bluuebunny/crossref_metadata_2025 huggingface dataset:
How to estimate population size in crocodylians? Population ecology of American crocodiles in Coiba Island as study case
Authors: Balaguera‐Reina Sergio A. , Venegas‐Anaya Miryam D. , Rivera‐Rivera Betzaida , Morales Ramírez Diego A. , Densmore Llewellyn D.
Published: October 2018

Reliable estimates of crocodylian population size are desirable for both understanding the ecology and natural history of species and developing sound conservation and management plans. However, choosing appropriate methods to estimate population numbers can be difficult due to the paucity of comprehensive analyses regarding their effectiveness, robustness, and applicability. We estimated the American crocodile population size in the southern tip of Coiba Island, Panama, using both spotlight surveys (Messel's and King's visible fraction estimations) and mark–recapture (POPAN formulation–superpopulation) methods. We assessed and compared the outcomes of these methods with the overall capture record for the study area from 2009 to 2013, evaluating their applicability, accuracy, strengths, and limitations. Using historical and current capture data, we defined a minimum population size of ~112 non‐hatchling animals in our study area, which was larger than both Messel's (19.00 ± 7.50 individuals) and King's (25.71 ± 7.25 individuals) population size estimates, revealing that these latter approaches clearly underestimate population numbers. We estimated a total population size that range between 147 and 257 individuals based on POPAN formulation grouping the data by sex and age groups as the most plausible population size of the American crocodile population in this area at the time. We analyzed and discussed sources of bias in population size estimations for all methods used in the present study, providing recommendations to minimize errors and improve estimations. Finally, we analyzed and compared population ecology attributes obtained in our study with what have been reported in other insular and coastal areas across the American crocodile range, increasing knowledge about the ecology of the species.
Experimental test of water, nutrients, and microclimate on leaf litter mass loss in headwater riparian forests
Authors: Ramey Tonya L. , Richardson John S.
Published: October 2018

Leaf litter decomposition is an essential function in forest ecosystems, and riparian areas may contribute to faster rates of litter mass loss due to higher moisture and nutrient levels in riparian than upland soils. We experimentally tested whether mass loss of red alder leaf litter was (1) greater closer to the stream than further away and (2) increased by nutrient and water additions in riparian habitat near four headwater streams in southwestern British Columbia. We set up blocks of nine transects extending from the bankfull edge of the stream into upland habitat. Leaf litter bags were placed at 1, 5, 10, 20, and 40 m from the stream along each transect, and data loggers recorded ambient air temperature and relative humidity at each distance. Litterbags received either water or fertilizer additions, both, or neither along each transect. Four trials were run which varied in duration (3 months to 1 yr). Relative humidity was on average 2.6% higher, air temperature 0.25°C lower, and vapor pressure deficit 0.14 kPa lower at 1 m from the stream compared to distances further upland. The addition of water significantly increased litter mass loss by 0.14 g (4%) on average than control litterbags. The addition of fertilizer was a significant factor in some trials but not in others, and its effect on mass loss varied. Although distance from the stream was not a significant parameter in the averaged models for each trial, it was in several top models. We conclude that (1) riparian communities within 1 m of the stream experience a different microclimate during the warmer, drier summer than those communities further upland, though this was not generally reflected in alder mass loss rates, and (2) water was a primary limiting factor to alder leaf mass loss in our study sites.
The role of spatial structure in the collapse of regional metapopulations
Authors: White Easton R. , Smith Andrew T.
Published: October 2018

Many wildlife populations are either naturally, or as a result of human land use, patchily distributed in space. The degree of fragmentation—specifically the remaining patch sizes and habitat configuration—is an important part of population dynamics. Demographic stochasticity is also likely to play an important role in patchy habitats that host small local populations. We develop a simulation model to evaluate the significance of demographic stochasticity and the role fragmentation plays in the determination of population dynamics and the risk of extinction of populations on habitat patches. Our model is formulated as a Markov‐chain stochastic process on a finite, spatially explicit array of patches in which probability of successful dispersal is a function of interpatch distance. Unlike past work, we explicitly model local population dynamics and examine how these scale up to the entire population. As a test case, we apply the model to the American pika (Ochotona princeps) population living on the ore dumps in the ghost mining town of Bodie, California. This population has been studied nearly continuously for over four decades and has been of conservation concern as the southern half of the population declined precipitously beginning in 1989. Our model suggests that both the specific configuration of habitat and landscape heterogeneity are necessary and sufficient predictors of the eventual extinction of the southern constellation of patches. This example has important implications, as it suggests that fragmentation alone can lead to regional extinctions within metapopulations.
Effect of MgO and TiO2 Coating on the Electrochemical Performance of Li‐Rich Cathode Materials for Lithium‐Ion Batteries
Authors: Xiao Bin , Wang Peng-bo , He Zhen-jiang , Yang Zhuo , Tang Lin-bo , An Chang-sheng , Zheng Jun-chao
Published: October 2018

