bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of silver sulphide on gold cyanidation with conductive sulphide minerals
Authors: Khalid Muhammad , Larachi Faïçal , Adnot Alain
Published: April 2017

Gold is mostly found in metallic form, while silver exists in various mineral forms. Pyrite, chalcopyrite, sphalerite, and stibnite were the sulphidic minerals investigated for the effect of silver sulphide on gold cyanidation. Four sets of mineral systems, pyrite‐silica, chalcopyrite‐silica, sphalerite‐silica, and stibnite‐silica, were established to investigate the effect of silver sulphide. Silver sulphide addition promoted gold dissolution for the pyrite‐silica and sphalerite‐silica systems. The gold dissolution was retarded with the chalcopyrite‐silica and stibnite‐silica systems, irrespective of the dispersion of gold and silver sulphide in the mineral as well as in the quartz layer. The surface characterization of the gold particles was attempted by using X‐ray photoelectron spectroscopy (XPS) in order to identify the surface obstructing species. XPS analysis showed that the passivation layers of silver sulphide (Ag2S), Cu2O/Cu(OH)2, and antimony oxide (Sb2O5) might form on the surface of goldparticles by the simultaneous dissolution of silver sulphide as well as sulphide minerals, resulting in the retardation of gold dissolution.
How many roads lead to cohesinopathies?
Authors: Banerji Rajeswari , Skibbens Robert V. , Iovine M. Kathryn
Published: April 2017

Genetic mapping studies reveal that mutations in cohesion pathways are responsible for multispectrum developmental abnormalities termed cohesinopathies. These include Roberts syndrome (RBS), Cornelia de Lange Syndrome (CdLS), and Warsaw Breakage Syndrome (WABS). The cohesinopathies are characterized by overlapping phenotypes ranging from craniofacial deformities, limb defects, and mental retardation. Though these syndromes share a similar suite of phenotypes and arise due to mutations in a common cohesion pathway, the underlying mechanisms are currently believed to be distinct. Defects in mitotic failure and apoptosis i.e. trans DNA tethering events are believed to be the underlying cause of RBS, whereas the underlying cause of CdLS is largely modeled as occurring through defects in transcriptional processes i.e. cis DNA tethering events. Here, we review recent findings described primarily in zebrafish, paired with additional studies in other model systems, including human patient cells, which challenge the notion that cohesinopathies represent separate syndromes. We highlight numerous studies that illustrate the utility of zebrafish to provide novel insights into the phenotypes, genes affected and the possible mechanisms underlying cohesinopathies. We propose that transcriptional deregulation is the predominant mechanism through which cohesinopathies arise. Developmental Dynamics 246:881–888, 2017. © 2017 Wiley Periodicals, Inc.
Historical harvests reduce neighboring old‐growth basal area across a forest landscape
Authors: Bell David M. , Spies Thomas A. , Pabst Robert
Published: April 2017

While advances in remote sensing have made stand, landscape, and regional assessments of the direct impacts of disturbance on forests quite common, the edge influence of timber harvesting on the structure of neighboring unharvested forests has not been examined extensively. In this study, we examine the impact of historical timber harvests on basal area patterns of neighboring old‐growth forests to assess the magnitude and scale of harvest edge influence in a forest landscape of western Oregon, USA. We used lidar data and forest plot measurements to construct 30‐m resolution live tree basal area maps in lower and middle elevation mature and old‐growth forests. We assessed how edge influence on total, upper canopy, and lower canopy basal area varied across this forest landscape as a function of harvest characteristics (i.e., harvest size and age) and topographic conditions in the unharvested area. Upper canopy, lower canopy, and total basal area increased with distance from harvest edge and elevation. Forests within 75 m of harvest edges (20% of unharvested forests) had 4% to 6% less live tree basal area compared with forest interiors. An interaction between distance from harvest edge and elevation indicated that elevation altered edge influence in this landscape. We observed a positive edge influence at low elevations (<800 m) and a negative edge influence at moderate to high elevations (>800 m). Surprisingly, we found no or weak effects of harvest age (13–60 yr) and harvest area (0.2–110 ha) on surrounding unharvested forest basal area, implying that edge influence was relatively insensitive to the scale of disturbance and multi‐decadal recovery processes. Our study indicates that the edge influence of past clearcutting on the structure of neighboring uncut old‐growth forests is widespread and persistent. These indirect and diffuse legacies of historical timber harvests complicate forest management decision‐making in old‐growth forest landscapes by broadening the traditional view of stand boundaries. Furthermore, the consequences of forest harvesting may reach across ownership boundaries, highlighting complex governance issues surrounding landscape management of old‐growth forests.
Spatial overlap of shark nursery areas and the salmon farming industry influences the trophic ecology of Squalus acanthias on the southern coast of Chile
Authors: Gaitán‐Espitia Juan Diego , Gómez Daniela , Hobday Alistair J. , Daley Ross , Lamilla Julio , Cárdenas Leyla
Published: April 2017

