bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Levodopa on Speech Dysfluency in Parkinson's Disease
Authors: Im Hannah , Adams Scott , Abeyesekera Anita , Pieterman Marcus , Gilmore Greydon , Jog Mandar
Published: December 2018

Objective

To examine the effect of levodopa medication on speech dysfluency in Parkinson's disease.

Methods

Fifty‐one individuals with Parkinson's disease (IWPD) read aloud during off‐ and on‐ medication states. Total speech dysfluencies were calculated from transcriptions of recorded speech samples.

Results

Severity of speech dysfluency was not significantly related to the severity of motor symptoms, duration of disease, levodopa equivalent dosage, or age. When the IWPD were divided into two groups based on dysfluency severity, there was a significant group‐by‐medication state interaction. There was a significant correlation between the medication‐related change in speech dysfluency and the off‐medication severity of speech dysfluency measure (r = −0.46).

Conclusions

The results of this study indicate that levodopa medication can have a significant effect on speech dysfluency. The beneficial levodopa effect appears to be related to the severity of the off‐medication speech dysfluency. Results did not provide strong support for the excess dopamine theory of stuttering in IWPD. A dualistic model of the effects of dopamine on speech fluency in PD is proposed.
Global convergence of the Euler‐Poisson system for ion dynamics
Authors: Liu Cunming , Peng Yue‐jun
Published: December 2018

We consider smooth solutions of the Euler‐Poisson system for ion dynamics in which the electron density is replaced by a Boltzmann relation. The system arises in the modeling of plasmas, where appear two small parameters, the relaxation time and the Debye length. When the initial data are sufficiently close to constant equilibrium states, we prove the convergence of the system for all time, as each of the parameters goes to zero. The limit systems are drift‐diffusion equations and compressible Euler equations. The proof is based on uniform energy estimates and compactness arguments.
Gallic Acid Suppresses Cardiac Hypertrophic Remodeling and Heart Failure
Authors: Yan Xiao , Zhang Yun‐Long , Zhang Liang , Zou Lei‐Xin , Chen Chen , Liu Ying , Xia Yun‐Long , Li Hui‐Hua
Published: December 2018

Scope

Gallic acid (GA) is a dietary phenolic acid found in tea, red wine, and some plants. It exhibits anti‐oxidative and anti‐inflammatory activities. Recent studies have revealed that GA has beneficial effects against several cardiovascular diseases; however, whether GA attenuates pressure‐overload‐induced cardiac hypertrophy and the underlying mechanism remains unclear.

Methods and results

Primary cardiomyocyte hypertrophy is stimulated with angiotensin II (Ang II). Cardiac hypertrophic remodeling is induced in mice by transverse aortic constriction (TAC). Myocardial function is evaluated by echocardiographic and hemodynamic analyses, while cardiac tissues are analyzed by histological staining. It is observed that GA significantly decreases Ang II‐induced increases in cardiomyocyte size in vitro. Administration of GA in mice markedly improves TAC‐induced cardiac dysfunction and attenuates pathological changes, including cardiac myocyte hypertrophy, fibrosis, inflammation, and oxidative stress. Mechanistically, GA inhibits ULK1 and activates autophagy, which induces the degradation of EGFR, gp130, and calcineurin A, thereby inhibiting the downstream signaling cascades (AKT, ERK1/2, JAK2/STAT3, and NFATc1).

Conclusions

The results demonstrate for the first time that GA prevents myocardial hypertrophy and dysfunction via an autophagy‐dependent mechanism. Thus, GA represents a promising therapeutic candidate for treating cardiac hypertrophy and heart failure.
Theoretical investigation on the optical and EPR spectra for Cu2+‐doped ZnO‐CdS nanocomposites
Authors: Zhang H.M. , Yan C. , Zhu Q.S.
Published: December 2018

The three optical absorption bands and EPR parameters of the [CuO6]10− center in the ZnO‐CdS composite nanopowders are theoretically studied from the perturbation formulas based on the cluster approach. In the formulas, the contributions to EPR parameters arising from the ligand orbital and spin–orbit coupling interactions via covalence effect are considered. For the studied [CuO6]10− cluster, the Cu–O bond lengths are suggested to show a relative elongation ratio ρ (≈ 4.1%) along the z‐axis due to Jahn–Teller effect. The defect models suggested in this work are different from the previous assumption that the impurity Cu2+ can replace the host Zn2+ site when it enters the lattices of the ΖnO and ΖnS nanocrystals, forming the tetrahedral [CuΧ4]6− clusters (Χ = O, S). The validity of the proposed model is discussed. The differences between the present calculations and the previous ones for the interstitial Cu2+ center in ZnO nanocrystals are analyzed in view of the dissimilar impurity behaviors due to the new composition CdS and distinct preparation conditions.
Fire hazard suppression of intumescent flame retardant polypropylene based on a novel Ni‐containing char‐forming agent
Authors: Dong Xiang , Qin Ruxiang , Nie Shibin , Yang Jinian , Zhang Chi , Wu Wei
Published: December 2018