0.5Li2MnO3·0.5LiNi0.5Mn0.3Co0.2O2 cathode materials with nano‐MgO and nano‐TiO2 coating layers are synthesized via a facile approach. These nanocoating layers with a thickness of ≈20 nm are homogeneously coated on the surface of the materials. With the nano‐MgO and nano‐TiO2 coating layers, the modified materials deliver excellent electrochemical performance. Nano‐MgO‐coated and nano‐TiO2‐coated Li‐rich materials exhibit 147.56 and 137.96 mAh g−1 after 100 cycles at 1C rate and deliver 156.13 and 130.69 mAh g−1 at 2C rate, respectively, in the voltage range of 2.0–4.8 V. The materials with nano‐MgO and nano‐TiO2 coating layers also show a high discharge voltage retention of more than 90% after 50 cycles, low impedance for Li+ migration, and high diffusion coefficients of the lithium ions. Nano‐MgO and nano‐TiO2 coating layers help decrease the content of Li2CO3 on the surface of the materials and suppress side reactions. Thus, these materials play a significant role in strengthening the electrochemical performance of Li‐rich cathode materials.
TODDLERS’ USE OF GESTURE AND SPEECH IN SERVICE OF EMOTION REGULATION DURING DISTRESSING ROUTINES
Authors: Konishi Haruka , Karsten Ashley , Vallotton Claire D.
Published: October 2018

Research on the intersections of young children's emerging communication skills and emotion regulation has increased, following recognition of the link between these skills as they emerge in toddlerhood and the long‐term impact of these skills on academic success. However, little is known about how toddlers use gesture and emerging language for emotion regulation. The current study describes toddlers’ use of both words and gestures in naturally occurring distressing routines in childcare (diaper change, separation from parents). Seventeen toddlers between 11 and 28 months old were observed over the course of 3½ months in a childcare setting where symbolic gestures (“infant signs”) were used as part of daily routines. Results show that toddlers communicated more frequently using gestures than speech, and used a greater range of self‐regulatory strategies through gesture than through speech. Moreover, older, verbal toddlers continued to use gestures during heightened distress when they could not find their words. Findings suggest that toddlers use symbolic communication to implement complex and diverse emotion regulation strategies during distressing daily routines, and that gestures provide children with opportunities to employ more diverse emotion regulation strategies than does speech alone, which may ultimately enhance children's abilities to regulate their emotions.
The internet of light: Impact of colors in LED‐to‐LED visible light communication systems
Authors: Matheus Luiz , Pires Letícia , Vieira Alex , Vieira Luiz F. M. , Vieira Marcos A. M. , Nacif José A.
Published: October 2018

LED‐to‐LED communication, in which an LED is used as both transmitter and receiver, is n ubiquitous technology that presents important advantages such as low‐cost devices and security enhancement. We investigate the performance of visible light LED‐to‐LED communication under realistic conditions. We analyze the impact on transmission performance imposed by different colors of LEDs and their combinations. In sum, our results evidence the importance of a correct LED setup. According to our results, lower frequency LEDs such as red and orange are highly efficient when used as receivers, while higher frequency LEDs are less sensitive and therefore more limited in these scenarios. Moreover, we highlight that the pattern created by a wide range of LEDs can be helpful for new visible light communication‐based mechanisms.
Study on the three‐dimensional orientation of the posterior facet of the subtalar joint using simulated weight‐bearing CT
Authors: Kleipool Roeland P. , Dahmen Jari , Vuurberg Gwen , Oostra Roelof‐Jan , Blankevoort Leendert , Knupp Markus , Stufkens Sjoerd A.S.
Published: October 2018

The purpose of this study was to describe the normal 3D orientation and shape of the subtalar calcaneal posterior facet. This is not adequately described in current literature. In a supine position both feet of 20 healthy subjects were imaged in a simulated weight‐bearing CT. A cylinder and plane were fitted to the posterior facet of the surface model. The orientation of both shapes was expressed by two angles in (1) the CT‐based coordinate system with the axis of the foot aligned with the sagittal axis and (2) a coordinate system based on the geometric principal axes of the subject's calcaneus. The subtalar vertical angle was determined in the intersection in three different coronal planes of the cylinder. The cylinder's axis oriented from supero‐postero‐laterally to infero‐antero‐medially. The plane's normal directed supero‐antero‐medially in the CT‐based coordinate system, and supero‐antero‐laterally in the other coordinate system. The subtalar vertical angle was significantly different (p < 0.001) between the three defined coronal planes and increased from anterior to posterior. The mean diameter of the fitted cylinder was 42.0 ± 7.7 mm and the root mean square error was 0.5 ± 0.1 mm. The posterior facet can be modelled as a segment of a cylinder with a supero‐postero‐lateral to infero‐antero‐medial orientation. The morphometry of the posterior facet in a healthy population serves as a reference in identifying abnormal subtalar joint morphology. More generally this study shows the need to include the full 3D morphology in assessing the orientation of the subtalar posterior facet. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:1–8, 2018.
A mini‐corer for precision sampling of the water‐sediment interface in subglacial lakes and other remote aqueous environments
Authors: Keen Peter , Saw Kevin , Rundle Nicholas , Brown Robin , Wyatt James , Shorter Stephen , Edwards Michael , Siegert Martin , Mowlem Matthew
Published: October 2018

