bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new tricrystalline triblock terpolymer by combining polyhomologation and ring‐opening polymerization. synthesis and thermal properties
Authors: Ladelta Viko , Zapsas George , Gnanou Yves , Hadjichristidis Nikos 
Published: October 2019

ABSTRACTNew tricrystalline triblock terpolymers, polyethylene‐block‐poly(ε‐caprolactone)‐block‐poly(L‐lactide) (PE‐b‐PCL‐b‐PLLA), were synthesized by ROP of ε‐caprolactone (CL) and L‐lactide (LLA) from linear ω‐hydroxyl polyethylene (PE‐OH) macroinitiators. The linear PE‐OH macroinitiators were prepared by C1 polymerization of methylsulfoxonium methylide (polyhomologation). Tin(II) 2‐ethylhexanoate was used as the catalyst for the sequential ROP of CL and LLA in one‐pot polymerization at 85 °C in toluene (PE‐OH macroinitiators are soluble in toluene at 80 °C). 1H NMR spectra confirmed the formation of PE‐b‐PCL‐b‐PLLA triblock terpolymers through the appearance of the characteristic proton peaks of each block. GPC traces showed the increase in the number average molecular weight from PE‐OH macroinitiator to PE‐b‐PCL, and PE‐b‐PCL‐b‐PLLA corroborating the successful synthesis. The existence of three crystalline blocks was proved by DSC and XRD spectroscopy. © 2019 The Authors. Journal of Polymer Science Part A: Polymer Chemistry published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2450–2456
Identification of molecular vibrations associated with tacticity in polypropylene: Density functional theory‐based simulations
Authors: Mitra Nilanjan , Prasad Dipak , Banerjee Susanta 
Published: October 2019

ABSTRACTThe polymerization of vinyl monomers with achiral carbon center forms polymers with different spatial arrangements resulting in products with a different set of mechanical and thermal properties. Therefore, control of the tacticity (stereochemistry) is of major importance for controlling the polymer properties. It is possible to manipulate the polymer stereoregularity through the application of appropriate synthetic protocols. However, the polymers obtained using these protocols are not perfect, and thereby, it is essential to know the amount of different stereoregular units in a polymer mass. Generally, extensive NMR techniques and vibrational spectroscopy are used in this regard. To investigate further, a detailed DFT has been employed in this manuscript for syndio and isotactic polypropylene. The DFT allows generation of the vibrational spectra in the far‐infrared (0–400 cm−1) region, demonstrating the distinct nature of both types of polymers. The vibrational spectra for pure syndio and isotactic polypropylene as well as their conformer defects have been identified in this study. These studies of vibration spectra in the far‐infrared regime can be used to identify signatures of pure racemo and meso dyads along with the type of conformer defects present in pristine varieties. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 1378–1385
Cog in the wheel: Resource release and the scope of interdependencies in corporate adjustment activities
Authors: Keum Dongil D. 
Published: October 2019

AbstractResearch SummaryThis study characterizes and tests interdependencies in corporate activities used to adjust resources and implement change. Because each activity contributes only a partial result and depends on others to complete an intended change, constraining one can create a bottleneck that traps multiple other activities. For my empirical analysis, I leverage the staggered adoptions of employment protection laws intended to constrain one specific adjustment to one specific resource: dismissing employees. The constraint, however, not only affects the contraction but also the expansion in labor as well as capital investments, acquisition, divestiture, CEO turnover, and other adjustments, and increases (shortens) the persistence of negative (positive) performance. The expansive interdependencies are critical to understanding firm rigidity and resilience, implementation failures, and the persistence of firm performance.Managerial SummaryThis study shows how executing even a seemingly straightforward improvement requires piecing together a series of interdependent corporate strategic activities. As a result, a constraint on just one is sufficient to foil a successful firm response. Using changes in employment laws, I show that a firm's ability to dismiss employees not only affects firing, but also hiring, capital investments, acquisition, divestiture, and CEO turnover, and increases (shortens) the persistence of negative (positive) performance. Underestimating the complex and interdependent nature of these activities can lead to bias‐for‐action and contribute to implementation failures, such as cost overruns, schedule delays, and a post‐merger integration process that fails to realize expected synergies.
Design of Multifunctional Fluorescent Hybrid Materials Based on SiO2 Materials and Core–Shell Fe3O4@SiO2 Nanoparticles for Metal Ion Sensing
Authors: Chatterjee Sobhan , Li Xiang‐Shuai , Liang Feng , Yang Ying‐Wei 
Published: October 2019