Reducing the fire hazard of polypropylene (PP) is an important research direction in the fields of fire safety materials. In this article, a novel Ni‐containing char‐forming agent (TTPN) was successfully synthesized, using tris(2‐hydroxyethyl) isocyanurate (THEIC), terephthalic acid, and nickel dihydrogen phosphate. Then, TTPN was combined with the silica‐gel microencapsulated ammonium polyphosphate (OS‐MCAPP) to prepare intumescent flame retardant PP composites. From the results of the limiting oxygen index (LOI) test and cone calorimeter, the composite containing 30% IFR (OS‐MCAPP: TTPN = 3:2) shows the highest LOI value of 33.5%, and its peak heat release rate is 275.5 kWm−2, decreased by 79.0% and 37.4% than those of pure PP and the composite containing the char‐forming agent without Ni. Meanwhile, the composite containing TTPN present the best smoke and CO2/CO suppression. The results indicate that TTPN has an excellent ability to dramatically reduce the fire hazard of PP.
Structural, morphological, optical and dielectric properties of M3+/PVA/PEG SPE Films (M = La, Y, Fe or Ir)
Authors: Mohammed Ghada , El Sayed Adel Mohamed
Published: December 2018

Low band gap polymer complexes are promising due to its flexibility, and exhibiting electronic and optical properties of inorganic semiconductors. The effect of PEG on the physical properties of PVA was evaluated. Then, blend (PVA: PEG = 50:50) doped with rare earth (La or Y) and transition metal (Fe or Ir) chlorides to obtain solid polymer electrolyte films. XRD shows that adding PEG to PVA results in a new peak, 2θ = 23owith increased intensity as PEG ratio increases. However, doping with La3+, Fe3+or Ir3+eliminate this peak and decrease the crystallinity. SEM exhibits significant changes in the morphology of films. FTIR confirms miscibility between PVA & PEG and the complexation of the salts. The optical band gap (Eg) of PVA ~ 5.37 eV, decreased slightly by blending with PEG. While it decreased significantly to 2.64 eV and 2.78 eV after doping with Fe3+or Ir3+. There are a consistency betweenEgvalues obtained by Tauc's model and that obtained from the optical dielectric loss. The dielectric constant and loss, in temperature range 303–405 K & frequency range 1.0 kHz ‐ 5.0 MHz, indicate one or two relaxation peak(s) depending on the film composition. Accordingly, conduction mechanism varied between correlated barrier hopping and large polaron tunneling. The DC conductivity was strongly depend on the dielectric loss. The transition metal salts appear to be more effective than the rare earth ones in increasingσacof films to higher values that candidates them in semiconductors industry.
Gene ontology improves template selection in comparative protein docking
Authors: Hadarovich Anna , Anishchenko Ivan , Tuzikov Alexander V. , Kundrotas Petras J. , Vakser Ilya A.
Published: December 2018

Structural characterization of protein‐protein interactions is essential for our ability to study life processes at the molecular level. Computational modeling of protein complexes (protein docking) is important as the source of their structure and as a way to understand the principles of protein interaction. Rapidly evolving comparative docking approaches utilize target/template similarity metrics, which are often based on the protein structure. Although the structural similarity, generally, yields good performance, other characteristics of the interacting proteins (eg, function, biological process, and localization) may improve the prediction quality, especially in the case of weak target/template structural similarity. For the ranking of a pool of models for each target, we tested scoring functions that quantify similarity of Gene Ontology (GO) terms assigned to target and template proteins in three ontology domains—biological process, molecular function, and cellular component (GO‐score). The scoring functions were tested in docking of bound, unbound, and modeled proteins. The results indicate that the combined structural and GO‐terms functions improve the scoring, especially in the twilight zone of structural similarity, typical for protein models of limited accuracy.
Disruption of sex‐specific doublesex exons results in male‐ and female‐specific defects in the black cutworm, Agrotis ipsilon
Authors: Chen Xien , Cao Yanghui , Zhan Shuai , Tan Anjiang , Palli Subba Reddy , Huang Yongping
Published: December 2018

BACKGROUND

Doublesex (dsx), the downstream gene in the insect sex‐determination pathway, is a key regulator of sexually dimorphic development and behavior across a variety of insects. Manipulating expression of dsx could be useful in the genetic control of insects. However, information on the sex‐specific function of dsx in non‐model insects is lacking.

RESULTS

In this work, we isolated a dsx homolog, which is alternatively spliced into six female‐specific and one male‐specific isoforms, from an important agricultural pest, the black cutworm, Agrotis ipsilon. Studies on the expression of sex‐specific Aidsx mRNA during embryonic development showed that the sixth hour post oviposition is the key stage for sex determination in A. ipsilon. Functional analysis of Aidsx was conducted using a CRISPR/Cas9 system targeting female‐ and male‐specific Aidsx exons. Disruptions of sex‐specific Aidsx exons resulted in sex‐specific, sexually dimorphic defects in external genitals, gonads and antennae, and expression of sex‐specific genes as well as production of offspring in both sexes.

