bluuebunny/crossref_metadata_2025 huggingface dataset:
Two‐component acrylic structural adhesive initiated by tributylborane for untreatedPETadhesion
Authors: Zhang Jian , Wang Jing‐Wen , Ge Ren‐Kui
Published: May 2018

In order to improve the adhesion strength of acrylic adhesive to untreated poly(ethylene terephthalate) (PET) substrate, two‐component acrylic structural adhesives initiated by tributylborane were prepared. The effects of acrylic monomers, elastomers, decomplexers, and oligomers on the adhesion properties of two‐component acrylic structural adhesive were investigated in sequence. It is found that the shear strength on PET of adhesives toughened by acrylonitrile–butadiene–styrene copolymer and carboxyl‐terminated butadiene–acrylonitrile copolymer is higher than that of commercial adhesives Dp8010NS and Loctite 3030. A tailored oligomer was synthesized from hydroxyl propyl–terminated polydimethylsiloxane and 3‐isopropenyl‐α,α‐dimethylbenzyl isocyanate. It is also noticed that premature failure usually takes place in the lap shear test samples due to the brittleness of the acrylic adhesive, except in the sample of adhesive modified by tailored oligomer. Excellent adhesion to the PET substrate is achieved by this adhesive modified by tailored oligomer, with a lap shear strength above 11 MPa and T‐peel strength up to 5.34 N/mm. Additionally, the resulting adhesive is qualified for the structural bonding of PET materials. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46612.
Unknown Input Reduced‐order Observer Design for One‐Sided Lipschitz Nonlinear Descriptor Markovian Jump Systems
Authors: Tian Jiaming , Ma Shuping , Zhang Chenghui
Published: May 2018

This paper deals with the reduced‐order unknown input observer (UIO) design problem for one‐sided Lipschitz nonlinear continuous‐time descriptor Markovian jump systems. First, with the assumption of a one‐sided Lipschitz condition and quadratic inner‐bounded condition, a sufficient condition is established, which guarantees that the error dynamic system is stochastically stable. Then, based on the symbol of nonlinear constants, and by using the matrix generalized inverse technique, a condition with the form of linear matrix inequalities (LMIs) is developed such that the reduced‐order UIO exists. Moreover, the design procedures of the reduced‐order UIO are given based on LMIs approach. Besides, the dimension of the reduced‐order UIO can be chosen freely in a certain range. Finally, some numerical examples are provided to illustrate the effectiveness of the proposed design methods.
Design and Implementation of a Hierarchical‐Clustering CMAC PID Controller
Authors: Liao Yuntao , Koiwai Kazushige , Yamamoto Toru
Published: May 2018

In industrial control processes, proportional‐integral‐derivative (PID) control algorithm is widely employed. Therefore, it is meaningful to design advanced PID controllers, especially for nonlinear control objects. One of the advanced PID controllers is a cerebellar model articulation controller (CMAC) PID controller. In this controller, the PID control parameters are calculated and tuned. The CMAC achieves a higher accuracy by increasing the number of labels of each weight table; this requires a larger memory, and the generalization ability of the controller decreases. On the other hand, if the CMAC requires less memory, the generalization ability increases and accuracy decreases. Hence, in this paper, a novel CMAC in which the accuracy is compatible with the generalization ability is proposed in this paper. In the proposed CMAC, the number of labels of each weight table can be decided by using a hierarchical clustering technology. Moreover, the efficiency of the memory allocation is improved. The effectiveness of the proposed method is verified by experiments.
Some critical aspects of the enzymatic hydrolysis at high dry‐matter content: a review
Authors: Battista Federico , Bolzonella David
Published: May 2018

Enzymatic hydrolysis represents the crucial phase in bioethanol production. Its aim is to convert pretreated lignocellulosic polymers in hexose sugars for fermentation into bioethanol. To be economically advantageous, the enzymatic hydrolysis should operate with a high concentration of dry matter. The drawback of this is the increase in the reaction medium's viscosity and consequently bad mixing within the bioreactor due to the complexity of the lignocellulosic polymers. Another critical aspect of the enzymatic hydrolysis is enzyme deactivation, which is mainly due to two factors: the presence of lignin by‐products, originating from the pretreatment of lignocellulosic biomass, and the accumulation of glucose in the reaction medium by cellulose hydrolysis. This review details these two critical aspects of enzymatic hydrolysis conducted with high dry‐matter content. The most relevant milestones and technological solutions to improve rheological performance and to reduce enzyme deactivation have been investigated. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.
The power of ‘evidence’: Reliable science or a set of blunt tools?
Authors: Wrigley Terry
Published: May 2018

In response to the increasing emphasis on ‘evidence‐based teaching’, this article examines the privileging of randomised controlled trials and their statistical synthesis (meta‐analysis). It also pays particular attention to two third‐level statistical syntheses: John Hattie's Visible learning project and the EEF's Teaching and learning toolkit. The article examines some of the technical shortcomings, philosophical implications and ideological effects of this approach to ‘evidence’, at all these three levels. At various points in the article, aspects of critical realism are referenced in order to highlight ontological and epistemological shortcomings of ‘evidence‐based teaching’ and its implicit empiricism. Given the invocation of the medical field in this debate, it points to critiques within that field, including the need to pay attention to professional experience and clinical diagnosis in specific situations. Finally, it briefly locates the appeal to ‘evidence’ within a neoliberal policy framework.
Electrical stimulation‐based nerve location prediction for cranial nerve VII localization in acoustic neuroma surgery
Authors: Puanhvuan Dilok , Chumnanvej Sorayouth , Wongsawat Yodchanan
Published: May 2018

Introduction

Cranial nerve (CN) VII localization is a critical step during acoustic neuroma surgery because the nerve is generally hidden due to the tumor mass. The patient can suffer from Bell's palsy if the nerve is accidentally damaged during tumor removal. Surgeons localize CN VII by exploring the target area with a stimulus probe. Compound muscle action potentials (CMAPs) are elicited when the probe locates the nerve. However, false positives and false negatives are possible due to unpredictable tissue impedance in the operative area. Moreover, a single CMAP amplitude is not correlated with probe‐to‐nerve distance.