Recent interest in Antarctic subglacial lakes has seen the development of bespoke systems for sampling them. These systems are considered pristine environments potentially harboring undisturbed sedimentary sequences and ecosystems adapted to these cold oligotrophic environments in the absence of sunlight. The water/sediment interface is considered a prime location for the detection of microbial life and so is of particular interest. This article describes the development of a small corer to capture and retain a short core that includes the water/sediment interface specifically to address the question of whether life exists in these lakes. This apparatus was developed as part of the UK led project to access, measure, and sample subglacial Lake Ellsworth. In addition to addressing the constraints of coring in this difficult environment, the results of subsequent testing suggest that this corer can be applied to sampling sediments in other environments and would be particularly useful in low energy environments when the water‐sediment interface is indistinct or unconsolidated.
Hyperbolic Metamaterial Devices for Wavefront Manipulation
Authors: Yin Xiang , Zhu Hua , Guo Huijie , Deng Ming , Xu Tao , Gong Zhijie , Li Xun , Hang Zhi Hong , Wu Chao , Li Hongqiang , Chen Shuqi , Zhou Lei , Chen Lin
Published: October 2018

Metasurfaces have shown great potential to reshape the wavefront of electromagnetic (EM) waves, but transmissive meta‐devices face challenges of low‐efficiency and/or fabrication complexities. Here, an alternative approach to realize high‐efficiency transmission‐mode meta‐devices to control EM wavefronts, based on hyperbolic metamaterial (HMM) waveguides supporting tailored spoof surface plasmons (SSPs) on their side walls, is proposed. By manipulating the dispersions of SSPs through adjusting the HMM geometrical parameters, the phases of EM waves passing through such waveguides, which enables the design of meta‐devices with desired transmission‐phase profiles for particular wave‐manipulation applications, can be controlled. Microwave experiments are implemented to demonstrate two wave‐control effects based on the mechanism, that is, beam‐deflection and focusing, and a maximum conversion efficiency of 42.9% is achieved for the anomalous refracted beam. By scaling down the HMM meta‐devices, the proposal herein is applicable to optical frequencies and in principle promises significantly raised conversion efficiencies. The scheme herein can offer a higher effective refractive index and more tunable dispersion without using high‐index dielectric materials, and thus can serve as an effective and robust approach to make high‐efficiency transmissive meta‐devices with diversified functionalities.
Cortical dynamics within and between parietal and motor cortex in essential tremor
Authors: Roy Arnab , Coombes Stephen A. , Chung Jae Woo , Archer Derek B. , Okun Michael S. , Hess Christopher W. , Wagle Shukla Aparna , Vaillancourt David E.
Published: October 2018

Background

Evidence from functional imaging in essential tremor suggests that activity within parietal and motor cortices may be associated with worsening of tremor at increased visual feedback.

Objectives

Examine how cortical oscillations within these regions and the connectivity between these regions is associated with worsening of tremor in essential tremor in response to high visual feedback.

Method

The study included 24 essential tremor participants and 17 controls. We measured cortical activity and tremor magnitude at low and high feedback conditions. Cortical activity was measured using high‐density electroencephalogram and isolated using source localization.

Results

Changes in power across feedback in the 4–12 Hz and 12–30 Hz bands were reduced within the contralateral motor cortex of essential tremor patients compared to controls. The 12–30 Hz bidirectional connectivity between the parietal and contralateral motor cortex was decreased in essential tremor patients. Worsening of tremor from low to high visual feedback was associated with 4–12 Hz activity in contralateral motor cortex. The greatest separation between groups was found when using the difference of the contralateral motor cortex activity at high and low feedback, rather than either feedback condition alone.

Conclusion

Our findings provide new evidence that tremor in essential tremor is associated with reduced power across feedback in the motor cortex and reduced connectivity between the parietal and motor cortices. Combined with previous work on the cerebellar‐thalamo‐cortical motor circuit, our findings suggest that the network level disturbances associated with essential tremor extend to the cortico‐cortical pathway between the parietal cortex and motor cortex. © 2018 International Parkinson and Movement Disorder Society
Penetrance and expressivity of the R858H CACNA1C variant in a five‐generation pedigree segregating an arrhythmogenic channelopathy
Authors: Gardner R. J. McKinlay , Crozier Ian G. , Binfield Alex L. , Love Donald R. , Lehnert Klaus , Gibson Kate , Lintott Caroline J. , Snell Russell G. , Jacobsen Jessie C. , Jones Peter P. , Waddell‐Smith Kathryn E. , Kennedy Martin A. , Skinner Jonathan R.
Published: October 2018

Background

Isolated cardiac arrhythmia due to a variant in CACNA1C is of recent knowledge. Most reports have been of singleton cases or of quite small families, and estimates of penetrance and expressivity have been difficult to obtain. We here describe a large pedigree, from which such estimates have been calculated.

Methods

We studied a five‐generation family, in which a CACNA1C variant c.2573G>A p.Arg858His co‐segregates with syncope and cardiac arrest, documenting electrocardiographic data and cardiac symptomatology. The reported patients/families from the literature with CACNA1C gene variants were reviewed, and genotype–phenotype correlations are drawn.

Results

The range of phenotype in the studied family is wide, from no apparent effect, through an asymptomatic QT interval prolongation on electrocardiography, to episodes of presyncope and syncope, ventricular fibrillation, and sudden death. QT prolongation showed inconsistent correlation with functional cardiology. Based upon analysis of 28 heterozygous family members, estimates of penetrance and expressivity are derived.

