bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption of Cu(II) and Methylene Blue by Succinylated Starch Nanocrystals
Authors: Chen Qi‐Jie , Zheng Xue‐Ming , Zhou Li‐Ling , Zhang Yue‐Fei
Published: February 2019

Starch nanocrystals (SNCs) have a small particle size and large surface area compared with traditional modified starch. In this study, SNCs were chemically modified by succinic anhydride in aqueous alkaline condition. With the ratio of succinic anhydride/SNCs (0.1–0.5) increasing, the degree of substitution of succinylated SNCs increases from 0.0481 to 0.1009, and the zeta potential becomes more negative. The SNCs and succinylated SNCs were characterized by Fourier transform infrared (FTIR), Scanning Electron Microscopy (SEM) and X‐ray diffraction (XRD). The adsorption of Cu(II) and methylene blue (MB) by SNCs and succinylated SNCs in aqueous solutions is also studied. The results show that succinylated SNCs have great adsorption capacity for Cu(II) and MB. The pseudo‐second‐order kinetics is correspond both with the adsorption of Cu(II) or MB and are also found to be well fitted by Freundlich isotherms model, which shows that adsorption of Cu(II) or MB on succinylated SNCs is mainly multilayer adsorption.
Assessment of model error for reinforced concrete beams with steel fibers in bending
Authors: Foster Stephen J. , Parvez Ahsan
Published: February 2019

Numerous models have been developed to determine the strength contributions of steel fibers in reinforced concrete beams in flexure; however, little work has been undertaken on determining their reliability, particularly when combined with use of inverse analysis procedures for determining the postcracking residual tensile strength provided by the fibers. Recently, leading codes have accepted design guidelines for designing flexurally reinforced concrete structural elements that also contain steel fibers using rational principles that are compatible with conventional reinforced concrete design. To provide confidence to the designer, it is imperative to verify the design models against experimental results and test their reliability. Despite extensive studies, design models have not been validated against large amount of test data. In this paper, 50 flexurally reinforced steel fiber reinforced concrete beams from the literature are analyzed for flexural strength. Ultimate moment capacities are predicted using the design procedures of NZS 3101–2–2006, fib Model Code 2010, DAfStb Guideline‐2015 and AS3600–2018. The results of the analyses show that the models perform well, with the AS3600 being the most conservative of the models assessed, and the NZS 3101–2–2006 the least conservative. The model errors for each are determined, and model reliability is discussed.
Plasmon‐Enhanced Fluorescence Resonance Energy Transfer
Authors: Zong Huan , Wang Xinxin , Mu Xijiao , Wang Jingang , Sun Mengtao
Published: February 2019

In this review, we firstly introduce physical mechanism of fluorescence resonance energy transfer (FRET), the methods to measure FRET efficiency, and the applications of FRET. Secondly, we introduce the principle and applications of plasmon‐enhanced fluorescence (PEF). Thirdly, we focused on the principle and applications of plasmon‐enhanced FRET. This review can promote further understanding of FRET and PE‐FRET.
Ligand Mediated Morphology of the Two‐Dimensional Uranyl Aqua Sulfates [UO2(X)(SO4)(H2O)] [X = Cl– or (CH3)3NCH2COO]
Authors: Smith Philip A. , Burns Peter C.
Published: February 2019

Two uranyl aqua sulfate compounds: [(CH3)3NCH2COOH] [UO2(Cl)(SO4)(H2O)] (1) and UO2((CH3)3NCH2COO)(SO4)(H2O) (2) were synthesized and their crystal structures were determined. The morphology changes between the two‐dimensional anionic structural unit of 1 and the neutral structural unit of 2 are examined, and the impact of their terminally coordinating ligands discussed.
Transactions for trading used electric vehicle batteries: theoretical underpinning and information systems design principles
Authors: Bräuer Sebastian , Plenter Florian , Klör Benjamin , Monhof Markus , Beverungen Daniel , Becker Jörg
Published: February 2019

Proof-of-concept projects have demonstrated that used electric vehicle batteries (EVBs), after their removal from electric vehicles due to insufficient performance, can be repurposed for less demanding applications. It is expected that numerous batteries will be available for repurposing in the 2020s. However, the information asymmetries and transaction costs of trading used EVBs have remained unexplored, as have principles that guide the design of information systems that support the trade. Based on existing literature and in-depth interviews with battery experts, we conceptualize two key transactions for trading used EVBs. We then identify potential information asymmetries and transaction costs based on new institutional economic theory and propose five design principles that information systems should implement to address these information asymmetries and transaction costs. Subsequent research can build on our results to further frame the economic properties of trading used EVBs and to design information systems in line with new institutional economic theory.
Early versus late MCI: Improved MCI staging using a neuropsychological approach
Authors: Edmonds Emily C. , McDonald Carrie R. , Marshall Anisa , Thomas Kelsey R. , Eppig Joel , Weigand Alexandra J. , Delano‐Wood Lisa , Galasko Douglas R. , Salmon David P. , Bondi Mark W. ,   Alzheimer's Disease Neuroimaging Initiative
Published: February 2019

Introduction

The Alzheimer's Disease Neuroimaging Initiative (ADNI) separates “early” and “late” mild cognitive impairment (MCI) based on a single memory test. We compared ADNI's MCI classifications to our neuropsychological approach, which more broadly assesses cognitive abilities.