Objectives

This paper presents a new modality for nerve localization. The probe‐to‐nerve distance is predicted by the proposed nerve location prediction model.

Methods

Input features are extracted from CMAP responses, tissue impedance, and stimulus current. The tissue impedance is calculated from the estimated resistance and capacitance of the tissue equivalent circuit. In this study, experiments were conducted in animals. A frog's sciatic nerve and gastrocnemius were used to represent CN VII and facial muscle in humans, respectively. Gelatin (2.8%) was used as a mock material to mimic an acoustic neuroma. The %NaCl applied to the mock material was used to emulate uncontrollable impedance of tissue in the operative area.

Results

The 10‐fold cross‐validation results revealed an average prediction accuracy of 86.71% and an average predicted error of 0.76 mm compared with the measurement data.

Conclusion

The proposed nerve location prediction model could predict the probe‐to‐nerve distance across various impedances of the mock material.
Improved stent expansion with prolonged compared with short balloon inflation: A meta‐analysis
Authors: Saad Marwan , Bavineni Mahesh , Uretsky Barry F. , Vallurupalli Srikanth
Published: May 2018

Background

Despite evidence from individual studies suggesting that prolonged inflation improves coronary stent expansion, relatively shorter inflation times are commonly employed in clinical practice.

Methods

We performed an electronic search of PubMed, Web of Science, Cochrane, and CINAHL databases to retrieve outcome studies comparing prolonged versus short inflation times during stent deployment. Outcomes studied included minimal stent diameter (MSD) and minimal stent area (MSA). Standardized mean difference (SMD) was used to estimate the effect sizes for these continuous variables.

Results

Seven studies with a total of 341 patients (415 lesions; mean age 67.6 years; 82% male) were included. Drug‐eluting stents were used in 89 ± 15% of coronary lesions. Prolonged stent inflation was associated with increased minimal stent diameter (2.93 ± 0.34 mm vs. 2.72 ± 0.28 mm; SMD = 0.42; 95% CI 0.25–0.59; P < 0.001) and minimal stent area (5.99 ± 1.21 mm2 vs. 5.17 ± 0.87 mm2; SMD = 0.46; 95% CI 0.19–0.73; P = 0.001) compared with shorter duration stent inflation. This difference remained significant in sensitivity analyses that excluded studies with very prolonged inflation duration or multiple stent balloon inflations.

Conclusion

Despite differences in duration and methodology, prolonged stent inflation is associated with improved expansion compared with shorter duration. The effect of this optimization recommends randomized trials to determine whether long‐term outcomes can be improved by this simple technical modification.
Manganese (II,III) Oxide‐Activated Carbon Black Supported PtRu Nanoparticles for Methanol Electrooxidation in Acid Medium
Authors: Comignani Vanina , Sieben Juan M. , Brigante Maximiliano E. , Duarte Marta M. E.
Published: May 2018

In this work, PtRu nanoparticles supported on hybrid manganese (II,III)‐carbon composites were prepared by a microwave‐assisted polyol process in ethylene glycol. The obtained PtRu/(100‐x) C.xMn3O4 catalysts were characterized by XRD diffraction, TEM, SEM‐EDX analysis, ICP‐AES and electrochemical techniques. Small and well‐distributed nanoparticles of about 2.6 nm were obtained over the hybrid support. The as‐prepared catalysts presented similar Pt : Ru atomic ratio (ca. 3.4 : 1), indicating that the composition of the bimetallic system is unaffected by the oxide content in the hybrid support. However, the noble metal loading increased with the increase in the oxide content due to the formation of more nucleation sites during microwave heating. The electrochemical experiments showed that the best performance and the lowest poisoning rate are obtained with PtRu/90C.10Mn3O4 followed by PtRu/70C.30Mn3O4. The bimetallic catalyst supported over 90C.10Mn3O4 exhibited a steady current density of 215 mA mgPtRu−1 at 0.5 V, which is 40 % higher than that of PtRu/C. This behavior is mainly associated with the ability of Mn3O4 to provide a large extra amount of hydroxyl groups and promote the dehydrogenation of methanol.
Direct Anodic Dehydrogenative Cross‐ and Homo‐Coupling of Formanilides
Authors: Schulz Lara , Franke Robert , Waldvogel Siegfried R.
Published: May 2018

The direct anodic dehydrogenative C−C cross‐ and homo‐coupling of formanilides is reported. This exceptional electrochemical synthesis allows one to prepare a broad variety of non‐symmetrical and symmetrical 2,2′‐diformamidobiphenyls as well as 2‐formamido‐2′‐amidobiphenyls. By applying an easy and simple to perform metal‐ and oxidizer‐free electrochemical protocol, and the formyl group as a highly atom‐economic amino‐protecting group, an important contribution to a sustainable and green‐minded chemistry was achieved.
Substituted 1H‐1,2,3‐Triazol‐4‐yl‐1H‐pyrrolo[2,3‐b]pyridines by De Novo One‐Pot Ring‐Forming Coupling/Cyclization/Desilylation Cu Alkyne/Azide Cycloaddition (AAC) Sequence
Authors: Lessing Timo , van Mark Hauke , Müller Thomas J. J.
Published: May 2018