CONCLUSION

Our results not only demonstrate that dsx is a key player determining A. ipsilon sexually dimorphic traits, but also provide a potential method for the genetic control of this pest. © 2018 Society of Chemical Industry
Altered clozapine concentrations associated with e‐cigarettes
Authors: Lam Y. W. Francis
Published: December 2018

Cigarette smokers have increasingly substituted traditional combustible cigarettes with electronic cigarettes, with the latter perceived by most consumers to be less harmful. However, there can be unanticipated drug interactions mediated by modulation of cytochrome P‐450 enzyme activity when a consumer switches from traditional cigarettes. This is especially relevant to patients with schizophrenia who are treated with clozapine, as they tend to smoke more and their smoking can affect metabolism of the antipsychotic.
On the dynamical coupling between atmospheric blocks and heavy precipitation events: A discussion of the southern Alpine flood in October 2000
Authors: Lenggenhager Sina , Croci‐Maspoli Mischa , Brönnimann Stefan , Martius Olivia
Published: December 2018

In October 2000, a high‐impact lake flood event occurred in southern Switzerland. During the month prior to the flood event three heavy precipitation events (HPEs) occurred. The first two events preconditioned the catchment and brought the lake close to its flood level. During the third event the lake level rose above the flood threshold. At the same time, anomalously high blocking activity was observed in the northern North Atlantic/European region. This study describes the synoptic development during the month prior to the flood and investigates the role of atmospheric blocking in the formation of the HPEs using ERA‐Interim data. Atmospheric blocks are identified as persistent negative potential vorticity (PV) anomalies in the upper troposphere. All three heavy precipitation events were forced by upper‐level equatorward elongated streams of stratospheric high‐PV air (PV streamers). These PV streamers formed in the strong deformation field upstream and downstream of single blocks or in between two blocks. During the third and most persistent heavy precipitation episode the eastward propagation of the PV streamer was prevented by a downstream block for several days leading to a stationary upper‐level northeastward flow and a prolonged period of heavy precipitation over the catchment. The study identifies and quantifies a potential feedback between heavy precipitation and blocks via diabatic depletion of PV. It is shown that a substantial fraction of the diabatically modified low‐PV air (63%) that reached and strengthened the blocks over the Atlantic and Europe during this month experienced heating in HPE areas.
Distributed containment control for first‐order and second‐order multiagent systems with arbitrarily bounded delays
Authors: Xiong Quan , Lin Peng , Chen Zhiyong , Ren Wei , Gui Weihua
Published: December 2018

This paper studies containment control with communication delays and switching topologies. Firstly, a containment control algorithm for first‐order discrete‐time followers is proposed. Then, it is extended to handle double‐integrator dynamics. The main approach is to use the convexity of the convex hull spanned by multiple stationary leaders to verify the nonincreasing monotonicity of the largest distance from the followers to the convex hull. It is shown that both algorithms are robust to arbitrarily bounded communication delays as long as each follower jointly has a path from some leaders to itself. Finally, a numerical example is implemented to illustrate the effectiveness of the theoretical results.
Regional sustainable development: The relationship between natural capital utilization and economic development
Authors: Hou Xianhui , Liu Jingming , Zhang Daojun
Published: December 2018

With the importance of sustainable development widely accepted, the relationship between natural capital utilization and economic development has become a global focus. This study analyzes the relationship between the utilization of natural capital and economic development in the countries along China's “Belt and Road” initiative using a panel regression model. The results show that the labor force, rural and urban populations, and exports and imports have a significant impact on both natural capital consumption and economic development. However, the impact of exports and imports on economic development here is contrary to economic theory and experience. We also find that there is still resource dependence in economic development and that natural capital consumption has a long‐run impact on it. To address this, the “Belt and Road” countries should adopt comprehensive national and regional measures to build a mutually beneficial cooperative mechanism and trade environment.
Analyses and Calculation of Steel Scrap Melting in a Multifunctional Hot Metal Ladle
Authors: Deng Shuai , Xu Anjun , Yang Guang , Wang Hongbing
Published: December 2018

To improve the utilization of steel scrap in the steel production process, the authors analyze the feasibility of adding scrap steel into the multifunctional ladle before hot metal tapping. Firstly, the authors provide an overview of the process. Secondly, theoretically study the melting process of scrap steel in the ladle along with the scrap steel melting mechanism is done. Finally, the effects of the addition of different types of scrap steel pretreated at various temperatures are examined using numerical calculation and simulation. The preheating temperature and specific surface area of the scrap steel had important effects on scrap steel melting. For the scrap steel with a specific surface area of 1.6 m2 t−1, the melting rate decreased by 4 min t−1 as the preheating temperature was increased from 300 °C to 800 °C. For a preheating temperature of 800 °C, the melting rate increased by 4.5 min t−1 as the specific surface area increased from 3.3 to 26.1 m2 t−1. Another 2.2%–6% of scrap steel can be added under certain conditions. This approach provides an effective solution to the problem of melting large amounts of scrap steel in steel works, further increases the utilization of scrap steel during steel production, and reduces the cost of steel production.
South African General Surgeon Preparedness for Humanitarian Disasters
Authors: Chu Kathryn M. , Karjiker Parveen , Naidu Priyanka , Kruger Deirdre , Taylor Allan , Trelles Miguel , Dominguez Lynette , Rayne Sarah
Published: December 2018

Background

Humanitarian medical organizations provide surgical care for a broad range of conditions including general surgical (GS), obstetric and gynecologic (OBGYN), orthopedic (ORTHO), and urologic (URO) conditions in unstable contexts. The most common humanitarian operation is cesarean section. The objective of this study was to identify the proportion of South African general surgeons who had operative experience and current competency in GS, OBGYN, ORTHO, and URO humanitarian operations in order to evaluate their potential for working in humanitarian disasters.