Methods

Three hundred thirty‐six ADNI‐2 participants were classified as “early” or “late” MCI. Cluster analysis was performed on neuropsychological test data, and participants were reclassified based on cluster results. These two staging approaches were compared on progression rates, cerebrospinal fluid biomarkers, and cortical thickness profiles.

Results

There was little correspondence between the two staging methods. ADNI's early MCI group included a large proportion of false‐positive diagnostic errors. The reclassified neuropsychological MCI groups showed steeper survival curves and more abnormal biomarkers.

Conclusions

Our novel neuropsychological approach improved the staging of MCI by (1) capturing individuals at an early symptomatic stage, (2) minimizing false‐positive cases, and (3) identifying a late MCI group further along the disease trajectory.
Aligning systems science and community-based participatory research: A case example of the Community Health Advocacy and Research Alliance (CHARA)
Authors: Davis Melinda M. , Lindberg Paul , Cross Suzanne , Lowe Susan , Gunn Rose , Dillon Kristen
Published: February 2019

Partnered research may help bridge the gap between research and practice. Community-based participatory research (CBPR) supports collaboration between scientific researchers and community members that is designed to improve capacity, enhance trust, and address health disparities. Systems science aims to understand the complex ways human-ecological coupled systems interact and apply knowledge to management practices. Although CBPR and systems science display complementary principles, only a few articles describe synergies between these 2 approaches. In this article, we explore opportunities to utilize concepts from systems science to understand the development, evolution, and sustainability of 1 CBPR partnership: The Community Health Advocacy and Research Alliance (CHARA). Systems science tools may help CHARA and other CBPR partnerships sustain their core identities while co-evolving in conjunction with individual members, community priorities, and a changing healthcare landscape. Our goal is to highlight CHARA as a case for applying the complementary approaches of CBPR and systems science to (1) improve academic/community partnership functioning and sustainability, (2) ensure that research addresses the priorities and needs of end users, and (3) support more timely application of scientific discoveries into routine practice.
Transition to adulthood and adult health care for patients with sickle cell disease or cystic fibrosis: Current practices and research priorities
Authors: Lanzkron Sophie , Sawicki Gregory S. , Hassell Kathryn L. , Konstan Michael W. , Liem Robert I. , McColley Susanna A.
Published: February 2019

Introduction

A growing population of adults living with severe, chronic childhood-onset health conditions has created a need for specialized health care delivered by providers who have expertise both in adult medicine and in those conditions. Optimal care of these patients requires systematic approaches to healthcare transition (HCT). Guidelines for HCT exist, but gaps in care occur, and there are limited data on outcomes of HCT processes.

Methods

The Single Disease Workgroup of the Lifespan Domain Task Force of the National Center for Advancing Translational Sciences Clinical and Translational Science Award programs convened a group to review the current state of HCT and to identify gaps in research and practice. Using cystic fibrosis and sickle cell disease as models, key themes were developed. A literature search identified general and disease-specific articles. We summarized key findings.

Results

We identified literature characterizing patient, parent and healthcare provider perspectives, recommendations for transition care, and barriers to effective transition.

Conclusions

With increased survival of patients with severe childhood onset diseases, ongoing study of effective transition practices is essential as survival increases for severe childhood onset diseases. We propose pragmatic methods to enhance transition research to improve health and key outcomes.
AMALGAMABLE DIAGRAM SHAPES
Authors: CHEN RUIYUAN
Published: February 2019

A category has the amalgamation property (AP) if every pushout diagram has a cocone, and the joint embedding property (JEP) if every finite coproduct diagram has a cocone. We show that for a finitely generated category I, the following are equivalent: (i) every I-shaped diagram in a category with the AP and the JEP has a cocone; (ii) every I-shaped diagram in the category of sets and injections has a cocone; (iii) a certain canonically defined category ${\cal L}\left( {\bf{I}} \right)$ of “paths” in I has only idempotent endomorphisms. When I is a finite poset, these are further equivalent to: (iv) every upward-closed subset of I is simply-connected; (v) I can be built inductively via some simple rules. Our proof also shows that these conditions are decidable for finite I.
Detecting DSM-5 somatic symptom disorder: criterion validity of the Patient Health Questionnaire-15 (PHQ-15) and the Somatic Symptom Scale-8 (SSS-8) in combination with the Somatic Symptom Disorder – B Criteria Scale (SSD-12)
Authors: Toussaint Anne , Hüsing Paul , Kohlmann Sebastian , Löwe Bernd
Published: February 2019

Background

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) introduced somatic symptom and related disorders (SSD) to improve the diagnosis of somatoform disorders. It is unclear whether existing questionnaires are useful to identify patients with SSD. Our study investigates the diagnostic accuracy of the Patient Health Questionnaire-15 (PHQ-15) and the Somatic Symptom Scale-8 (SSS-8) in combination with the Somatic Symptom Disorder – B Criteria Scale (SSD-12).

Methods

For this cross-sectional study, participants were recruited from a psychosomatic outpatient clinic. PHQ-15, SSS-8, and SSD-12 were administered and compared with SSD criteria from a diagnostic interview. Sensitivity and specificity were calculated for optimal individual and combined cutpoints. Receiver operator curves were created and area under the curve (AUC) analyses assessed.