Conclusions

These estimates of penetrance and expressivity, for this specific variant, may be useful in clinical practice. Review of the literature indicates that individual CACNA1C variants have their own particular genotype–phenotype correlations. We suggest that, at least in respect of the particular variant reported here, “arrhythmogenic channelopathy” may be a more fitting nomenclature than long QT syndrome.
More bilingual mental health counselors needed to serve as language brokers
Authors: Canady Valerie A.
Published: October 2018

The rapid increase in the Spanish‐speaking immigration population in the United States, coupled with a mental health workforce that predominantly speaks one language, has bilingual mental health counselors confronted with serving as language brokers and having to provide psychological services in two languages. Language brokering is defined as the process by which family or community members provide translation services to a monolingual English‐speaking service provider, according to a new report published in the Journal of Mental Health Counseling.
People seeking care on their own likely to rate it effective
Authors: Canady Valerie A.
Published: October 2018

Observing that the gap between need and effective treatment for mental health problems continues to be a challenge, researchers found that people who seek care on their own rate the treatment more effectively, compared to those who are coerced into care, suggests a study published online in Society and Mental Health.
Improving care transitions helps individuals and organizations
Authors: Rosenberg Linda
Published: October 2018

When I had triple bypass surgery last fall, I left the hospital with a clear plan for what would happen next. I was enrolled in a cardio rehab program, and my primary care physician's care navigator called to remind me about screenings and appointments. I used my providers' patient portals to request appointments, send messages and track my progress.
MDD treatment found effective for patients with insomnia
Authors: Canady Valerie A.
Published: October 2018

An estimated 70 to 90 percent of patients with major depressive disorder (MDD) suffer from insomnia, say researchers in Rome, Italy, who tested the sleep quality of some patients with an antidepressant recently approved by the Food and Drug Administration for MDD treatment. Their findings are published in the British Journal of Clinical Pharmacology.
Functional lung imaging with transient spoiled gradient echo
Authors: Bauman Grzegorz , Pusterla Orso , Bieri Oliver
Published: October 2018

Purpose

To introduce an alternative framework for perfusion and ventilation lung imaging at 3 T using transient spoiled gradient echo (tSPGR) acquisitions.

Methods

Sets of coronal 2D time‐resolved lung image series were acquired in 5 healthy volunteers using tSPGR and compared with contemporary SPGR and ultrafast balanced SSFP (uf‐bSSFP) implementations at 1.5 T and 3 T. Sequence parameters and view ordering were optimized for tSPGR to yield maximum signal intensity in the lung tissue. Signal‐to‐noise ratio and contrast‐to‐noise ratio analyses were performed in all acquired tSPGR, SPGR, and uf‐bSSFP data sets. Matrix pencil decomposition was applied to generate functional parameter maps, including fractional ventilation, relative perfusion, and blood arrival time.

Results

For the lung, the signal intensity of tSPGR imaging was maximal for minimal TR and TE settings of 0.99 ms and 0.43 ms, respectively. Moreover, low RF spoiling increments in combination with a centric view ordering resulted in a further signal‐to‐noise ratio increase of about 30% to 40%. The average signal‐to‐noise ratio in the lung parenchyma was 73.3 for uf‐bSSFP, 38.1 for tSPGR, 20.7 for SPGR at 1.5 T, and 31.2 for uf‐bSSFP, 35.6 for tSPGR, and 21.3 for SPGR at 3 T. The average ventilation and perfusion contrast‐to‐noise ratio was 33.2 and 36.2 for uf‐bSSFP, 15.4 and 12.5 for tSPGR, 13.5 and 4.1 for SPGR at 1.5 T, and 16.5 and 11.3 for uf‐bSSFP, 29.7 and 50.8 for tSPGR, and 22.4 and 16.5 for SPGR at 3 T, respectively.

Conclusion

At 3 T, application of balanced SSFP is limited, so tSPGR offers an alternative framework for successful lung function assessment using matrix pencil MRI.
Effect of Eccentric Initiation on the Fragment Velocity Distribution of D‐Shaped Casings Filled with Explosive Charges
Authors: Guo Zhi‐wei , Huang Guang‐yan , Liu Chun‐mei , Feng Shun‐shan
Published: October 2018

Irregular casings filled with explosive charges are increasingly being developed for the designs of new warheads and explosive protection. In this work, we studied the fragment velocity of a semicircular D‐shaped casing, which is a typical asymmetric casing. Static explosive experiments were conducted with D‐shaped casings with different eccentric detonation coefficients (1/8, 3/8, 5/8, and 7/8) to determine their circumferential fragment velocity distributions. An empirical formula was then established to calculate the circumferential fragment velocity distribution for the D‐shaped casing, and the calculation results of formula were found to agree well with experimental data. The D‐shaped casing would have a uniform circumferential fragment velocity distribution when detonated at its central point, and the central point was determined by considering the empirical formula and the experimental data in combination. The results of the current work pave way for the innovative design of directional warhead and for further studying the dynamic response of asymmetric casing.
Multiple Exciton Generation in SiGe Nanoclusters: A Numerical Study
Authors: Gordi Mahdi , Moravvej‐Farshi Mohammad K.
Published: October 2018