Methods

This was a cross‐sectional online survey of South African general surgeons administered from November 2017–July 2018. Rotations in OBGYN, ORTHO, and URO were quantified. Experience and competency in eighteen humanitarian operations were queried.

Results

There were 154 SA general surgeon participants. Prior to starting general surgery (GS) residency, 129 (83%) had OBGYN, 125 (81%) ORTHO, and 84 (54%) URO experience. Experience and competency in humanitarian procedures by specialty included: 96% experience and 95% competency for GS, 71% experience and 51% competency for OBGYN, 77% experience and 66% competency for ORTHO, and 86% experience and 81% competency for URO. 82% reported training, and 51% competency in cesarean section.

Conclusions

SA general surgeons are potentially well suited for humanitarian surgery. This study has shown that most SA general surgeons received training in OBGYN, ORTHO, and URO prior to residency and many maintain competence in the corresponding humanitarian operations. Other low‐ to middle‐income countries may also have broad‐based surgery training, and the potential for their surgeons to offer humanitarian assistance should be further investigated.
‘Across the Divide’: Developing Professional Learning Ecosystems in STEM Education
Authors: Ralls Deborah , Bianchi Lynne , Choudry Sophina
Published: December 2018

This paper reports the findings from a cross-sector research project designed to question how the development of university-school partnerships can influence university academics’ pedagogic practice in Science, Technology, Engineering and Mathematics (STEM). Findings from this research are offered at time when, in parallel with countries around the world, universities and schools in England are being encouraged to review and reflect on the quality of teaching and professional development, in line with the Teaching Excellence Framework consultation (2016) and the Standards for Professional Development (Department for Education 2016b) (Bianchi 2017). This paper seeks to develop a coherent response to two major issues; the policy imperative to develop greaterscienceexpertise in schools and to improve the quality of teaching and learning of science in higher education institutions. The research seeks to advance the notion of critical reflection on the quality of cross-sector STEM teaching and learning, by moving to what the OECD (Organisation for Economic Co-operation and Development) (2015, p.15) terms a “‘meso’ networked level” of professional development in STEM education. This paper highlights how interpreting the imperative of constant change in education reform as a relational, outward looking endeavour offers the potential to help both universities and schools to better address the global education challenges that lie ahead.
Dimensions of Reproductive Attitudes and Knowledge Related to Unintended Childbearing Among U.S. Adolescents and Young Adults
Authors: Guzzo Karen Benjamin , Hayford Sarah R. , Lang Vanessa Wanner , Wu Hsueh-Sheng , Barber Jennifer , Kusunoki Yasamin
Published: December 2018

Measures of attitudes and knowledge predict reproductive behavior, such as unintended fertility among adolescents and young adults. However, there is little consensus as to the underlying dimensions these measures represent, how to compare findings across surveys using different measures, or how to interpret the concepts captured by existing measures. To guide future research on reproductive behavior, we propose an organizing framework for existing measures. We suggest that two overarching multidimensional concepts—reproductive attitudes and reproductive knowledge—can be applied to understand existing research using various measures. We adapt psychometric analytic techniques to analyze two data sets: the National Longitudinal Survey of Adolescent to Adult Health (Add Health) and the Relationship Dynamics and Social Life study (RDSL). Although the specific survey measures and sample composition of the two data sets are different, the dimensionality of the concepts and the content of the items used to measure their latent factors are remarkably consistent across the two data sets, and the factors are predictive of subsequent contraceptive behavior. However, some survey items do not seem strongly related to any dimension of either construct, and some dimensions of the two concepts appear to be poorly measured with existing survey questions. Nonetheless, we argue that the concepts of reproductive attitudes and reproductive knowledge are useful for categorizing and analyzing social psychological measures related to unintended fertility. The results can be used to guide secondary data analyses to predict reproductive behavior, compare results across data sets, and structure future data collection efforts.
Links Between Strokes and Hereditary Hemorrhagic Telangiectasia: A Population-Based Study
Authors: Chowdhury Farah N. , Chandrarathne G. Sanjaya , Masilamani Kristopher D. , LaBranche Jennifer T. N. , Malo Shaun , Svenson Lawrence W. , Jeerakathil Thomas , Vethanayagam Dilini P.
Published: December 2018

Background

Hereditary hemorrhagic telangiectasia (HHT) is a disease of abnormal vasculature where patients are predisposed to strokes of multiple etiologies. We assessed yearly stroke incidence among Albertans with HHT and compared with the general population. Given the tendency for stroke in HHT patients, we expected HHT patients to have higher stroke incidence, in particular at younger ages.

Methods

Population-based administrative health data on inpatient and ambulatory admissions were extracted over a 16-year period using International Classification of Diseases (ICD)-9 and ICD-10, Canada codes. We analyzed overall occurrence of strokes in Alberta by age, gender, stroke subtype, and diagnosis of HHT.