Potential interactions between marine predators and humans arise in the southern coast of Chile where predator feeding and reproduction sites overlap with fisheries and aquaculture. Here, we assess the potential effects of intensive salmon aquaculture on food habits, growth, and reproduction of a common predator, the spiny dogfish—identified as Squalus acanthias via genetic barcoding. A total of 102 (89 females and 13 males) individuals were collected during winter and summer of 2013–2014 from the Chiloé Sea where salmon aquaculture activities are concentrated. The low frequency of males in our study suggests spatial segregation of sex, while immature and mature females spatially overlapped in both seasons. Female spiny dogfish showed a functional specialist behavior as indicated by the small number of prey items and the relative high importance of the austral hake and salmon pellets in the diet. Immature sharks fed more on pellets and anchovies than the larger hake‐preferring mature females. Our results also indicate that spiny dogfish switch prey (anchovy to hake) to take advantage of seasonal changes in prey availability. Despite differences in the trophic patterns of S. acanthias due to the spatial association with intensive salmon farming, in this region, there appears to be no difference in fecundity or size at maturity compared to other populations. Although no demographic effects were detected, we suggest that a range of additional factors should be considered before concluding that intensive aquaculture does not have any impact on these marine predators.
Contamination assessment and the risk associated with the accumulation of trace metals in sediments of the Mitidja plain, Algeria
Authors: Laribi Abdelkader , Mouhouche Brahim , Benayad Tahar , Dehnoun Zahida
Published: April 2017

This study was carried out to assess the degree of contamination by trace metals in sediments of the main rivers of the eastern Mitidja plain. In order to achieve this objective, the enrichment factor, the geoaccumulation index and the potential ecological risk were calculated. Possible sources of trace metals in sediments were performed using a multivariate statistical analysis. The concentrations of the studied metals decreased in the order of Fe ≫ Zn > Cr > Pb > Ni > Cu> Cd. The results showed that Cd had a higher enrichment factor than the other metals. The geoaccumulation index results of trace metals revealed that the studied sediment were strongly contaminated with Cd, moderately contaminated with Zn and Pb and not contaminated with Cr, Cu, Fe, and Ni. Among the studied trace metals, only the Cd may present an ecological potential risk to the ecosystem. Furthermore, the results indicated a geochemical association of the elements Cr, Fe and Ni, suggesting natural source of these metals. In addition, Cd, Cu, Pb, and Zn appear to have originated from different sources. The results of this study are important for the development of any future strategies to protect the aquatic environment. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1650–1657, 2017
Naringin abates adverse effects of cadmium‐mediated hepatotoxicity: An experimental study using HepG2 cells
Authors: Rathi Visesh Kumar , Das Shubhankar , Parampalli Raghavendra Archana , Rao Bola Sadashiva Satish
Published: April 2017

This study investigated the protective potential of Naringin (NIN) against cadmium chloride (CdCl2) mediated hepatotoxicity using human hepatocellular carcinoma (HepG2) cells. An optimal concentration of NIN (5 μM) was potent enough to confer cytoprotection against CdCl2 (50 μM) as was observed by MTT assay. Preconditioning with NIN maintained redox homeostasis, mitochondrial membrane potential, and reduced apoptosis as marked by decrease in the percentage sub‐G0/G1 and Annexin V‐FITC/propidium iodide positive cells (apoptotic). NIN pretreatment maintained the levels of protein thiol along with endogenous activities of Superoxide dismutase, Glutathione S‐transferase, and Catalase and lowered lipid peroxidation. Decreased Bax/Bcl2 ratio along with reduced Caspase 3 cleavage and Cytochrome c release indicated that NIN conditioning blocked mitochondrial‐mediated apoptosis. Increased Nrf2 and metallothionein (MT) acted as adaptive response in the presence of cadmium. Thus, the protective mechanism of NIN is attributed to its antioxidant potential which aids in redox homeostasis and prevents CdCl2 mediated cytotoxicity.
High‐theabrownins instant dark tea product by Aspergillus niger via submerged fermentation: α‐glucosidase and pancreatic lipase inhibition and antioxidant activity
Authors: Wang Yuwan , Zhang Mingyue , Zhang Zhengzhu , Lu Hengqian , Gao Xueling , Yue Pengxiang
Published: April 2017

BACKGROUND

Theabrownins (TB) are bioactive components that are usually extracted from Chinese dark tea, in which they are present at low concentrations. The present study aimed to produce an instant dark tea high in theabrownins via submerged fermentation by the fungus Aspergillus niger. Three fermentation parameters that affect theabrownins content (i.e. inoculum size, liquid–solid ratio and rotation speed) were optimized using response surface methodology.

RESULT

Optimum fermentation conditions were modeled to be an inoculum of 5.40% (v/v), a liquid–solid ratio of 27.45 mL g−1 and a rotation speed of 184 rpm and were predicted to yield 292.99 g kg−1 TB. Under these experimentally conditions, the TB content of the instant dark tea was 291.93 g kg−1. The antioxidant capacity and α‐glucosidase and pancreatic lipase inhibitory activities of the high‐TB instant black tea were higher than four other typical instant dark tea products.

CONCLUSION

The results of the present study show that careful management of culture conditions can produce a dark tea high in theabrownins. Furthermore, high‐theabrownins instant dark tea could serve as a source of bioactive products and be used in functional foods as an ingredient imparting antioxidant properties and the ability to inhibit pancreatic lipase and α‐glucosidase. © 2017 Society of Chemical Industry
Migratory connectivity of american woodcock using band return data
Authors: Moore Joseph D. , Krementz David G.
Published: April 2017

