bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility of Activation Energy Prediction of Gas‐Phase Reactions by Machine Learning
Authors: Choi Sunghwan , Kim Yeonjoon , Kim Jin Woo , Kim Zeehyo , Kim Woo Youn
Published: February 2018

Machine learning based on big data has emerged as a powerful solution in various chemical problems. We investigated the feasibility of machine learning models for the prediction of activation energies of gas‐phase reactions. Six different models with three different types, including the artificial neural network, the support vector regression, and the tree boosting methods, were tested. We used the structural and thermodynamic properties of molecules and their differences as input features without resorting to specific reaction types so as to maintain the most general input form for broad applicability. The tree boosting method showed the best performance among others in terms of the coefficient of determination, mean absolute error, and root mean square error, the values of which were 0.89, 1.95, and 4.49 kcal mol−1, respectively. Computation time for the prediction of activation energies for 2541 test reactions was about one second on a single computing node without using accelerators.
Ligand‐ and Metal‐Based Reactivity of a Neutral Ruthenium Diolefin Diazadiene Complex: The Innocent, the Guilty and the Suspicious
Authors: Sinha Vivek , Pribanic Bruno , de Bruin Bas , Trincado Monica , Grützmacher Hansjörg
Published: February 2018

Invited for the cover of this issue is the group of Bas de Bruin at the University of Amsterdam, Monica Trincado and Hansjörg Grützmacher at ETH Zürich. The image is inspired by Sergio Leone's spaghetti western “The Good, the Bad and the Ugly”, and matches the theme of the paper. Non‐innocent ligands not only give rise to intriguing electronic structures, but can also trigger unexpected ligand‐centered reactivity. The trop2dad molecule is a “pure‐blood” example. Read the full text of the article at 10.1002/chem.201705957.
Direct Integration of Red‐NIR Emissive Ceramic‐like AnM6Xi8Xa6 Metal Cluster Salts in Organic Copolymers Using Supramolecular Interactions
Authors: Robin Malo , Dumait Noée , Amela‐Cortes Maria , Roiland Claire , Harnois Maxime , Jacques Emmanuel , Folliot Hervé , Molard Yann
Published: February 2018

Hybrid nanomaterials made of inorganic nanocomponents dispersed in an organic host raise an increasing interest as low‐cost solution‐processable functional materials. However, preventing phase segregation while allowing a high inorganic doping content remains a major challenge, and usual methods require a functionalization step prior integration. Herein, we report a new approach to design such nanocomposite in which ceramic‐like metallic nanocluster compounds are embedded at 10 wt % in organic copolymers, without any functionalization. Dispersion homogeneity and stability are ensured by weak interactions occurring between the copolymer lateral chains and the nanocluster compound. Hybrids could be ink‐jet printed and casted on a blue LED. This proof‐of‐concept device emits in the red‐NIR area and generates singlet oxygen, O2 (1Δg), of particular interest for lights, display, sensors or photodynamic based therapy applications.
Chemie Ingenieur Technik, Band 90
Authors: Böck Barbara
Published: February 2018

No abstract.
The minimal clinically important difference of the Richmond Agitation‐Sedation Scale in patients with cancer with agitated delirium
Authors: Hui David , Hess Kenneth , Dibaj Seyedeh S. , Arthur Joseph , Dev Rony , Dalal Shalini , Reddy Suresh , Bruera Eduardo
Published: February 2018

BACKGROUND

The Richmond Agitation‐Sedation Scale (RASS) is commonly used to assess psychomotor activity; however, to the authors' knowledge, its minimal clinically important difference (MCID) has not been determined to date. The objective of the current study was to identify the MCID for RASS using 2 anchor‐based approaches.

METHODS

The current study was a secondary analysis of a randomized controlled trial to compare the effect of lorazepam versus placebo as an adjuvant to haloperidol for persistent agitation in patients with delirium. The primary outcome was change in RASS (10‐point numeric rating scale ranging from ‐5 [unarousable] to +4 [combative]) from baseline to 8 hours after treatment administration. The sensitivity‐specificity and within‐patient change methods were used to identify the MCID, with the anchor being patient comfort after the study intervention as perceived by caregivers and nurses.

RESULTS

A total of 90 patients were randomized and 58 (64%) received the study medication for restlessness/agitation (mean baseline RASS, 1.6). A total of 23 caregivers (61%) and 23 nurses (55%) perceived that the patient was more comfortable after treatment. Using the sensitivity‐specificity method, the optimal RASS reduction was ≥4 points according to both caregivers (sensitivity of 61% and specificity of 80%; area under the curve, 0.71) and nurses (sensitivity of 73% and specificity of 84%; area under the curve, 0.78). The RASS cutoff value based on the within‐patient change method was similar (‐4.2 for caregivers and ‐4.0 for nurses).