Results

The age-standardized incidence rate of stroke in HHT was 450 per 100,000 compared with 260 per 100,000 in the general population with a rate ratio of 1.73 (95% confidence interval (CI) [1.046-2.842]). This study found a higher HHT prevalence in Alberta (1 in 3800) compared to the world average of 1 in 5000. Women were also more likely to be diagnosed with HHT, with a 3.25:1 female gender preponderance in the yearly incidence.

Interpretation

This study not only shows that HHT patients are at higher risk of having a stroke but also quantifies that risk using an age-adjusted metric in Alberta. This province has a higher than expected disease burden of HHT, with the majority of cases affecting women. Our study found that acute ischemic strokes and transient ischemic attacks are far more common than hemorrhage in HHT. As HHT is a rare, multi-system, chronic disease, these patients should be referred to an HHT Centre of Excellence.
The verbatim access effect: implicature in experimental context
Authors: SIEGEL MUFFY , ZEHR JÉRÉMY , BACOVCIN HEZEKIAH AKIVA , SCHOFIELD LYNNE STEUERLE , SCHWARZ FLORIAN
Published: December 2018

abstract

Implicature interpretation is sensitive to many contextual factors. This experimental study investigates two:

(A)

instructions to think carefully about exactly what is said

(B)

access to the verbatim form of what has been said

Participants encountered (1) below, which can give rise to the contradictory relevance implicature in (2), as feedback during a decoy task:

(1)

I’m not suggesting that you’re responding too slowly, but it’s important to give the first response that comes to mind.

(2)

(I am suggesting that) you’re responding too slowly.

When participants were questioned post-task, (B) significantly reduced rates of agreement that the speaker of (1) had said (2), whether the verbatim form provided was written (Experiment 1) or audio (Experiment 2). (A) had no such effect. In Experiment 3, we added a final task for participants: to recall (1) verbatim. One-third had forgotten it, typically substituting the implicature (2). We argue that this memory loss can explain the lower implicature rates associated with verbatim access: verbatim access reminds forgetful participants of (1)’s compositional interpretation, and that interpretation is inconsistent with the implicature in (2). Consequently, verbatim access reduces the chances of endorsing (2), thus introducing an inherent literal meaning bias in interpreting previous conversation.
Ecology and distribution ofDermatocarpon(Verrucariaceae,Ascomycota) in the catchment areas of two Bulgarian rivers
Authors: SHIVAROV Veselin V. , DENCHEV Cvetomir M. , THÜS Holger
Published: December 2018

Temperature preferences and small-scale distribution patterns of fourDermatocarpontaxa in the catchment areas of two Bulgarian rivers were analyzed. Taxa with an overall alpine or arctic-alpine distribution were restricted to microhabitats with the lowest water and rock surface temperatures. A trend for increasingDermatocarpon rivulorumthallus diameter and colony size (aggregates of thalli) with decreasing temperature was identified. Data on pH and conductivity of the water for the study sites are provided for all taxa.Dermatocarpon arnoldianumis reported for the first time from Bulgaria, confirmed by ITS sequence data, and its known range extends to South-East Europe. All previous records ofD. rivulorumfrom Bulgaria were based on misidentified specimens ofD. arnoldianum. Freshwater taxa ofDermatocarponare proposed as a tool for monitoring the biological effects of temperature changes due to global climate change. Thallus and colony size are recommended as additional features for monitoring populations of threatenedDermatocarponspecies.
From natural forest to coffee agroforest: implications for communities of large mammals in the Ethiopian highlands
Authors: Mertens Jan E. J. , Emsens Willem-Jan , Jocqué Merlijn , Geeraert Lore , De Beenhouwer Matthias
Published: December 2018

In tropical regions the extent of agricultural land is increasing rapidly at the expense of natural forest, with associated losses of biodiversity and ecosystem services. Agroforestry has long been proposed as a more sustainable agricultural system, conserving biodiversity while providing significant local livelihoods. In this context, camera traps were deployed to compare communities of large mammals between natural forest (22,272 hours across 24 deployments) and extensively managed coffee forest (19,059 hours, 23 deployments) for the first time in the south-west Ethiopian highlands. Mammal communities in the two forest types were similar in species richness and Shannon diversity but differed in community composition. Significant indicator species of coffee forest were the crested porcupineHystrix cristataand the Ethiopian hareLepus fagani, whereas leopardsPanthera pardusand civetsCivettictis civettahad a preference for natural forest. The number of detections of mammals was higher in coffee forest, where activity patterns were predominantly crepuscular and nocturnal, which may be a direct adaptation to frequent human disturbance. In natural forest, mammal activity peaked during daytime. Despite the high mammal diversity in extensively managed coffee forest, it cannot fully replace natural forest as a habitat for large mammals. We suggest that a balanced landscape mosaic of coffee and natural forest may be a valuable combination for both conservation and coffee cultivation.
Effect of selective serotonin reuptake inhibitor on prefrontal-striatal connectivity is dependent on the level of TNF-α in patients with major depressive disorder
Authors: Liu Kai , Zhao Xiaohua , Lu Xiaobing , Zhu Xiaoxia , Chen Hui , Wang Mengmeng , Yan Weixin , Jing Linlin , Deng Yanjia , Yu Lin , Wu Huawang , Wen Ge , Sun Xuegang , Lv Zhiping
Published: December 2018

Background

We hypothesize that the tumor necrosis factor-α (TNF-α) may play a role in disturbing the effect of selective serotonin reuptake inhibitor (SSRI) on the striatal connectivity in patients with major depressive disorder (MDD).