American woodcock (Scolopax minor) are managed as a Central and an Eastern population in the United States and Canada based on band return data showing little crossover between populations or management regions. The observed proportion of crossover between management regions, however, depends on the criteria used to subset the band return data. We analyzed the amount of crossover between management regions using only band return records that represent complete migrations between the breeding and wintering grounds by using only band return records in which the capture took place during the breeding season and the band recovery took place during the wintering season or vice versa (n = 224). Additionally, we applied spatial statistics and a clustering algorithm to investigate woodcock migratory connectivity using this subset of migratory woodcock band return records. Using raw counts, 17.9% of records showed crossover between management regions, a higher proportion than the <5% crossover reported in studies that did not use only migratory band returns. Our results showed woodcock from the breeding grounds in the Central Region largely migrate to destinations within the Central Region, whereas woodcock from the breeding grounds in the Eastern Region migrate to destinations across the entire wintering range and mix with individuals from the Central Region. Using the division coefficient, we estimated that 54% of woodcock from the breeding grounds of the Eastern Region migrate to the Central Region wintering grounds. Our result that many woodcock from separate regions of the breeding grounds mix on the wintering grounds has implications for the 2‐region basis for woodcock management. Elucidating finer scale movement patterns among regions provides a basis for reassessing the need for separate management regions to ensure optimal conservation and management of the species. © 2017 The Wildlife Society.
White‐tailed deer carrying capacity, intercropping switchgrass, and pine plantations
Authors: Loman Zachary G. , Greene Ethan J. , Wheat Bradley R. , Demarais Stephen , Miller Darren A. , Rush Scott A. , Riffell Samuel K.
Published: April 2017

Switchgrass (Panicum virgatum) is a cellulosic feedstock for alternative energy production that can be grown between rows of planted pines (Pinus spp.) within intensively managed forests. Southeastern planted pine occupies 15.8 million ha and thus, switchgrass intercropping could have far‐ranging effects on plant communities and biomass production within these forests if broadly implemented. Such intercropping could lead to alterations to plant communities that may cause bottom‐up ecological changes affecting ecologically, economically, and socially important wildlife, such as white‐tailed deer (Odocoileus virginianus; deer). Therefore, we tested whether intercropping switchgrass in loblolly pine (P. taeda) plantations would cause switchgrass to dominate vegetative biomass thereby decreasing biomass of forages and reducing white‐tailed deer nutritional carrying capacity (NCC), or whether disturbance associated with establishment and harvest of switchgrass would facilitate ruderal forbs, and thereby increase biomass of preferred deer forages and increase NCC. In a randomized complete block design, we assigned 2 treatments (intercropped switchgrass and a standard pine management control) to 4 replicates of 10‐ha experimental units in Kemper County, Mississippi during summers of 2011−2015. We detected 323 plant species. Intercropping switchgrass had little effect on plant biomass production, and did not affect white‐tailed deer NCC at a maintenance diet of 6% crude protein. Intercropping provided additional disturbance allowing high‐protein content ruderal plants to colonize, and temporarily increased (3 yr) deer NCC at the 14% crude protein diet considered necessary to support lactation. However, concomitant with a sharp increase in switchgrass biomass in the third year of the study, NCC dropped to levels similar to traditionally managed pine stands. Switchgrass intercropping is not a reliable means of increasing deer NCC as a management strategy but does not appear to reduce carrying capacity in the short‐term relative to standard intensive pine management. © 2017 The Wildlife Society.
Shelf‐basin gradients shape ecological phytoplankton niches and community composition in the coastal Arctic Ocean (Beaufort Sea)
Authors: Ardyna M. , Babin M. , Devred E. , Forest A. , Gosselin M. , Raimbault P. , Tremblay J.‐É.
Published: April 2017

The contiguous Arctic shelf is the green belt of the Arctic Ocean. Phytoplankton dynamics in this environment are driven by extreme physical gradients and by rapid climate change, which influence light and nutrient availability as well as the growth and ecological characteristics of phytoplankton. A large dataset collected across the Canadian Beaufort Shelf during summer 2009 was analyzed to assess how the interplay of physical and biogeochemical conditions dictates phytoplankton niches and trophic regimes. Nonmetric multidimensional scaling and cluster analysis demonstrated marked partitioning of phytoplankton diversity. Elevated phytoplankton biomass (∼ 2.41 μg Chl a L−1) was observed in association with the surface mixed layer near the coast, close to the mouth of the Mackenzie River, and at the shelf‐break as a result of nutrient‐rich Pacific water intrusions. The coastal communities were supported by high levels of nitrogen nutrients and were taxonomically uniform, with diatoms accounting for 95% of total cell numbers. By contrast, adjacent oceanic waters were characterized by low autotrophic biomass near the surface (∼ 0.09 μg Chl a L−1) and below the mixed layer (∼ 0.23 μg Chl a L−1) due to mainly nutrient limitation. However, the oceanic community was more diverse with a mixed assemblage of diatoms and small mixotrophs/heterotrophs near the surface and a predominance of autotrophic nanoflagellates at depth. We conclude that as climate change intensifies freshening and stratification in the Western Arctic Ocean, coastal hotspots of high autotrophic productivity may play an even greater role in supporting Arctic marine ecosystems while offshore environments become increasingly oligotrophic.
Effect of Isomeric Structures on Photovoltaic Performance of D–A Copolymers
Authors: Xie Fangyuan , He Dan , Pan Han , Jiang Jiaxing , Ding Liming
Published: April 2017

Two donor–acceptor copolymers based on isomeric acceptor units, [7,7′‐bithieno[2′,3′:4,5]thieno[2,3‐d]thieno[3,2‐b]pyridine]‐5,5′(4H,4′H)‐dione (BTTP) and [2,2′‐bithieno[2′,3′:4,5]thieno[2,3‐d]thieno[3,2‐b]pyridine]‐5,5′(4H,4′H)‐dione (iBTTP), are developed to study the effect of isomeric structures on photovoltaic performance. Compared with PBDTBTTP, PBDTiBTTP possesses a smaller bandgap for good light harvesting and a better π–π stacking for higher hole mobility. PBDTiBTTP solar cells present balanced mobilities and good nanoscale phase separation, giving a power conversion efficiency (PCE) of 6.51%, with higher short‐circuit current (Jsc) and fill factor (FF).

