bluuebunny/crossref_metadata_2025 huggingface dataset:
Methyl Internal Rotation in the Microwave Spectrum of o‐Methyl Anisole
Authors: Ferres Lynn , Mouhib Halima , Stahl Wolfgang , Nguyen Ha Vinh Lam
Published: May 2017

The microwave spectrum of o‐methyl anisole (2‐methoxytoluene), CH3OC6H4CH3, has been measured by using a pulsed molecular jet Fourier transform microwave spectrometer operating in the frequency range 2–26.5 GHz. Conformational analysis using quantum chemical calculations at the MP2/6–311++G(d,p) level of theory yields only one stable conformer with a Cs structure, which was assigned in the experimental spectrum. A–E splittings due to the internal rotation of the ring methyl group could be resolved and the barrier to internal rotation was determined to be 444.05(41) cm−1. The experimentally deduced molecular parameters such as rotational and centrifugal distortion constants as well as the torsional barrier of the ring methyl group are in agreement with the calculated values.
Rational Design of Stable Dianions by Functionalizing Polycyclic Aromatic Hydrocarbons
Authors: Zhong Mingmin , Zhou Jian , Jena Puru
Published: May 2017

Using density functional theory, we have carried out a systematic study of the stability and electronic properties of neutral and multiply charged molecules BnC10‐nX8 (n=0, 1, 2; X=H, F, CN). Our main objective is to explore if the replacements of core C atoms and/or H atoms in naphthalene (C10H8) can enhance the stability of their dianions. Indeed, we find that the dianions of BnC10‐n(CN)8 are more stable than their monoanions with energies of 0.61 eV, 0.57 eV, and 1.97 eV for n=0, 1, 2, respectively. In addition, polycyclic aromatic hydrocarbons become stable as dianions only when H atoms are substituted by more electronegative species. Thus, a rational design approach by tailoring composition and ligands can lead to a new class of organic molecules that are capable of carrying multiple charges.
The Bound Structures of 17β‐Estradiol‐Binding Aptamers
Authors: Hilder Tamsyn A. , Hodgkiss Justin M.
Published: May 2017

DNA aptamers can exhibit high affinity and selectivity towards their targets, but the aptamer–target complex structures are rarely available from crystallography and often difficult to elucidate. This is particularly true of small molecule targets, including 17β‐estradiol (E2), which is becoming one of the most widely encountered endocrine‐disrupting chemicals in the environment. Using molecular dynamics simulations, we demonstrate that E2 binds to a thymine loop region common to all E2‐specific aptamers in the literature. Analyzing these structures allows us to design new E2 binding sequences. As well as illuminating the essential sequence and structural factors for generating specificity for E2, we demonstrate the effectiveness of molecular dynamics simulations for aptamer science.
Renal Effects of SGLT‐2 Inhibitors and Other Anti‐diabetic Drugs: Clinical Relevance and Potential Risks
Authors: Lioudaki E , Whyte M , Androulakis ES , Stylianou KG , Daphnis EK , Ganotakis ES
Published: May 2017

Type 2 diabetes mellitus (T2DM) is a metabolic disease affecting an increasing percentage of general population worldwide. Patients with T2DM are frequently characterized by impaired renal function, primarily as a result of diabetic kidney injury, but also by other contributing factors, such as hypertension, atherosclerosis, and medications. Sodium‐glucose cotransporter (SGLT)‐2 inhibitors have emerged as a new, promising class of antidiabetic agents with actions that seem to extend beyond their hypoglycemic effect.
Embryonic development of the annual killifish Austrofundulus limnaeus: An emerging model for ecological and evolutionary developmental biology research and instruction
Authors: Podrabsky Jason E. , Riggs Claire L. , Romney Amie L. , Woll S. Cody , Wagner Josiah T. , Culpepper Kristin M. , Cleaver Timothy G.
Published: May 2017

Background: Austrofundulus limnaeus is an annual killifish from the Maracaibo basin of Venezuela. Annual killifishes are unique among vertebrates in their ability to enter into a state of dormancy at up to three distinct developmental stages termed diapause I, II, and III. These embryos are tolerant of a wide variety of environmental stresses and develop relatively slowly compared with nonannual fishes. Results: These traits make them an excellent model for research on interactions between the genome and the environment during development, and an excellent choice for developmental biology laboratories. Furthermore, A. limnaeus is relatively easy to maintain in a laboratory setting and has a high fecundity, making it an excellent candidate as an emerging model for studies of development, and for defining the limits of developmental buffering in vertebrates. Conclusions: This study reports for the first time on the detailed development of A. limnaeus and provides a photographic and illustrated atlas of embryos on the two developmental trajectories possible in this species. Developmental Dynamics 246:779–801, 2017. © 2017 Wiley Periodicals, Inc.
Pollution‐tolerant invertebrates enhance greenhouse gas flux in urban wetlands
Authors: Mehring Andrew S. , Cook Perran L. M. , Evrard Victor , Grant Stanley B. , Levin Lisa A.
Published: May 2017