Methods

We performed a longitudinal observation by combining resting-state functional magnetic resonance imaging (rs-fMRI) and biochemical analyses to identify the abnormal striatal connectivity in MDD patients, and to evaluate the effect of TNF-α level on these abnormal connectivities during SSRI treatment. Eighty-five rs-fMRI scans were collected from 25 MDD patients and 35 healthy controls, and the scans were repeated for all the patients before and after a 6-week SSRI treatment. Whole-brain voxel-wise functional connectivity (FC) was calculated by correlating the rs-fMRI time courses between each voxel and the striatal seeds (i.e. spherical regions placed at the striatums). The level of TNF-α in serum was evaluated by Milliplex assay. Factorial analysis was performed to assess the interaction effects of ‘TNF-α × treatment’ in the regions with between-group FC difference.

Results

Compared with controls, MDD patients showed significantly higher striatal FC in the medial prefrontal cortex (MPFC) and bilateral middle/superior temporal cortices before SSRI treatment (p < 0.001, uncorrected). Moreover, a significant interaction effect of ‘TNF-α × treatment’ was found in MPFC-striatum FC in MDD patients (p = 0.002), and the significance remained after adjusted for age, gender, head motion, and episode of disease.

Conclusion

These findings provide evidence that treatment-related brain connectivity change is dependent on the TNF-α level in MDD patients, and the MPFC-striatum connectivities possibly serve as an important target in the brain.
Legitimacy, Development and Sustainability: Understanding Water Policy and Politics in Contemporary China
Authors: Moore Scott M.
Published: December 2018

More so than for other countries, the management of China's water resources is an important aspect of its policy and politics, yet existing scholarly attempts to understand this importance are scattered among a wide range of sub-literatures that lack a unifying theoretical framework. This article attempts to identify common themes and features of the relationship between water, politics and governance in contemporary China by examining how this relationship has unfolded in historical perspective. It identifies three basic objectives that have shaped the politics and governance of China's water resources over time: legitimacy, economic development and environmental sustainability. These objectives map, though imperfectly, onto different periods in the history of the People's Republic of China, thereby highlighting how they have evolved. Together, these objectives explain policies towards, and the politics of, water resources in contemporary China. This understanding shows that water both shapes and reflects Chinese politics, and highlights the need for a theoretically coherent sub-literature on Chinese water policy and politics.
Role of adolescent exposure to rockets in the links between personality vulnerability and psychopathology
Authors: Shahar Golan , Henrich Christopher C.
Published: December 2018

The aim of this study is to examine the role of repeated exposure to rocket attacks in the links between personality vulnerability (dependency and self-criticism) and internalizing/externalizing psychopathology. A main-effect vulnerability model (personality leads to psychopathology) was compared with a main-effect scarring model (psychopathology leads to personality vulnerability). Also, a stress-diathesis pattern (personality vulnerability is activated under stress) was compared to a dual-vulnerability pattern (either personality vulnerability or stress, but not both, lead to psychopathology). Israeli adolescents (N = 362) repeatedly exposed to rocket attacks were assessed annually over 3 years. In 2008 and 2010, personality and psychopathology were assessed. Cumulative exposure was measured as the sums of exposure across the three assessment waves. Theoretical models were tested via Autoregressive Cross-Lagged Structural Equation Modeling analyses. Baseline dependency and self-criticism were associated with an increase in anxiety, whereas baseline depression was associated with an increase in dependency. Under low, not high, levels of rocket exposure, self-criticism and depression were longitudinally associated. Violence commission was associated with an increase in dependency under high, not low, cumulative exposure. Results are consistent with both scarring and vulnerability models, and with both stress-diathesis and dual-vulnerability patterns of adolescent risk and resilience.
Role of FGF signalling in neural crest cell migration during early chick embryo development
Authors: Zhang Xiao-tan , Wang Guang , Li Yan , Chuai Manli , Lee Kenneth Ka Ho , Yang Xuesong
Published: December 2018

Fibroblast growth factor (FGF) signalling acts as one of modulators that control neural crest cell (NCC) migration, but how this is achieved is still unclear. In this study, we investigated the effects of FGF signalling on NCC migration by blocking this process. Constructs that were capable of inducing Sprouty2 (Spry2) or dominant-negative FGFR1 (Dn-FGFR1) expression were transfected into the cells making up the neural tubes. Our results revealed that blocking FGF signalling at stage HH10 (neurulation stage) could enhance NCC migration at both the cranial and trunk levels in the developing embryos. It was established that FGF-mediated NCC migration was not due to altering the expression of N-cadherin in the neural tube. Instead, we determined that cyclin D1 was overexpressed in the cranial and trunk levels when Sprouty2 was upregulated in the dorsal neural tube. These results imply that the cell cycle was a target of FGF signalling through which it regulates NCC migration at the neurulation stage.
Diminished Risk-Aversion After Right DLPFC Stimulation: Effects of rTMS on a Risky Ball Throwing Task
Authors: Tulviste Jaan , Bachmann Talis
Published: December 2018