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Exploration of Ideal Polymer Networks
Authors: Shibayama Mitsuhiro
Published: April 2017

The history of exploration of ideal polymer networks is reviewed, followed by a demonstration of fabrication and applications of novel polymer networks free from defects/entanglements. The networks, we call, are Tetra‐PEG gels, consisting of two types of tetra‐arm poly(ethylene glycol) (PEG) prepolymers that have mutually reactive amine (Tetra‐PEG‐NH2) and activated ester (Tetra‐PEG‐NHS) terminal groups, respectively. Here NHS represents N‐hydroxysuccinimide. The novelty lies in “cross‐end‐coupling” of symmetrical tetra‐arm PEGs having complementary end groups. Small‐angle neutron scattering (SANS) results on Tetra‐PEG gels, together with mechanical properties and swelling behaviors, strongly suggest that thus prepared Tetra‐PEG gels are near‐“ideal” polymer networks with very small fractions of defects. In order to answer the reasons why such a structure could be formed, the kinetics of gelation was investigated by IR, UV, and time‐resolved rheological and SANS measurements. Furthermore, fabrication of Tetra‐PEG ion gels, having good mechanical properties, is demonstrated.
Amphiphilic Polymer Conetworks Based on Interconnected Hydrophobic Star Block Copolymers: Synthesis and Characterization
Authors: Kepola Eleni J. , Kyriacou Kyriacos , Patrickios Costas S. , Simon Miriam , Gradzielski Michael , Kushnir Michelle , Wesdemiotis Chrys
Published: April 2017

Herein we report on the preparation and structural characterization of six amphiphilic polymer conetworks (APCN) based on end‐linked amphiphilic “core‐first” star block copolymers, comprising methyl methacrylate and 2‐(dimethylamino)ethyl methacrylate as the monomer repeating units in the hydrophobic and hydrophilic blocks, respectively. The various APCNs differed either in the arm composition or in the arm molecular weight. APCN synthesis was accomplished via the one‐pot, sequential group transfer polymerization (GTP) of cross‐linker, hydrophobic monomer, hydrophilic monomer, and cross‐linker again. The soluble precursors to the APCNs, i.e., the star homopolymers, the star block copolymers and the initial cross‐linker cores, were characterized in terms of their composition, size and size dispersity. The degrees of swelling in tetrahydrofuran were found to increase with the molecular weight of the arms of the stars of the APCNs, whereas the degrees of swelling in water increased with the content in hydrophilic units in the arms of the constituting stars. Small‐angle neutron scattering (SANS) indicated that most APCNs nanophase separated in D2O. The structure and size of the hydrophobic domains determined by fitting the SANS data to an appropriate model could be correlated with the molecular architecture of the APCNs. Finally, polarized light microscopy showed that all APCNs were birefringent both in water and in the dried state.
Structure and Properties of Cartilage Proteoglycans
Authors: Horkay Ferenc , Basser Peter J. , Hecht Anne‐Marie , Geissler Erik
Published: April 2017

The most abundant cartilage proteoglycan is aggrecan, a bottlebrush shaped molecule that possesses over 100 glycosaminoglycan (chondroitin sulfate and keratan sulfate) chains. The side‐chains are linear sulfated polysaccharides that are negatively charged under physiological conditions. Aggrecan interacts with hyaluronic acid (HA) to form large aggregates. Osmotic pressure measurements and rheological measurements are used to study the static and dynamic behavior of aggrecan assemblies at the macroscopic length scales. The microscopic properties of aggrecan solutions are determined by small angle neutron scattering, and static and dynamic light scattering (SLS and DLS). In dilute solutions aggrecan forms microgels with a diffuse boundary, composed of loosely connected clusters. The osmotic pressure of the aggrecan‐HA system decreases with increasing HA content. DLS yields a relaxation rate that varies as q3, arising from internal modes in the microgel. The relaxation rate in the solutions of the aggrecan‐HA complex is slightly greater than in the pure aggrecan solution.
Polarimetric Doppler radar analysis of squall line systems crossing Salento Peninsula
Authors: Congedo F. , Prodi F. , Pasqualucci F. , Trivellone G.
Published: April 2017

A detailed observational study of squall line thunderstorms, a particular form of mesoscale convective systems arranged in a line that repeatedly affected Salento Peninsula (southern Apulia, Italy) throughout 2015, is presented and discussed. Specifically, three relevant events that occurred in January, at the end of September and in October are described, combining thermodynamic and synoptic analysis with radar imagery delivered by the cutting‐edge polarimetric Doppler radar recently installed in Torchiarolo, in the central part of Salento Peninsula. Reported observational information reveals that, regardless of the season of the year, convergence along an approaching cold front represents the common initiating mechanism leading to the formation of linear convective systems. Furthermore, high resolution Doppler data provided by Torchiarolo radar allows better detection and prompt recognition of severe weather signatures, such as bow echoes and cyclonic mesovortices, commonly associated with squall line thunderstorms. Therefore, the present study clearly confirms the key role of the new advanced weather radar installed in Torchiarolo which thus represents a powerful tool giving researchers and forecasters valuable information about kinematic and microphysical properties of severe weather systems crossing Apulia region, especially Salento Peninsula.
A modified Leslie–Gower predator–prey model with ratio‐dependent functional response and alternative food for the predator
Authors: Flores José D. , González‐Olivares Eduardo
Published: April 2017