Substituted 1H‐1,2,3‐triazol‐4‐yl‐pyrrolo[2,3‐b]pyridines are efficiently prepared by a one‐pot coupling/cyclization/desilylation Cu alkyne/azide cycloaddition (CuAAC) sequence in the sense of a consecutive three‐component fashion. The key feature of this new de novo formation of azole and triazole anellation is the sequentially Pd/Cu‐catalyzed process employing tri(iso‐propyl)silyl (TIPS) butadiyne as a four‐carbon building block. In addition, the sequence can be expanded in a four‐component fashion also employing the in situ formation of the required azides.
Effect of comprehensive remote ischemic conditioning in anterior ST‐elevation myocardial infarction undergoing primary percutaneous coronary intervention: Design and rationale of the CORIC‐MI randomized trial
Authors: Song Li , Yan Hongbing , Zhou Peng , Zhao Hanjun , Liu Chen , Sheng Zhaoxue , Tan Yu , Yi Chen , Li Jiannan , Zhou Jinying
Published: May 2018

Remote ischemic conditioning (RIC) applied during or after ST‐segment elevation myocardial infarction (STEMI) is currently the most promising adjuvant therapy to reduce reperfusion injury. Recent animal studies showed that RIC may help the myocardium recover if applied daily during the month after STEMI. The Comprehensive Remote Ischemic Conditioning in Myocardial Infarction (CORIC‐MI) trial is a single‐center randomized controlled study in which 200 patients undergoing primary percutaneous coronary intervention (PPCI) for anterior STEMI will be randomized in a 1:1 ratio into comprehensive RIC (CORIC) or no intervention (control) groups. CORIC consists of per‐RIC (5 cycles of 5‐minute ischemia and 5‐minute reperfusion of the lower limb immediately after randomization and before reperfusion), post‐RIC (5 cycles of 5‐minute ischemia and 5‐minute reperfusion of the lower limb immediately post‐PPCI), and delayed RIC (5 cycles of 5‐minute ischemia and 5‐minute reperfusion of the lower limb once daily on 2–28 days). Primary endpoint is left ventricular ejection fraction assessed by cardiac magnetic resonance imaging at 30 days. Major secondary endpoints include infarct size and left ventricular volume assessed by cardiac magnetic resonance imaging at 30 days, left ventricular ejection fraction assessed by echocardiography, and major adverse cardiovascular events up to 12 months. This report presents the baseline characteristics of 93 patients (CORIC group, n = 49; control group, n = 44) enrolled into the study as of March 31, 2018. The CORIC‐MI trial aims to test the hypothesis that CORIC will improve cardiac function and remodeling in patients with anterior STEMI undergoing PPCI.
Etiologies, predictors, and economic impact of readmission within 1 month among patients with takotsubo cardiomyopathy
Authors: Shah Mahek , Ram Pradhum , Lo Kevin Bryan U. , Sirinvaravong Natee , Patel Brijesh , Tripathi Byomesh , Patil Shantanu , Figueredo Vincent M.
Published: May 2018

Background

Limited data exist on readmission among patients with takotsubo cardiomyopathy (TC), a commonly reversible cause of heart failure.

Hypothesis

We sought to identify etiologies and predictors for readmission among TC patients.

Methods

We queried the National Readmissions Database for 2013–2014 to identify patients with primary admission for TC using ICD‐9‐CM code 429.83. Patients readmitted to hospital within 1 month after discharge were further evaluated to identify etiologies, predictors, and resultant economic burden of readmission. Additionally, we analyzed readmission for TC at 6 months.

Results

We studied 5997 patients admitted with TC, of whom 1.2% experienced in‐hospital mortality. Median age was 67 years, with 91.5% being female. Among survivors, 10.3% were readmitted within 1 month; 25% of the initial 1‐month readmissions occurred within 4 days, 50% within 10 days, and 75% within 20 days from discharge. The most common etiologies for readmission were cardiac (26%), respiratory (16%), and gastrointestinal (11%) causes. Heart failure was the most common cardiac etiology. Significant predictors of increased 1‐month readmission included systemic thromboembolic events, length of stay ≥3 days, and underlying psychoses. Obesity and private insurance predicted lower 1‐month readmission. The annual national cost impact for index admission and 1‐month readmissions was ≈$112 million. Recurrent TC was seen among 1.9% of patients readmitted within 6 months.