Results

Data of n = 372 patients [31.2% male, mean age: 39.3 years (s.d. = 13.6)] were analyzed. A total of 56.2% fulfilled the SSD criteria. Diagnostic accuracy was moderate for each questionnaire (PHQ-15: AUC = 0.70; 95% CI = 0.65–0.76; SSS-8: AUC = 0.71; 95% CI = 0.66–0.77; SSD-12: AUC = 0.74; 95% CI = 0.69–0.80). Combining questionnaires improved diagnostic accuracy (PHQ-15 + SSD-12: AUC = 0.77; 95% CI = 0.72–0.82; SSS-8 + SSD-12: AUC = 0.79; 95% CI = 0.74–0.84). Optimal combined cutpoints were ⩾9 for the PHQ-15 or SSS-8, and ⩾23 for the SSD-12 (sensitivity and specificity = 69% and 70%).

Conclusions

The combination of the PHQ-15 or SSS-8 with the SSD-12 provides an easy-to-use and time- and cost-efficient opportunity to identify persons at risk for SSD. If systematically applied in routine care, effective screening and subsequent treatment might help to improve quality of life and reduce health care excess costs.
Environmental contaminants and child’s growth
Authors: Kadawathagedara M. , de Lauzon-Guillain B. , Botton J.
Published: February 2019

Experimental data have suggested that some contaminants in the environment may increase the risk of obesity. Infants can be exposed to chemicals either prenatally, by trans-placental passage of chemicals, or postnatally by their own diet and by other external pathways (air inhalation, dust, hand-to-mouth exposure) after birth. To provide a review of epidemiological evidence on the association between prenatal exposure to chemicals and prenatal and postnatal growth, we present the literature from systematic review articles and international meta-analyses, when available, or recent research articles when summarizing articles were not available. The most studied contaminants in this field were persistent organic pollutants (e.g. organochlorinated pesticides, polychlorinated biphenyls), non-persistent pollutants (e.g. phthalates, bisphenol A), toxic heavy metals (i.e. cadmium, lead and mercury), arsenic, mycotoxins and acrylamide. Mounting evidence suggests that child’s growth may be associated with prenatal or postnatal exposures to environmental contaminants. Improving exposure assessment and studying the contaminants as mixtures should allow to gain knowledge about the environmental determinants of growth and obesity.
Significant Floodplain Soil Organic Carbon Storage Along a Large High‐Latitude River and its Tributaries
Authors: Lininger K. B. , Wohl E. , Rose J. R. , Leisz S. J.
Published: February 2019

High‐latitude permafrost regions store large stocks of soil organic carbon (OC), which are vulnerable to climate warming. Estimates of subsurface carbon stocks do not take into account floodplains as unique landscape units that mediate and influence the delivery of materials into river networks. We estimate floodplain soil OC stocks within the active layer (seasonally thawed layer) and to a maximum depth of 1 m from a large field data set in the Yukon Flats region of interior Alaska. We compare our estimated stocks to a previously published data set and find that the OC stock estimate using our field data could be as much as 68% higher than the published data set. Radiocarbon measurements indicate that sediment and associated OC can be stored for thousands of years before erosion and transport. Our results indicate the importance of floodplains as areas of underestimated carbon storage, particularly because climate change may modify geomorphic processes in permafrost regions.
Intensification of El Niño Rainfall Variability Over the Tropical Pacific in the Slow Oceanic Response to Global Warming
Authors: Zheng Xiao‐Tong , Hui Chang , Xie Shang‐Ping , Cai Wenju , Long Shang‐Min
Published: February 2019

Changes in rainfall variability of El Niño–Southern Oscillation (ENSO) are investigated under scenarios where the greenhouse gases increase and then stabilize. During the period of increasing greenhouse forcing, the ocean mixed layer warms rapidly. After the forcing stabilizes, the deeper ocean continues to warm the surface (the slow response). We show that ENSO rainfall variability over the tropical Pacific intensifies in both periods but the rate of increase per degree global mean surface temperature (GMST) warming is larger for the slow response because of greater relative warming in the base state as the mean upwelling changes from a damping to a driver of the surface warming. Our results have important implications for climate extremes under GMST stabilization that the Paris Agreement calls for. To stabilize GMST, the fast surface cooling offsets the slow warming from the prior greenhouse gas increase, while ENSO rainfall variability would continue to increase.
Conditions for the Long‐Term Preservation of a Deep Brine Reservoir in Ceres
Authors: Castillo‐Rogez Julie C. , Hesse M. A. , Formisano M. , Sizemore H. , Bland M. , Ermakov A. I. , Fu R. R.
Published: February 2019

We propose a new internal evolution model for the dwarf planet Ceres matching the constraints on Ceres' present internal state from the Dawn mission observations. We assume an interior differentiated into a volatile‐dominated crust and rocky mantle, and with remnant brines in the mantle, all consistent with inferences from the Dawn geophysical observations. Simulations indicate Ceres should preserve a warm crust until present if the crust is rich in clathrate hydrates. The temperature computed at the base of the crust exceeds 220 K for a broad range of conditions, allowing for the preservation of a small amount of brines at the base of the crust. However, a temperature ≥250 K, for which at least 1 wt.% sodium carbonate gets in solution requires a crustal abundance of clathrate hydrates greater than 55 vol.%, a situation possible for a narrow set of evolutionary scenarios.
Mid‐Proterozoic Ferruginous Conditions Reflect Postdepositional Processes
Authors: Slotznick Sarah P. , Webb Samuel M. , Kirschvink Joseph L. , Fischer Woodward W.
Published: February 2019