One of the goals of urban ecology is to link community structure to ecosystem function in urban habitats. Pollution‐tolerant wetland invertebrates have been shown to enhance greenhouse gas (GHG) flux in controlled laboratory experiments, suggesting that they may influence urban wetland roles as sources or sinks of GHG. However, it is unclear if their effects can be detected in highly variable conditions in a field setting. Here we use an extensive data set on carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) flux in sediment cores (n = 103) collected from 10 urban wetlands in Melbourne, Australia during summer and winter in order to test for invertebrate enhancement of GHG flux. We detected significant multiplicative enhancement effects of temperature, sediment carbon content, and invertebrate density on CH4 and CO2 flux. Each doubling in density of oligochaete worms or large benthic invertebrates (oligochaete worms and midge larvae) corresponded to ~42% and ~15% increases in average CH4 and CO2 flux, respectively. However, despite exceptionally high densities, invertebrates did not appear to enhance N2O flux. This was likely due to fairly high organic carbon content in sediments (range 2.1–12.6%), and relatively low nitrate availability (median 1.96 μmol/L NO3−‐N), which highlights the context‐dependent nature of community structural effects on ecosystem function. The invertebrates enhancing GHG flux in this study are ubiquitous, and frequently dominate faunal communities in impaired aquatic ecosystems. Therefore, invertebrate effects on CO2 and CH4 flux may be common in wetlands impacted by urbanization, and urban wetlands may make greater contributions to the total GHG budgets of cities if the negative impacts of urbanization on wetlands are left unchecked.
Arbuscular mycorrhizal colonization has little consequence for plant heavy metal uptake in contaminated field soils
Authors: Dietterich Lee H. , Gonneau Cédric , Casper Brenda B.
Published: May 2017

The factors affecting plant uptake of heavy metals from metalliferous soils are deeply important to the remediation of polluted areas. Arbuscular mycorrhizal fungi (AMF), soil‐dwelling fungi that engage in an intimate exchange of nutrients with plant roots, are thought to be involved in plant metal uptake as well. Here, we used a novel field‐based approach to investigate the effects of AMF on plant metal uptake from soils in Palmerton, Pennsylvania, USA contaminated with heavy metals from a nearby zinc smelter. Previous studies often focus on one or two plant species or metals, tend to use highly artificial growing conditions and metal applications, and rarely consider metals’ effects on plants and AMF together. In contrast, we examined both direct and AMF‐mediated effects of soil concentrations on plant concentrations of 8–13 metals in five wild plant species sampled across a field site with continuous variation in Zn, Pb, Cd, and Cu contamination. Plant and soil metal concentration profiles were closely matched despite high variability in soil metal concentrations even at small spatial scales. However, we observed few effects of soil metals on AMF colonization, and no effects of AMF colonization on plant metal uptake. Manipulating soil chemistry or plant community composition directly may control landscape‐level plant metal uptake more effectively than altering AMF communities. Plant species identities may serve as highly local indicators of soil chemical characteristics.
Conservation of wildlife populations: factoring in incremental disturbance
Authors: Stewart Abbie , Komers Petr E.
Published: May 2017

Progressive anthropogenic disturbance can alter ecosystem organization potentially causing shifts from one stable state to another. This potential for ecosystem shifts must be considered when establishing targets and objectives for conservation. We ask whether a predator–prey system response to incremental anthropogenic disturbance might shift along a disturbance gradient and, if it does, whether any disturbance thresholds are evident for this system. Development of linear corridors in forested areas increases wolf predation effectiveness, while high density of development provides a safe‐haven for their prey. If wolves limit moose population growth, then wolves and moose should respond inversely to land cover disturbance. Using general linear model analysis, we test how the rate of change in moose (Alces alces) density and wolf (Canis lupus) harvest density are influenced by the rate of change in land cover and proportion of land cover disturbed within a 300,000 km2area in the boreal forest of Alberta, Canada. Using logistic regression, we test how the direction of change in moose density is influenced by measures of land cover change. In response to incremental land cover disturbance, moose declines occurred where <43% of land cover was disturbed; in such landscapes, there were high rates of increase in linear disturbance and wolf density increased. By contrast, moose increases occurred where >43% of land cover was disturbed and wolf density declined. Wolves and moose appeared to respond inversely to incremental disturbance with the balance between moose decline and wolf increase shifting at about 43% of land cover disturbed. Conservation decisions require quantification of disturbance rates and their relationships to predator–prey systems because ecosystem responses to anthropogenic disturbance shift across disturbance gradients.
Truffle biogeography—A case study revealing ecological niche separation of different Tuber species
Authors: Gryndler Milan , Šmilauer Petr , Šťovíček Václav , Nováková Kristýna , Hršelová Hana , Jansa Jan
Published: May 2017

Ecology of hypogeic mycorrhizal fungi, such as truffles, remains largely unknown, both in terms of their geographical distribution and their environmental niches. Occurrence of true truffles (Tuber spp.) was therefore screened using specific polymerase chain reaction (PCR) assays and subsequent PCR amplicon sequencing in tree roots collected at 322 field sites across the Czech Republic. These sites spanned a wide range of climatic and soil conditions. The sampling was a priori restricted to areas thought to be suitable for Tuber spp. inasmuch as they were characterized by weakly acidic to alkaline soils, warmer climate, and with tree species previously known to host true truffles. Eight operational taxonomic units (OTUs) corresponding to Tuber aestivum, T. borchii, T. foetidum, T. rufum, T. indicum, T. huidongense, T. dryophilum, and T. oligospermum were detected. Among these, T. borchii was the OTU encountered most frequently. It was detected at nearly 19% of the sites. Soil pH was the most important predictor of Tuber spp. distribution. Tuber borchii preferred weakly acidic soils, T. foetidum and T. rufum were most abundant in neutral soils, and T. huidongense was restricted to alkaline soils. Distribution of T. aestivum was mainly dictated by climate, with its range restricted to the warmest sites. Host preferences of the individual Tuber spp. were weak compared to soil and climatic predictors, with the notable exception that T. foetidum appeared to avoid oak trees. Our results open the way to better understanding truffle ecology and, through this new knowledge, also to better‐informed trufficulture.
Using regional bird density distribution models to evaluate protected area networks and inform conservation planning
Authors: Alexander John D. , Stephens Jaime L. , Veloz Sam , Salas Leo , Rousseau Josée S. , Ralph C. John , Sarr Daniel A.
Published: May 2017