Conclusions

Though the overall rate of 1‐month readmission following TC is low, associated economic burden from readmission is still significant. Patients are readmitted mostly for noncardiac causes. Readmission for another episode of TC within 6 months was uncommon.
A trust management framework for software‐defined network applications
Authors: Yao Zhen , Yan Zheng
Published: May 2018

The emergence of software‐defined network (SDN) has brought unprecedented innovation to current networks. SDN's two most notable features are decoupling and programmability. Decoupling makes network management centralized in a control plane. Meanwhile, having benefitted from the programmable characteristic of SDN, new functions of networking can be easily realized. However, these features also introduce new security issues to SDN. Through the programming interface provided by SDN, software engineers can easily develop network applications to generate networking policies for SDN's control planes for the purpose of guiding network routing. However, it is hard to guarantee the security and quality of these new applications. Malicious or low‐quality applications could damage a whole network. To solve this problem, we propose a novel trust management framework for SDN applications in this paper. It can evaluate applications' trust values based on their impact on the network performance (such as time delay, packet loss rate, throughput, etc). These trust values further play a decisive role for managing and selecting applications in SDN. We evaluate this framework's performance through a prototype system implemented based on a floodlight controller. The experimental results show the accuracy and effectiveness of our design.
Fluorescence Endomicroscopy Imaging of Mesenchymal Stem Cells in the Rat Lung
Authors: Perez Jessica R. , Ybarra Norma , Chagnon Frederic , Lesur Olivier , Seuntjens Jan , Naqa Issam El
Published: May 2018

Stem cell therapy has shown great promise for organ repair and regeneration. In the context of lung disease, such as radiation‐induced lung damage (RILD) in cancer radiotherapy, mesenchymal stem cells (MSCs) have shown the ability to reduce damage possibly due to their immunomodulatory properties and other unknown mechanisms. However, once MSCs are transplanted into the body, little is known as to their localization or their mechanisms of action. In this work, we proposed, implemented, and validated a fluorescence endomicroscopy (FE) imaging technique that allows for the real‐time detection and quantification of transplanted pre‐labeled MSCs in vivo and tracking in a rat model. This protocol covers aspects related to MSCs extraction, labeling, FE imaging, and image analysis developed in a RILD rat model but applicable to other biological systems. © 2018 by John Wiley & Sons, Inc.
Retinal blood vessel segmentation for macula detachment surgery monitoring instruments
Authors: Hajabdollahi Mohsen , Karimi Nader , Reza Soroushmehr S.M. , Samavi Shadrokh , Najarian Kayvan
Published: May 2018

In recent years image processing has improved detection and diagnosis in medical application. Image processing applications are now embedded in medical instruments such as MRI and CT. In the case of retinopathy, fast extraction of blood vessels can allow the physician to view injury regions during surgery. Macula detachment surgeries, or computer‐aided intraocular surgeries, require precise and real‐time knowledge of the vasculature during the operation. Use of artificial neural network has produced good results in image processing applications, but its implementation may not be suitable for real‐time applications in small, embedded hardware. Because of error resiliency of the neural network, its structure can be pruned and simplified. In this paper an efficient hardware implementation of neural network for retinal vessel segmentation is proposed. We simplify the neural network structure in such a way that the accuracy of the results is not altered significantly. Simulation results and FPGA implementation show that our proposed network has low complexity and can be applied for segmentation of retinal vessels with acceptable accuracy. This makes the proposed method a good candidate to be implemented in any device such as a binocular indirect ophthalmoscope.
Integrating dynamic spectrum access and device‐to‐device via cloud radio access networks and cognitive radio
Authors: Marotta Marcelo Antonio , Roveda Faganello Leonardo , Kist Maicon , Bondan Lucas , Wickboldt Juliano Araujo , Zambenedetti Granville Lisandro , Rochol Juergen , Bonato Both Cristiano
Published: May 2018

Dynamic Spectrum Access (DSA) can be integrated with Device‐to‐Device (D2D) communications to enable the exploitation of unused spectrum portions and to address the spectrum scarcity problem. Spectrum management mechanisms integrated into DSA and D2D allow low‐power communications between User Equipments without interfering with licensed primary users. However, these mechanisms tend to be energy and processing intensive, being unfeasible to implement in User Equipments with strict battery and processing limitations. On the other hand, Cloud Radio Access Networks already leverage the virtually unlimited computing capacity of clouds for baseband processing functions. Thus, in this article, we propose the Cognitive Radio Device‐to‐Device (CRD2D) approach aiming to offload spectrum management functionality to the cloud taking advantage of Cloud Radio Access Networks architecture to support the integration of DSA and D2D.
A liquid chromatography–tandem mass spectrometry method for the determination of cocaine and metabolites in blood and in dried blood spots collected from postmortem samples and evaluation of the stability over a 3‐month period
Authors: Moretti Matteo , Visonà Silvia Damiana , Freni Francesca , Tomaciello Ilaria , Vignali Claudia , Groppi Angelo , Tajana Luca , Osculati Antonio Marco Maria , Morini Luca
Published: May 2018

The aims of this study were (1) to identify and quantify cocaine (COC), benzoylecgonine (BE), ecgonine methyl ester (EME), and cocaethylene (CE) in DBS; (2) to compare dried blood spots (DBSs) analytical results with the routine blood analyses; (3) to monitor analytes stability on DBS within a 3‐month period. Eighty‐five μL of blood from postmortem cases were put on a card for DBS analysis and kept in the dark, at room temperature. Samples were extracted through solid‐phase extraction (SPE) cartridges and injected in the liquid chromatography–tandem mass spectrometry (LC–MS/MS) system. The analytical procedure is simple, sensitive, and specific. Limits of detection (LODs) and quantification (LOQs) were calculated at 1.0 and 5.0 ng/mL(g) for COC and CE, and at 0.5 and 2 ng/mL for EME and BE, respectively. Validation parameters fulfilled all the acceptance criteria. Fifty‐five postmortem cases were evaluated. Eighteen cases were positive for COC (44–2456 ng/mL) and BE (228–4700 ng/mL), 12 for EME (92–1500 ng/mL), and 11 cases for CE (11–273 ng/mL). Stability was evaluated on 8 cases collected in the period January 2017–January 2018. For each case, 5 DBSs were collected at T0. Four DBSs were analyzed within the 4 following weeks and 1 sample was analyzed after 3 months. The concentrations on DBSs, stored at room temperature, always matched the ones obtained on blood samples kept at −20°C (<20% variation, both at T0 and after 3 months). BE and COC concentrations remained stable after a 3‐month storage, EME concentrations slightly increased after 3 weeks in the 2 analyzed samples, while CE provided a less homogeneous stability depending on the sample.
Comparing the rates of speciation and extinction between phylogenetic trees
Authors: Revell Liam J.
Published: May 2018