AbstractHybrid fluorescent materials constructed from organic chelating fluorescent probes and inorganic solid supports by covalent interactions are a special type of hybrid sensing platform that has gained much interest in the context of metal ion sensing applications owing to their excellent advantages, recyclability, and solubility/dispersibility in particular, as compared with single organic fluorescent molecules. In recent decades, SiO2 materials and core–shell Fe3O4@SiO2 nanoparticles have become important inorganic solid materials and have been used as inorganic solid supports to hybridize with organic fluorescent receptors, resulting in multifunctional fluorescent hybrid systems for potential applications in sensing and related research fields. Therefore, recent progress in various fluorescent‐group‐functionalized SiO2 materials is reviewed, with a focus on mesoporous silica nanoparticles and core–shell Fe3O4@SiO2 nanoparticles, as interesting fluorescent organic–inorganic hybrid materials for sensing applications toward essential and toxic metal ions. Selective examples of other types of silica/silicon materials, such as periodic mesoporous organosilicas, solid SiO2 nanoparticles, fibrous silica spheres, silica nanowires, silica nanotubes, and silica hollow microspheres, are also mentioned. Finally, relevant perspectives of metal‐ion‐sensing‐oriented silica‐fluorescent probe hybrid materials are provided.
Behavioral fingerprinting of Internet‐of‐Things devices
Authors: Bezawada Bruhadeshwar , Ray Indrakshi , Ray Indrajit 
Published: October 2019

AbstractRapid advances in the Internet‐of‐Things (IoT) domain have led to the development of several useful and interesting devices that have enhanced the quality of home living and industrial automation. The vulnerabilities in the IoT devices have rendered them susceptible to compromise and forgery. The problem of device authentication, that is, the question of whether a device's identity is what it claims to be, is still an open problem. Device fingerprinting seems to be a promising authentication mechanism. Device fingerprinting profiles a device based on information available about the device and generate a robust, verifiable and unique identity for the device. Existing approaches for device fingerprinting may not be feasible or cost‐effective for the IoT domain due to the resource constraints and heterogeneity of the IoT devices. Due to resource and cost constraints, behavioral fingerprinting provides promising directions for fingerprinting IoT devices. Behavioral fingerprinting allows security researchers to understand the behavioral profile of a device and to establish some guidelines regarding the device operations. In this article, we discuss existing approaches for behavioral fingerprinting of devices in general and evaluate their applicability for IoT devices. Furthermore, we discuss potential approaches for fingerprinting IoT devices and give an overview of some of the preliminary attempts to fingerprint IoT devices. We conclude by highlighting the future research directions for fingerprinting in the IoT domain.This article is categorized under:
Application Areas > Science and Technology
Application Areas > Internet
Technologies > Machine Learning
Application Areas > Industry Specific Applications
Optogenetic Reconstitution: Light-Induced Assembly of Protein Complexes and Simultaneous Visualization of Their Intracellular Functions
Authors: Kiyomitsu Tomomi 
Published: October 2019

AbstractDynamic behaviors of cells require optimized functions and regulations of protein complexes within a cell. In vitro reconstitution is a powerful method to dissect the molecular functions and structure of reconstituted protein complexes. However, owing to the difficulties associated with in vitro reconstitution of complicated supra-molecular complexes, such as the mitotic spindle and cortical force-generating machinery, key molecular features underlying their functions and regulations are not fully understood. Recently, several light-inducible dimerization tools have been developed to control localization of target proteins within a cell in a spatiotemporally controlled manner. In this chapter, I have summarized the recent progress in optogenetic tools and fluorescent proteins/probes and have determined strategies to achieve light-induced in cell reconstitution of protein complexes coupled with visualization of its downstream events. Moreover, I have discussed the advantages and potential of the optogenetic reconstitution system in diverse cell and developmental biology fields.
Investigating Evolutionary Rate Variation in Bacteria
Authors: Gibson Beth , Eyre-Walker Adam 
Published: October 2019

