autumn Royal) in terms of quality parameters. We also used a solid‐state voltammetry methodology to analyze the effect of the 3‐day gaseous treatment in berry tissues from both cultivars in the first stage of storage. We determined the role of the non‐enzymatic (total phenols, total anthocyanins, and antioxidant activity) and the enzymatic antioxidant (catalase (GCAT), ascorbate peroxidase (VcAPX) gene expression) systems in the behaviors of both cultivars.

RESULTS

Our results indicate that the application of a 3‐day gaseous treatment was effective in maintaining the quality of black and white table grapes for up to 28 days of storage at 0 °C. The electrochemical methodology applied was useful for differentiating between skin and pulp samples, and between black and white table grape cultivars. Some molecular mechanisms were modulated in the skin of both cultivars to overcome oxidative stress, which was not manifested with the same intensity in grapes treated with CO2 for 3 days. However, some differences were observed in relation to the non‐enzymatic system.

CONCLUSION

The 3‐day gaseous treatment was useful to maintain black and white table grape quality at 0 °C. The voltammetry analysis indicated that CO2‐treated samples from the skin and pulp showed more similarity to freshly harvested ones. © 2019 Society of Chemical Industry
In vitro studies on the interactions of blood lipid level‐related biological molecules with gallic acid and tannic acid
Authors: Zeng Xiangquan , Sheng Zhongting , Li Xiangxin , Fan Xinguang , Jiang Weibo
Published: August 2019

BACKGROUND

To provide the scientific evidence for a possible new mechanism of hypolipidemic effects of gallic acid (GA) and tannic acid (TA), the binding capacity of GA and TA with blood lipid level‐related biological molecules, including fat, cholesterol and cholates, were investigated in vitro. Additionally, we attempted to study the interactions of cholates with GA and TA by spectroscopic methods, high‐performance liquid chromatography electrospray‐ionization mass spectrometry (HPLC‐ESI‐MS) analysis and molecular modeling studies.

RESULTS

Our results demonstrated that both GA and TA were capable of binding with the blood lipid level‐related biological molecules in vitro. The fat‐binding capacity of TA was 122.1% that of GA when the addition of polyphenol was 90 mg. The inhibitory effects of GA and TA on the cholesterol solubility in mixed micelles and liquid egg yolk exhibited a dose‐dependent relationship (0.5–2.0 mg mL−1). In cholate‐binding tests, TA showed higher affinity for sodium cholate than GA at a concentration of 2.0 mg mL−1, while no significant difference in the affinity for sodium deoxycholate was found between GA and TA. Moreover, the data of spectroscopic methods, HPLC‐ESI‐MS analysis and molecular modeling studies indicated that GA and TA might precipitate cholates through hydrophobic interactions and intermolecular hydrogen bonds rather than covalent bonds.

CONCLUSION

The findings of the present study suggested that the binding capacity of GA and TA with blood lipid level‐related biological molecules might play a crucial role in their hypolipidemic effects in animals. © 2019 Society of Chemical Industry