The multiple exciton generation (MEG) in Si(0≤x≤7)Ge(7−x) nanoclusters using the equation‐of‐motion coupled‐cluster (EOM‐CCSD) method has been studied here. Simulation results indicate that the energy normalized to the optical bandgap, at which the absorptivity profile peaks, depends on the elemental structure of the nanocluster (NC). Moreover, the results show that the larger the number of Si atoms (x) in the NC, the larger the normalized MEG threshold to the optical energy gap (ETh), and the larger the optical absorption cross section. As an example, the maximum absorptivity in Si7Ge0 nanocluster is about 2.37 times that in Si0Ge7, and ETh for the former NC is larger than that of the latter. Hence, the superior optical absorptivity of Si7 shows, despite its larger normalized MEG threshold, it is the most desirable option for the MEG process in light‐harvesting devices, including solar cells. This is contrary to the concluding remark in our previous study that was made solely on the basis of comparing the normalized MEG thresholds.
Grafting of Polyacrylic Acid onto Thermo‐Sensitive Polyvinyl Methyl Ether for Fluoxetine Extraction from Human Urine and Plasma
Authors: Mohammadvalipour Sanaz , Panahi Homayon A. , Nezhati Mahshid N.
Published: October 2018

In this research, a new solid adsorbent was prepared by grafting acrylic acid monomer onto polyvinyl methyl ether for extraction and determination of trace amount of fluoxetine in biological human samples. Poly acrylic acid was grafted on the backbone of polyvinyl methyl ether as a thermo‐sensitive polymer by radical polymerization for thermal‐controlled sorption of fluoxetine as a target drug. The effect of pH, temperature and contact time on adsorption has been evaluated. The synthetic polymer was characterized via Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis and scanning electron microscopy. The proposed method has been successfully operated selective for fluoxetine. The profile of fluoxetine uptake with the new sorbent indicated good availability and accessibility of the reactive sites in the polymeric sorbent. From the mathematical calculation, the equilibrium adsorption findings of fluoxetine by the novel polymer were evaluated using a Langmuir isotherm model. The introduced method by using thermo‐sensitive monomer was used for assessment of fluoxetine in human plasma and urine samples by high performance liquid chromatography with great results.
Conversion of Fructose and Xylose into Platform Chemicals Using Organo‐Functionalized Mesoporous Material
Authors: Kalita Pranjal , Datta Prantu , Baruah Pranjal K
Published: October 2018

5‐Hydroxymethyl furfural and furfural are considered as platform chemicals. Due to global warming and climate change, more attention is now being paid for renewable feed stocks such as lignocellulosic biomass due to their easy availability for production of these important platform chemicals. Such greener routes for producing value‐added compounds include liquid bio‐fuels in the ranges of C8‐C15 through aldol‐condensation followed by catalytic hydrogenolysis or hydrogenation or hydrodeoxygenation. Herein we describe the use of KIT‐5 mesoporous material functionalized with trifluoromethanesulfonic acid in the conversion of fructose and xylose. The yield of the desired products 5‐hydroxymethyl furfural and furfural were found to be 80 and 75% within 6 hrs, respectively.
Development of Non‐Traditional Vegetable‐Oil‐Based Two‐Pack Polyurethane for Wood‐Finished Coating: An Alternative Approach
Authors: Raychura Ashish J. , Dholakiya Bharatkumar Z. , Patel Kalpesh I. , Jauhari Smita
Published: October 2018

Nowadays, the use of non‐traditional vegetable oils as polymer precursors is the subject of growing interest because of increasing price of crude oil and eco‐friendly approach. In this context, present work reports the synthesis of mahua oil fatty amide (MFA) from the mahua oil. The synthesized MFA was characterized by chemical and spectroscopic methods and utilized as a hydroxyl component of “two‐component polyurethane (2K‐PU)” system. The prepared 2K‐PU was used as wood protective coating material. The coating performance of the formulated 2K‐PU was evaluated by the measurement of mechanical, thermal and antimicrobial properties as well as water and chemical resistance. The study reveals that MFA can be used as the hydroxyl component in 2K‐PU coating system. MFA was derived from a relatively economical and renewable resource and the use of MFA can substantially reduce the cost of polyurethane coating formulations.
Modulation of Lactam‐Lactim Tautomerism of Quinoxalin‐2‐one Induced by Cucurbit[7]uril: A Comparative Study with Oxazin‐2‐one
Authors: Aliaga Margarita E. , De la Fuente Julio R. , García‐Rio Luis , Rojas‐Romo Carlos , Uribe Iván , Díaz‐Hernández Dafne , Fierro Angélica , Cañete. Álvaro
Published: October 2018

The formation of inclusion complexes between cucurbit[7]uril (CB7) and N,N‐(dimethylamino)styrylquinoxalin‐2‐one (Me2NSQx) or the N,N‐(dimethylamino)styryloxazin‐2‐one (Me2NSOxa) dyes, was carried out using spectroscopy techniques (UV‐vis, fluorescence and NMR), flash photolysis, mass spectrometry and docking studies. Results show that: (i) both dyes form inclusion complexes with a CB7 excess, which depicts huge bathochromic shifts (>100 nm); (ii) Me2NSQx and Me2NSOxa, firstly form a 1:1 complex and at higher CB7 concentrations, a 2:1 host:guest complex is generated; (iii) the inclusion complex for Me2NSQx changes from its stable lactam form to the lactim tautomer, while for Me2NSOxa the equilibrium is shifted to the oxazinium tautomer. Finally, in the case of Me2NSQx dye, spectroscopic and docking studies indicate that the most stable complex is Me2NSQx@CB7 (1:2) in its lactim form, while in Me2NSOxa the equilibrium is shifted to the oxazinium containing complex. Therefore, our results evidence the importance of the interaction of CB7 as another form of controlling the tautomerism equilibrium of lactam or lactones derivatives.
NAD+ Cofactor Regeneration by TMB‐Mediated Horseradish‐Peroxidase‐Catalyzed Reactions
Authors: Li Yunzhe , Wang Zhen‐Gang , Li Huanrong , Ding Baoquan
Published: October 2018