AbstractRates of molecular evolution are known to vary between species and across all kingdoms of life. Here, we explore variation in the rate at which bacteria accumulate mutations (accumulation rates) in their natural environments over short periods of time. We have compiled estimates of the accumulation rate for over 34 species of bacteria, the majority of which are pathogens evolving either within an individual host or during outbreaks. Across species, we find that accumulation rates vary by over 3700-fold. We investigate whether accumulation rates are associated to a number potential correlates including genome size, GC content, measures of the natural selection and the time frame over which the accumulation rates were estimated. After controlling for phylogenetic non-independence, we find that the accumulation rate is not significantly correlated to any factor. Furthermore, contrary to previous results, we find that it is not impacted by the time frame of which the estimate was made. However, our study, with only 34 species, is likely to lack power to detect anything but large effects. We suggest that much of the rate variation may be explained by differences between species in the generation time in the wild.
Breast Reconstruction with a Tissue Engineering and Regenerative Medicine Approach (Systematic Review)
Authors: Donnely E. , Griffin M. , Butler P. E. 
Published: October 2019

AbstractCurrent techniques for breast reconstruction include an autologous-tissue flap or an implant-based procedure, although both can impose further morbidity. This systematic review aims to explore the existing literature on breast reconstruction using a tissue engineering approach; conducted with the databases Medline and Embase. A total of 28 articles were included, mainly comprising of level-5 evidence within vitroand animal studies focusing on utilizing scaffolds to support the migration and growth of new tissue; scaffolds can be either biological or synthetic. Biological scaffolds were composed of collagen or a decellularized tissue matrix scaffold. Synthetic scaffolds were primarily composed of polymers with customisable designs, adjusting the internal morphology and pore size. Implanting cells, including adipose-derived stem cells, with combined use of basic fibroblast growth factor has been studied in an attempt to enhance tissue regeneration. Lately, a level-4 evidence human case series was reported; successfully regenerating 210 mL of tissue using an arterio-venous pedicled fat flap within a tissue engineering chamber implanted on the chest wall. Further research is required to evaluate whether the use of cells and other growth factors could adjust the composition of regenerated tissue and improve vascularity; the latter a major limiting factor for creating larger volumes of tissue.
Solar Eclipses and the Surface Properties of Water
Authors: Fuchs Elmar C. , Oudakker Gerrit , Justinek Martin , Dyer Nigel , Woisetschläger Jakob , Godines Kevin , Mäder Matthias , Freund Friedemann T. 
Published: October 2019

Abstract
During four solar eclipse events (two annular, one total and one partial) a correlation was observed between a change in water surface tension and the magnitude of the optical coverage. During one eclipse, evaporation experiments were carried out which showed a reduction in water evaporation at the same time as a rise in the surface tension. The changes did not occur on a day without a solar eclipse and are not correlated to changes in temperature, pressure, humidity of the environment. The effects are delayed by 20, 85, 30 and 37 min, respectively, compared to the maximum eclipse. Possible mechanisms responsible for this effect are presented, the most likely hypothesis being reduced water/muon interaction due to solar wind and cosmic radiation blocking during an eclipse. As an alternative hypotheses, we propose a novel neutrino/water interaction and overview of other, less likely mechanisms.
Comparison of the antimicrobial activity of propolis extracts obtained by means of various extraction methods
Authors: Pobiega Katarzyna , Kraśniewska Karolina , Derewiaka Dorota , Gniewosz Małgorzata 
Published: September 2019