To evaluate the mechanics of mid‐Proterozoic environmental iron transport and deposition, we coupled microscale textural and bulk rock magnetic techniques to study the ~1.4‐Ga lower Belt group, Belt Supergroup, Montana and Idaho. We identified a pyrrhotite‐siderite isograd that marks metamorphic iron‐bearing mineral reactions beginning in subgreenschist facies samples. Even in the best‐preserved parts of the basin, secondary overprints were common including recrystallization of iron‐bearing sulfides, base metal sulfides, and nanophase pyrrhotite. Despite these overprints, a record of redox chemistry was preserved in the early diagenetic framboidal pyrite and detrital iron oxides including trace nanoscale magnetite that remained after sulfidization in anoxic and sulfidic sedimentary pore fluids. Based on these results, we interpret the Belt Basin as having oxic waters, at least in shallow‐water environments, with no indication of abundant ferrous iron in the water column; this is consistent with the cooccurrence of early eukaryotic fossils within the same strata.
Greening in Rural Areas Increases the Surface Urban Heat Island Intensity
Authors: Yao Rui , Wang Lunche , Huang Xin , Gong Wei , Xia Xiangao
Published: February 2019

In this study, Moderate Resolution Imaging Spectroradiometer land cover, land surface temperature (LST), and enhanced vegetation index (EVI) data were used to investigate the trends of surface urban heat island intensity (SUHII, urban LST minus rural LST) and their relations with vegetation in 397 global big cities during 2001–2017. Major findings include the following: (1) Annual daytime and nighttime SUHII increased significantly (p < 0.05, Mann‐Kendall trend test) in 42.1% and 30.5% cities, respectively. (2) The daytime SUHII in the growing season was significantly and positively correlated with rural EVI in 58.9% cities. This is because high rural EVI can increase the EVI difference between urban and rural areas. (3) Rural greening contributed 22.5% of the increased daytime SUHII in the growing season at the global scale. This study highlights that the effect of greening in rural areas was a significant and widespread driver for the increased daytime SUHII.
Crustal Structure Across the Lord Howe Rise, Northern Zealandia, and Rifting of the Eastern Gondwana Margin
Authors: Gallais Flora , Fujie Gou , Boston Brian , Hackney Ron , Kodaira Shuichi , Miura Seiichi , Nakamura Yasuyuki , Kaiho Yuka
Published: February 2019

During the Late Cretaceous, the fragmentation of eastern Gondwana led to the formation of the narrow eastern Australian margin and the wide Lord Howe Rise during the opening of the oceanic Tasman Basin. To provide crustal‐scale constraints on this margin, a 680‐km‐long, east‐west oriented refraction transect with 100 ocean bottom seismometers was acquired from the Tasman Basin to the Lord Howe Rise. After traveltime tomographic inversion of the first refracted arrivals and reflected arrivals from the Moho, the final P wave velocity model reveals strong variations in crustal thickness. The Tasman Basin is floored by a two‐layered and 7‐km‐thick oceanic crust. To the east, the Middleton Basin separates the Dampier Ridge, with 16‐km‐thick continental crust, from the Lord Howe Rise, where the extended continental crust is 20–23 km thick. Below the Middleton Basin, Moho reflections are recorded at the base of 7‐km‐thick crust. The velocity gradient of this two‐layer crust suggests an oceanic origin for the Middleton Basin. Our results show no clear evidence for mantle exhumation or a sizable igneous intrusion within three separate and relatively narrow (<70 km) necking zones. The northwestern Zealandia margin thus appears to be magma poor and, despite the considerable width of this margin (>1,000 km), the lack of evidence for mantle exhumation, the evidence for oceanic crust under the Middleton Basin, and the narrow necking zones combine to suggest that northern Zealandia is not a hyperextended margin.
Shallow Creep Along the 1999 Izmit Earthquake Rupture (Turkey) From GPS and High Temporal Resolution Interferometric Synthetic Aperture Radar Data (2011–2017)
Authors: Aslan Gokhan , Lasserre Cécile , Cakir Ziyadin , Ergintav Semih , Özarpaci Seda , Dogan Ugur , Bilham Roger , Renard François
Published: February 2019

Characterizing the spatiotemporal evolution of creep is essential to constrain fault slip budget and understand creep mechanism. Studies based on interferometric synthetic aperture radar and Global Positioning System (GPS) satellite observations until 2012 have shown that the central segment of the 17 August 1999 Mw 7.4 Izmit earthquake on the North Anatolian Fault began slipping aseismically following the event. In the present study, we combine new interferometric synthetic aperture radar time series, based on TerraSAR‐X and Sentinel 1A/B radar images acquired over the period 2011–2017, with near‐field GPS measurement campaigns performed every 6 months from 2014 to 2016. The mean velocity fields reveal that creep on the central segment of the 1999 Izmit fault rupture continues to decay, more than 19 years after the earthquake, in overall agreement with models of postseismic afterslip decaying logarithmically with time for a long period of time. Along the fault section that experienced supershear velocity rupture during the Izmit earthquake creep continues with a rate up to ~ 8 mm/year. A significant transient accelerating creep is detected in December 2016 on the Sentinel‐1 time series, near the maximum creep rate location, associated with a total surface slip of 10 mm released in 1 month only. Additional analyses of the vertical velocity fields show a persistent subsidence on the hanging wall block of the Golcuk normal fault that also ruptured during the Izmit earthquake. Our results demonstrate that afterslip processes along the North Anatolian Fault east‐southeast of Istanbul are more complex than previously proposed as they vary spatiotemporally along the fault.
Spatial Variability and Temporal Persistence of Event Runoff Coefficients for Cropland Hillslopes
Authors: Chen Bo , Krajewski Witold F. , Helmers Matthew J. , Zhang Zhuodong
Published: February 2019