As data about populations of indicator species become available, proactive strategies that improve representation of biological diversity within protected area networks should consider finer‐scaled evaluations, especially in regions identified as important through course‐scale analyses. We use density distribution models derived from a robust regional bird abundance dataset, coupled with habitat conservation plans, to evaluate a network of protected areas and to inform conservation and biodiversity planning in the greater Klamath Siskiyou Bioregion, an area recognized globally as a region of outstanding biological diversity. Our novel modeling approach allowed for comparisons of abundance of conservation focal species on federal vs. non‐federal lands, federal lands that are protected to maintain natural habitats vs. federal lands managed for multiple uses, and seven protected areas of interest. Our comparisons highlight conservation opportunities for suites of species associated with coniferous forests, oak woodlands, and grasslands. Specifically, we found that species associated with oak woodland and grassland habitats, both habitats of conservation concern, were not well represented in the Bioregion's existing protected areas. These species would benefit from expanding the regional protected area network to include their associated at‐risk habitats. In contrast, our results suggest that coniferous forests birds are well represented in the Bioregion's protected areas. We identify management opportunities specifically associated with the restoration of fire‐adapted ecosystems that would benefit coniferous forest focal species on both federally protected areas and other multiple‐use lands. Our analysis provides an example of how a finer‐scaled evaluation of a regional protected area network adds value to course‐scale evaluations of protected areas and biological diversity. Data and results from this research were used to inform science‐based expansion of the Bioregion's network of protected areas.
Regulation of immune cell signaling by SHIP1: A phosphatase, scaffold protein, and potential therapeutic target
Authors: Pauls Samantha D. , Marshall Aaron J.
Published: May 2017

The phosphoinositide phosphatase SHIP is a critical regulator of immune cell activation. Despite considerable study, the mechanisms controlling SHIP activity to ensure balanced cell activation remain incompletely understood. SHIP dampens BCR signaling in part through its association with the inhibitory coreceptor Fc gamma receptor IIB, and serves as an effector for other inhibitory receptors in various immune cell types. The established paradigm emphasizes SHIP's inhibitory receptor‐dependent function in regulating phosphoinositide 3‐kinase signaling by dephosphorylating the phosphoinositide PI(3,4,5)P3; however, substantial evidence indicates that SHIP can be activated independently of inhibitory receptors and can function as an intrinsic brake on activation signaling. Here, we integrate historical and recent reports addressing the regulation and function of SHIP in immune cells, which together indicate that SHIP acts as a multifunctional protein controlled by multiple regulatory inputs, and influences downstream signaling via both phosphatase‐dependent and ‐independent means. We further summarize accumulated evidence regarding the functions of SHIP in B cells, T cells, NK cells, dendritic cells, mast cells, and macrophages, and data suggesting defective expression or activity of SHIP in autoimmune and malignant disorders. Lastly, we discuss the biological activities, therapeutic promise, and limitations of small molecule modulators of SHIP enzymatic activity.
Crystal Growth and Characterization of the Mixed‐Cation Rb+/[XeF5]+ and Cs+/[XeF5]+ Salts
Authors: Mazej Zoran , Goreshnik Evgeny
Published: May 2017

Invited for the cover of this issue is research led by Zoran Mazej in collaboration with Evgeny Goreshnik, both from the Jožef Stefan Institute, Ljubljana, Slovenia. The cover image shows the formation of a new type of noble gas coordination compounds A[XeF5][MF6]2 (A = Rb, Cs; M = Sb, Bi) that crystallize in two modifications.
Base‐Promoted [3+2] Cycloaddition of In Situ Formed Azaoxyallyl Cations with Isothiocyanides
Authors: Zhao Hong‐Wu , Zhao Yu‐Di , Liu Yue‐Yang , Du Juan , Pang Hai‐Liang , Chen Xiao‐Qin , Song Xiu‐Qing , Feng Ning‐Ning
Published: May 2017

In the presence of Na2CO3, the [3+2] cycloaddition of azaoxyallyl cations, in situ formed from α‐halohydroxamates by reaction with isothiocyanides, proceeded smoothly and furnished (Z)‐2‐iminothiazolidin‐4‐ones in 25–99 % chemical yields. The chemical structure of the title compounds was confirmed by X‐ray single‐crystal structure analysis.
Enantioselective Mannich Reaction Employing 1,3,5‐Triaryl‐1,3,5‐triazinanes Catalyzed by Chiral‐at‐Metal Rhodium Complexes
Authors: Gong Jun , Li Shi‐Wu , Qurban Saira , Kang Qiang
Published: May 2017