The regeneration of nicotinamide adenine dinucleotide (NAD+) has attracted substantial interest in the enzymatic chemical transformations. In this work, we report the use of a traditional horseradish peroxidase (HRP)/H2O2 system for the catalytic transformation of reduced nicotinamide adenine dinucleotide (NADH) into NAD+, in the presence of a common HRP substrate, 3,3′,5,5′‐tetramethylbenzidine (TMB), as an electron mediator. The effect of H2O2, HRP or TMB concentration on the oxidization rate of NADH was systematically investigated. The results show that a small amount of HRP and TMB resulted in high efficient oxidization of NADH into NAD+, through the switching between the oxidized and reduced states of TMB. The enzymatic system also exhibited pH‐dependent catalytic properties, so that a XOR logic gate was constructed with H2O2 and H+ as the gate inputs, and the generated TMB charge transfer complex as the output signals. The addition of glucose dehydrogenase (GDH)/glucose allows the cycling between the NADH and NAD+ and the coupled activation of HRP and GDH. This work provides a strategy for efficient regeneration of the NAD+ cofactor and enzyme‐driven transformations.
Mesoporous Titania‐Alumina Mixed Oxide: A Heterogeneous Nanocatalyst for the Synthesis of 2‐Substituted Benzimidazoles, Benzothiazoles and Benzoxazoles
Authors: Bahrami Kiumars , Bakhtiarian Mohsen
Published: October 2018

Mesoporous titania‐alumina mixed oxide (MTAMO) was synthesized by sol‐gel pathway using sodium dodecyl sulfate as a structure directing agent and successfully employed as a highly efficient nanocatalyst for the synthesis of 2‐substituted benzimidazoles, benzothiazoles, and benzoxazoles using 30% H2O2 as a green oxidant. The described methodology offers the benefits of operational simplicity, excellent yields, short reaction times and mild conditions. The catalyst characterized by various techniques like Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X‐ray (EDX) and N2 adsorption‐desorption.
Effective Preparation of One‐Dimensional Boron‐Nitride‐ Nanotube‐Supported Nanosheet Hierarchical Structures and Their Optical/Adsorption Properties
Authors: Wang Jilin , Ji Yuchun , Gu Yunle , Liao Hejie , Yang Liuzhong , Long Fei , Zhou Bing , Wang Weimin , Fu Zhengyi
Published: October 2018

A novel boron nitride nanotube‐supported nano‐sheets one‐dimensional hierarchical structures (BNNT‐BNNS) were efficiently prepared via a ball milling assisting chemical vapor deposition method. X‐ray powder diffraction (XRD), fourier transform infrared spectrometer (FTIR), Raman, field scanning electron microscopy (FSEM), energy dispersive spectroscopy (EDX), transmission electron microscopy (TEM) and high‐resolution transmission electron microscopy (HRTEM) were used to characterize the as‐synthesized samples. The samples presented a length of more than 20 μm and wide diameter ranges from 20 nm to 600 nm. Abundant nano‐sheets grew in random directions and intertwined closely on the surface of the one‐dimensional structures. Every nano‐sheet was transparent and demonstrated a thickness of less than 10 nm with irregular size and shape. Ultraviolet‐visible (UV‐vis) and photoluminescence (PL) results indicated that the band gap was 5.71 eV and the maximum fluorescence emission peak was located at 368 nm. In addition, it was worth noting that the BNNT‐BNNS hierarchical structures also presented excellent adsorption property for methylene blue (MB). When the adsorption time was 5 min, MB could be removed by 75.2% from water solution. The adsorption rate could increase to 97.3% when the adsorption time was 115 min. Finally, the possible chemical reactions and the corresponding catalytic cracking growth mechanism of the special hierarchical structures also were investigated carefully.
A DFT Study on the One‐Electron Reduction/Oxidation of Biologically Relevant Pteridine Derivatives
Authors: Reibnegger Gilbert
Published: October 2018

Pteridine derivatives occur ubiquitously in living systems. The biological functions of these nitrogen‐rich heterocyclic compounds remain partly unknown. The most intensively studied role is that of tetrahydrobiopterin as cofactor for the monooxygenases hydroxylating the aromatic amino acids phenylalanine, tyrosine and tryptophan. In these and other reactions pteridine derivatives act as redox catalysts; therefore, their redox behavior is of particular interest. Using density functional theory, one‐electron reduction/oxidation processes involving relevant pteridine derivatives in aqueous solution are studied. For pterins and lumazines, the results reproduce very satisfactorily the experimentally known increasing reductive strength in the order aromatic, dihydro and tetrahydro compound. The influence of simple substituents at different molecular sites is studied. Results on quinoid dihydropterins not only confirm earlier experimental conclusions regarding the structure of these quite instable compounds, they also provide a theoretical rationale why quinoid dihydrobiopterin may have evolved as intermediate in the cofactor role of tetrahydrobiopterin.
A Potentiometric Study of the Briggs‐Rauscher Oscillatory Reaction in a Solution of Ionic Surfactants and Tetrabutylammonium Hydrogensulphate
Authors: Pribus Marek , Trnková Libuše , Grančičová Oľga , Olexová Anna
Published: October 2018