Using data collected from collocated hillslopes in central Iowa, the United States, the authors (1) explored the spatial variability of runoff coefficient at the event scale by examining the relationships between the standard deviation and coefficient of variation of runoff coefficient and the mean and (2) analyzed the temporal persistence of spatial pattern of runoff coefficient using Spearman rank and Pearson correlation coefficient. This study considered 12 cropland hillslopes with 0–20% native prairie vegetation coverage distributed at different hillslope locations. Seventy runoff events over the period 2008–2011 were investigated, of which 51 occurred during crop active growing season, when the hydrologic responses of crops and prairie vegetation are similar. For these events, the spatial coefficient of variation had a median value of 0.80, which indicate high variation of event‐scale runoff coefficients across neighboring hillslopes. This spatial variation largely cannot be consistently explained by the individual hillslope structural properties investigated. The standard deviation and mean of runoff coefficient showed a convex upward relationship across the range of runoff coefficients, with the maximum standard deviation value at the mean runoff coefficient of about 0.48. The coefficient of variation exponentially decreased with increasing runoff coefficient. For 71% of the cases, the results of both correlation analyses were statistically significant (p ≤ 0.05), which indicate stable spatial pattern of runoff coefficient across events. This temporal persistence could be disrupted under extremely dry and wet conditions. The spatial variation‐mean empirical relation and the temporal persistence of spatial pattern provide insight for parameterizing spatial variability of runoff coefficient in distributed hydrologic models.
Simulation Model for Collaborative Decision Making on Sediment Source Reduction in an Intensively Managed Watershed
Authors: Cho Se Jong , Wilcock Peter R. , Belmont Patrick , Gran Karen B. , Hobbs Benjamin F.
Published: February 2019

We developed a watershed sediment source and delivery model for use in evaluating conservation trade‐offs in southern Minnesota, where sediment loading has been identified as a priority and there is substantial public investment in cleaner water. The model was developed in a stakeholder process and links user‐specified management options to reductions in sediment loading at the outlet of a 2,880‐km2 intensively farmed watershed. The simulation model was formulated to allocate total sediment load among sources, which provides robustness to the model by constraining the relative magnitude of sediment loads and their reduction. A novel topographic filtering approach was used to develop spatially distributed maps of sediment delivery ratio, addressing the problem of storage between source and outlet. The dominant sediment source in the watershed is erosion of steep streamside bluffs in response to increases in river discharge. Rates of bluff erosion as a function of river discharge were determined from sediment loads measured at pairs of gages on individual streams. Using this analysis, upland water storage to reduce peak river flow was included as an option in the model. The model development process was designed to promote transparency and develop stakeholder trust through multiple meetings in which an underlying sediment budget was developed and refined. The model runs rapidly, providing real‐time response to user choice and supporting Monte Carlo simulation of the influence of uncertainty on the calculated sediment load. The stakeholder group used the model to identify a priority strategy for investing public funds to improve water quality.
The Meteorological Culprits Behind Strange and Deadly Floods
Authors: Sidder Aaron
Published: February 2019

A new study examines how unusual meteorology interacted with topography and other local conditions to generate some of the most devastating floods in American history.
Offshore Pumping Impacts Onshore Groundwater Resources and Land Subsidence
Authors: Yu Xuan , Michael Holly A.
Published: February 2019

Freshened groundwater exists offshore along many coastlines worldwide. Pumping of these offshore resources has been proposed for more efficient oil production as well as drinking and agriculture. Although pumping can occur tens to hundreds of kilometers offshore, these activities may threaten connected onshore aquifer systems. We conducted numerical simulations of variable‐density groundwater flow and salt transport in coastal aquifers with different geologic structure subject to offshore pumping to assess potential impacts. Results show that offshore pumping can diminish both onshore groundwater availability and submarine groundwater discharge and can cause widespread land subsidence. Heterogeneity increases water resource vulnerability relative to equivalent homogeneous and layered systems and exacerbates the magnitude of land subsidence. More continuous geologic structure causes propagation of maximum subsidence farther landward. This work suggests that coastal aquifers may be vulnerable to offshore pumping activities and that these effects should be considered in feasibility assessments for offshore drilling.
Electroactive materials with tunable response based on block copolymer self-assembly
Authors: Terzic Ivan , Meereboer Niels L. , Acuautla Mónica , Portale Giuseppe , Loos Katja
Published: February 2019