Chiral‐at‐metal RhIII complexes catalyze the efficient enantioselective Mannich reaction of 2‐acyl imidazoles with 1,3,5‐triazinanes, affording the corresponding adducts in 81–99 % yield with up to >99 % enantioselectivity. This protocol performs with 0.1 mol‐% of RhIII complex on gram scale without any loss in enantioselectivity.
Membranes with a low loading of Metal–Organic Framework‐Supported Ionic Liquids for CO2/N2 separation in CO2 capture
Authors: Monteiro Bernardo , Nabais Ana Rita , Almeida Paz Filipe A. , Cabrita Luis , Branco Luis C. , Marrucho Isabel M. , Neves Luisa A. , Pereira Cláudia C. L.
Published: May 2017

Immobilization of ionic liquids (ILs) into 3D metal–organic frameworks (MOFs) is reported. The incorporation of these composites in a polyimide‐based matrix (Matrimid® 5218) to yield [IL@MOF]@Matrimid® 5218 is an efficient strategy to improve the permeability and selectivity toward CO2/N2 mixtures, presenting also a remarkable improvement in membrane flexibility and mechanical resistance. Using MOF‐5, a crystalline phase different to its original phase is obtained after the incorporation of hydrated IL without loss of adsorptive properties.
Catalytic oxidative degradation of 4‐chlorophenol: Effect of operating parameters and prediction of intermediates/by‐products
Authors: Singh Swati , Garg Anurag
Published: May 2017

The presence of chlorophenols (CP) in industrial wastewater is a major concern due to their microbial toxicity. The present study was performed to investigate the efficacy of advanced oxidation process (i.e., conventional and modified Fenton's process) for the degradation of 4‐chlorophenol (4‐CP) in an aqueous solution (concentration = 200 mg L−1) under varying reaction conditions. The decomposition of 4‐CP was confirmed by chemical oxygen demand (COD) reduction, total organic carbon (TOC) reduction, detection of low molecular weight carboxylic acids (such as oxalic, acetic, formic and malonic) and Cl‐ concentration in the treated 4‐CP aqueous solution. The maximum COD and TOC reductions were 74% and 42% after 30 min of Fenton reaction at an initial pH, Fe2+ concentration, and H2O2 to Fe2+ molar ratio of 3.0, 1.26 mM and 20, respectively which were found to increase to 79 and 55%, respectively when Cu2+ was also added with Fe2+ during modified Fenton process. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1734–1742, 2017
Physical Activity in Bariatric Surgery Patients: Does Temperament Matter?
Authors: Gruner‐Labitzke Kerstin , Claes Laurence , Bartsch Merle , Schulze Mareike , Langenberg Svenja , Köhler Hinrich , Marschollek Michael , de Zwaan Martina , Müller Astrid
Published: May 2017

Objective

Our aim was to investigate if physical activity (PA) in bariatric surgery patients is related to temperament.

Methods

Preoperative (n = 70) and post‐operative (n = 73) patients were categorized as being physically ‘active’ versus ‘inactive’ on the basis of objective PA monitoring. Assessment included the behavioural inhibition system (BIS)/behavioural activation system (BAS) scales, the effortful control (EC) subscale of the Adult Temperament Questionnaire‐Short Form, a numeric pain rating scale and measures for depressive and eating disorder symptoms.

Results

‘Active’ did not differ from ‘inactive’ patients with regard to temperament (BIS, BAS, and EC). Regressions with PA grouping as dependent variable (adjusted for age, gender, body mass index (BMI), depressive or eating disorder symptoms, or pain intensity) indicated an association between lower BMI and more PA in the preoperative and the post‐operative group. In the post‐operative group, in addition to lower BMI, also lower age and higher BIS reactivity contributed to more PA. Furthermore, there was a significant interaction between BMI and BIS suggesting that low BMI was only associated with more PA in post‐operative patients with high BIS.

Discussion

The results indicate that temperament per se does not contribute to the level of PA in bariatric surgery patients. However, in post‐operative patients, lower BMI was associated with a higher likelihood of being physically active particularly in patients with anxious temperament. These preliminary findings need further investigation within longitudinal studies. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.
Inferring pathobiology from structural MRI in schizophrenia and bipolar disorder: Modeling head motion and neuroanatomical specificity
Authors: Yao Nailin , Winkler Anderson M. , Barrett Jennifer , Book Gregory A. , Beetham Tamara , Horseman Rachel , Leach Olivia , Hodgson Karen , Knowles Emma E. , Mathias Samuel , Stevens Michael C. , Assaf Michal , van Erp Theo G. M. , Pearlson Godfrey D. , Glahn David C.
Published: May 2017

Despite over 400 peer‐reviewed structural MRI publications documenting neuroanatomic abnormalities in bipolar disorder and schizophrenia, the confounding effects of head motion and the regional specificity of these defects are unclear. Using a large cohort of individuals scanned on the same research dedicated MRI with broadly similar protocols, we observe reduced cortical thickness indices in both illnesses, though less pronounced in bipolar disorder. While schizophrenia (n = 226) was associated with wide‐spread surface area reductions, bipolar disorder (n = 227) and healthy comparison subjects (n = 370) did not differ. We replicate earlier reports that head motion (estimated from time‐series data) influences surface area and cortical thickness measurements and demonstrate that motion influences a portion, but not all, of the observed between‐group structural differences. Although the effect sizes for these differences were small to medium, when global indices were covaried during vertex‐level analyses, between‐group effects became nonsignificant. This analysis raises doubts about the regional specificity of structural brain changes, possible in contrast to functional changes, in affective and psychotic illnesses as measured with current imaging technology. Given that both schizophrenia and bipolar disorder showed cortical thickness reductions, but only schizophrenia showed surface area changes, and assuming these measures are influenced by at least partially unique sets of biological factors, then our results could indicate some degree of specificity between bipolar disorder and schizophrenia. Hum Brain Mapp 38:3757–3770, 2017. © 2017 Wiley Periodicals, Inc.
Neural correlates of fine‐grained meaning distinctions: An fMRI investigation of scalar quantifiers
Authors: Zhan Jiayu , Jiang Xiaoming , Politzer‐Ahles Stephen , Zhou Xiaolin
Published: May 2017