Abstract
The objective of the study was to compare the antimicrobial activities of ethanolic propolis extracts obtained using different extraction methods. Extraction of propolis was carried out using 70% ethanol, propolis to ethanol ratios of 1:10 and 1:5, extraction times of 1 or 7 days, and shaking extraction (SE), ultrasound-assisted extraction (UAE), and ultrasound-assisted shaking extraction (SUAE) methods. A total of 12 propolis extract lyophilizates were obtained. Samples were tested for extraction yield and for total phenol content by the Folin–Ciocalteau colourimetric method, and total flavonoid content using a spectrophotometric method. GLC/MS was used for the identification of chemical compounds in selected extract lyophilizates. Antimicrobial activity against selected bacterial and fungal species was assessed using the disk diffusion method. Propolis extracts obtained as the result of 1-day and 7-day shaking extraction followed by 20 min of ultrasound-assisted extraction (SUAE) had better antimicrobial properties as compared to those obtained by SE or UAE alone. SE and UAE gave lower extraction yields as well as lower phenol and flavonoid contents compared to SUAE. No differences were observed with regard to the qualitative composition of extracts obtained by any of the methods. It is best to obtain the extract using the combined method of 1-day extraction and 20-min sonication.
Transient and slim versus recurrent and fat: Random walks and the trees they grow
Authors: Iacobelli Giulio , Figueiredo Daniel R. , Neglia Giovanni 
Published: October 2019

AbstractThe no restart random walk (NRRW) is a random network growth model driven by a random walk that builds the graph while moving on it, adding and connecting a new leaf node to the current position of the walker every s steps. We show a fundamental dichotomy in NRRW with respect to the parity of s: for

${s}=1$

we prove that the random walk is transient and non-leaf nodes have degrees bounded above by an exponential distribution; for s even we prove that the random walk is recurrent and non-leaf nodes have degrees bounded below by a power law distribution. These theoretical findings highlight and confirm the diverse and rich behaviour of NRRW observed empirically.
Reproductive sublethal effects of macrocyclic lactones and synthetic pyrethroids on the dung beetle Onthophagus similis
Authors: Weaving H. , Sands B. , Wall R. 
Published: October 2019

AbstractDung-colonizing beetles provide a range of ecosystem services in farmland pasture systems. However, such beetles are declining in Northern temperate regions. This may, in part, be due to the widespread use of macrocyclic lactones (MLs) and synthetic pyrethroids (SPs) in livestock farming. These chemicals are used to control pests and parasites of cattle; the residues of which are excreted in dung at concentrations toxic to insects. While the lethal effects of such residues are well known, sublethal effects are less understood. Any effects, however, may have important consequences for beetle populations, particularly if they affect reproduction. To investigate, the impact of ML and SP exposure on the reproductive output of Onthophagus similis (Scriba), a Northern temperate dung beetle species, was examined. In laboratory trials, field-collected adult O. similis exposed to the ML ivermectin at 1 ppm (wet weight) over a period of 3 weeks had smaller oocytes (p = 0.016), smaller fat bodies and reduced motility compared to the control. In a farm-level investigation, cattle dung-baited pitfall trapping was undertaken on 23 beef cattle farms in SW England, which either used MLs (n = 9), SPs (n = 7) or neither chemical (n = 7). On farms that used no MLs or SPs, 24.2% of females caught were gravid. However, on farms that used MLs no gravid females were caught, and only 1% of the beetles caught on farms using SPs were gravid (p < 0.001). The association between ML and SP use and impaired reproductive output suggests that the use of such chemicals is likely to be ecologically damaging.
Retrospective Voting and the Polarization of Available Alternatives
Authors: Stiers Dieter , Dassonneville Ruth 
Published: October 2019

AbstractGovernment cohesiveness is known to moderate retrospective voting. While previous work on this topic has focused on characteristics of the government, we build on the literature on clarity of responsibility and the literature on valence to argue that the extent to which government and opposition are ideologically distinct also moderates retrospective voting. Two alternative expectations follow from these two theoretical perspectives. While the clarity of responsibility framework leads to the expectation that a larger difference between government and opposition will strengthen retrospective voting, the valence literature presumes that retrospective voting is stronger when ideological differences are small. Using the data of the Comparative Study of Electoral Systems (CSES) project, we find evidence that is in line with the clarity of responsibility framework: the higher the degree of ideological polarization between government and opposition, the larger the effect of retrospective performance evaluations on the vote.
War, International Finance, and Fiscal Capacity in the Long Run
Authors: Queralt Didac 
Published: September 2019