Ferroelectric polymers represent one of the key building blocks for the preparation of flexible electronic devices. However, their lack of functionality and ability to simply tune their ferroelectric response significantly diminishes the number of fields in which they can be applied. Here we report an effective way to introduce functionality in the structure of ferroelectric polymers while preserving ferroelectricity and to further tune the ferroelectric response by incorporating functional insulating polymer chains at the chain ends of ferroelectric polymer in the form of block copolymers. The block copolymer self-assembly into lamellar nanodomains allows confined crystallization of the ferroelectric polymer without hindering the crystallinity or chain conformation. The simple adjustment of block polarity leads to a significantly different switching behavior, from ferroelectric to antiferroelectric-like and linear dielectric. Given the simplicity and wide flexibility in designing molecular structure of incorporated blocks, this approach shows the vast potential for application in numerous fields.
Transition metal dichalcogenides bilayer single crystals by reverse-flow chemical vapor epitaxy
Authors: Zhang Xiumei , Nan Haiyan , Xiao Shaoqing , Wan Xi , Gu Xiaofeng , Du Aijun , Ni Zhenhua , Ostrikov Kostya
Published: February 2019

Epitaxial growth of atomically thin two-dimensional crystals such as transition metal dichalcogenides remains challenging, especially for producing large-size transition metal dichalcogenides bilayer crystals featuring high density of states, carrier mobility and stability at room temperature. Here we achieve in epitaxial growth of the second monolayer from the first monolayer by reverse-flow chemical vapor epitaxy and produce high-quality, large-size transition metal dichalcogenides bilayer crystals with high yield, control, and reliability. Customized temperature profiles and reverse gas flow help activate the first layer without introducing new nucleation centers leading to near-defect-free epitaxial growth of the second layer from the existing nucleation centers. A series of bilayer crystals including MoS2 and WS2, ternary Mo1−xWxS2 and quaternary Mo1−xWxS2(1−y)Se2y are synthesized with variable structural configurations and tunable electronic and optical properties. The robust, potentially universal approach for the synthesis of large-size transition metal dichalcogenides bilayer single crystals is highly-promising for fundamental studies and technological applications.
−60 °C solution synthesis of atomically dispersed cobalt electrocatalyst with superior performance
Authors: Huang Kai , Zhang Le , Xu Ting , Wei Hehe , Zhang Ruoyu , Zhang Xiaoyuan , Ge Binghui , Lei Ming , Ma Jing-Yuan , Liu Li-Min , Wu Hui
Published: February 2019

Temperature can govern morphologies, structures and properties of products from synthesis in solution. A reaction in solution at low temperature may result in different materials than at higher temperature due to thermodynamics and kinetics of nuclei formation. Here, we report a low-temperature solution synthesis of atomically dispersed cobalt in a catalyst with superior performance. By using a water/alcohol mixed solvent with low freezing point, liquid-phase reduction of a cobalt precursor with hydrazine hydrate is realized at −60 °C. A higher energy barrier and a sluggish nucleation rate are achieved to suppress nuclei formation; thus atomically dispersed cobalt is successfully obtained in a catalyst for oxygen reduction with electrochemical performance superior to that of a Pt/C catalyst. Furthermore, the atomically dispersed cobalt catalyst is applied in a microbial fuel cell to obtain a high maximum power density (2550 ± 60 mW m−2) and no current drop upon operation for 820 h.
Targets of complement-fixing antibodies in protective immunity against malaria in children
Authors: Reiling Linda , Boyle Michelle J. , White Michael T. , Wilson Danny W. , Feng Gaoqian , Weaver Rupert , Opi D. Herbert , Persson Kristina E. M. , Richards Jack S. , Siba Peter M. , Fowkes Freya J. I. , Takashima Eizo , Tsuboi Takafumi , Mueller Ivo , Beeson James G.
Published: February 2019

Antibodies against P. falciparum merozoites fix complement to inhibit blood-stage replication in naturally-acquired and vaccine-induced immunity; however, specific targets of these functional antibodies and their importance in protective immunity are unknown. Among malaria-exposed individuals, we show that complement-fixing antibodies to merozoites are more strongly correlated with protective immunity than antibodies that inhibit growth quantified using the current reference assay for merozoite vaccine evaluation. We identify merozoite targets of complement-fixing antibodies and identify antigen-specific complement-fixing antibodies that are strongly associated with protection from malaria in a longitudinal study of children. Using statistical modelling, combining three different antigens targeted by complement-fixing antibodies could increase the potential protective effect to over 95%, and we identify antigens that were common in the most protective combinations. Our findings support antibody-complement interactions against merozoite antigens as important anti-malaria immune mechanisms, and identify specific merozoite antigens for further evaluation as vaccine candidates.
Age-associated Impairment of the Mucus Barrier Function is Associated with Profound Changes in Microbiota and Immunity
Authors: Sovran Bruno , Hugenholtz Floor , Elderman Marlies , Van Beek Adriaan A. , Graversen Katrine , Huijskes Myrte , Boekschoten Mark V. , Savelkoul Huub F. J. , De Vos Paul , Dekker Jan , Wells Jerry M.
Published: February 2019