In this work, a modified Leslie–Gower predator–prey model is analyzed, considering an alternative food for the predator and a ratio‐dependent functional response to express the species interaction. The system is well defined in the entire first quadrant except at the origin (0,0). Given the importance of the origin (0,0) as it represents the extinction of both populations, it is convenient to provide a continuous extension of the system to the origin. By changing variables and a time rescaling, we obtain a polynomial differential equations system, which is topologically equivalent to the original one, obtaining that the non‐hyperbolic equilibrium point (0,0) in the new system is a repellor for all parameter values. Therefore, our novel model presents a remarkable difference with other models using ratio‐dependent functional response. We establish conditions on the parameter values for the existence of up to two positive equilibrium points; when this happen, one of them is always a hyperbolic saddle point, and the other can be either an attractor or a repellor surrounded by at least one limit cycle. We also show the existence of a separatrix curve dividing the behavior of the trajectories in the phase plane. Moreover, we establish parameter sets for which a homoclinic curve exits, and we show the existence of saddle‐node bifurcation, Hopf bifurcation, Bogdanov–Takens bifurcation, and homoclinic bifurcation. An important feature in this model is that the prey population can go to extinction; meanwhile, population of predators can survive because of the consumption of alternative food in the absence of prey. In addition, the prey population can attain their carrying capacity level when predators go to extinction. We demonstrate that the solutions are non‐negatives and bounded (dissipativity and permanence of population in many other works). Furthermore, some simulations to reinforce our mathematical results are shown, and we further discuss their ecological meanings. Copyright © 2017 John Wiley & Sons, Ltd.
A molecular mechanics and ab initio prediction of the 1H chemical shifts of pinanes
Authors: Abraham Raymond J. , Ashley Cooper M.
Published: April 2017

Molecular mechanics calculations plus the application of a refined Karplus equation gave the conformations of 19 pinanes. These range from a Y‐shaped geometry in the apopinene and α‐pinene series to a pseudo chair conformation in β‐pinene, nopinone and verbanone, a flattened chair in pinocarvone and the pinocarveols and a distorted Y shape for iso‐verbanone.

These structures were then used as input to predict the 1H chemical shifts of these compounds by semi‐empirical (1H‐NMR spectra (HSPEC)) and ab initio gauge‐invariant atomic orbital (GIAO) calculations, the latter at the B3LYP hybrid density functional theory level using 6‐31++G** basis set. The two methods gave generally good agreement with the 184 observed shifts with root mean square (RMS) errors 0.07 ppm (HSPEC) and 0.10 ppm (GIAO), but the GIAO calculations gave several significant (>0.25 ppm) errors. One was for the H3 proton in apopinenone and other α,β unsaturated ketones; the others occurred for protons in close proximity to hydroxyl groups. To provide more information, smaller analogues of known geometry and chemical shifts were subject to the same analysis. In cyclopentenone, the Gaussian geometry gave good agreement with the observed shifts, but the MMFF94, MMX and MM3 geometries all gave errors for different protons. These results show clearly that the molecular geometries of the α,β unsaturated ketones are responsible for the errors. The errors for the alcohols were examined using ethanol as model and were shown to be due to the different possible conformations of the OH group. Similar GIAO calculations on substituted methanes gave good agreement for the methyl compounds but poor agreement for di and tri halosubstituted methanes.

The aforementioned method of molecular mechanics plus GIAO calculations is shown to be a very useful tool for the investigation of molecular geometries and conformations. However, multihalogen compounds may require different basis sets for accurate calculations. Copyright © 2017 John Wiley & Sons, Ltd.
Synthesis of Poly(n‐butyl acrylate/methyl methacrylate)/CNC Latex Nanocomposites via In Situ Emulsion Polymerization
Authors: Dastjerdi Zahra , Cranston Emily D. , Dubé Marc A.
Published: April 2017

Cellulose nanocrystals (CNCs) are renewable, nontoxic and naturally available organic nanoparticles derived from cellulosic resources such as cotton and wood pulp. Poly(n‐butyl acrylate‐co‐methyl methacrylate)/CNC latexes are successfully synthesized via in situ emulsion polymerization. The effect of CNC loading on overall conversion, polymer particle size, glass transition temperature (Tg), gel content, latex viscosity, and storage and loss moduli of dried latex are studied. While the effect of CNC content on overall conversion, polymer particle size, and Tg of the resulting latexes is negligible, significant increase in gel content, latex viscosity, and storage and loss moduli are observed.