Over the past decade or so it has become increasingly popular to use reconstructed evolutionary trees to investigate questions about the rates of speciation and extinction. Although the methodology of this field has grown substantially in its sophistication in recent years, here I will take a step back to present a very simple model that is designed to investigate the relatively straightforward question of whether the tempo of diversification (speciation and extinction) differs between two or more phylogenetic trees, without attempting to attribute a causal basis to this difference. It is a likelihood method, and I demonstrate that it generally shows type I error that is close to the nominal level. I also demonstrate that parameter estimates obtained with this approach are largely unbiased. As this method can be used to compare trees of unknown relationship, it will be particularly well‐suited to problems in which a difference in diversification rate between clades is suspected, but in which these clades are not particularly closely related. As diversification methods can easily take into account an incomplete sampling fraction, but missing lineages are assumed to be missing at random, this method is also appropriate for cases in which we have hypothesized a difference in the process of diversification between two or more focal clades, but in which many unsampled groups separate the few of interest. The method of this study is by no means an attempt to replace more sophisticated models in which, for instance, diversification depends on the state of an observed or unobserved discrete or continuous trait. Rather, my intention is to provide a complementary approach for circumstances in which a simpler hypothesis is warranted and of biological interest.
The genetic network of greater sage‐grouse: Range‐wide identification of keystone hubs of connectivity
Authors: Cross Todd B. , Schwartz Michael K. , Naugle David E. , Fedy Brad C. , Row Jeffrey R. , Oyler‐McCance Sara J.
Published: May 2018

Genetic networks can characterize complex genetic relationships among groups of individuals, which can be used to rank nodes most important to the overall connectivity of the system. Ranking allows scarce resources to be guided toward nodes integral to connectivity. The greater sage‐grouse (Centrocercus urophasianus) is a species of conservation concern that breeds on spatially discrete leks that must remain connected by genetic exchange for population persistence. We genotyped 5,950 individuals from 1,200 greater sage‐grouse leks distributed across the entire species’ geographic range. We found a small‐world network composed of 458 nodes connected by 14,481 edges. This network was composed of hubs—that is, nodes facilitating gene flow across the network—and spokes—that is, nodes where connectivity is served by hubs. It is within these hubs that the greatest genetic diversity was housed. Using indices of network centrality, we identified hub nodes of greatest conservation importance. We also identified keystone nodes with elevated centrality despite low local population size. Hub and keystone nodes were found across the entire species’ contiguous range, although nodes with elevated importance to network‐wide connectivity were found more central: especially in northeastern, central, and southwestern Wyoming and eastern Idaho. Nodes among which genes are most readily exchanged were mostly located in Montana and northern Wyoming, as well as Utah and eastern Nevada. The loss of hub or keystone nodes could lead to the disintegration of the network into smaller, isolated subnetworks. Protecting both hub nodes and keystone nodes will conserve genetic diversity and should maintain network connections to ensure a resilient and viable population over time. Our analysis shows that network models can be used to model gene flow, offering insights into its pattern and process, with application to prioritizing landscapes for conservation.
Shrimp ponds lead to massive loss of soil carbon and greenhouse gas emissions in northeastern Brazilian mangroves
Authors: Kauffman J. Boone , Bernardino Angelo F. , Ferreira Tiago O. , Bolton Nicholas W. , Gomes Luiz Eduardo de O. , Nobrega Gabriel Nuto
Published: May 2018

Mangroves of the semiarid Caatinga region of northeastern Brazil are being rapidly converted to shrimp pond aquaculture. To determine ecosystem carbon stocks and potential greenhouse gas emissions from this widespread land use, we measured carbon stocks of eight mangrove forests and three shrimp ponds in the Acaraú and Jaguaribe watersheds in Ceará state, Brazil. The shrimp ponds were paired with adjacent intact mangroves to ascertain carbon losses and potential emissions from land conversion. The mean total ecosystem carbon stock of mangroves in this semiarid tropical landscape was 413 ± 94 Mg C/ha. There were highly significant differences in the ecosystem carbon stocks between the two sampled estuaries suggesting caution when extrapolating carbon stock across different estuaries even in the same landscape. Conversion of mangroves to shrimp ponds resulted in losses of 58%–82% of the ecosystem carbon stocks. The mean potential emissions arising from mangrove conversion to shrimp ponds was 1,390 Mg CO2e/ha. Carbon losses were largely from soils which accounted for 81% of the total emission. Losses from soils >100 cm in depth accounted for 33% of the total ecosystem carbon loss. Soil carbon losses from shrimp pond conversion are equivalent to about 182 years of soil carbon accumulation. Losses from mangrove conversion are about 10‐fold greater than emissions from conversion of upland tropical dry forest in the Brazilian Caatinga underscoring the potential value for their inclusion in climate change mitigation activities.
Functional diversity positively affects prey suppression by invertebrate predators: a meta‐analysis
Authors: Greenop Arran , Woodcock Ben A. , Wilby Andy , Cook Samantha M. , Pywell Richard F.
Published: May 2018