CONCLUSIONS

For patients with persistent restlessness/agitation, a reduction of ≥4 points in RASS was considered to be the MCID for both nurses and caregivers. These preliminary findings may have implications for sample size calculation and the interpretation of treatment effect in future delirium trials. Cancer 2018;124:2246‐52. © 2018 American Cancer Society.
Neural oscillations in the infralimbic cortex after electrical stimulation of the amygdala. Relevance to acute stress processing
Authors: Luque‐García Aina , Teruel‐Martí Vicent , Martínez‐Bellver Sergio , Adell Albert , Cervera‐Ferri Ana , Martínez‐Ricós Joana
Published: February 2018

The stress system coordinates the adaptive reactions of the organism to stressors. Therefore, dysfunctions in this circuit may correlate to anxiety‐related disorders, including depression. Comprehending the dynamics of this network may lead to a better understanding of the mechanisms that underlie these diseases. The central nucleus of the amygdala (CeA) activates the hypothalamic–pituitary–adrenal axis and brainstem nodes by triggering endocrine, autonomic and behavioral stress responses. The medial prefrontal cortex plays a significant role in regulating reactions to stressors, and is specifically important for limiting fear responses. Brain oscillations reflect neural systems activity. Synchronous neuronal assemblies facilitate communication and synaptic plasticity, mechanisms that cooperatively support the temporal representation and long‐term consolidation of information. The purpose of this article was to delve into the interactions between these structures in stress contexts by evaluating changes in oscillatory activity. We particularly analyzed the local field potential in the infralimbic region of the medial prefrontal cortex (IL) in urethane‐anesthetized rats after the electrical activation of the central nucleus of the amygdala by mimicking firing rates induced by acute stress. Electrical CeA activation induced a delayed, but significant, change in the IL, with prominent slow waves accompanied by an increase in the theta and gamma activities, and spindles. The phase‐amplitude coupling of both slow waves and theta oscillations significantly increased with faster oscillations, including theta‐gamma coupling and the nesting of spindles, theta and gamma oscillations in the slow wave cycle. These results are further discussed in neural processing terms of the stress response and memory formation.
Numerical study on the hemodynamics of patient‐specific carotid bifurcation using a new mesh approach
Authors: Pinto S.I.S. , Campos J.B.L.M. , Azevedo E. , Castro C.F. , Sousa L.C.
Published: February 2018

The definition of a suitable mesh to simulate blood flow in the human carotid bifurcation has been investigated. In this research, a novel mesh generation method is proposed: hexahedral cells at the center of the vessel and a fine grid of tetrahedral cells near the artery wall, in order to correctly simulate the large blood velocity gradients associated with specific locations. The selected numerical examples to show the pertinence of the novel generation method are supported by carotid ultrasound image data of a patient‐specific case. Doppler systolic blood velocities measured during ultrasound examination are compared with simulated velocities using 4 different combinations of hexahedral and tetrahedral meshes and different fluid dynamic simulators. The Lin's test was applied to show the concordance of the results. Wall shear stress–based descriptors and localized normalized helicity descriptor emphasize the performance of the new method. Another feature is the reduced computation time required by the developed methodology. With the accurate combined mesh, different flow rate partitions, between the internal carotid artery and external carotid artery, were studied. The overall effect of the partitions is mainly in the blood flow patterns and in the hot‐spot modulation of atherosclerosis‐susceptible regions, rather than in their distribution along the bifurcation.
Controlling the Sulfidation Process of Iron Nanoparticles: Accessing Iron−Iron Sulfide Core‐Shell Structures
Authors: Heift Dominikus , Lacroix Lise‐Marie , Lecante Pierre , Fazzini Pier‐Francesco , Chaudret Bruno
Published: February 2018

Iron sulfide nanocomposites have been prepared through reactions of bis[bis(trimethylsilyl)amido]iron(II) or zerovalent iron nanoparticles (NPs) with hydrogen sulfide gas. The chemical composition of these materials was analyzed by TEM, XRD, WAXS and Mössbauer measurements. Decomposition of bis[bis(trimethylsilyl)amido]iron(II) under an H2S atmosphere in the presence of palmitic acid produces thin iron sulfide nanoflakes, which seemingly consist of Fe2S2 and Fe7S8. The sulfidation of 9 nm zerovalent iron NPs with H2S yields thin nano flakes exhibiting the same iron sulfide phases and residual iron. Remarkably, treatment of slightly larger iron NPs (13 nm) with H2S (or alternatively benzylthiol) yields well‐shaped iron–iron sulfide core‐shell particles. These particles exhibit a crystalline iron core and an amorphous iron sulfide shell, which likely consists of Fe2S2, Fe7S8 and Fe1−XS. Magnetic measurements on these core‐shell particles show a decrease of the total magnetization (compared to bulk iron) coming along with the sulfidation process. Owing to the partially preserved ferromagnetic character these iron–iron sulfide core‐shell particles were found to have magnetic heating properties.
Reverse Genetics for Newcastle Disease Virus as a Vaccine Vector
Authors: Kim Shin‐Hee , Samal Siba K.
Published: February 2018