Aging significantly increases the vulnerability to gastrointestinal (GI) disorders but there are few studies investigating the key factors in aging that affect the GI tract. To address this knowledge gap, we used 10-week- and 19-month-old litter-mate mice to investigate microbiota and host gene expression changes in association with ageing. In aged mice the thickness of the colonic mucus layer was reduced about 6-fold relative to young mice, and more easily penetrable by luminal bacteria. This was linked to increased apoptosis of goblet cells in the upper part of the crypts. The barrier function of the small intestinal mucus was also compromised and the microbiota were frequently observed in contact with the villus epithelium. Antimicrobial Paneth cell factors Ang4 and lysozyme were expressed in significantly reduced amounts. These barrier defects were accompanied by major changes in the faecal microbiota and significantly decreased abundance of Akkermansia muciniphila which is strongly and negatively affected by old age in humans. Transcriptomics revealed age-associated decreases in the expression of immunity and other genes in intestinal mucosal tissue, including decreased T cell-specific transcripts and T cell signalling pathways. The physiological and immunological changes we observed in the intestine in old age, could have major consequences beyond the gut.
Effects of Land cover change on Great Apes distribution at the Lobéké National Park and its surrounding Forest Management Units, South-East Cameroon. A 13 year time series analysis
Authors: Yuh Yisa Ginath , Dongmo Zacharie N. , N’Goran Paul K. , Ekodeck Herbert , Mengamenya Achile , Kuehl Hjalmar , Sop Tenekwetche , Tracz Wiktor , Agunbiade Michael , Elvis Tangwa
Published: February 2019

Understanding the effects of land cover change on wildlife distribution is very important for resource management and conservation planning. This paper aimed at detecting the effects of land cover change on great apes distribution at the Lobéké National Park and its bounded forest management units (FMUs). Data on great ape nests were collected in the field for the years 2001 and 2014 through distance sampling with line transects. Landsat TM images of South-East Cameroon for the years 2001 and 2014 were acquired from earth explorer and corrected atmospherically for proper visualization. An area of interest comprising the Lobéké National Park and its FMUs was extracted for classification and change detection. A comparison in great apes nest distribution and change per land cover change category was done for both years through point pattern analysis, whereas a time series analysis of the detected land cover change impacts on great apes nest distribution for a period of 13 years was modeled using logistic growth and regression equations in Vensim 7.2. The results could illustrate that, as land cover changes from one cover type in 2001 to another in 2014, increases or decreases in great apes nests were observed within each changed area.
Analysis of Corneal Spherical Aberrations in Cataract Patients with High Myopia
Authors: Zhang Min , Qian Dongjin , Jing Qinghe , Chen Jiahui , Jiang Yongxiang
Published: February 2019

To evaluate the corneal spherical aberrations in cataract patients with and without high myopia, we conducted a retrospective case series of 502 cataract eyes with high myopia and 1500 age-related cataract eyes and measure their corneal biometric data and axial length using Pentacam and IOLMaster. Both the anterior and total corneal primary spherical aberrations were lower in the high myopia group than that in the control group (0.317 ± 0.215 vs 0.338 ± 0.148 μm, P = 0.043; and 0.281 ± 0.207 vs 0.314 ± 0.153 μm, P < 0.001). The incidence of eyes with negative total corneal primary spherical aberration increased as axial length increased in the high myopia group, and the overall incidence was higher in the high myopia group than that in the control group (2.59% vs 1.47%). These were mainly contributed to the younger age of cataract patients with high myopia (55.76 ± 13.10 vs 60.18 ± 15.72 years, P < 0.001), along with the positive correlations between age and anterior and total corneal primary spherical aberrations. In clinical practice, an aspheric IOL with a low negative or zero primary spherical aberration is recommended for cataract patients with high myopia. Negative total ocular primary spherical aberrations resulting from aspheric IOL implantation should be avoided in extremely high myopic eyes.
Modelling the current fractional cover of an invasive alien plant and drivers of its invasion in a dryland ecosystem
Authors: Shiferaw Hailu , Schaffner Urs , Bewket Woldeamlak , Alamirew Tena , Zeleke Gete , Teketay Demel , Eckert Sandra
Published: February 2019

The development of spatially differentiated management strategies against invasive alien plant species requires a detailed understanding of their current distribution and of the level of invasion across the invaded range. The objectives of this study were to estimate the current fractional cover gradient of invasive trees of the genus Prosopis in the Afar Region, Ethiopia, and to identify drivers of its invasion. We used seventeen explanatory variables describing Landsat 8 image reflectance, topography, climate and landscape structures to model the current cover of Prosopis across the invaded range using the random forest (RF) algorithm. Validation of the RF algorithm confirmed high model performance with an accuracy of 92% and a Kappa-coefficient of 0.8. We found that, within 35 years after its introduction, Prosopis has invaded approximately 1.17 million ha at different cover levels in the Afar Region (12.3% of the surface). Normalized difference vegetation index (NDVI) and elevation showed the highest explanatory power among the 17 variables, in terms of both the invader’s overall distribution as well as areas with high cover. Villages and linear landscape structures (rivers and roads) were found to be more important drivers of future Prosopis invasion than environmental variables, such as climate and topography, suggesting that Prosopis is likely to continue spreading and increasing in abundance in the case study area if left uncontrolled. We discuss how information on the fractional cover and the drivers of invasion can help in developing spatially-explicit management recommendations against a target invasive plant species.
Spectroscopy and SEM imaging reveal endosymbiont-dependent components changes in germinating kernel through direct and indirect coleorhiza-fungus interactions under stress
Authors: Vujanovic Vladimir , Kim Seon Hwa , Lahlali Rachid , Karunakaran Chithra
Published: February 2019