The use of pesticides within agricultural ecosystems has led to wide concern regarding negative effects on the environment. One possible alternative is the use of predators of pest species that naturally occur within agricultural ecosystems. However, the mechanistic basis for how species can be manipulated in order to maximize pest control remains unclear. We carried out a meta‐analysis of 51 studies that manipulated predator species richness in reference to suppression of herbivore prey to determine which components of predator diversity affect pest control. Overall, functional diversity (FD) based on predator's habitat domain, diet breadth and hunting strategy was ranked as the most important variable. Our analysis showed that increases in FD in polycultures led to greater prey suppression compared to both the mean of the component predator species, and the most effective predator species, in monocultures. Further analysis of individual traits indicated these effects are likely to be driven by broad niche differentiation and greater resource exploitation in functionally diverse predator communities. A decoupled measure of phylogenetic diversity, whereby the overlap in variation with FD was removed, was not found to be an important driver of prey suppression. Our results suggest that increasing FD in predatory invertebrates will help maximize pest control ecosystem services in agricultural ecosystems, with the potential to increase suppression above that of the most effective predator species.
The Control of the Tautomeric Equilibrium of Isocytosine by Intermolecular Interactions
Authors: Pohl Radek , Socha Ondřej , Šála Michal , Rejman Dominik , Dračínský Martin
Published: May 2018

Isocytosine has two stable tautomers, which can form a dimer with each other, stabilised by three intermolecular hydrogen bonds similar to those in the guanine–cytosine base pair. Molecules with suitable donor/acceptor hydrogen‐bonding patterns can form intermolecular complexes with one or the other isocytosine tautomer. These intermolecular interactions stabilise the selected isocytosine tautomer, leading to an increase of its relative concentration. The integration of the 1H NMR spectra acquired at various temperatures and concentrations was used for the determination of free‐energy changes of the formation of the isocytosine dimer/complex. The experimental free‐energy changes contain contributions from the formation of the isocytosine dimer/complex itself and from the rearrangement of the solvation shell. The latter contribution was estimated through a comparison of the experimental free‐energy changes with those calculated for the dimer/complex formation at the DFT level. The study demonstrates that the molecular environment can change relative tautomer stabilities, which supports the hypothesis of the involvement of rare nucleobase tautomers in the catalytic function of RNA enzymes.
The dynamic effects of sediment availability on the relationship between wind speed and dust concentration
Authors: Mockford Tom , Bullard Joanna E. , Thorsteinsson Throstur
Published: May 2018

Where sediment supply is unlimited, previous research suggests that a strong, positive relationship between wind speed and dust concentration exists at the event scale. This relationship can break down if sediment availability is limited or changes during an event. This paper explores the dynamic effects of sediment availability on the relationship between wind speed and dust concentration using data from nine high‐latitude dust events recorded in Iceland. Of these events, six showed a strong positive relationship between wind speed and dust concentration. For the remainder, the relationship breaks down periodically during the event due to changing surface moisture conditions and atmospheric humidity. Results suggest a need to understand how spatial and temporal changes in humidity, surface soil moisture, soil texture and threshold velocity interact and control sediment availability for dust emissions in all environments, including at high latitudes. Copyright © 2018 John Wiley & Sons, Ltd.
Dating of paleolandslides in western Finnish Lapland
Authors: Ojala Antti E.K. , Markovaara‐Koivisto Mira , Middleton Maarit , Ruskeeniemi Timo , Mattila Jussi , Sutinen Raimo
Published: May 2018

The dating of landslide‐buried organic materials potentially indicates non‐stationary seismicity in northern Finland attributable to the release of lithospheric stresses during and after retreat of the Scandinavian Ice Sheet. The landslide age data reveals three episodes of increased slope instability and formation of landslides, from 9000 to 11 000 cal BP, from 5000 to 6000 cal BP, and from 1000 to 3000 cal BP. While a seismogenic origin cannot be unequivocally established, we interpret that at least the early Holocene episode reflects increased seismic activity in northern Finland in association with late‐glacial and postglacial faulting. The foci of slope instabilities changes through time, implying that different segments of the postglacial fault systems were active at different times during the Holocene. We also show that the correlation of landslide ages with the surface roughness and backwall slope is complicated. The morphology of landslide scarps is significantly affected by thickness of glacial sediments, liquefaction during landslide formation, and accumulation of peat upon landslide scars and deposits, and thus, the time‐dependent erosional smoothing of the surfaces should be considered as descriptive and non‐qualitative. Copyright © 2018 John Wiley & Sons, Ltd.
A distributed density optimized scheduling function for IEEE 802.15.4e TSCH networks
Authors: Municio Esteban , Spaey Kathleen , Latré Steven
Published: May 2018