Newcastle disease virus (NDV) is an economically important pathogen in the poultry industry worldwide. Recovery of infectious NDV from cDNA using reverse genetics has made it possible to manipulate the genome of NDV. This has greatly contributed to our understanding of the molecular biology and pathogenesis of NDV. Furthermore, NDV has modular genome and accommodates insertion of a foreign gene as a transcriptional unit, thus enabling NDV as a vaccine vector against diseases of humans and animals. Avirulent NDV strains (e.g., LaSota and B1) have been commonly used as vaccine vectors. In this protocol, we have described reverse genetics of NDV to be used as a vaccine vector by exemplifying the recovery of NDV vectored avian influenza virus vaccine. Specifically, cloning and recovery of NDV expressing the hemagglutinin protein of highly pathogenic influenza virus were explained. © 2018 by John Wiley & Sons, Inc.
A proof‐of‐concept pilot randomized comparative trial of brief Internet‐based compassionate mind training and cognitive‐behavioral therapy for perinatal and intending to become pregnant women
Authors: Kelman Alex R. , Evare Benjamin S. , Barrera Alinne Z. , Muñoz Ricardo F. , Gilbert Paul
Published: February 2018

Objective

Depression is a prevalent and costly mental health problem that affects women as well as their larger communities, with substantial impacts on mother and infant during childbearing years. Face‐to‐face care has not adequately addressed this global concern due to difficulties in scaling these resources. Internet interventions, which can provide psychological tools to those lacking adequate access, show promise in filling this void.

Method

We conducted a 2‐condition proof‐of‐concept pilot randomized trial comparing brief Internet‐based cognitive behavioural therapy (CBT) and brief Internet‐based compassionate mind training (CMT) for women who are currently pregnant, became pregnant within the last year, and intend to become pregnant in the future.

Results

We found that, although CMT and CBT demonstrated near equivalence in improving affect, self‐reassurance, self‐criticism, and self‐compassion, CMT showed superiority to CBT in reducing depression and anxiety symptoms.

Conclusion

These findings provide a compelling initial argument for the use of CMT as an avenue for addressing problems associated with negative affect. Implications, limitations, and future directions along this line of research will also be discussed.
Protein Production using the Baculovirus Expression System
Authors: Irons Sarah L. , Chambers Adam C. , Lissina Olga , King Linda A. , Possee Robert D.
Published: February 2018

Baculovirus expression systems are well established as an easy and reliable way to produce high quality recombinant proteins. Baculoviruses can also be used to transduce mammalian cells, termed ‘BacMam’, with considerable potential in biomedical applications. This chapter explains the process of making a recombinant baculovirus, encompassing production of a recombinant virus by homologous recombination in insect cells, followed by amplification and titration of the virus—all steps needed before commencing gene expression and protein production. We also cover the use of small‐scale test expression to provide an initial indication of quality and protein yield. Whereas proteins expressed at high levels can be directly scaled up, more challenging proteins may require optimization of cell lines, growth conditions, or harvest times. Scale‐up and purification approaches are discussed, focusing on working with large shake cultures and use of the Wave bioreactor. © 2018 by John Wiley & Sons, Inc.
Highly Crystalline Carbon Nitride Nanosheets for Ultrahigh Photocatalytic Hydrogen Evolution
Authors: Wang Yang , Hou Xudong , Zhang Junxiang , Xu Tingting , Liu Shengjun , Liu Bo
Published: February 2018

Photocatalytic activity for H2 evolution of carbon nitrides (CNs) is very sensitive to synthetic procedures. CNs prepared under different conditions are featured with varied crystallinity and texture, which in turn rule over their intrinsic electronic and chemical states as well as band energy level, thus determining their photocatalytic activities towards H2 evolution. In comparison with CN obtained by polymerization of melamine in air (CN‐a), CN prepared in an outgassed and sealed tube (CN‐s) exhibits much improved photocatalytic activity towards H2 evolution, increasing from 90 to 594 μmol/g/h under visible light. Exfoliation of CN‐s into ultrathin CN nanosheets (CN‐n) further leads to an ultrahigh photocatalytic H2 evolution rate, rising to 2570 μmol/g/h, which is among the highest photocatalytic activities for CNs reported to date. Detailed characterization reveals that the superior photocatalytic performance originates from the high crystallinity, extended visible‐light absorption, efficient separation of photoexcited electron‐hole pairs, enhanced electron delocalization, as well as increased active sites in CNs. This study uncovers the positive effects over photocatalytic activity of CNs and, hence, could provide new inspiration towards CN syntheses for improved photocatalytic performance.
Determination of Mycophenolic Acid and Mycophenolic Acid Glucuronide Using Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS)
Authors: Garg Uttam , Munar Ada , Frazee Clinton
Published: February 2018

Mycophenolic acid (MPA) is an immunosuppressant that is used in renal, liver, and heart transplantation. Due to its narrow therapeutic range, monitoring of MPA levels is essential to avoid toxicity and organ rejection. Although immunoassays are available for the determination of MPA, due to their higher specificity, mass spectrometry methods are preferred. In this unit, we describe a liquid chromatography tandem mass spectrometry (LC/MS/MS) method utilizing positive ionization electrospray and multiple reaction monitoring (MRM) for the quantification of levels of MPA and its conjugate MPA glucuronide (MPAG). Blood collected in a plain, EDTA, or heparin‐containing tube is centrifuged to separate the serum or plasma. Proteins are precipitated using a solution containing zinc sulfate and acetonitrile that has been spiked with deuterated internal standards. The resulting protein‐free supernatant is injected into the LC/MS/MS system for analysis. The chromatography involves the use of a C18 column and ammonium acetate/water/formic acid and ammonium acetate/methanol/formic acid mobile phases. Quantification of MPA and MPAG levels is achieved by comparing the MRM peak area ratios of analytes and internal standards, consisting of specific precursor/product pairs, with those of calibrators at various concentrations. Calibration curves are constructed from the MRM peak area ratios of calibrators and internal standards versus concentration. © 2018 by John Wiley & Sons, Inc.
Synchronous and asynchronous operation in dual‐band VCOs
Authors: Buonomo Antonio , Lo Schiavo Alessandro
Published: February 2018