Communication involves successfully deriving a speaker's meaning beyond the literal expression. Using fMRI, it was investigated how the listener's brain realizes distinctions between enrichment‐based meanings and literal semantic meanings. The neural patterns of the Mandarin scalar quantifieryou‐de(similar tosomein English) which implies the meaningsnot allandnot mostvia scalar enrichment, with the specific quantifiershao‐shu‐de(similar toless than halfin English) which lexico‐semantically encodes the meaningsnot allandnot most, were compared. Listeners heard sentences using either quantifier, paired with pictures in which either less than half, more than half, or all of the people depicted in the picture were doing the described activity; thus, the conditions included both implicature‐based and semantics‐based picture‐sentence mismatches. Imaging results showed bilateral ventral IFG was activated for both kinds of mismatch, whereas basal ganglia and left dorsal IFG were activated uniquely for implicature‐based mismatch. These findings suggest that resolving conflicts involving inferential aspects of meaning employs different neural mechanisms than the processing based on literal semantic meaning, and that the dorsal prefrontal/basal ganglia pathway makes a contribution to implicature‐based interpretation. Furthermore, within the implicature‐based conditions, different neural generators were implicated in the processing of strong implicature mismatch (you‐dein the context of a picture in which “all” would have been true) and weak implicature mismatch (you‐dein the context of a picture in which “most” would have been true), which may have important implications for theories of pragmatic comprehension.Hum Brain Mapp 38:3848–3864, 2017. ©2017 Wiley Periodicals, Inc.
Cognitive and neuroimaging changes in healthy immigrants upon relocation to a high altitude: A panel study
Authors: Chen Xiaoming , Zhang Qian , Wang Jiye , Liu Jie , Zhang Wenbin , Qi Shun , Xu Hui , Li Chen , Zhang Jinsong , Zhao Haitao , Meng Shanshan , Li Dan , Lu Huanyu , Aschner Michael , Li Bin , Yin Hong , Chen Jingyuan , Luo Wenjing
Published: May 2017

Background

Cognitive and neuroimaging changes under chronic high‐altitude exposure have never been followed up and dynamically assessed.

Objectives

To investigate the cognitive and brain structural/functional alterations associated with chronic high‐altitude exposure.

Methods

Sixty‐nine college freshmen that were immigrating to Tibet were enrolled and followed up for two years. Neuropsychological tests, including verbal/visual memory and simple/recognition reaction time, were utilized to determine whether the subjects' cognitive function had changed in response to chronic high‐altitude exposure. Structural magnetic resonance imaging (MRI) and resting‐state functional MRI (rs‐fMRI) were used to quantify brain gray matter (GM) volumes, regional homogeneity (ReHo) and functional connectivity (FC) alterations before and after exposure. Areas with changes in both GM and ReHo were used as seeds in the inter‐regional FC analysis.

Results

The subjects showed significantly lower accuracy in memory tests and longer reaction times after exposure, and neuroimaging analysis showed markedly decreased GM volumes and ReHo in the left putamen. FC analysis seeding of the left putamen showed significantly weakened FC with the superior temporal gyrus, anterior/middle cingulate gyrus and other brain regions. In addition, decreased ReHo was found in the superior temporal gyrus, superior parietal lobule, anterior cingulate gyrus and medial frontal gyrus, while increased ReHo was found in the hippocampus. Differences in ReHo/FC before and after high‐altitude exposure in multiple regions were significantly correlated with the cognitive changes.

Conclusion

Cognitive functions such as working memory and psychomotor function are impaired during chronic high‐altitude exposure. The putamen may play an important role in chronic hypoxia‐induced cognitive impairment. Hum Brain Mapp 38:3865–3877, 2017. © 2017 Wiley Periodicals, Inc.
Resting state functional connectivity of the ventral auditory pathway in musicians with absolute pitch
Authors: Kim Seung‐Goo , Knösche Thomas R.
Published: May 2017

Absolute pitch (AP) is the ability to recognize pitch chroma of tonal sound without external references, providing a unique model of the human auditory system (Zatorre: Nat Neurosci 6 () 692–695). In a previous study (Kim and Knösche: Hum Brain Mapp () 3486–3501), we identified enhanced intracortical myelination in the right planum polare (PP) in musicians with AP, which could be a potential site for perceptional processing of pitch chroma information. We speculated that this area, which initiates the ventral auditory pathway, might be crucially involved in the perceptual stage of the AP process in the context of the “dual pathway hypothesis” that suggests the role of the ventral pathway in processing nonspatial information related to the identity of an auditory object (Rauschecker: Eur J Neurosci 41 () 579–585). To test our conjecture on the ventral pathway, we investigated resting state functional connectivity (RSFC) using functional magnetic resonance imaging (fMRI) from musicians with varying degrees of AP. Should our hypothesis be correct, RSFC via the ventral pathway is expected to be stronger in musicians with AP, whereas such group effect is not predicted in the RSFC via the dorsal pathway. In the current data, we found greater RSFC between the right PP and bilateral anteroventral auditory cortices in musicians with AP. In contrast, we did not find any group difference in the RSFC of the planum temporale (PT) between musicians with and without AP. We believe that these findings support our conjecture on the critical role of the ventral pathway in AP recognition. Hum Brain Mapp 38:3899–3916, 2017. © 2017 Wiley Periodicals, Inc.
GABA metabolism and its role in gamma‐band oscillatory activity during auditory processing: An MRS and EEG study
Authors: Wyss Christine , Tse Desmond H.Y. , Kometer Michael , Dammers Jürgen , Achermann Rita , Shah N. Jon , Kawohl Wolfram , Neuner Irene
Published: May 2017