Objectives: Several studies on human risk taking and risk aversion have reported the involvement of the dorsolateral prefrontal cortex (DLPFC). Yet, current knowledge of the neural mechanisms of risk-related decision making is not conclusive, mainly relying on studies using non-motor tasks. Here we examine how modulation of DLPFC activity by repetitive transcranial magnetic stimulation (rTMS) affects risk-taking behavior during a motor response task. Methods: One-Hertz rTMS to the right DLPFC was applied to monitor risk-taking and risk-aversion performance during a goal-directed risky task with motor response. Healthy participants were instructed to aim for a high score by throwing a ball as close to the ceiling as possible, while avoiding touching the ceiling with the ball. Results: One-Hertz rTMS stimulation to the right DLPFC significantly increased the frequency of ceiling hits, compared to Sham-stimulation. Conclusions: Our results suggest that the right DLPFC is a valid target for manipulating risky behavior in tasks with a motor-response. Following rTMS stimulation participants' preference shifts toward immediate awards, while becoming significantly less sensitive to potential negative consequences. The results confirm that the right DLPFC is involved in impulse control in goal-directed executive tasks. (JINS, 2019, 25, 72–78)
Subduction Erosion, Crustal Structure, and an Evolutionary Model of the Northern Yap Subduction Zone: New Observations From the Latest Geophysical Survey
Authors: Zhang Z. Y. , Dong D. D. , Sun W. D. , Wu S. G. , Bai Y. L. , Wang X. J. , Fan J. K.
Published: December 2018

The Yap subduction zone is a distinctive erosive margin with an extremely slow convergence rate. The high relief of the subducting plate, generated by horst and graben structures and seamounts, leads to attenuation of the crust. In this study, we present the latest geophysical data, collected by the Chinese research vessel Kexue, to investigate subduction erosion at the Yap subduction zone and develop subduction models for Yap subduction zone structures. We show an anomalous distance between the Yap Trench and the adjacent volcanic arc, the steep slope of the trench arcward, a frontal prism, and rare sediment in the trench, all typical features of erosive margins. We propose that the high‐relief subducting plate has led to erosion of the overlying plate and that different subduction processes, controlled locally by the topography of the subducting plate, have modified the Yap subduction zone. Numerous normal faults increase the relief of the seafloor entering the trench, and an anomalously large slope angle along the trench reflects uplift of the fore‐arc high via seamount subduction. In addition, the thin crust of the subducted horst and graben structures, along with the normal faults, might have eroded the fore‐arc crust and subsequently eroded the Yap arc crust during subduction. These subduction erosional processes at the Yap Trench provide one of the best cases of an erosive margin in the world, particularly for a subduction zone with an extremely slow convergence rate.
Constraints on the Physical Mechanism of Frictional Aging From Nanoindentation
Authors: Thom C. A. , Carpick R. W. , Goldsby D. L.
Published: December 2018

The increase in the frictional strength of rocks with the time of quasi‐stationary contact, known as frictional aging, may ultimately determine whether unstable slip (i.e., earthquakes) can nucleate. In spite of its importance, the physical mechanism that underlies frictional aging in rocks is still uncertain. The widely held view is that aging results from an increase in contact area due to asperity creep. Here we show via nanoindentation testing that the hardness and creep rate of quartz are independent of relative humidity from <10−4% to 50%. This contrasts strongly with the standard interpretation of previous friction experiments on quartz tested over a similar humidity range, which reveal an absence of frictional aging for humidity <5%. Our results demonstrate that frictional aging in quartz cannot result from asperity creep and instead argue in favor of other mechanisms, including time‐dependent chemical bond formation or slip‐induced strengthening.
What Caused the Remarkable February 2018 North Greenland Polynya?
Authors: Moore G. W. K. , Schweiger A. , Zhang J. , Steele M.
Published: December 2018

During late February and early March 2018, an unusual polynya was observed off the north coast of Greenland. This period was also notable for the occurrence of a sudden stratospheric warming. Here we use satellite and in situ data, a reanalysis and an ice‐ocean model to document the evolution of the polynya and its synoptic forcing. We show that its magnitude was unprecedented and that it was associated with the transient response to the sudden stratospheric warming leading to anomalous warm southerly flow in north Greenland. Indeed, regional wind speeds and temperatures were the highest during February going back to the 1960s. There is evidence that the thinning sea ice has increased its wind‐driven mobility. However, we show that the polynya would have developed under thicker ice conditions representative of the late 1970s and that even with the predicted trend toward thinner sea ice, it will only open during enhanced southerly flow.
Response of the Atmospheric Boundary Layer to Submesoscale Sea Surface Temperature Fronts
Authors: Wenegrat J. O. , Arthur R. S.
Published: December 2018