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(BEDT‐TTF)2Cu2(HCOO)5: An Organic–Inorganic Hybrid Conducting Magnet
Authors: Zhang Bin , Zhang Yan , Wang Zheming , Gao Zengqiang , Yang Deliang , Wang Dongwei , Guo Yanjun , Zhu Daoben
Published: April 2017

A dual‐functional organic–inorganic hybrid (BEDT‐TTF)2Cu2(HCOO)5 (1) (BEDT‐TTF=bis(ethylenedithio)tetrathiafulvalene) was obtained through the electrochemical oxidation of neutral BEDT‐TTF in the presence of an ammonium salt of the one‐dimensional copper‐formate framework [(C2H5)3NH]2Cu2(HCOO)5 in a C6H5Cl–C2H5OH solution. Compound 1 was composed of organic donor BEDT‐TTF+0⋅5 in a θ‐phase arrangement and Jahn–Teller distorted (4,4) grid anion sheets [Cu2(HCOO)5‐]n with S=1/2. We identified the material as a semiconductor with values of σ300K=10−1 S cm−1. The anion sheet is a coordination isomer of [Cu2(HCOO)5‐]n and, compared with the starting material, shows antiferromagnetic behavior as the well‐known inorganic Cu−O, Co−O square layers for creating inorganic conducting magnets. Long‐range antiferromagnetic ordering was observed at 8.0 K.
Facial asymmetry in head and neck rhabdomyosarcoma survivors
Authors: Schoot Reineke A , Hol Marinka L. F. , Merks Johannes H. M. , Suttie Michael , Slater Olga , van Lennep Marinde , Hopman Saskia M. J. , Dunaway David , Syme‐Grant Jonathan , Smeele Ludi E. , Zwinderman Koos H. , Caron Huib N. , Hammond Peter
Published: April 2017

Introduction

Radiotherapy is essential for achieving and maintaining local control in head and neck rhabdomyosarcoma (HNRMS) patients. However, radiotherapy may cause outgrowth disturbances of facial bone and soft tissue, resulting in facial asymmetry. The aim of this study was to develop a method to visualize and measure facial asymmetry in HNRMS survivors using three‐dimensional (3D) imaging techniques.

Methods

Facial deformity was evaluated in a multidisciplinary clinical assessment of 75 HNRMS survivors, treated with external beam radiotherapy (EBRT, n = 26) or Ablative surgery, MOulage brachytherapy, and REconstruction (AMORE, n = 49). Individual facial asymmetry was measured using 3D photogrammetry and expressed in a raw asymmetry index and a normalized sex–age–ethnicity‐matched asymmetry signature weight. Facial asymmetry was also compared between British and Dutch controls and between survivors and their matched controls.

Results

Facial asymmetry was more pronounced with increasing age (P < 0.01) in British controls compared with Dutch controls (P = 0.04). Survivors developed more facial asymmetry than matched controls (P < 0.001). The clinical assessment of facial deformity correlated with the raw asymmetry index (r = 0.60, P < 0.001).

Discussion

3D imaging can be used for objective measurement of facial asymmetry in HNRMS survivors. The raw asymmetry index correlated with a clinical assessment of facial deformity. Comparisons between treatment groups seemed inappropriate given the differences in facial asymmetry between British and Dutch controls. In future studies, pretreatment images could act as matched controls for posttreatment evaluation.
Does touch inhibit visual imagery? A case study on acquired blindness
Authors: von Trott zu Solz Jana , Paolini Marco , Silveira Sarita
Published: April 2017

In a single‐case study of acquired blindness, differential brain activation patterns for visual imagery of familiar objects with and without tactile exploration as well as of tactilely explored unfamiliar objects were observed. Results provide new insight into retrieval of visual images from episodic memory and point toward a potential tactile inhibition of visual imagery.
Prenatal exposure to β2‐adrenoreceptor agonists and the risk of autism spectrum disorders in offspring
Authors: Su XiuJuan , Yuan Wei , Chen JianPing , Miao MaoHua , Olsen Jørn , Pedersen Lars Henning , Liang Hong , Li Jiong
Published: April 2017

Purpose

We aimed to examine the risk of autism spectrum disorders (ASDs) in the offspring who were exposed to maternal use of β2‐adrenoreceptor agonist (β2AA) during pregnancy.

Methods

This is a population‐based cohort study including all live singleton births in Denmark from 1 January 1997 to 31 December 2008. Children born to mothers who used β2AA during pregnancy were categorized as exposed, and all other children were included in the unexposed group. Cases of ASDs were identified from the Danish Psychiatric Central Register and the Danish Patient Register. Incidence rate ratio (IRR) and 95% confidence interval were estimated by Poisson regression models.

Results

Among 751 888 children in the cohort, 9098 (1.21%) received a diagnosis of ASDs. We observed an increased risk of ASDs in the exposed children (IRR = 1.28, 1.11–1.47), especially for those who were exposed during the second trimester period (IRR = 1.38, 1.14–1.67). However, when extending the exposure time window to 1 year prior to pregnancy, we observed a similar association in children born to women who received β2AA treatment during pregnancy (IRR = 1.33, 1.11–1.59) to that in children born to women who received β2AA treatment 1 year prior to pregnancy (IRR = 1.35, 1.17–1.56).