Gamma‐aminobutyric acid (GABA) and glutamate are believed to have inhibitory and exhibitory neuromodulatory effects that regulate the brain's response to sensory perception. Furthermore, frequency‐specific synchronization of neuronal excitability within the gamma band (30–80 Hz) is attributable to a homeostatic balance between excitation and inhibition. However, our understanding of the physiological mechanism underlying gamma rhythms is based on animal models. Investigations of the relationship between GABA concentrations, glutamate concentrations, and gamma band activity in humans were mostly restricted to the visual cortex and are conflicting. Here, we performed a multimodal imaging study combining magnetic resonance spectroscopy (MRS) with electroencephalography (EEG) in the auditory cortex. In 14 healthy subjects, we investigated the impact of individual differences in GABA and glutamate concentration on gamma band response (GBR) following auditory stimulus presentation. We explored the effects of bulk GABA on the GBR across frequency (30–200 Hz) and time (−200 to 600 ms) and found no significant relationship. Furthermore, no correlations were found between gamma peak frequency or power measures and metabolite concentrations (GABA, glutamate, and GABA/glutamate ratio). These findings suggest that, according to MRS measurements, and given the auditory stimuli used in this study, GABA and glutamate concentrations are unlikely to play a significant role in the inhibitory and excitatory drive in the generation of gamma band activity in the auditory cortex. Hum Brain Mapp 38:3975–3987, 2017. © 2017 Wiley Periodicals, Inc.
Atovaquone/proguanil‐induced autoimmune‐like hepatitis
Authors: Terziroli Beretta‐Piccoli Benedetta , Mieli‐Vergani Giorgina , Bertoli Raffaela , Mazzucchelli Luca , Nofziger Charity , Paulmichl Markus , Vergani Diego
Published: May 2017

We report a novel association between the commonly used antimalarial medication atovaquone/proguanil and drug‐induced autoimmune‐like hepatitis. The patient developed severe liver disease fulfilling biochemical, immunologic, and histologic criteria for the diagnosis of autoimmune hepatitis after the inadvertent rechallenge with the offending drug, which had caused self‐limited hepatitic symptoms a year previously. Over a period of 18 months, the patient underwent two follow‐up liver biopsies showing progressive resolution of the liver inflammation and achieved complete biochemical and immunologic remission on steroids. This remission persisted for 20 months following treatment withdrawal. Conclusion: This well documented case raises awareness of the potential hepatotoxicity of atovaquone/proguanil. (Hepatology Communications 2017;1:293–298)
Current density analysis of electron transport through molecular wires in open quantum systems
Authors: Nozaki Daijiro , Schmidt Wolf Gero
Published: May 2017

The current density in molecular wires connected to contacts is investigated within the nonequilibrium Green's function formalism combined with the Landauer approach. Energy‐dependent and total current density through a series of molecular junctions are calculated in real space representation. A rich variety of current patterns including pronounced ring currents (“vortices”) are found even in the defect‐free minimal building blocks of molecular devices. The influences of contact positions, functional groups as well as atomic defects on the transport properties are examined systematically for prototypical ortho‐, meta‐, and para‐substituted benzenes as well as heteroaromatic systems. It is found that substitutional functional groups mainly shift the molecular levels and retain characteristic transport channels, while a significant change of electronic pathways and conductance is induced by hetero‐aromaticity. The current distribution is used to calculate the static magnetic field distribution in the carbon‐based conductors. © 2017 Wiley Periodicals, Inc.
Decreased frequency of circulating Th9 cells in patients with chronic hepatitis B infection
Authors: Cui Meilan , Lv Ying , Lu Jianhua , Zhang Wei , Duan Yuanyuan , Huang Yan , Yang Lei , Li Man , Liu Wenxuan , Liu Dianwu , Yan Huimin
Published: May 2017

Background

Chronic hepatitis B (CHB) is one of the major infectious diseases in which CD4+ T helper (Th) cells play a crucial role. Th9 cells are a distinct subset of CD4+ Th cells with important physiological functions.

Objective

The study aimed to assess the potential involvement of Th9 cells in the inadequate immune response leading to chronic HBV infection.

Patients and Methods

Peripheral blood samples were collected from 22 CHB patients and 16 healthy controls (HC). The frequencies of circulating Th9, Tc9, Th1, and Tc1 cells were determined by flow cytometry. Serum levels of IL‐9 and IL‐10 were analyzed by ELISA. Serum biochemical indices of liver function were measured using an automated analyzers. Serum HBV DNA loads were analyzed by real‐time PCR. The potential association of the frequency of Th9, Tc9, Th1 or Tc1 cells with clinical parameters was assessed.