The Industrial Internet of Things is a challenge for wireless sensor networks, where ultrareliability, guaranteed performance, and ultralow‐power consumption are mandatory requirements to enable critical IoT applications. The time‐slotted channel hopping (TSCH) mode of the IEEE 802.15.4e standard is one of the most promising technologies to accomplish these requirements by yielding guaranteed performance and, simultaneously, efficiently combating external interference and multipath fading. One of the challenges in TSCH networks is to build an efficient schedule for managing the access of the nodes to the timeslots and channels. Several scheduling algorithms have been proposed. Currently, the Scheduling Function Zero SFx is one of the proposed scheduling algorithms for 6TiSCH, the ongoing standard for an IPv6‐enabled stack working over TSCH. SFx is based on random resource allocation according to the traffic demand, which makes it inadequate for large‐scale and dense deployments due to internal collisions. This paper has two main goals. First, we extensively investigate the performance of SFx for large‐scale and dense scenarios, analyze its scalability, and identify its scheduling limitations. Second, we present a new TSCH‐based scheduling function, ie, the distributed broadcast‐based scheduling (DeBraS) algorithm, a scheduling solution designed for dense deployments based on sharing scheduling information between nodes to reduce collisions proactively. We show, through extensive and large‐scale simulations, that DeBraS supports much larger densities than state‐of‐the‐art scheduling functions, outperforming the current distributed 6TiSCH algorithm SFx up to 1.61 times in terms of throughput for large network sizes, at the expense of an increase in power consumption.
Hierarchical decision model for throughput maximization in D2D‐enabled LTE‐WiFi HetNets
Authors: Gbenga‐Ilori Abiodun , Sezgin Aydin
Published: May 2018

This paper proposes a hierarchical decision model for efficient and fair coexistence of Wireless Fidelity (WiFi) and heterogeneous cellular networks with device‐to‐device (D2D) communications. The first submodel is an allocation game formulated to model the data rate gain possible through the deployment of D2D communication in cellular networks. This is to guarantee that the Long‐Term Evolution (LTE) network is optimally utilized before offloading traffic to WiFi small cells. The second submodel is a Markovian model proposed as an optimal spectrum sharing scheme that guarantees efficient spectrum utilization and interference reduction in LTE‐WiFi heterogeneous networks (HetNets). Simulation results verify that the proposed decision model not only provides a more spectrum efficient sharing scheme but also shows better network throughput while ensuring fairness in spectrum access for WiFi users.
Maximum‐likelihood synchronization and channel estimation with multiuser detection in GFDMA
Authors: Shayanfar Hamidreza , Saeedi‐Sourck Hamid , Farhang Arman , Doyle Linda E.
Published: May 2018

Accurate estimation and correction of channel distortions and carrier frequency offset (CFO) are of a great importance in any multicarrier communication system. Hence, in this paper, we propose data‐aided CFO and channel estimation techniques for both multiuser uplink and downlink of the generalized frequency division multiple access (GFDMA). Our proposed solutions jointly estimate the CFO and channel responses based on the maximum‐likelihood criterion. To simplify the implementation of the proposed estimation algorithms, we suggest a preamble composed of two similar Zadoff‐Chu training sequences in a generalized frequency division multiplexing block. It is worth mentioning that our proposed technique can estimate both integer and fractional CFO values without any limitation on the acquisition range of CFO. In the uplink phase, each user aligns its carrier frequency with the base station using the estimated CFO in the downlink. However, the CFO estimates may get outdated for the uplink transmission. Thus, residual CFOs may still remain in the received signal at the base station. While being trivial in the downlink, CFO correction is a challenging task in the uplink. Thus, we also propose a joint CFO correction and channel equalization technique for the uplink of GFDMA systems. Finally, we evaluate our proposed estimation and correction algorithms in terms of estimation mean square error and bit error rate performance through simulations.
Numerische Modellierung der Überfahrung von bestehenden U‐Bahntunneln am Beispiel des Transportsiels Wallring
Authors: Umar Ako , Blaschko Michael , Grubert Thomas
Published: May 2018

Beim Projekt Transportsiel Wallring in Hamburg sind zwei U‐Bahntunnel aus den Jahren 1967 bis 1969 mit einem querenden Rohrvortrieb DN 1800 zu überfahren. Dazu gilt es, die Standsicherheit der bestehenden Tunnelschalen, die mit Tübbingen aus Gusseisen ausgebaut sind, vorab rechnerisch zu überprüfen und ein geeignetes Konzept für die messtechnische Überwachung während des Rohrvortriebs zu entwickeln. Hierfür wird ein dreidimensionales FE‐Modell (Finite‐Elemente‐Modell) aufgebaut, mit dem die Überfahrungssituation numerisch anhand der Step‐by‐step‐Methode analysiert wird. Ebenso muss der Last‐ und Verformungszustand, der aus dem Bau der Bestandstunnel resultiert, berechnet und eingeprägt werden. Es kann gezeigt werden, dass der Rohrvortrieb unterschiedliche asymmetrische Belastungen sowie asymmetrische Bettungssituationen an den Bestandstunneln erzeugt, so dass die Standsicherheit der Streckentunnel nachzuweisen ist. An einem separaten FE‐Schalenmodell werden zusätzlich die Traglastreserven für die asymmetrische Belastung aus dem Rohrvortrieb für die Tunnelinnenschale ermittelt. Daraus resultierend können die Grenzverformungen abgeleitet werden, die als Warn‐ und Alarmwerte zur Interpretation der baubegleitenden Vermessung der Streckentunnel dienen. Die Überfahrung wurde erfolgreich ohne jegliche Überschreitung der Warn‐ und Alarmwerte und mit guter Übereinstimmung zwischen prognostizierten und gemessenen Konvergenzen der Tunnelinnenschale abgeschlossen.
Metabolomic‐based noninvasive serum test to diagnose nonalcoholic steatohepatitis: Results from discovery and validation cohorts
Authors: Mayo Rebeca , Crespo Javier , Martínez‐Arranz Ibon , Banales Jesus M , Arias Mayte , Mincholé Itziar , Aller de la Fuente Rocío , Jimenez‐Agüero Raúl , Alonso Cristina , de Luis Daniel A. , Vitek Libor , Stritesky Jan , Caballería Joan , Romero‐Gómez Manuel , Martín‐Duce Antonio , Mugüerza Huguet Jose Maria , Busteros‐Moraza José Ignacio , Idowu Michael O. , Castro Azucena , Martínez‐Chantar M. Luz , Ortiz Pablo , Bruha Radan , Lu Shelly C. , Bedossa Pierre , Noureddin Mazen , Sanyal Arun J. , Mato José M.
Published: May 2018