The concentration effect of ionic surfactants (sodium dodecyl sulphate, N‐hexadecyl‐N,N,N‐trimethylammonium hydrogensulphate, 3‐(N,N‐dimethyl‐N‐myristylammonio)propanesulfonate) and tetrabutylammonium hydrogensulphate was investigated on the Briggs‐Rauscher (BR) oscillatory reaction in a stirred batch reactor at 25 ± 0.1 °C in both the absence and presence of an ionic surfactant. In the presence of the anionic surfactant, the induction period (IP) and the oscillation period (OP) increase markedly, and the amplitude of oscillations decreases with increasing concentration of sodium dodecyl sulphate. These effects have been observed when the concentration of surfactant is much higher than its critical micelle concentration. Another effect on IP and OP has been observed in the presence of cationic and zwitterionic surfactants. A decrease in IP leads to its extinction at a certain concentration and at the same time, chemical oscillations divide into two series of chemical oscillations. TBAH does not have a major influence on IP and OP of the BR oscillatory reaction. The observed effects are explained in terms of micellar catalysis or inhibition in different extents of individual reactants solubilisation respectively.
Hybrid Architectures based on 2D MXenes and Low‐Dimensional Inorganic Nanostructures: Methods, Synergies, and Energy‐Related Applications
Authors: Liu Yi‐Tao , Zhu Xiao‐Dong , Pan Long
Published: October 2018

Being conductive and flexible, MXenes, including transition metal carbides and nitrides, are expected to compete with, or even outperform graphene as 2D substrates serving in versatile applications. On the other hand, the extraordinary electrochemical activities of MXenes make them promising candidates as electrode materials in rechargeable batteries and supercapacitors, or as electrocatalysts in water splitting. However, MXenes are inclined to self‐restack due to hydrogen bonding or van der Waals interactions, which may lead to substantial loss of electroactive area as well as inaccessibility of ions and electrolytes. In this sense, hybridizing 2D MXenes and low‐dimensional inorganic nanostructures in elaborately designed architectures is of utmost significance, and provides a chance to integrate their unique properties in a complementary way. As such, this review is dedicated to highlighting recent progress in this regime, putting emphasis on the methods, structural and functional synergies, and energy‐related applications. Moreover, the present challenges and the future development directions are also discussed in depth.
Simulation of Microstructure Evolution in Ultra‐Heavy Plates Rolling Process Based on Abaqus Secondary Development
Authors: Chen Xu , Cai Qingwu , Xie Baosheng , Yun Yang , Zhou Zhaoyuan
Published: October 2018

Grain refinement caused by deformed austenite recrystallization is an important way to enhance the property of ultra‐heavy plates during hot rolling process. In the present study, with the model coupled microstructure evolution based on Abaqus secondary development, numerical simulation of hot rolling process with different rolling parameters is carried out. The calculation result showed that gradient temperature rolling process can increase the accumulated strain in the center of plate so that 4.9–11.8 µm smaller grains can be obtained. Compared with the microscopic scale numerical simulation for grain nucleation and growth, the model above can accomplish the microstructure evolution simulation of steel plates during rolling process on macroscopic scale. The prediction of grain size can be achieved with the calculation result, which assists engineers in formulating steel plates rolling schedules.
Protonation of p‐Benzoquinone in Superacidic Solutions
Authors: Schickinger Manuel , Siegert Markus , Morgenstern Yvonne , Zischka Florian , Stierstorfer Karin , Kornath Andreas
Published: October 2018

The reaction of p‐benzoquinone in the binary superacidic systems XF/MF5 (M = As, Sb; X = H, D) leads to the formation of the corresponding salts [OC6H4(OX)][MF6] (M = As, Sb; X = H, D). Threefold excess of Lewis acid in relation to p‐benzoquinone is required to form these salts quantitatively. The salts are characterized by infrared spectroscopy and in the case of [OC6H4(OH)][SbF6] (2) by a single‐crystal X‐ray structure analysis, according to which it is more correctly described as a double hemi‐protonated salt of p‐benzoquinone. The salt crystallizes in the triclinic space group P1 with one formula unit per unit cell. In the solid state the cations are arranged in chains, linked via O···(H)···O bonds. The vibrational spectra were compared to quantum chemical calculations of the cation [OC6H4(OH)]+.
A Novel Mobile Phone Text Messaging Platform Improves Collection of Patient-Reported Post-operative Pain and Opioid Use Following Orthopedic Surgery
Authors: Premkumar Ajay , Lovecchio Francis C. , Stepan Jeffrey G. , Kahlenberg Cynthia A. , Blevins Jason L. , Albert Todd J. , Cross Michael B.
Published: October 2018

Background

Prospective collection of patient-reported opioid consumption and pain levels post-surgically may hold value in highlighting solutions related to the opioid crisis. Traditional methods for collecting patient-reported outcomes after surgery, such as paper surveys, often have poor response rates, and electronic messaging may offer more convenience and therefore yield more robust data.

Questions/Purposes

The purpose of this study was to evaluate whether a novel mobile phone short message service (SMS) platform would lead to better patient response rates to surveys on pain and opioid use than data-collection tools.