We present a comprehensive analysis of the asynchronous and synchronous operations of fourth‐order oscillators underlying dual‐band voltage‐controlled oscillators. We analyze the occurrence of the self‐synchronization phenomenon (internal resonance) if the ratio of normal frequencies is nearly a ratio of integers, which is 1:3 in the cubic approximation of the nonlinear oscillator characteristic. In this case, we have the simultaneous presence of 2 oscillations with a frequency ratio 1:3, which was demonstrated to be very effective in generating high‐frequency signals in mm‐wave range. The analysis is carried out by developing an analytical approach relying on the averaging principle, as it follows the van der Pol method. The averaging equations, derived simply by a quadrature, allow us to analyze easily the stationary and transient oscillations, and their stability, both in asynchronous and synchronous operations. Expressions for the amplitudes and phases were derived for a cubic nonlinearity and verified by Spice simulations.
Universal cell type identifier based on number theory
Authors: Cosma Antonio
Published: February 2018

Cell type classification and handling is a key issue for understanding biological systems. The advent of high multiplexing technologies increased the complexity of the classification process and new tools are needed to support the organization of this knowledge. I propose a classification based on both prime numbers and the fundamental theorem of arithmetic. As a not limiting example, I show the application of this method to unambiguously define any existing cell type using the CD nomenclature established by the Human Leukocyte Differentiation Antigens Workshops. This system allows for the unique identification of any possible combination of markers hence any cell population without previous knowledge and without the need to increment the system. This method can be the future basis of any database and ontology system dealing with cell types and beyond the biological field applies to the description of any entity characterized by a list of discrete qualities. © 2018 International Society for Advancement of Cytometry
Multicast beamforming with LOS self‐interference cancellation in full‐duplex wireless communications
Authors: Wu Fei , Ma Wanzhi , Liu Donglin
Published: February 2018

In this paper, we consider a full‐duplex system where the access point installed with multiple transmitting antennas and a single receiving antenna serves several single‐antenna remote users. In this case, there are 2 kinds of interferences. One is the near‐field self‐interference (SI) induced by the simultaneous transmitting and receiving over the same band, and the other is the cochannel interference caused by the multicast broadcasting in the same band. A problem of near‐field SI cancellation and the cochannel interference suppression using transmit beamforming is formulated at the access point. This problem of ensuring the near‐field line‐of‐sight SI suppression benchmark and maximizing the minimum received signal‐to‐interference‐plus‐noise ratio of remote receivers leads to a nonconvex NP‐hard optimization. Furthermore, we introduce a semidefinite relaxation technique coupled with linear program power adjustment and an outer bisection search loop to transform the problem into a convex optimization. This can be solved by the modern interior point methods. Simulations show that the proposed method is feasible even when the local receive antenna in near‐field and the remote receivers in far field are in the same direction.
Big solutions for small groups in health science programs
Authors: Sullivan Linda , Meeks Lisa M.
Published: February 2018

Small group learning and instructional design play a significant role in the educational process for health education students. Small groups in health science curricula provide learners with opportunities to engage as a team, learn through observation and collaboration, hone communication skills, develop higher‐order thinking, synthesize information, and develop group consensus. Team‐based care (the standard in many health fields) necessitates that learners acquire these essential skills prior to entering the clinic. In health science education, faculty members present the “case” and facilitate small groups. The groups then engage in deductive reasoning to arrive at a diagnosis, and in some cases a treatment plan.
Prevalence of early and late prematurity is similar among pediatric type 1 diabetes patients and the general population
Authors: Adar Adi , Shalitin Shlomit , Eyal Ori , Loewenthal Neta , Pinhas‐Hamiel Orit , Levy Milana , Dally‐Gottfried Orna , Landau Zohar , Zung Amnon , Levy‐Khademi Floris , Zangen David , Tenenbaum‐Rakover Yardena , Rachmiel Marianna
Published: February 2018

Background

The incidence of type 1 diabetes mellitus (T1DM) has increased in recent decades, as has the incidence of preterm births (<37 weeks). We aimed to evaluate and compare the prevalence of prematurity and early prematurity (<34 weeks) and birth season variability among T1DM and non‐T1DM children.

Methods

A nationwide cross‐sectional study was conducted, with linkage of data from 13 paediatric diabetes centers and Israeli National Registries, including T1DM patients and general non‐T1DM population, born during 2000 to 2013. Gathered data included ethnicity, gender, birth week, weight, and season. The prevalence of prematurity and birth season were compared with the general population birth registry using Pearson Chi‐square test.