Results

The frequency of circulating Th9 cells was significantly lower in CHB patients than those in HC. However, no significant differences in the frequency of Tc9, Th1 or Tc1 cells were observed between the two groups. The percentages of Th9 cells, but not Tc9 cells, were negatively correlated with HBV DNA loads, whereas the percentages of Tc1 cells were positively correlated with viral loads in CHB patients. Moreover, there was a positive correlation between serum levels of IL‐9 and IL‐10 and HBV DNA loads in patients with chronic HBV infection.

Conclusion

The depletion of Th9 cells is associated with the development of chronic HBV infection.
Investigation of MTHFR gene C677T polymorphism in cardiac syndrome X patients
Authors: Kandaz Cemre , Önal Burak , Özen Deniz , Demir Bülent , Akkan A. Gökhan , Özyazgan Sibel
Published: May 2017

Background

Definition of Cardiac Syndrome X (CSX) refers to groups of patients with positive exercise stress test and normal epicardial coronary arteries on coronary angiography accompanied by chest pain. Although the etiology of CSX is not completely understood, there is a common consensus that its pathophysiology may be associated with endothelial dysfunction resulting in impaired coronary flow. Some polymorphisms observed on the MTHFR gene cause inactivation of the MTHFR enzyme, leading to hyperhomocysteinemia and homocysteinuria, which are prominent risk factors of cardiovascular and cerebrovascular diseases. It was aimed to explain the association of the endothelial dysfunction, which is thought to play a role in the pathophysiology of CSX, with C677T polymorphism on MTHFR gene based on genetic basis.

Methods

A total of 176 CSX patients and 196 healthy subjects with similar age and clinical features were compared in terms of C677T polymorphism of the MTHFR gene.

Results and Conclusion

There was no significant difference in terms of MTHFR gene C677T polymorphism between CSX patients and controls. When genotypic distribution was compared based on gender in both patients and controls, no significant difference was found between male and female subjects (P>.05). As fasting blood sugar and urea values were significantly higher, alanine aminotransferase and gamma‐glutamyl transferase levels were significantly lower in the patients than the controls (P<.05). Described family story of the patients was significantly higher than the controls (P<.05). These suggest that homocysteine metabolism in CSX is not directly related to the endothelial dysfunction and thus the effect on the microvascular circulation.
Reproducibility of point‐of‐care ultrasonography for central vein diameter measurement: Separating image acquisition from interpretation
Authors: Lucas Brian P. , D'Addio Antonietta , Clark Jennifer , Block Clay , Manning Harold , Remillard Brian , Leiter J.C.
Published: May 2017

Purpose

Central vein point‐of‐care ultrasonography must be reproducible to detect intravascular volume changes. We sought to determine which measurement step, image acquisition or interpretation, could be more compromising for reproducibility.

Methods

Three investigators each acquired inferior vena cava (IVC) and internal jugular (IJV) vein ultrasonographic sequences (US) from a convenience sample of 21 hospitalized general medicine participants and then interpreted each US three separate times. We partitioned the random errors of acquisition and interpretation, attributing wider dispersions of each to larger reductions in reproducibility.

Results

We analyzed 351 interpretations of 39 IVC and 432 interpretations of 48 IJV US. Reproducibility of the maximum (standard error of measurement 3.3 mm [95% confidence interval, CI 2.7–4.2 mm]) and minimum (4.8 mm [3.9–6.3 mm]) IVC diameter measurements were worse than that of the mediolateral (2.5 mm [2.0–3.2 mm]) and anteroposterior (2.5 mm [2.0–3.1 mm]) IJV diameters. The dispersions of random measurement errors were wider among acquisitions than interpretations.

Conclusions

Among our investigators, central vein diameter measurements obtained by point‐of‐care ultrasonography are not sufficiently reproducible to distinguish clinically meaningful intravascular volume changes from measurement errors. Reproducibility could be most effectively improved by reducing the random measurement errors of acquisition. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:488–496, 2017
Pulmonary metastasis from uterine leiomyosarcoma in a patient with limited cutaneous systemic scleroderma
Authors: Okauchi Shinichiro , Watanabe Hiroko , Tamura Tomohiro , Takayashiki Norio , Iguchi Kesato , Satoh Hiroaki , Sato Taiki , Sakata Akiko , Noguchi Masayuki
Published: May 2017

A 51‐year‐old woman, who was diagnosed as having limited cutaneous systemic scleroderma, presented with pulmonary nodules incidentally detected in a chest radiograph. The patient had surgical biopsy of the nodules. In microscopic examination of the specimens, proliferation, mitotic activity, and cellular anaplasia of spindle cells were present. Fluorodeoxyglucose‐positron emission tomography showed tumors in lungs as well as uterus. The diagnosis of the tumor was pulmonary metastases from uterine leiomyosarcoma. We should be on alert the possibility of developing malignant disease in patient with this autoimmune disease. If it is certain that there is metastasis, we believe that therapy for the primary lesion will be preceded by biopsy and surgery for the metastatic lesions.
A complete survey of normal pores on a smooth shell ostracod (Crustacea): Landmark‐based versus outline geometric morphometrics
Authors: Karanovic Ivana , Lavtižar Vesna , Djurakic Marko
Published: May 2017