Conclusion

Our finding suggested that children born to women who used β2AA during pregnancy have an increased risk of ASDs in later life, which is more likely due to underlying maternal diseases rather than the exposure to β2AA itself. However, further study, which would better differentiate the effects between indication and medicine, is needed to corroborate the finding. Copyright © 2017 John Wiley & Sons, Ltd.
Ultrasonic decrosslinking of peroxide crosslinked HDPE in twin screw extrusion. I. Process model and simulation
Authors: Huang Keyuan , Isayev Avraam I.
Published: April 2017

A process model for ultrasonic decrosslinking of peroxide crosslinked high‐density polyethylene (XHDPE) is proposed. The model is developed by modifying the earlier model describing ultrasonic devulcanization of rubber vulcanizates under static (no flow) conditions. The bubble cavitation during ultrasonic wave propagation in a viscoelastic solid containing small concentration of voids is considered. A method to calculate the ultrasonic power consumption and acoustic pressure in a bubble filled polymer is proposed based on the linear acoustic analysis. The rupture of network is modeled by considering the breakage of main chains caused by the large deformation arising during the bubble oscillation. Unlike the earlier process model for ultrasonic devulcanization of rubbers, the current model does not require kinetic parameters assigned to describe the rupture of network. The nonisothermal flow of decrosslinked XHDPE in the ultrasonic treatment zone in the twin screw extruder (TSE) is modeled by considering a helical flow of a power‐law fluid with its material parameters related to the gel fraction. The simulation algorithms describing ultrasonic decrosslinking of XHDPE under static (no flow) condition and in TSE are presented. POLYM. ENG. SCI., 57:1035–1046, 2017. © 2017 Society of Plastics Engineers
Synthesis of a selenium and germanium containing random copolymer as an acceptor for all‐polymer solar cells
Authors: Fang Hsin‐Wei , Lien‐Chung Hsu Steve
Published: April 2017

For the need of electron‐transporting and electron‐affinity materials, n‐type polymers (as acceptor) have gained a lot of attention recently. We have synthesized a selenium and germanium containing copolymer as the acceptor for all‐polymer solar cells (all‐PSCs). The copolymer has larger p‐orbital selenium and germanium atoms for more electron transition from pi to pi* to enlarge light harvest of polymer. To prepare the copolymer, a monomer containing d‐orbital atom, selenium, was first synthesized from low‐cost starting materials. A random copolymer was prepared from the monomer with a commercial germanium containing monomer via palladium catalyzed Stille coupling reaction. Taking the side‐chain effect into account, we incorporated dodecyloxy group to increase the solubility of the polymer and also increase the coplanarity by oxygen–sulfur (S–O) interaction. Despite the low short‐circuit current density (Jsc) value, the random copolymer with 3d‐orbital electrons has the potential to be the candidate for n‐type material. In comparison, we also fabricated P3HT/PffBT4T‐2OD all‐PSCs, acquiring PCE of about 0.5% without any additive. POLYM. ENG. SCI., 58:387–394, 2018. © 2017 Society of Plastics Engineers
Influence of surface topography, crystallinity, and thermal conductivity on reflectance and color of metallic‐effect high‐density polyethylene parts filled with aluminum pigments
Authors: Hong Xinmi , Xiao Xiaoting , Zhang Zhengrong , Yang Jie , Zhang Jingjing
Published: April 2017

Metallic effect in injection molded parts is created using composites of high‐density polyethylene (HDPE) filled with high‐sparkle aluminum (Al) pigments (HDPE/Al). The mechanism of micro shrinkage induced by the leafing phenomenon influences the surface topography and roughness, and has been studied with SEM and AFM. Reflectance, whiteness index (WI), and luminance (L*) of the surface were assessed in relation to the surface roughness, the particle sizes, the crystallinity and thermal conductivity of composites. The results show that the leafing induces the micro shrinkage and causes micro caverns, which increased surface roughness. Besides, the length of micro caverns and surface roughness increased as the particle size increased. These morphologies were not benefit for improving reflectance, WI, and L* values, therefore the reflectance, WI, and L* values decreased proportionally with the surface roughness and particle sizes increased. High‐sparkle Al pigments improved the crystallinity and thermal conductivity of the composites. A higher reflectance, WI, and L* were associated with a higher crystallinity and a higher thermal conductivity. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers
Modeling and parameter estimation of step‐growth polymerization of poly(ethylene‐2,5‐furandicarboxylate)
Authors: L.T. Brandão Amanda , F. Oechsler Bruno , W. Gomes Frederico , G. Souza Fernando , Carlos Pinto José
Published: April 2017

The production of polymers from renewable materials has arisen increasing interest because of the environmental impacts caused by conventional processes. In this context, the present manuscript investigates the step‐growth polymerization of poly(ethylene 2,5‐furandicarboxylate), PEF, a furanic polyester with structural similarity to poly(ethylene terephthalate), PET, using ethylene glycol (EG), and 2,5‐furandicarboxylic acid (FDCA) as monomers. The polymerization is performed in two steps: direct esterification of EG and FDCA under continuous nitrogen flow, followed by the transesterification of produced diesters and oligomers under reduced pressure. In order to do that, experiments were performed at distinct reaction temperatures and using different nitrogen flow rates. Based on the obtained experimental data, a mathematical model was built and model parameters were estimated to allow for appropriate description of available data. The obtained results indicate that the rates of polymerization are highly limited by mass transfer and removal of reaction byproducts. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers
Improvement of thermoelectric properties of Bi2Te3 and Sb2Te3 films grown on graphene substrate
Authors: Lee Chang Wan , Kim Gun Hwan , Choi Ji Woon , An Ki‐Seok , Kim Jin‐Sang , Kim Hyungjun , Lee Young Kuk
Published: April 2017