AbstractIn this article I revisit the relationship between war and state making in modern times by focusing on two prominent types of war finance: taxes and foreign loans. Financing war with tax money enhances the capacity to assess wealth and monitor compliance, namely fiscal capacity. Tax-financed war facilitates the adoption of power-sharing institutions, which transform taxation into a non-zero-sum game, carrying on the effect of war in the long run. Financing war with external capital does not contribute to long-term fiscal capacity if borrowers interrupt debt service and, as part of the default settlement, war debt is condoned or exchanged for nontax revenue. The empirical evidence draws from war around the world as early as 1816. Results suggest that globalization of capital markets in the nineteenth century undermined the association between war, state making, and political reform.
The Seagoing Scientist's Toolbox: Integrated Methods for Quality Control of Marine Geophysical Data at Sea
Authors: Hamilton Michael , Wessel Paul , Luis Joaquim , Taylor Brian , Ko Youngtak 
Published: October 2019

AbstractWe announce a new and integrated system for planning and executing marine geophysical surveys and for scrutinizing and visualizing incoming shipboard data. The system incorporates free software designed for use by scientists and shipboard operators and pertains to underway geophysics and multibeam sonar surveys. Regarding underway data, a crucial first step in the approach is to reduce and merge incoming center beam depth, gravity, and towed magnetic data with navigation, then reformat to the standard exchange format. We are then able to apply established quality control methods including along‐track and cross‐track analyses to identify error sources and to incrementally build the candidate archive file as new data are acquired. Regarding multibeam data, these are subjected to both an automated error removal scheme for quick visualization and to subsequent ping editing in detail. The candidate archive file and sonar data are automatically and periodically updated and adapted for display in Google Earth, wherein survey planning is also carried out. Data layers are also updated automatically in Google Earth, allowing scientists to focus on visual inspection and interpretation of incoming data. By visualizing underway and sonar data together with reference gravity, magnetic, and bathymetry grids in Google Earth, data familiarity is enhanced and the likelihood of noticing extreme errors increased. We hope scientists will embrace these techniques so that each data set being submitted to a data repository is vetted by the seagoing science party.
Seasonal, Spring‐Neap, and Tidal Variation in Cohesive Sediment Transport Parameters in Estuarine Shallows
Authors: Allen Rachel M. , Lacy Jessica R. , Stacey Mark T. , Variano Evan A. 
Published: October 2019

AbstractNumerical models for predicting sediment concentrations and transport rely on parameters such as settling velocity and bed erodibility that describe sediment characteristics, yet these parameters are rarely probed directly. We investigated temporal and spatial variation in sediment parameters in the shallows of San Pablo Bay, CA. Flow, turbulence, and suspended sediment data were measured at sites located at 1 and 2 m below mean lower low water (MLLW) from November 2013 through April 2015, supplemented by monthlong periods in 2011, 2012, and 2016. Maximum current velocities were 0.40–0.47 m s-1 at these depths; the strongest currents decreased to 0.27–0.34 m s-1 during neap periods. Winters 2013–2014 and 2014–2015 experienced strong drought conditions, limiting the potential for seasonal impact on sediment conditions during this experiment. Despite this, the more storm‐influenced site showed clear changes during the winter: the roughness parameter decreased from 10−4 to 10−5 m, from hydrodynamically rough to smooth conditions, and bed erodibility increased by an order of magnitude. Median settling velocity was 2.05·10−4 m s-1; it varied twofold within a tidal cycle, decreasing as current velocity grew during flood and ebb. This tidal control on floc size affected settling velocity on the spring‐neap timescale, possibly driving a spring‐neap oscillation in erodibility. Our findings highlight variation in sediment dynamics that is commonly ignored in numerical models and the need for field observations to ground truth ongoing modeling efforts.