Pores and sensilla on ostracod shell have often been used in studies of ontogeny, taxonomy, and phylogeny of the group. However, an analysis of sexual dimorphism and variation between valves in the number and distribution of pores is lacking. Also, such studies have never been done on a widely distributed, morphologically variable, and weakly ornamented freshwater ostracod. Here, we survey pores in one such species, Physocypria kraepelini. We choose 27 homologous pores as landmarks for 2D‐geometric morphometric analysis, with the aim to assess intersexual and between valves variation in size and shape relative to the Fourier outline analysis. This species has only simple (Type A) pores with and without a lip, and each pore carries an undivided sensory seta. Our results show that the total number of pores varies (from 270 to 296), but this is not associated with a specific valve. Males carry fewer pores than females, however no sex specific pores are found. Small intrapopulation divergence of the Cyt b molecular marker (1%) indicates that morphological variability is not species related. We found that P. kraepelini exhibits directional asymmetry of size and shape, sexual size dimorphism (SSD) but lacks sexual shape dimorphism (SShD). Two geometric morphometrics methods were congruent in the estimation of SSD, SShD, and directional asymmetry of shape but differ in the statistical evaluation of directional asymmetry of size. Contrary to other animal groups, our study suggests that ostracods have more pronounced directional asymmetry of shape compared to directional asymmetry of size.
Cranial suture complexity in caviomorph rodents (Rodentia; Ctenohystrica)
Authors: Buezas Guido , Becerra Federico , Vassallo Aldo
Published: May 2017

Due to their flexibility, sutures are regions that experience greater strains than the surrounding rigid cranial bones. Cranial sutures differ in their degree of interdigitation or complexity. There is evidence indicating that a more convoluted suture better enables the absorption of high stresses coming from dynamic masticatory forces, and other functions. The Order Rodentia is an interesting clade to study this because of its taxa with diverse chewing modes. Due to repeated loading resulting from gnawing and grinding, energy absorption by the sutures might be a crucial factor in these mammals. Species within the infraorder Caviomorpha were chosen as a case study because of their ecomorphological and dietary diversity. This study compared five sutures from the rostrum and cranial vault across seven caviomorph families, and assessed their complexity by means of the relative length and fractal dimension. Across these rodents, cranial sutures are morphologically quite diverse. We found that the sutures connecting the rostrum with the vault were relatively more interdigitated than those in the cranial vault itself, especially premaxillofrontal sutures. Suture interdigitation was higher in species that display chisel‐tooth digging and burrowing behaviors, especially in the families Ctenomyidae and Octodontidae, than those in families Dasyproctidae and Cuniculidae, which have more gracile masticatory systems. The reconstruction of the ancestral character state, on family and species phylogeny, points toward low suture interdigitation (i.e., low length ratio) as a likely ancestral state for interfrontal, premaxillofrontal and maxillofrontal sutures. Interspecific differences in suture morphology shown here might represent adaptations to different mechanical demands (i.e., soft vs. tough foods) or behaviors (e.g., chisel‐tooth digging), which evolved in close association with the diverse environments occupied by caviomorph rodents.
Comparison of arterial spin labeling registration strategies in the multi‐center GENetic frontotemporal dementia initiative (GENFI)
Authors: Mutsaerts Henri J.M.M. , Petr Jan , Thomas David L. , De Vita Enrico , Cash David M. , van Osch Matthias J.P. , Golay Xavier , Groot Paul F.C. , Ourselin Sebastien , van Swieten John , Laforce Robert , Tagliavini Fabrizio , Borroni Barbara , Galimberti Daniela , Rowe James B. , Graff Caroline , Pizzini Francesca B. , Finger Elizabeth , Sorbi Sandro , Castelo Branco Miguel , Rohrer Jonathan D. , Masellis Mario , MacIntosh Bradley J. ,   on behalf of the GENFI investigators
Published: May 2017

Purpose

To compare registration strategies to align arterial spin labeling (ASL) with 3D T1‐weighted (T1w) images, with the goal of reducing the between‐subject variability of cerebral blood flow (CBF) images.

Materials and Methods

Multi‐center 3T ASL data were collected at eight sites with four different sequences in the multi‐center GENetic Frontotemporal dementia Initiative (GENFI) study. In a total of 48 healthy controls, we compared the following image registration options: (I) which images to use for registration (perfusion‐weighted images [PWI] to the segmented gray matter (GM) probability map (pGM) (CBF‐pGM) or M0 to T1w (M0‐T1w); (II) which transformation to use (rigid‐body or non‐rigid); and (III) whether to mask or not (no masking, M0‐based FMRIB software library Brain Extraction Tool [BET] masking). In addition to visual comparison, we quantified image similarity using the Pearson correlation coefficient (CC), and used the Mann‐Whitney U rank sum test.

Results

CBF‐pGM outperformed M0‐T1w (CC improvement 47.2% ± 22.0%; P < 0.001), and the non‐rigid transformation outperformed rigid‐body (20.6% ± 5.3%; P < 0.001). Masking only improved the M0‐T1w rigid‐body registration (14.5% ± 15.5%; P = 0.007).

Conclusion

The choice of image registration strategy impacts ASL group analyses. The non‐rigid transformation is promising but requires validation. CBF‐pGM rigid‐body registration without masking can be used as a default strategy. In patients with expansive perfusion deficits, M0‐T1w may outperform CBF‐pGM in sequences with high effective spatial resolution. BET‐masking only improves M0‐T1w registration when the M0 image has sufficient contrast.

Level of Evidence: 1

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2018;47:131–140.