In the present study, FTIR spectroscopy and hyperspectral imaging was introduced as a non-destructive, sensitive-reliable tool for assessing the tripartite kernel-fungal endophyte environment interaction. Composition of coleorhizae of Triticum durum was studied under ambient and drought stress conditions. The OH-stretch IR absorption spectrum suggests that the water-deficit was possibly improved or moderated by kernel’s endophytic partner. The OH-stretch frequency pattern coincides with other (growth and stress) related molecular changes. Analysis of lipid (3100–2800 cm−1) and protein (1700–1550 cm−1) regions seems to demonstrate that drought has a positive impact on lipids. The fungal endosymbiont direct contact with kernel during germination had highest effect on both lipid and protein (Amide I and II) groups, indicating an increased stress resistance in inoculated kernel. Compared to the indirect kernel-fungus interaction and to non-treated kernels (control), direct interaction produced highest effect on lipids. Among treatments, the fingerprint region (1800–800 cm−1) and SEM images indicated an important shift in glucose oligosaccharides, possibly linked to coleorhiza-polymer layer disappearance. Acquired differentiation in coleorhiza composition of T. durum, between ambient and drought conditions, suggests that FTIR spectroscopy could be a promising tool for studying endosymbiont-plant interactions within a changing environment.
The differences of lipid profiles between only children and children with siblings: A national survey in China
Authors: Cai Li , Ma Bingjie , Lin Lizi , Chen Yajun , Yang Wenhan , Ma Jun , Jing Jin
Published: February 2019

With the increasing number of the one-child family, it is important to investigate whether the only-child status is associated with dyslipidemia. Among a national sample of 65,347 Chinese children aged 6–17 years, 16,100 lipid profiles were available. Children’s height, weight, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured. In comparison to children with siblings, only children (OC) were more likely to be boys and live in urban areas. OC had less physical activity, less fried food intake, but more meat and dairy intakes. OC had significantly higher levels of TC (3.97 ± 0.78 vs. 3.89 ± 0.77) and LDL-C (2.12 ± 0.65 vs. 2.06 ± 0.64) in the overall group, and also in the subgroups of rural boys and girls. The prevalence of hyper-TC (5.48% vs. 4.43%) and hyper-LDL-C (3.97% vs. 2.96%) were significantly higher in OC than their counterparts. Furthermore, we found higher odds of hyper-LDL-C [1.43 (1.12, 1.83)] in OC after adjustments. In the subgroup analysis, only-child status was associated with increased risk of hyper-TC [1.86 (1.06, 3.26)] and hyper-LDL-C [2.65 (1.14, 6.16)] among rural boys, and hyper-LDL-C among rural girls [2.20 (1.14, 4.22)]. In conclusion, higher levels of TC and LDL-C were found in OC especially for rural children. Being an only-child was associated with increased risk of hyper-LDL-C.
Clustering patterns in efficiency and the coming-of-age of the cryptocurrency market
Authors: Sigaki Higor Y. D. , Perc Matjaž , Ribeiro Haroldo V.
Published: February 2019

The efficient market hypothesis has far-reaching implications for financial trading and market stability. Whether or not cryptocurrencies are informationally efficient has therefore been the subject of intense recent investigation. Here, we use permutation entropy and statistical complexity over sliding time-windows of price log returns to quantify the dynamic efficiency of more than four hundred cryptocurrencies. We consider that a cryptocurrency is efficient within a time-window when these two complexity measures are statistically indistinguishable from their values obtained on randomly shuffled data. We find that 37% of the cryptocurrencies in our study stay efficient over 80% of the time, whereas 20% are informationally efficient in less than 20% of the time. Our results also show that the efficiency is not correlated with the market capitalization of the cryptocurrencies. A dynamic analysis of informational efficiency over time reveals clustering patterns in which different cryptocurrencies with similar temporal patterns form four clusters, and moreover, younger currencies in each group appear poised to follow the trend of their ‘elders’. The cryptocurrency market thus already shows notable adherence to the efficient market hypothesis, although data also reveals that the coming-of-age of digital currencies is in this regard still very much underway.
Deaf moths employ acoustic Müllerian mimicry against bats using wingbeat-powered tymbals
Authors: O’Reilly Liam J. , Agassiz David J. L. , Neil Thomas R. , Holderied Marc W.
Published: February 2019

Emitting ultrasound upon hearing an attacking bat is an effective defence strategy used by several moth taxa. Here we reveal how Yponomeuta moths acquire sophisticated acoustic protection despite being deaf themselves and hence unable to respond to bat attacks. Instead, flying Yponomeuta produce bursts of ultrasonic clicks perpetually; a striated patch in their hind wing clicks as the beating wing rotates and bends. This wing structure is strikingly similar to the thorax tymbals with which arctiine moths produce their anti-bat sounds. And indeed, Yponomeuta sounds closely mimic such arctiine signals, revealing convergence in form and function. Because both moth taxa contain noxious compounds, we conclude they are mutual Müllerian acoustic mimics. Yponomeuta’s perpetual clicking would however also attract bat predators. In response, their click amplitude is reduced and affords acoustic protection just as far as required, matching the distance over which bat biosonar would pick up Yponomeuta echoes anyway – advanced acoustic defences for a deaf moth.