Nonalcoholic fatty liver disease (NAFLD) is the most common type of chronic liver disease worldwide and includes a broad spectrum of histologic phenotypes, ranging from simple hepatic steatosis or nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). While liver biopsy is the reference gold standard for NAFLD diagnosis and staging, it has limitations due to its sampling variability, invasive nature, and high cost. Thus, there is a need for noninvasive biomarkers that are robust, reliable, and cost effective. In this study, we measured 540 lipids and amino acids in serum samples from biopsy‐proven subjects with normal liver (NL), NAFL, and NASH. Using logistic regression analysis, we identified two panels of triglycerides that could first discriminate between NAFLD and NL and second between NASH and NAFL. These noninvasive tests were compared to blinded histology as a reference standard. We performed these tests in an original cohort of 467 patients with NAFLD (90 NL, 246 NAFL, and 131 NASH) that was subsequently validated in a separate cohort of 192 patients (7 NL, 109 NAFL, 76 NASH). The diagnostic performances of the validated tests showed an area under the receiver operating characteristic curve, sensitivity, and specificity of 0.88 ± 0.05, 0.94, and 0.57, respectively, for the discrimination between NAFLD and NL and 0.79 ± 0.04, 0.70, and 0.81, respectively, for the discrimination between NASH and NAFL. When the analysis was performed excluding patients with glucose levels >136 mg/dL, the area under the receiver operating characteristic curve for the discrimination between NASH and NAFL increased to 0.81 ± 0.04 with sensitivity and specificity of 0.73 and 0.80, respectively. Conclusion: The assessed noninvasive lipidomic serum tests distinguish between NAFLD and NL and between NASH and NAFL with high accuracy. (Hepatology Communications 2018;2:807‐820)
Dominant strictures in primary sclerosing cholangitis: A multicenter survey of clinical definitions and practices
Authors: Hilscher Moira B. , Tabibian James H. , Carey Elizabeth J. , Gostout Christopher J. , Lindor Keith D.
Published: May 2018

Dominant strictures (DSs) of the biliary tree occur in approximately 50% of patients with primary sclerosing cholangitis (PSC) and may cause significant morbidity. Nevertheless, the definition and management of DSs lacks consensus. We aimed to better understand current perceptions and practices regarding PSC‐associated DSs. We conducted an anonymous, 23‐question, survey‐based study wherein electronic surveys were distributed to 131 faculty in the Division of Gastroenterology and Hepatology at the three Mayo Clinic campuses (Rochester, Scottsdale, and Jacksonville) as well as the affiliated practice network. Responses were aggregated and compared, where applicable, to practice guidelines of the American Association for the Study of Liver Diseases and European Association for the Study of the Liver. A total of 54 faculty (41.2%) completed the survey, of whom 24 (44.4%) were hepatologists, 21 (38.9%) gastroenterologists, and 9 (16.7%) advanced endoscopists. One of the major study findings was that there was heterogeneity among participants' definition, evaluation, management, and follow‐up of DSs in PSC. The majority of participant responses were in accordance with societal practice guidelines, although considerable variation was noted. Conclusion: Despite the prevalence and morbidity of DSs in PSC, clinical perceptions and practices vary widely among hepatologists, gastroenterologists, and advanced endoscopists who manage these patients, even within a single health care system. Further studies are needed to address these variations, develop general and evidence‐based consensus, and increase adherence to societal guidelines. (Hepatology Communications 2018;2:836‐844)
Mixed convection inside a fluid‐porous composite cavity with centrally rotating cylinder
Authors: Malla Laxman K. , Jena Sofen K. , Mahapatra Swarup K. , Chamkha Ali J.
Published: May 2018

The mixed convection in a fluid‐porous composite medium lying inside a square cavity with a centrally rotating cylinder has been investigated in the present work. The bottom half of the cavity is filled with a porous material and the top half is filled with a clear fluid. The bottom wall of the cavity is at a higher temperature, and the top wall is at a lower temperature. The vertical walls are thermally insulated. The convection inside the cavity sets through the combined mechanisms of the thermal buoyancy force and the shearing action of the centrally rotating cylinder. The relative importance of each driving mechanism over the other is featured through the Richardson number. The Darcy–Brinkman–Forchheimer equation is used for the flow modeling in the porous medium, and a single‐domain approach is adopted for the numerical solution in the fluid‐porous composite medium. The simulation is carried out with ANSYS Fluent software, and a parametric analysis involving the Rayleigh number (), Richardson number (), and the Darcy number () is conducted showing their effects on the flow and heat transfer. The phenomena are quite interesting at higher Darcy number and Rayleigh number. The distributions of isotherms, streamlines, and vector plots are plotted, along with the local Nusselt numbers for different parameters, to explore the underlying physics of the phenomenon. The system is found stable at lower Darcy number, and the heat transfer is minimum around Ri = 10. From the numerical study, an empirical correlation for the average Nusselt number is developed as a function of the other dimensionless numbers.