Submesoscale sea surface temperature fronts are ubiquitous throughout much of the global ocean; however, the response of the marine atmospheric boundary layer (MABL) to the ocean submesoscale is not well understood. In this manuscript large‐eddy simulation is used to explore the time‐dependent response of the MABL to idealized submesoscale sea surface temperature fronts, with an emphasis on how the dynamics of the MABL determine the strength and position of gradients in wind speed and air temperature. Results suggest that horizontal mixing only becomes important in response to frontogenesis by horizontally convergent ageostrophic flows, contrary to the common assumption that the MABL response will be strongly dependent on horizontal turbulent mixing. The fronts that develop in the MABL are also associated with large vertical relative vorticity, suggesting the possibility that submesoscale fronts may induce inertial instability in the MABL. These results provide guidance for high‐resolution ocean and atmosphere modeling and for interpreting observations.
Geochronology of a Bouguer Gravity Low
Authors: Gaynor Sean P. , Coleman Drew S. , Rosera Joshua M. , Tappa Michael J.
Published: December 2018

Dense drill core and subsurface mapping at the Questa molybdenum mine, combined with regional structural tilt, permit detailed 3‐D documentation of plutonic rocks in the Latir magmatic center, New Mexico. Integration of mapping with new and existing U‐Pb zircon geochronology (a total of 136 analyses from 15 intrusions) allows for examination of the space‐time evolution of the Bouguer gravity low associated with the magmatic center. The Questa batholith at Latir was assembled by discrete pulses of magma over a 5.5‐Ma interval (approximately 25.3–19.8 Ma) of generally downward stacking intrusions following the volcanic peak at 25.52 Ma. This contradicts interpretations that the Bouguer gravity lows here and elsewhere are the plutonic crystal cumulate residues left after extraction of large‐volume silicic magmas. Estimates of magma flux based on the volume of plutonic rocks inferred from gravity data combined with the extrapolation of geochronology of exposed surface rocks are questionable because the assumption that unexposed plutonic rocks are the same age as dated surface rocks directly above them likely underestimates the true range of ages.
Thermal, Deformation, and Degassing Remote Sensing Time Series (CE 2000–2017) at the 47 most Active Volcanoes in Latin America: Implications for Volcanic Systems
Authors: Reath K. , Pritchard M. , Poland M. , Delgado F. , Carn S. , Coppola D. , Andrews B. , Ebmeier S. K. , Rumpf E. , Henderson S. , Baker S. , Lundgren P. , Wright R. , Biggs J. , Lopez T. , Wauthier C. , Moruzzi S. , Alcott A. , Wessels R. , Griswold J. , Ogburn S. , Loughlin S. , Meyer F. , Vaughan G. , Bagnardi M.
Published: December 2018

Volcanoes are hazardous to local and global populations, but only a fraction are continuously monitored by ground‐based sensors. For example, in Latin America, more than 60% of Holocene volcanoes are unmonitored, meaning long‐term multiparameter data sets of volcanic activity are rare and sparse. We use satellite observations of degassing, thermal anomalies, and surface deformation spanning 17 years at 47 of the most active volcanoes in Latin America and compare these data sets to ground‐based observations archived by the Global Volcanism Program. This first comparison of multisatellite time series on a regional scale provides information regarding volcanic behavior during, noneruptive, pre‐eruptive, syneruptive, and posteruptive periods. For example, at Copahue volcano, deviations from background activity in all three types of satellite measurements were manifested months to years in advance of renewed eruptive activity in 2012. By quantifying the amount of degassing, thermal output, and deformation measured at each of these volcanoes, we test the classification of these volcanoes as open or closed volcanic systems. We find that ~28% of the volcanoes do not fall into either classification, and the rest show elements of both, demonstrating a dynamic range of behavior that can change over time. Finally, we recommend how volcano monitoring could be improved through better coordination of available satellite‐based capabilities and new instruments.
On the Effects of Increased Vertical Mixing on the Arctic Ocean and Sea Ice
Authors: Liang Xi , Losch Martin
Published: December 2018

Against the backdrop of Arctic sea ice decline, vertical mixing in the interior Arctic Ocean will most likely change, but it is still unclear how the Arctic Ocean and sea ice will respond. In this paper, a sea ice‐ocean model with a simple parameterization for interior background mixing is used to investigate the Arctic Ocean and sea ice response to a scenario of increased vertical mixing. It is found that more vertical mixing reduces sea ice thickness all year round and decreases summertime sea ice concentration. More vertical mixing leads to a cooling of the Arctic halocline layer and Atlantic Water layer below. The increased vertical mixing speeds up vertical heat and salinity exchange, brings the underlying warm and saline water into the surface layer, and contributes to the sea ice decline. Vertical salinity gradient of the Arctic halocline layer reduces together with a much fresher Atlantic Water layer, and more volume of saline water enters the deep ocean below the Atlantic Water layer. As a result, the reduced Arctic Ocean stratification leads to an adjustment of the circulation pattern. Cyclonic circulation anomalies occur in the surface layer shallower than 20‐m depth and in the interior ocean deeper than 700‐m depth, while anticyclonic circulation anomalies occur between these depths. Our study suggests that the extra heat and salinity exchange induced by more vertical mixing will have a noticeable impact on the upper ocean structure, ocean circulation, and sea ice in a changing Arctic Ocean.