A study of substrate effect on the thermoelectric (TE) properties of Bi2Te3 (BT) and Sb2Te3 (ST) thin films grown by plasma‐enhanced chemical vapor deposition (PECVD) was performed. Graphene substrates which have small lattice mismatch with BT and ST were used for the preparation of highly oriented BT and ST thin films. Carrier mobility of the epitaxial BT and ST films grown on the graphene substrates increased as the deposition temperature increased, which was not observed in that of SiO2/Si substrates. Seebeck coefficients of the as‐grown BT and ST films were observed to be maintained even though carrier concentration increased in the epitaxial BT and ST films on graphene substrate. Although Seebeck coefficient was not improved, power factor of the as‐grown BT and ST films was considerably enhanced due to the increase of electrical conductivity resulting from the high carrier mobility and moderate carrier concentration in the epitaxial BT and ST films.
Local reconstruction of low‐rank matrices and subspaces
Authors: David Roee , Goldenberg Elazar , Krauthgamer Robert
Published: April 2017

We study the problem of reconstructing a low‐rank matrix, where the input is an n × m matrix M over a field and the goal is to reconstruct a (near‐optimal) matrix that is low‐rank and close to M under some distance function Δ. Furthermore, the reconstruction must be local, i.e., provides access to any desired entry of by reading only a few entries of the input M (ideally, independent of the matrix dimensions n and m). Our formulation of this problem is inspired by the local reconstruction framework of Saks and Seshadhri (SICOMP, 2010).

Our main result is a local reconstruction algorithm for the case where Δ is the normalized Hamming distance (between matrices). Given M that is ‐close to a matrix of rank (together with d and ), this algorithm computes with high probability a rank‐d matrix that is ‐close to M. This is a local algorithm that proceeds in two phases. The preprocessing phase reads only random entries of M, and stores a small data structure. The query phase deterministically outputs a desired entry by reading only the data structure and 2d additional entries of M.

We also consider local reconstruction in an easier setting, where the algorithm can read an entire matrix column in a single operation. When Δ is the normalized Hamming distance between vectors, we derive an algorithm that runs in polynomial time by applying our main result for matrix reconstruction. For comparison, when Δ is the truncated Euclidean distance and , we analyze sampling algorithms by using statistical learning tools.

A preliminary version of this paper appears appears in ECCC, see: http://eccc.hpi-web.de/report/2015/128/ © 2017 Wiley Periodicals, Inc. Random Struct. Alg., 51, 607–630, 2017
Retracted: Bayesian inference on mixed‐effects location scale models with skew‐t distribution and mismeasured covariates for longitudinal data
Authors: Lu Tao
Published: April 2017

In AIDS studies, heterogeneous between and within subject variations are often observed on longitudinal endpoints. To accommodate heteroscedasticity in the longitudinal data, statistical methods have been developed to model the mean and variance jointly. Most of these methods assume (conditional) normal distributions for random errors, which is not realistic in practice. In this article, we propose a Bayesian mixed‐effects location scale model with skew‐t distribution and mismeasured covariates for heterogeneous longitudinal data with skewness. The proposed model captures the between‐subject and within‐subject (WS) heterogeneity by modeling the between‐subject and WS variations with covariates as well as a random effect at subject level in the WS variance. Further, the proposed model also takes into account the covariate measurement errors, and commonly assumed normal distributions for model errors are substituted by skew‐t distribution to account for skewness. Parameter estimation is carried out in a Bayesian framework. The proposed method is illustrated with a Multicenter AIDS Cohort Study. Simulation studies are performed to assess the performance of the proposed method. Copyright © 2017 John Wiley & Sons, Ltd.
The Numbers Count
Authors: Graham Peter A. ,   Philosophy Documentation Center
Published: April 2017

Numbers Skeptics deny that when faced with a choice between saving some innocent people from harm and saving a larger number of different, though equally innocent, people from suffering a similar harm you ought to save the larger number. In this article, I aim to put pressure on Numbers Skepticism.
Postcolonial Media Culture in Britain
Authors: Brunt Rosalind , Cere Rinella
Published: April 2017

This fascinating text introduces readers to postcolonial theory using the context of British media culture in ethnic minority communities to explain key ideas and debates. Each chapter considers a specific media output and uses a wealth of examples to offer an absorbing insight into postcolonial media for all students of cultural and media studies.
Formal Synthesis of (±)-Allocolchicine Via Gold-Catalysed Direct Arylation: Implication of Aryl Iodine(III) Oxidant in Catalyst Deactivation Pathways
Authors: Corrie Tom J. A. , Lloyd-Jones Guy C.
Published: April 2017

A concise formal synthesis of racemic allocolchicine has been developed, centred on three principal transformations: a retro-Brook alkylation reaction to generate an arylsilane, a gold-catalysed arylative cyclisation to generate the B-ring via biaryl linkage, and a palladium-catalysed carbonylation of an aryl chloride to generate an ester. 1H NMR monitoring of the key gold-catalysed cyclisation step reveals that a powerful catalyst deactivation process progressively attenuates the rate of catalyst turnover. The origins of the catalyst deactivation have been investigated, with an uncatalysed side-reaction, involving the substrate and the iodine(III) oxidant, identified as the source of a potent catalyst poison. The side reaction generates 1–4% of a diaryliodonium salt, and whilst this moiety is shown not to be an innate catalyst deactivator, when it is tethered to the arylsilane reactant, the inhibition becomes powerful. Kinetic modelling of processes run at two different catalyst concentrations allows extraction of the partitioning of the gold catalyst between the substrate and its diaryliodonium salt, with a rate of diaryliodonium salt generation consistent with that independently determined in the absence of catalyst. The high partition ratio between substrate and diaryliodonium salt (5/1) results in very efficient, and ultimately complete, diversion of the catalyst off-cycle.

Graphical Abstract