Results

The study population included 1452 T1DM patients, 52.7% males, and 2 138 668 subjects in the general non‐T1DM population, 51.2% males. The prevalence of late and early prematurity was similar between groups (6.1% and 2.2% in the T1DM group vs 5.6% and 2.0% in the general non‐T1DM group, P = 0.25 and P = 0.38, respectively). OR for prematurity among T1DM patients was 1.15 (0.95‐1.39), P = 0.16. No difference in birth season was demonstrated between preterm and term, in T1DM and general non‐T1DM populations. Ethiopian descent was more prevalent among T1DM patients compared with the non‐T1DM population, in both term and preterm born.

Conclusions

This is the largest population‐based study, and the first in the Middle East geographical area, indicating that prematurity, including early prematurity, is not associated with T1DM during childhood.

The study was registered at https://clinicaltrials.gov/: NCT02929953.
Implicit attitudes toward eating stimuli differentiate eating disorder and non‐eating disorder groups and predict eating disorder behaviors
Authors: Smith April R. , Forrest Lauren N. , Velkoff Elizabeth A. , Ribeiro Jessica D. , Franklin Joseph
Published: February 2018

Objective

The current study tested whether people with and without eating disorders (EDs) varied in their implicit attitudes toward ED‐relevant stimuli. Additionally, the study tested whether implicit evaluations of ED‐relevant stimuli predicted ED symptoms and behaviors over a 4‐week interval.

Method

Participants were people without EDs (N = 85) and people seeking treatment for EDs (N = 92). All participants completed self‐report questionnaires and a version of the affect misattribution procedure (AMP) at baseline. The AMP indexed implicit evaluations of average body stimuli, eating stimuli, and ED‐symptom stimuli. Participants with EDs completed weekly follow‐up measures of ED symptoms and behaviors for 4 weeks.

Results

Contrary to predictions, the anorexia nervosa (AN) group did not differ from the no ED group on implicit attitudes toward ED‐symptom stimuli, and the bulimia nervosa (BN) group had less positive implicit attitudes toward ED‐symptom stimuli relative to the no ED group. In line with predictions, people with AN and BN had more negative implicit attitudes toward average body and eating stimuli relative to the no ED group. In addition, among the ED group more negative implicit attitudes toward eating stimuli predicted ED symptoms and behaviors 4 weeks later, over and above baseline ED symptoms and behaviors.

Discussion

Taken together, implicit evaluations of eating stimuli differentiated people with AN and BN from people without EDs and longitudinally predicted ED symptoms and behaviors. Interventions that increase implicit liking of eating‐related stimuli may reduce ED behaviors.
Spatially explicit modeling and prediction of shrub cover increase near Umiujaq, Nunavik
Authors: Lemay Marc‐André , Provencher‐Nolet Laurence , Bernier Monique , Lévesque Esther , Boudreau Stéphane
Published: February 2018

A circumpolar increase in shrub growth and cover has been underway in Arctic and subarctic ecosystems for the last few decades, but there is considerable spatial heterogeneity in this shrubification process. Although topography, hydrology, and edaphic factors are known to influence shrubification patterns, a better understanding of the landscape‐scale factors driving this phenomenon is needed to accurately predict its impacts on ecosystem function. In this study, we generated land cover change models in order to identify variables driving shrub cover increase near Umiujaq (Québec, Canada). Using land cover maps from 1990/1994 and 2010, we modeled observed changes using two contrasting conceptual approaches: binomial modeling of transitions to shrub dominance and multinomial modeling of all land cover transitions. Models were used to generate spatially explicit predictions of transition to shrub dominance in the near future as well as long‐term predictions of the abundance of different land cover types. Model predictions were validated using both field data and current Landsat‐derived trends of normalized difference vegetation index (NDVI) increase in the region in order to assess their consistency with observed patterns of change. We found that both variables related to topography and to vegetation were useful in modeling land cover changes occurring near Umiujaq. Shrubs tended to preferentially colonize low‐elevation areas and moderate slopes, while their cover was more likely to increase in the vicinity of existing shrub patches. Deterministic realizations of the spatially explicit models of land cover change had a good predictive capability, although they performed better at predicting the proportion of different cover types than at predicting the precise location of the changes. Binomial models performed as well as multinomial models, indicating that neglecting land cover changes other than shrubification does not result in decreased prediction accuracy. The predicted probabilities of shrub increase in the region were consistent with patterns of change inferred from field data, but only partly supported by recent local increases in NDVI. Our findings increase the current understanding of the factors driving shrubification, while warranting further research on its impacts on ecosystem function and on the link between land cover changes and shifts in remotely sensed vegetation indices.
Predators mediate above‐ vs. belowground herbivory in a salt marsh crab
Authors: Vu Huy D. , Pennings Steven C.
Published: February 2018