Methods

An SMS text messaging platform was created and implemented between September 2017 and May 2018 at an orthopedic specialty hospital. The purpose was to collect reports on opioid consumption and pain levels twice a day for 6 weeks post-surgery from patients who had undergone total hip or knee arthroplasty or a single-level lumbar microdiscectomy or decompression spine surgery. Patients who responded to fewer than 50% of the text messages were excluded.

Results

Our mobile phone text messaging platform was used by 183 patients, demonstrating a significantly higher response rate (96.1%) than our institution's post-operative email registry capture, as well as the majority of published response rates for post-operative outcomes captured through electronic and traditional data-collection systems. Response rate remained consistently high among the various surgeons and across patients, regardless of age.

Conclusions

This application of a widely available technology can improve the measurement of post-operative patient-reported outcomes. Such data can in turn be used in the development of strategies to reduce post-operative opioid use. The adoption of novel technologies at a patient level will play a key role in combating the opioid epidemic.
Effects of gain-loss frames on advantageous inequality aversion
Authors: Boun My Kene , Lampach Nicolas , Lefebvre Mathieu , Magnani Jacopo
Published: October 2018

This paper studies individuals’ preference for reducing advantageous inequality in the distribution of gains and losses. Combining the inequality aversion model of Fehr and Schmidt (Q J Econ 114(3):817–868, 1999) with loss aversion à la Kahneman and Tversky (Econom J Econom Soc:263–291, 1979), we predict the relative dislike for advantageous inequality is lower when outcomes are framed as losses than when outcomes are framed as gains. We test this prediction using data from two modified dictator game experiments. Consistent with the model, we find that the amount of payoff that subjects are willing to sacrifice to increase the net payoff of others and reduce advantageous inequality is smaller under a loss frame than under a gain frame. The results also show that women are more inequality averse than men in both gains and losses.
The great debate: study proves whether people or algorithms are best at facial ID
Authors: Phillips P Jonathon , O'toole Alice J
Published: October 2018

Face recognition is a vital and controversial area, with its use by police and government under scrutiny worldwide. Accurate use of the technology is paramount, and in law enforcement the responsibility for identification falls primarily to professional forensic facial experts. Yet despite the societal importance of face ID applications, remarkably little is known about the accuracy of professionals relative to others with no training – and nothing is known about how human experts compare to state-of-the-art face recognition technology.
Measuring cyber-risk
Authors: McKenna Benedict
Published: October 2018

Resilience is the capacity for a business to quickly recover from disruption. Under pressure, a resilient organisation is able to quickly adapt to challenges and maintain continuous business operations that safeguard people, assets and reputation. However, due to risk factors that vary across countries, it is difficult to predict the specific challenges that businesses may face.
The best form of defence – the benefits of red teaming
Authors: Mansfield-Devine Steve
Published: October 2018

One of the best ways to understand how well your defences would withstand a cyber-attack is, in fact, to come under attack. Nothing exposes your weaknesses better than having them revealed by skilled hackers. That's the idea behind penetration testing. However, if you have systems or information assets you know are especially valuable, you might want to consider ramping things up a notch and engage in red teaming exercises, as Gemma Moore, a director at Cyberis, explains in this interview.

One of the best ways to understand how well your defences would withstand a cyber-attack is, in fact, to come under attack.

Nothing exposes your weaknesses better than having them revealed by skilled hackers. That's the idea behind penetration testing. However, if you have systems or information assets you know are especially valuable, you might want to consider ramping things up a notch and engage in red teaming exercises, as Gemma Moore explains in this interview.
Delone dynamical systems and spectral convergence
Authors: BECKUS SIEGFRIED , POGORZELSKI FELIX
Published: October 2018

In the realm of Delone sets in locally compact, second countable Hausdorff groups, we develop a dynamical systems approach in order to study the continuity behavior of measured quantities arising from point sets. A special focus is both on the autocorrelation, as well as on the density of states for random bounded operators. It is shown that for uniquely ergodic limit systems, the latter measures behave continuously with respect to the Chabauty–Fell convergence of hulls. In the special situation of Euclidean spaces, our results complement recent developments in describing spectra as topological limits: we show that the measured quantities under consideration can be approximated via periodic analogs.
Prediction of compressible turbulent boundary layer via a symmetry-based length model
Authors: She Zhen-Su , Zou Hong-Yue , Xiao Meng-Juan , Chen Xi , Hussain Fazle
Published: October 2018

A recently developed symmetry-based theory is extended to derive an algebraic model for compressible turbulent boundary layers (CTBL) – predicting mean profiles of velocity, temperature and density – valid from incompressible to hypersonic flow regimes, thus achieving a Mach number ($Ma$) invariant description. The theory leads to a multi-layer analytic form of a stress length function which yields a closure of the mean momentum equation. A generalized Reynolds analogy is then employed to predict the turbulent heat transfer. The mean profiles and the friction coefficient are compared with direct numerical simulations of CTBL for a range of$Ma$from 0 (e.g. incompressible) to 6.0 (e.g. hypersonic), with an accuracy notably superior to popular current models such as Baldwin–Lomax and Spalart–Allmaras models. Further analysis shows that the modification is due to an improved eddy viscosity function compared to competing models. The results confirm the validity of our$Ma$-invariant stress length function and suggest the path for developing turbulent boundary layer models which incorporate the multi-layer structure.