Predators can significantly affect prey by removing prey individuals and by changing prey behavior. The tradeoff between foraging behavior and predation risk may result in a trophic cascade that can have important effects on ecosystem processes. For herbivores that can feed both above‐ and belowground, it is likely that predation risk affects the location of feeding. We tested whether two species of predatory marsh crabs affected feeding behavior of the herbivorous crab, Sesarma reticulatum. We found that predatory crabs could kill or injure Sesarma and that Sesarma did less damage to its food plant Spartina alterniflora in the presence of the more dangerous predator. Sesarma prefers to feed on and grows better on belowground rhizomes than aboveground leaves; however, the costs of digging burrows to access rhizomes lead to higher mortality if it is the only diet option. The location of feeding did not affect total biomass of S. alterniflora. For Sesarma, a choice in feeding location allows the crabs the behavioral flexibility to balance the risks of predation, the nutritional benefit of feeding belowground, and the survival costs of belowground feeding. Similar tradeoffs are likely to increase the success of other herbivores that can feed both above‐ and belowground.
Monitoring pigment‐driven vegetation changes in a low‐Arctic tundra ecosystem using digital cameras
Authors: Beamish Alison L. , Coops Nicholas C. , Hermosilla Txomin , Chabrillat Sabine , Heim Birgit
Published: February 2018

Arctic vegetation phenology is a sensitive indicator of a changing climate, and rapid assessment of vegetation status is necessary to more comprehensively understand the impacts on foliar condition and photosynthetic activity. Airborne and space‐borne optical remote sensing has been successfully used to monitor vegetation phenology in Arctic ecosystems by exploiting the biophysical and biochemical changes associated with vegetation growth and senescence. However, persistent cloud cover and low sun angles in the region make the acquisition of high‐quality temporal optical data within one growing season challenging. In the following study, we examine the capability of “near‐field” remote sensing technologies, in this case digital, true‐color cameras to produce surrogate in situ spectral data to characterize changes in vegetation driven by seasonal pigment dynamics. Simple linear regression was used to investigate relationships between common pigment‐driven spectral indices calculated from field‐based spectrometry and red, green, and blue (RGB) indices from corresponding digital photographs in three dominant vegetation communities across three major seasons at Toolik Lake, North Slope, Alaska. We chose the strongest and most consistent RGB index across all communities to represent each spectral index. Next, linear regressions were used to relate RGB indices and extracted leaf‐level pigment content with a simple additive error propagation of the root mean square error. Results indicate that the green‐based RGB indices had the strongest relationship with chlorophyll a and total chlorophyll, while a red‐based RGB index showed moderate relationships with the chlorophyll to carotenoid ratio. The results suggest that vegetation color contributes strongly to the response of pigment‐driven spectral indices and RGB data can act as a surrogate to track seasonal vegetation change associated with pigment development and degradation. Overall, we find that low‐cost, easy‐to‐use digital cameras can monitor vegetation status and changes related to seasonal foliar condition and photosynthetic activity in three dominant, low‐Arctic vegetation communities.
Sequential Tether‐Directed Synthesis of Pentakis‐Adducts of C60 with a Mixed [3:2] Octahedral Addition Pattern
Authors: Maxouti Katerina L. , Hirsch Andreas
Published: February 2018

The design of a novel concept for the synthesis of [3:2] pentakis‐adducts of fullerene C60 is presented. A sequential tether‐directed, remote functionalization approach is introduced for the construction of the pentakis‐adducts. This fullerene derivative embellished with two different addends in two different directions can be considered as a valuable tecton for further functionalization. The stepwise cyclopropanation of C60 with a macrocyclic tris‐malonate and a bis(β‐keto ester) yielded the corresponding pentakis‐adduct with an incomplete octahedral addition pattern. This reaction sequence gave access to two pairs of enantiomers that were easily separated by column chromatography on an achiral stationary phase and subsequently characterized.
α‐Hydroxy‐Tetrazoles as Latent Ethynyl Moieties: A Mechanistic Investigation
Authors: Quinodoz Pierre , Wright Karen , Drouillat Bruno , Kletskii Mikhail E. , Burov Oleg N. , Lisovin Anton. V. , Couty François
Published: February 2018

This article focuses on the dehydration of α‐hydroxy‐tetrazoles, leading to tetraazafulvenes and then to vinylic carbenes that rearrange into ethynyl moieties through the Fritsch–Buttenberg–Wiechell rearrangement. Each step of this sequence was scrutinized, either by examination of the substrate and/or dehydrating agent scope, or through AM1 calculations, in order to understand the limiting step of this process. This underrated transformation appears to be a viable alternative to existing methods used for transforming aldehydes into alkynes.
Advanced biofuel production via gasification – lessons learned from 200 man‐years of research activity with Chalmers’ research gasifier and the GoBiGas demonstration plant
Authors: Thunman Henrik , Seemann Martin , Berdugo Vilches Teresa , Maric Jelena , Pallares David , Ström Henrik , Berndes Göran , Knutsson Pavleta , Larsson Anton , Breitholtz Claes , Santos Olga
Published: February 2018

This paper presents the main experiences gained and conclusions drawn from the demonstration of a first‐of‐its‐kind wood‐based biomethane production plant (20‐MW capacity, 150 dry tonnes of biomass/day) and 10 years of operation of the 2–4‐MW (10–20 dry tonnes of biomass/day) research gasifier at Chalmers University of Technology in Sweden. Based on the experience gained, an elaborated outline for commercialization of the technology for a wide spectrum of applications and end products is defined. The main findings are related to the use of biomass ash constituents as a catalyst for the process and the application of coated heat exchangers, such that regular fluidized bed boilers can be retrofitted to become biomass gasifiers. Among the recirculation of the ash streams within the process, presence of the alkali salt in the system is identified as highly important for control of the tar species. Combined with new insights on fuel feeding and reactor design, these two major findings form the basis for a comprehensive process layout that can support a gradual transformation of existing boilers in district heating networks and in pulp, paper and saw mills, and it facilitates the exploitation of existing oil refineries and petrochemical plants for large‐scale production of renewable fuels, chemicals, and materials from biomass and wastes. The potential for electrification of those process layouts are also discussed. The commercialization route represents an example of how biomass conversion develops and integrates with existing industrial and energy infrastructures to form highly effective systems that deliver a wide range of end products. Illustrating the potential, the existing fluidized bed boilers in Sweden alone represent a jet fuel production capacity that corresponds to 10% of current global consumption.
Open outcry versus electronic trading: Tests of market efficiency on crude palm oil futures
Authors: Snaith Stuart , Kellard Neil M. , Ahmad Norzalina
Published: February 2018

Given the widespread transfer of trading to electronic platforms we ask whether such trading is more efficient than open outcry. Examining the Crude Palm Oil (CPO) market from 1995:06 to 2008:07, our findings, derived from a novel threshold autoregressive relative efficiency measure, are that efficiency is conditional on: (i) volatility; (ii) the maturity of the futures contract; and (iii) the market trading system. Specifically, when volatility is high, open outcry is superior for shorter maturities and electronic trading for longer maturities. These results suggest an efficiency skew and that there may be benefits to the coexistence of trading mechanisms.
Geoheritages in the Qinling Orogenic Belt of China: Features and comparative analyses
Authors: Yang Wangtun , Yan Ying , Zhang Yang , Guo Wei , Zha Fangyong
Published: February 2018

The Qinling Orogenic Belt is a typical composite continental orogenic belt in China. The Qinling Mountains is not only a natural demarcation that separates China into a southern part and a northern part, in terms of Qinling Orogenic Belt's geography, climate, organisms, and river systems, but also forms a cultural boundary between the Yellow River Civilization to the north and the Yangtze River Civilization to the south. The Xi'an Qinling Zhongnanshan World Geopark is situated in the major portion of the collision zone between the South China and North China plates, which is also a typical section of the Qinling Orogenic Belt. It has been the focus of great attention for its long history of geological evolution, intensive tectonism, various rock types, unique strata, frequent magmatism, and abundant geological heritage sites. This paper clarifies the regional geological background of the Qinling Zhongnanshan World Geopark in 3 aspects, that is, the regional geological setting, regional evolution, and regional strata. With an integrated analysis and classification, the paper describes the main features of geological relics and geological remains of scientific significance in the geopark, on the basis of an investigation and systematic analysis for the geological relic resources of the world geopark. Compared with the geosites in other world geoparks, the sites in the Zhongnanshan area are particularly distinctive, even unique.
Detrital zircon U–Pb ages, Hf isotopic constraints, and trace element analysis of Upper Cretaceous–Neogene sedimentary units in the Western Nepal Himalaya: Implications for provenance changes and India–Asia collision
Authors: Baral Upendra , Lin Ding , Chamlagain Deepak , Qasim Muhammad , Paudayal Khum N. , Neupane Bhupati
Published: February 2018

The present study integrates detrital zircon U–Pb–Hf isotopic analysis from 13 sandstone samples from an Upper Cretaceous–Miocene sedimentary sequence in Nepal Himalaya to determine their provenance. These sequences constrain a shifting of provenance from south to north. The U–Pb ages from Upper Cretaceous–Palaeocene strata (Amile Formation) mainly cluster between ~1,860 and 1,400 Ma with a peak at ~1,630 Ma and an absence of grains younger than the Palaeoproterozoic (1,400 Ma) age. The detritus yielded positive detrital zircon ƐHf (t) values (as high as +10). However, the detrital zircon U–Pb ages from Eocene–Miocene sequence cluster at ~500–650, ~700–900, ~1,600–1,850, and ~2,500 Ma, and in addition, they have both positive and negative ƐHf (t) values (+11 to −25). This finding further elucidates that the detritus in the Amile Formation was entirely sourced from India, which changed following the time of the Bhainskati Formation deposition, to a mixture of both Asian and Indian affinities (the Himalayan region). This change in source region marks the possible time of the India–Asia collision during this transition phase, that is, Late Palaeocene–Earliest Eocene.
Glioma infiltration and extracellular matrix: key players and modulators
Authors: Ferrer Valéria Pereira , Moura Neto Vivaldo , Mentlein Rolf
Published: February 2018

An outstanding characteristic of gliomas is their infiltration into brain parenchyma, a property that impairs complete surgical resection; consequently, these tumors might recur, resulting in a high mortality rate. Gliomas invade along preferential routes, such as those along white matter tracts and in the perineuronal and perivascular spaces. Brain extracellular components and their partners and modulators play a crucial role in glioma cell invasion. This review presents an extensive survey of the literature, showing how the brain extracellular matrix (ECM) is modulated during the glioma infiltration process. We explore aspects of ECM interaction with glioma cells, reviewing the main glycosaminoglycans, glycoproteins and proteoglycans. We discuss the roles of ECM‐binding proteins, including CD44, RHAMM, integrins and axonal guidance molecules, and highlight the role of proteases and glycosidases in glioma infiltration; in binding and release chemokines, cytokines and growth factors;and in generating new bioactive ECM fragments. We also consider the roles of cytoskeletal signaling, angiogenesis, miRNAs and the glial‐to‐mesenchymal transition linked to glioma invasion. We closely discuss therapeutic approaches based on the modulation of the extracellular matrix, targeting the control of glioma infiltration, its relative failure in clinical trials, and potential means to overcome this difficulty.
Semaphorin4A and H‐ferritin utilize Tim‐1 on human oligodendrocytes: A novel neuro‐immune axis
Authors: Chiou Brian , Lucassen Elisabeth , Sather Michael , Kallianpur Asha , Connor James
Published: February 2018

Deficiency of trophic factors relating to the survival of oligodendrocytes, combined with direct interactions with the immune system, are favored paradigms that are increasingly implicated in demyelinating diseases of the central nervous system. We and others have previously shown that Sema4A and H‐ferritin interact through the T‐cell immunoglobulin and mucin domain (Tim‐2) receptor in mice. H‐ferritin has been identified as the iron delivery protein for oligodendrocytes, whereas Sema4A causes a direct cytotoxic effect. However, the expression of Tim‐2 has not been detected in humans. Here, we demonstrate that, similar to rodents, human oligodendrocytes undergo apoptosis when exposed to Sema4A and take up H‐ferritin for meeting iron requirements and that these functions are mediated via the Tim‐1 receptor. Moreover, we also demonstrate the ability of H‐ferritin to block Sema4A‐mediated cytotoxicity. Furthermore, we show in a series of pilot studies that Sema4A is detectable in the CSF of multiple sclerosis patients and HIV‐seropositive persons and can induce oligodendrocyte cell death. Together, these results identify a novel iron uptake mechanism for human oligodendrocytes and a connection between oligodendrocytes and the immune system.
Minimum spanning tree analysis of the human connectome
Authors: van Dellen Edwin , Sommer Iris E. , Bohlken Marc M. , Tewarie Prejaas , Draaisma Laurijn , Zalesky Andrew , Di Biase Maria , Brown Jesse A. , Douw Linda , Otte Willem M. , Mandl René C.W. , Stam Cornelis J.
Published: February 2018

One of the challenges of brain network analysis is to directly compare network organization between subjects, irrespective of the number or strength of connections. In this study, we used minimum spanning tree (MST; a unique, acyclic subnetwork with a fixed number of connections) analysis to characterize the human brain network to create an empirical reference network. Such a reference network could be used as a null model of connections that form the backbone structure of the human brain. We analyzed the MST in three diffusion‐weighted imaging datasets of healthy adults. The MST of the group mean connectivity matrix was used as the empirical null‐model. The MST of individual subjects matched this reference MST for a mean 58%–88% of connections, depending on the analysis pipeline. Hub nodes in the MST matched with previously reported locations of hub regions, including the so‐called rich club nodes (a subset of high‐degree, highly interconnected nodes). Although most brain network studies have focused primarily on cortical connections, cortical–subcortical connections were consistently present in the MST across subjects. Brain network efficiency was higher when these connections were included in the analysis, suggesting that these tracts may be utilized as the major neural communication routes. Finally, we confirmed that MST characteristics index the effects of brain aging. We conclude that the MST provides an elegant and straightforward approach to analyze structural brain networks, and to test network topological features of individual subjects in comparison to empirical null models.
Theta frequency decreases throughout the hippocampal formation in a focal epilepsy model
Authors: Kilias Antje , Häussler Ute , Heining Katharina , Froriep Ulrich P. , Haas Carola A. , Egert Ulrich
Published: February 2018

Mesial temporal lobe epilepsy is characterized by focal, recurrent spontaneous seizures, sclerosis and granule cell dispersion (GCD) in the hippocampal formation. Changes in theta rhythm properties have been correlated with the severity of hippocampal restructuring and were suggested as a cause of memory deficits accompanying epilepsy. For severe sclerosis, it has even been questioned whether theta band oscillations persist. We asked how theta oscillations change with graded restructuring along the longitudinal hippocampal axis and whether these changes correlate with the overall severity of temporal lobe epilepsy. We recorded local field potentials in the medial entorhinal cortex and along the septo‐temporal axis of the dentate gyrus at sites with different degrees of GCD in freely behaving epileptic mice. Theta frequency was decreased at all recording positions throughout the dentate gyrus and in the medial entorhinal cortex, irrespective of the extent of GCD or the rate of severe epileptic events. The frequency reduction by up to 1.7 Hz, corresponding to 1/3 octaves within the theta range, was present during rest, exploration and running. Despite the frequency reduction, theta oscillations remained coherent across the hippocampal formation and were modulated by running speed as in controls. The reduction in theta frequency thus is likely not a consequence of the local restructuring but rather a global phenomenon affecting the hippocampal formation as a whole.